I want to try my hands at making a mini homebrew project and am starting this thread to post future updates and get advice.

So, first, what is a "mini" homebrew project? Simply put, the idea is to create a tabletop pinball machine with simple rules, scoring and electronics. Someday, when I retire, I want to try a full homebrew project, but I've only recently gotten into electronics, and my mechanical and carpentry skills (as well as ownership of tools) is severely lacking. However, all this year, I've been teaching myself basic circuitry and Arduino programming. I've made several projects including a game where you duel against an opponent using ultrasonic sensors and led lights, a lighted coffee mug holder that you can adjust the color of and that senses your mug and changes its lighting effects when the mug is on it, a 5x5 LED light cube with programmed modes, etc. I need to find a new project, and I thought that I have learned enough to try putting together a simple pinball machine. As I said, it will be tabletop, but have real flippers, functioning targets, hopefully ramps or wireforms, etc. I will program some simplified code and rules with Arduinos. This will take a while, but I think it will be a really good learning experience, especially as I get more used to assembling and creating things mechanically.

As soon as I make progress, I'll post some updates. But, first, I need advice, and I hope to ask a lot of it here.

Here's my first question: I am hoping to run a set of mini-flippers off of a 12v power supply. Based on some preliminary searching, I think this will work. Keep in mind that I don't need a lot of force as I will only be shooting the balls a short distance, and I plan to use ball bearings somewhere between the size of a standard pinball and a marble. Keeping things at 12v will help me ensure safety, and also enable me to use one power supply for all components, including the arduinos and LEDs. Do you agree that 12v should be sufficient? If so, do you know a source for mini flipper assemblies? Pinballlife.com only seems to have larger assemblies, and it is hard for me to decipher Marco Specialties' website in this regard. My hope is to first get the flippers and hook them up to ensure I have enough force. I'll then take this project to the next steps.

Many thanks in advance for your help!

(Oh, one more thing. I do have a theme in mind, but I think I will wait for a later date to reveal it. )

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Index of updates:

Testing the flipper mechs with different voltages: https://pinside.com/pinball/forum/topic/my-mini-homebrew-updates-and-advice#post-5984596

Code to control flippers: https://pinside.com/pinball/forum/topic/my-mini-homebrew-updates-and-advice#post-5986341

Testing assembled flippers: https://pinside.com/pinball/forum/topic/my-mini-homebrew-updates-and-advice#post-5996978 and https://pinside.com/pinball/forum/topic/my-mini-homebrew-updates-and-advice#post-6009773

Theme revealed: https://pinside.com/pinball/forum/topic/my-mini-homebrew-updates-and-advice#post-6010828

VUK prototype: https://pinside.com/pinball/forum/topic/my-mini-homebrew-updates-and-advice/page/2#post-6063446 and https://pinside.com/pinball/forum/topic/my-mini-homebrew-updates-and-advice/page/2#post-6065153 and https://pinside.com/pinball/forum/topic/my-mini-homebrew-updates-and-advice/page/3#post-6080913

Middle orbit with servo motors: https://pinside.com/pinball/forum/topic/my-mini-homebrew-updates-and-advice/page/3#post-6120934 and https://pinside.com/pinball/forum/topic/my-mini-homebrew-updates-and-advice/page/4#post-6196940

Left ramp: https://pinside.com/pinball/forum/topic/my-mini-homebrew-updates-and-advice/page/4#post-6135572 and https://pinside.com/pinball/forum/topic/my-mini-homebrew-updates-and-advice/page/4#post-6136862

Right ramp: https://pinside.com/pinball/forum/topic/my-mini-homebrew-updates-and-advice/page/4#post-6148122

General layout and test gameplay: https://pinside.com/pinball/forum/topic/my-mini-homebrew-updates-and-advice/page/4#post-6196754 and https://pinside.com/pinball/forum/topic/my-mini-homebrew-updates-and-advice/page/5#post-6219627

Revised VUK: https://pinside.com/pinball/forum/topic/my-mini-homebrew-updates-and-advice/page/5#post-6284100

What would happen if I ran 12v through those coils? Are you saying the resistance is so high, I wouldn’t have enough current to move the plunger? I don’t think I need them to be as powerful as the ones in the actual pins they were made for, but I do need them to move.

Just looked up the specs. 8.88 ohms resistance. Supply 12v and get 1.35 amps current. It seems like one of the smaller coils out there. Watching this video at 2:30 makes me think it might work (but this will be an expensive experiment if not):

Well, I just ordered two mini flipper assemblies from Marco. The ones for Stern. Last ones they had. Kind of expensive, so I hope it works. I suppose I could always go with 20v if necessary and then just step down the voltage for the other components, but I hope 12v will be sufficient.

I bought a power drive that is selectable from 12 to 24 volts, so I will be able to do some experimenting.

I had not, but that one looks great. I wish he posted more details about the build.

I was going to use transistors to turn the coils on and off. Does it matter whether the transistor is upstream of the coil or downstream? In other words, does it matter whether the transistor is controlling whether power is connected to the coil or whether the coil is connected to ground? Is one better or preferred than the other?

I have some TIP120 Darlington transistors lying around from when I was learning how to control motors with my Arduino. I'll probably just use those (at least for the prototype) assuming they work ok.

What's the purpose of this? Is it the same as when I was playing around with motors? There, I put a diode from the negative side of the motor to the positive to protect the circuit so when it was switched off, stray current is allowed to dissipate. Same here?

Also, am I correct in assuming that these coils have no polarity:

https://www.marcospecialties.com/control/keywordsearch?SEARCH_STRING=090-5046-01-nd

So, it doesn't matter which lug goes to power and which goes to the transistor?

Thanks, but I think I want to try this by creating as much of the electronics I can by myself, to test what I’ve learned over the past year and solve problems while I go along. If I ever do a full size home brew, I definitely will use existing systems. Here, I think I can do most of the things I want with an Arduino, or two or three.

I’m more worried about making the mechanics of it work than the electronics.

Happy Thanksgiving everyone!

My flipper mechs arrive tomorrow, and I want to start testing them out. I note that they only have one wire winding, not a separate one for kick and hold like larger flipper mechs.

https://www.marcospecialties.com/pinball-parts/500-7019-00

Do I need to worry about them burning out if I hold the flippers, keep them engaged? Do I need to PWM them with an Arduino once they kick?

Or will the voltage be so low for these little mechs that I needn’t worry?

Thanks. By any chance, do you know what the standard is for how much to PWM?

I love parts deliveries:

IMG_1595 (resized).JPG

Having now received my flipper mechs, I was able to test one out. The below video shows me testing it at 12V, 20V and 24V. When I first did it, I thought 12V was significantly weaker than the other two. However, when I took the video, the difference is less noticeable. I think I need to attach it to wood and try to hit a ball with it to see. I have both 11mm (Pachinko) balls and 3/4" balls to try. However, the wood I bought for the playfield (a large piece of particle board) is 1/2" wide, and the mech won't fit on it. I wonder if Stern uses a slightly smaller size. So, back to Home Depot to get the 1/4" version. Also, I'm missing a small roll pin on one of the mechs so can't assemble it fully. I've written to the supplier and hope they can send me one as my local hardware stores don't have them. I'm still really hoping that I can keep this at 12V for a number of reasons, one of which is it will likely mean that I can keep my existing power supply and don't need to buy a larger one with more current, but we'll see.

I hate assembling stuff sometimes. One screw’s head fell off. The other one won’t go down all the way. And, this was the last bracket in stock for the left mini flipper. Luckily I think it is on well enough to function. Not sure I’ll be replacing the coil any time soon though.

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My friend helped me cut the cabinet and playfield wood out of fiber board with his table saw.

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Waiting for parts today to complete the second flipper assembly and to assemble the cabinet. Home Depot never has the right size screw that I need for pinball. It is always one size lower than their lowest size. So, I'll try one of the few Ace Hardwares in my area when they open tomorrow.

In the meantime, I decided to write a little sketch to control the flippers with the Arduino. I haven't tested this yet, so there may be bugs in it, but the idea is to apply high power to the flippers for X milliseconds and then apply lower power through pulse-width modulation after that. I have two variables that I can play with to optimize the control -- HighKickTime controls how long the flipper receives high power, and PWM controls the amount of reduced power after the high kick time, with 0 being no power and 255 being full power. So, when I get my flippers hooked up, I can experiment with different values for both as well as the voltage going to the flippers themselves.

I'll post code for anyone interested. However, please keep in mind that this is untested at this time and may have bugs. If I discover any, I'll post and update the code.

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// Flipper control with PWM

#define RightFlipper 9 // Pins for PWM to the transistors
#define LeftFlipper 10

#define RightButton 7 // Pins for receiving input from the buttons
#define LeftButton 8

int PWM = 100; // How much to PWM? Value can go between 0-255.
int HighKickTime = 200; // Time to apply high power to flipper to get the initial kick.

boolean FirstPushRight = false; // Variable to keep track of when you first push a button.
boolean FirstPushLeft = false;

unsigned long StartRight, CurrentRight, ElapsedRight; // Variables to keep track of how long a button is depressed.
unsigned long StartLeft, CurrentLeft, ElapsedLeft;

void setup() {

pinMode(RightButton, INPUT);
pinMode(LeftButton, INPUT);
pinMode(RightFlipper, OUTPUT);
pinMode(LeftFlipper, OUTPUT);

}

void CheckRightFlipper() {

if (digitalRead(RightButton) == HIGH) { // Right flipper button is depressed.

if (FirstPushRight == false) { // First time the button is pushed, start timer.
StartRight = millis(); // Start timer by recording time button is pushed.
FirstPushRight = true; // Keep track that button is pushed so as to not repeat this step.
analogWrite(RightFlipper, 255); // Full power to do the initial kick.
}

if (FirstPushRight == true) { // Button has already been pushed. Now measure elapsed time.
CurrentRight = millis(); // Check current time.
ElapsedRight = CurrentRight - StartRight; // Calculate elapsed time for how long the button has been pushed.
}

if (ElapsedRight >= HighKickTime) { // If time elapsed exceeds the time for the initial high voltage kick, then start PWMing the signal to the flipper.
analogWrite(RightFlipper, PWM);
}

}

if (digitalRead(RightButton) == LOW) { // Right flipper button not depressed or has been released.
FirstPushRight = false; // Reset variable.
analogWrite(RightFlipper, 0); // Turn off signal to flipper.
}

}

void CheckLeftFlipper() {

if (digitalRead(LeftButton) == HIGH) { // Left flipper button is depressed.

if (FirstPushLeft == false) { // First time the button is pushed, start timer.
StartLeft = millis(); // Start timer by recording time button is pushed.
FirstPushLeft = true; // Keep track that button is pushed so as to not repeat this step.
analogWrite(LeftFlipper, 255); // Full power to do the initial kick.
}

if (FirstPushLeft == true) { // Button has already been pushed. Now measure elapsed time.
CurrentLeft = millis(); // Check current time.
ElapsedLeft = CurrentLeft - StartLeft; // Calculate elapsed time for how long the button has been pushed.
}

if (ElapsedLeft >= HighKickTime) { // If time elapsed exceeds the time for the initial high voltage kick, then start PWMing the signal to the flipper.
analogWrite(LeftFlipper, PWM);
}

}

if (digitalRead(LeftButton) == LOW) { // Left flipper button not depressed or has been released.
FirstPushLeft = false; // Reset variable.
analogWrite(LeftFlipper, 0); // Turn off signal to flipper.
}

}

void loop() {

CheckRightFlipper();
CheckLeftFlipper();

}

Changed HighKickTime variable to 50 and PWM variable to 75. (5 Dec 2020)

Changed high kick time to 60. (12-12-20)

Thanks for the tip. I guess I’ll try starting there and see how it goes.

Ugh. I already see bugs in my code. Stupid double equal signs gets me every time.

Thank goodness for Ace Hardware. They have the types of screws Home Depot doesn’t bother to carry. It allowed me to create my cabinet. I even found a roll pin to allow me to complete my left flipper assembly.

The cabinet is held together by metal brackets. The playfield sits on top of the brackets. I can easily remove it to work on the playfield and then put it back in. If this all works out, I’ll try to make something more permanent, but this is good for my “white wood”.

My first attempt to get a 6.5 degree pitch didn’t really work out. My second attempt was a lot closer, and I can easily dial it in with some rubber feet.

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Rainy day making boards and soldering.

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Here's my first test of the flippers:

20 Volts seems to be the magic number. The right flipper seems a bit weaker than the left, and I'm not entirely sure why. The left will work a bit more at lower voltages, while the right has trouble. And, the right seems a little weak when I hit the ball from the cradle position (i.e., when it has been held up, released, and then hit quickly again).

The right has an older flipper coil labeled from Stern on it. It was in the kit I got and it seemed a bit old. The left has a brand new looking generic coil from Marco. It could also be a bad solder joint. I'm not sure. I want to get things set up a bit more, and then I'll really be able to tell. I'll take some videos of it hitting the ball when I do. Right now, the flippers hit the ball (which is .75" in diameter) fairly hard, and it easily thumps against the top of the cabinet. I expect it will go up ramps no problem.

I've used Schottky diodes across the flipper coils. Not sure that was necessary, but since I'm PWMing the hold signal, I thought it couldn't hurt. Right now, I'm PWMing at 75/255. It seems plenty powerful and holds well at that level. That's assuming my code is actually working correctly. I think I'll try dropping it lower to see.

Finished my flipper control boards and attached them to a scrap piece of wood just to get everything organized. Put a buck converter on there as well which steps down the voltage from 24V to 5V to control the logic circuits. Also hooked up flipper buttons on the side of the pinball cabinet.

IMG_1623 (resized).JPG

I settled on 24V to the flippers. I apply full power for 60ms and then PWM at a duty rate of 75/255. I played around with other values, but this seems to be the sweet spot. At that PWM rate, it takes a lot of force for me to try to lower the flipper when it is held up, and the ball coming at it at normal speed, won't send it down. At lower rates, I could easily push the flipper down when activated, and the ball could also lower the flipper.

Here's a video of me testing the flippers at these settings (I added some foam board return rails just to keep things moving for now):

At first, I was a little disappointed in the force the flippers applied. They would hit the ball pretty hard straight up or with a back hand. But, if I tried to hit the ball to the other side of the table by hitting it more with the tip of the flipper, it would be a very weak hit. It would never make an orbit or ramp. I tried lowering the pitch of my flippers so that I could aim for the opposite side of the table higher up on the flipper, and that seems to have helped significantly.

Right now, I'm using a 3/4" ball. I like the size, but if I use a 5/8" ball, I can hit it with more force, it will be more in line with the scale of the table, and I can probably have a bit more space to play with on the table in terms of lanes, ramps, etc. I have some 5/8" balls coming Monday to see how they feel. One issue with going lower in size is that all the rubber rings, targets and stuff that I eventually plan to put on the table will likely have to be that much lower to the playfield itself. I also am not sure if the ball will have enough mass to trigger stand up targets if I buy standard ones. Ball size is going to dictate layout and other stuff, so I need to make a decision eventually. Next step will be to add some test ramps, orbits and stuff to start testing the layout. So maybe I'll just see how it goes and play it by ear.

It might be time to reveal the theme I have in mind. Anyone able to guess?

BathHouse (resized).jpg

Yeah, I did. I lengthened it all the way to 200. No better.

Also, I don’t know if you noticed the whine from the flippers in my video. Is that normal? It is pretty loud in person.

For the win!

Spirited Away is one of my favorite movies. So much amazing and rich content in it. I have some ideas for how to incorporate some of it in the pin. We’ll see how practical those idea are when working at this size and also how well I’m able to do any of it. For instance, I would love to be able to do a recreation of the bath house in my picture on the back of the playfield, but I have a long ways to go before I can start figuring that part out.

My 5/8" balls arrived today. I definitely get better hits off the tip of the flipper and to the side of the table with the smaller diameter. However, when I hit them straight up the playfield, they fly. I'm worried about airballs. Unfortunately, it just seems like there is going to have to be a tradeoff here. I'm going to start building a playfield layout around the 5/8" balls first and see how that goes. The balls are more in keeping with the scale of the table overall.

I didn't realize this when I bought the mini flipper assemblies that are used for Munsters, Family Guy, etc., but the Munsters sub-playfield actually uses the 5/8" balls. I've been watching some videos, and those balls fly around. But that playfield is more compact and seems designed for it. I'll just have to see how things go.

So, onto something I'm not very familiar with, and that is prototyping the layout itself. I have lots of cardboard from Amazon boxes to try to make ball guides, ramps, etc., just to try certain things out. zacaj , I've also been skimming your own homebrew thread. Looks impressive. I saw that you started experimenting with Future Pinball to design a layout. I haven't read through the whole thread, but was that useful? I downloaded it and started playing around, but there is a bit of a learning curve. I might be better off just trying things by hand.

Not standard mechs, but everything will retain roughly the same scale as a normal table, just 50% smaller. I just want to get a feel for how to fit things around each other, which it may allow me to do.

Looking a little more like a pinball machine.

3CF39492-A362-4C5E-B227-1BF99907F22C (resized).jpeg

Time to make a shooter rod.

3C46BA42-8E1E-42D1-BAEB-AF0438DB1099 (resized).jpeg

You have to get creative when working at half the scale. Luckily, Ace Hardware to the rescue again. They have those odd parts that Home Depot just doesn’t, like collar shafts.

9237891B-156B-4191-952C-90E4A5C56A7A (resized).jpeg

It needs to be centered and have some sort of housing on the outside to prevent wiggle, but it works!

I’m getting kind of sick of cutting cardboard and hot gluing stuff together. I thought prototyping the layout would be the fun part, but it is pretty repetitive so far. Still, I’m slowly making progress.

C76A4401-C34B-445D-845A-8AB781CB952D (resized).jpeg

Just spent 90 minutes trying to make a darn ramp and failing. So much cardboard. So much hot glue.

I never got it to fit right. All my parts are currently held onto the playfield by fun tac so I can adjust and move them around. But they also keep coming undone as I try to fit more stuff. I’m feeling frustrated and taking a break for the day. Think I’ll go to the store and pick up more hot glue sticks.

Luckily, I have an idea to try to get this ramp to work better next time.

Yes. It bonds well. I’m just screwing up on the dimensions. And while the individual pieces are solid, I’m attaching them to the playfield with fun tac which is not a great bond. But, it helps me play around with the exact spacing and fit for now. I have an idea for my ramp which should help. I think a lot of this is just that it’s all new to me, and I’m learning as I’m going.

My second attempt at making a ramp went better. Here's a video of me testing it out. I plan to add a wireform on the end that returns the ball to the left flipper, but for now, it just drops the ball into the orbit.

As you can see, my shot geometry needs some improvement. Lots of cheap drains. But, I can also see this coming together with some nice flow.

Made a second ramp today, and while it worked, I am not that happy with my shot geometry. I also thought there would be space for a saucer / VUK, but it didn't leave enough space. So, I need to adjust.

For those of you who have played around with making homebrew games, how does the process of adjusting and improving usually work? Is it just trial and error? Do you try a ramp out of cardboard or foamboard, find out it doesn't work, tear it up and try again? Are you constantly moving shots around by a few millimeters here and there? I feel like I need to remove most stuff on my playfield, adjust and put back on. I just am wondering if there is an easier way to all this. I'm guessing not, but figured I would ask if there are any tips and tricks.

Thanks. I just realized you’re the home brew Fight Club guy. That thing looks awesome! One of my favorite movies, too. I’ve been following your thread from time to time. I should go back and review it start to finish.

I made some adjustments yesterday, and I now have space for my saucer (possible VUK). It also shoots better.

One thing I’m struggling with is the inconsistency in my shots. For instance, hitting the orbit will return the ball nicely about 60-70% of the time, but I still get quite a lot of cheap drains straight down the middle. I know every machine has some inconsistency, but I’m wondering if things just get worse on the smaller scale I’m dealing with. Less room for adjustments and small changes create larger variability. I also feel my flipper gap is too wide, but that will have to wait for the next playfield. And, I find these mini flippers to be a bit frustrating. They work ok, but they are super strong hitting straight up and lose a lot of strength when hitting to the side.

I seem like I’m full of complaints today. I just need to realize that this is mainly a fun project, and it won’t feel exactly like a real pinball machine when working on the scale I’m dealing with.

I definitely have a lot more respect for pinball designers. Having interesting layouts that actually shoot well I don’t think is as simple as we all take for granted.

I think you’re probably right, which likely means get the general layout done now and save the real fine tuning for later.

Starting making wire forms. It is a slow process. I’m trying a new (to me) kind of solder for repairing jewelry. I can barely get it to melt, let alone stick to anything. I finally got the base together by applying large amounts of flux. I may try regular electrical 60/40 rosin core solder on the next one to see if that is any easier. I give myself a B- on this one, but it is my first attempt so hopefully I’ll get better.

76F9E2AC-2DAA-4D78-8755-8E4015ADF0B5 (resized).jpeg

14 gauge (2mm) stainless steel. Decent size for the size ball I’m using. I can also bend and shape it pretty well by hand. It wouldn’t work for a regular sized ball and table.

Trying the 60/40 rosin core solder was worse. Back to the original. I’m also having a difficult time making the 3D structures that stick up and out around the bends and at the ends. Need some more hands.

This guy makes it seem so easy:

What do you mean by making forms? Thanks.

Got it. I did clip them down to a sheet of wood when I did that wire form just like the guy in the video I posted. Maybe for some of the ones where you have 4 wires connecting to a ramp, I can drill some holes in wood to keep them evenly spaced.

Mine’s about 1/2 size. We’ll see how it goes.

I took a break today. But, I did get a package. A little 24V solenoid from Amazon. This will be my attempt to make a VUK. I want to put a saucer between the left ramp and the middle orbit that returns the ball to the wire form that will be the return from the right ramp. I plan to build something simple first on a scrap board just to see if this will have enough force. I’m thinking it will — I only need to move a small ball a short distance — but I’ll just have to see. If not, . . . well, then I’ll come up with a plan B.

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I’m getting more used to soldering these steel rods together. This works as intended. Just need to make the end piece next and get it more stably mounted.

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I’m making less progress than I hoped to during my end of the year vacation. I blame my wife who was kind enough to get me an Oculus Quest 2 for the holidays. Very distracting!

Not pretty, but functional.

I set it up, and it works. I need to more permanently mount it, but hearing the ball travel down the rail for the first time and end back at the return lane was pretty cool.

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Thanks. Right now, it seems pretty strong. I was worried because I had a few bad joints that failed, but I think I got the hang of it and started doing a better job. You also can't tell from the picture, but the main rails are actually four rails -- two joined end to end. I was especially worried about that joint, but it seems pretty solid.

I am a little bit afraid of making adjustments though. I would like the entrance to bend at slightly more of an angle, but I worry that I may disturb the joints if I try that. I think it is good enough for now for the prototype. I may eventually redo the rails, if this whole project works out.

Next up: I have to make a second rail. And, I have to test out whether my idea for a VUK will work. I'm just having trouble motivating at the moment as my vacation is coming to an end. . . . I think things are going to move a bit more slowly for the time being. I want to move on to the electronics, but I really need to nail down the layout first.

Been thinking about my VUK. I had a bit of luck over New Years. I was wondering the best way to mount that little solenoid that I bought. Lo and behold, the goat cheese I bought to eat on New Years Eve came in this little wooden box. It seems like a perfect bracket to hold the coil.

I was also wondering how best to create a saucer. I want the hole to be large enough that it captures the ball, but it also needs to center the ball under the plunger of the solenoid. I thought maybe I could find a cheap funnel to do the trick. I found this one. Not only is it the perfect size once I cut the end off, but it also bends. I may not have to make a wireform for the prototype. This actually seems like the perfect size to feed the ball onto the return rail. If it works, I’ll replace with something more permanent, but I’m pretty happy with this idea so far.

Do you guys have any experience making saucers? Ideally, it would have a beveled edge, but I’m not sure how to do that and am wondering if just a hole will do.

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Thanks. I’ve been thinking about that and agree that I’ll probably need a 3D printer. I’ve wanted one for some time. As I move from turning the prototype to something more permanent, I will be looking into this in more detail. I have no experience with them, so that will be a whole other learning process, but likely one that will benefit me a lot in the future.

Thanks for the offer. I may take you up on it. I also want to learn how to make my own models someday. Let me see how far I can get on this initial prototype with just some simple materials and then I’ll look into 3D printing in a lot more detail.

Just watched those Jack Danger clips. That’s really impressive! Part of this project is for me to pick up new skills like 3D printing. It is just that the thought of buying another device and learning how to use it at this point in time is a bit overwhelming. That time will definitely come. I just want to make some progress on these other parts first.

Thanks. I was initially thinking of modeling the VUK off of the ones on my WOZ which hit the ball straight up into a circular wireform. I think for the prototype I’m going to try the funnel / tube idea. For the size ball I’m using, I think it will work, but time will tell. I will replace it with something more permanent down the road and likely turn to 3D printing at that time.

The VUK is supposed to represent the elevator scene in Spirited Away where the protagonist takes an elevator up in the bath house to get a job and gets stuck in the elevator with a Radish Spirit.

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It will go here:

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If the tube works, I can surround it with cardboard to be the sides of the elevator. Again, with the idea of replacing it down the road with a 3D print. And, I will need a hole in the side or to mount it above the playfield to allow space for the ball to get in as you say.

So, my next steps are:

1. Try the VUK on a scrap piece of wood just to see if it works. Right now, I don’t even know if the coil is strong enough, but I imagine it is.

2. Remove left ramp, cut off end, create and add wireform.

3. Mount both wire forms.

4. Add VUK assuming it works.

Once all that is done, I want to move on to switches and electronics. I have ideas for targets and one other mech which I’ll describe later. Before doing that, I may try to move everything to a fresh playfield and mount it all in a more secure fashion, either by still working in cardboard or starting to replace with metal and (possibly) 3D prints.

Agreed. And, nice illustration.

That picture, though, is not current. Take a look at the one above where I adjusted the left orbit. It is better but still needs more adjustment. I plan to move things around again when I take off the left ramp to mount the wire forms. I’m thinking I can solve some of the issues I am having with the consistency of my shots by narrowing the orbit. That said, I still want to keep the entrances a bit wide as it is a little harder to aim with the flippers and ball I’m using.

And, I’m not 100% yet on the design for the left outlane. I kind of like this idea of a wide outlane with a star post in it, but I don’t think I have it quite right yet, and don’t want to have too many frustrating drains.

Perhaps I should think of today as any knowledge gained is making progress. That might make me feel better.

I spent a while trying to make a VUK. Unfortunately, the coil only launches the ball to the top of the bend in the curve. I think this idea of using an undulated tube is not going to work. When I try the coil with just the ball and no tube, it seems like it goes pretty high. (See video below.) I wonder if I got the ball perfectly centered and had a very smooth guide, whether I could get it up and onto the return wireform that I want.

toyotaboy You may be right that I'm going to need some 3D prints to proceed with this project. It might be time to seriously explore getting a printer. Perhaps if I can make a better bracket that has the coil perfectly centered and create a nice guide, it will have enough force to do what I want. I need to figure this out as it will affect the rest of the pin. I would like a nice VUK that sends the ball to the return wireform from the right ramp. Alternatively, if I can't get that, I could just create a scoop type kick-out. I probably have enough force for that at a minimum.

Any thoughts from the experts?

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I should give that a try. toyotaboy has the cut out template in one of his posts above.

You guys were right. I should have listened from the get go rather than try that funnel tube. This got it to work. I still need to make sure I can position it well enough to get the ball onto the wire form, but I think that will just be a matter of final adjustments.

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Just out of curiosity, what brand and model of 3D printer do you all have? It is becoming increasingly clear to me that in order to effectively move this project forward, I will need one at some point. And, that point may be coming sooner than I realized. The Ender 3 seems like a good low budget one. But, it also seems that if I pay a little more, I can get one with an enclosure and some self-balancing features. I may be willing to do that. I have cats, and I don't want them bothering the prints. I know you can get an enclosure for the Ender, but that just adds to the cost. I also know that people make their own enclosures, but I don't want to tackle an added project right now.

Also, it seems like PLA may be the best choice of polymer for printing, as it is the least toxic (perhaps non-toxic), and I don't have a great place to put the printer where there is a lot of ventilation. I assume PLA is perfectly acceptable for the types of prints I would be doing, is that right?

Thanks guys for all the advice and input. After doing some research, I’m thinking about this one:

https://www.amazon.com/dp/B07TJG431N/ref=cm_sw_em_r_mt_dp_MvB.Fb5GRW9HK

It is a little pricier than the ender 3, but it is fully assembled and enclosed. Also, based on some research, people seem pretty happy with it and it’s software. The printing area is a bit smaller than the ender at 6” cubed. However, that should be large enough for most prints. It won’t be large enough if I want to print ramps, but I assume I can do those in parts and attach them together in some way, correct?

toyotaboy I hear you about the ender and the ability to make my own enclosure. I just don’t want to get sidetracked and am willing to pay a little more for one that has a bit less hassle to get started.

Are you sure? The Monoprice Voxel was a flashforge clone so I steered away from it. I didn’t think this one was.

I probably should just listen to you. You were right about the VUK.

Ok. You’re turning me around in the right direction. This is why I turn to pinside.

Ender 3 ordered! Thanks for keeping me on the right track, guys!

Will do. Thank you! I’m going to try to play around with tinkercad this weekend to learn the basics while I wait for delivery.

And, I may tackle soldering the second wireform . . . . which I’ve kind of been avoiding.

Sure. Will look into it.

Been messing around with CAD programs today. I thought I would start with tinkerCAD since it seems very intuitive and user friendly. However, I quickly discovered that it is also very limited. For instance, you can only make right triangles. I wanted to try to model my slingshots since they will be small and non-active. Just triangles with a rubber ring around them. And, they won't be right triangles.

So, once again, toyotaboy had it right, and I started learning freeCAD. It is definitely not intuitive. However, there are lots of good tutorials and videos to learn various things. I quickly was able to make this model. I need to add a groove around the edge for the rubber ring, and I haven't quite figured out how to do that yet. But, I'm still learning the tools. Once I figure that out, I'll add some holes for screws as well, which I know how to do.

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Thanks. Appreciate it. I do want to learn this stuff. That said, the groove is driving me a bit crazy. There’s a sweep function in freecad that I think I need to use, but I can’t get it to work right. I think I did stumble on a video that will help and will try again tomorrow.

Just signed up for onshape. The interface itself just seems like a huge improvement over freecad. Will try to start learning it tomorrow. Good excuse to keep procrastinating from making my second wireform.

Woo hoo!

Thanks, zacaj ! Onshape to the rescue! Much, much, much easier to use.

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VUK bracket for my little solenoid.

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Set up my 3D printer this weekend and have been trying to print my mini slingshot. Turns out 7th times the charm thanks to some spot on advice from toyotaboy

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This weekend, I adjusted everything -- the size of my lanes, a bit of the geometry, etc. I also added the stationary slingshots. Overall, it shoots better with fewer cheap drains down the sides. I still think my flipper gap is too large, but we'll save that for down the road.

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I needed to adjust the curve of my return rail from the right ramp. I 3D printed some tools using the theory that they would keep the rails separated evenly while I twisted and perhaps not dislodge the cross pieces. Unfortunately, I did in fact dislodge a cross piece so that will have to be fixed down the road when I work on these again.

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I also 3D printed the coil bracket for my VUK. This one took many attempts to get right.

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Even now, it is only 90%, but that is probably good enough. I continue to get a few layers that don't bond together perfectly. You can see that in this picture towards the top.

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I really think it has to be my slicer settings rather than something wrong with my Ender mechanically. I printed the dog model that came pre-loaded on the SD card that came with the Ender, and it printed perfectly. That was pre-sliced.

I've tried upping the extruder temperature, lowering the fan, lowering print speed, etc. What worked the best was increasing the number of layers for my walls, but even then, I still get these lines. Perhaps I need to increase that even further. I'm still getting used to 3D printing, but this one thing has me the most frustrated. I just haven't been able to nail the setting that is causing this. I tried making a small test model -- just a small, vertical wall -- that I could print and try multiple settings until it works. That way I would have results in an hour instead of waiting the 5 hours it takes me to print the bracket. However, just my luck, the test "wall" printed perfectly the first time on settings that don't seem to work for the bracket, despite it being the same thickness. I'm going to try a few other things and then try to post in some online forums for help.

It's a good thought. I was wondering about the filament. It's Ender branded filament.

I did buy a second spool of grey Sunlu PLA, as I heard that was a good brand, so I can try that when I get a chance.

If the filament is bad, however, I wonder why the pre-sliced dog model that came with the SD card printed so perfectly?

I'm using 0.2 mm for my layer thickness. I did at one point go down to 0.16 mm, and that seemed to do a bit better. However, when I made my test wall, I went back to 0.2 to start testing from there, and that printed so perfectly, that I assumed the layer thickness wasn't the issue. But, perhaps I should go back to playing around with that.

Separately, when you guys build your prototype playfields with cardboard ramps, what do you use to keep the ramps in place on the playfield itself? I think I mentioned, I've been using poster tack because I can easily get things in place and then later move things around. However, it doesn't stick great to everything, and some things get pushed out of place by the ball. I don't want to hot glue them directly to the playfield, as I then can't adjust things. Is there something better to use?

Great idea. Thanks.

Found this video about moisture and filament. It pretty much summarizes what’s been happening with my prints, down to the fact of being able to snap some prints in half. Though, it does seem that this guy has it worse. I guess I’ll be switching my filament out for the Sunlu brand and hope that solves things.

Hard to say so far because I’m still optimizing things and playing on a rough prototype. It’s fast, and there seems to be less room for error. Also, so much of pinball is about nudging, and I’m not sure that will be possible with the smaller size. I mean, it will be possible, but a little slap would likely go a lot further.

I reprinted my mini sling shots with new filament. Both came out nearly perfect with no layer separation. I do think my original filament was bad, so hopefully that’s now solved. I’ll try to reprint my solenoid bracket tomorrow as a final test. I also kind of like the grey color even though I haven’t settled on a final color scheme yet.

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Unfortunately, when I moved things around last weekend to optimize my lane geometry, I made one fatal flaw:

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That wall along the back orbit can’t be flat like that. The ball sometimes gets caught up. So, today I was back at it moving stuff around. I think I have a geometry that works, but I’m sick of cardboard, poster board, and sticky tack. I’m thinking about 3D printing the lane guides and getting a more solid, permanent structure in there. I think my game is small enough that printing those guides will work. I was originally thinking of making them out of metal, but I have no welding skills. So, this seems like a decent solution. Can anyone think of any issues with doing that?

I found a model for the Radish Spirit from Spirited Away and printed it. This guy’s definitely going near the VUK. ED178E71-7DDD-4BA2-8B22-7D28921645DD (resized).jpeg

Really good point about the ability to make small adjustments. I like the idea of trying to print some clips that can hold a metal strip in place. I may try that, and then once I get the dimensions, do something more permanent. Either way, I’m ready to move on from disposable materials. I need something solid that stays in place before I do more on the ramps and wire forms. Right now, every time I move something, I mess a bunch of stuff up.

Anyone have decent experience with servo motors? Here’s my idea for the middle orbit. I’ll have two motors at each entrance which control arms that will either block a set of three targets, block the orbit itself, or stay open, all depending upon what’s going on. For instance, my idea is that they initially block the orbit. You then open the orbit by hitting all three targets. I could even just close one end of the orbit to make a ball lock.

My question is whether the force of the ball will move the servo motor itself and thus move the arms? Is this just a matter of getting the right motors? Also, if it does move the arms, will that create short bursts of electrical current that could damage stuff?

I could probably block the movement of the arms physically in at least one direction, but harder to do both directions.

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Thanks. I’ll be using an arduino. If I remembered correctly, there’s a great library to control servo motors. You basically just set the angle you want, and that’s it. I’m fairly confident on the programming part. I wasn’t so sure on the stability of a motor that repeatedly takes a force.

Interesting. It does look like the door moves with the ball but then goes back into position. So, there may be a bit of movement. I wonder if it creates any electrical surges. For instance, if you accidentally move the 3D printer without disengaging the stepper motors, it’s not good and the LCD screen will flash.

Perfect print. Further proof that my PLA was bad.

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Thanks all. Useful information.

I found a 10 foot strip of tin used for making cookie cutters on Amazon for $10. Seemed perfect for making ball guides for my mini pin. Following zacaj advice, I 3D printed some brackets. They’re a bit difficult to get on, but once on, they slide along the strip quite well and stay on. I’ve cut up my hands quite a bit just with two brackets so far. Time to put on some cut resistant gloves, or perhaps change the bracket dimensions a bit. This weekend I’ll hopefully replace my poster board ball guides with something more stable.

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Got the metal ball guides in yesterday. It is very nice to have something that stays in place and lets you fine tune more precisely.

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The cookie cutter tin strips I got are fine for a prototype, but do deform pretty easily so they don’t look perfect. Once the geometry is nailed down, I may 3D print the guides just to have a more smooth and cleaner look.

Already this is shooting better.

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I do think that my left ramp is taking up too much space and not leaving enough room for where I want to put the VUK. I have a really cool idea for how to change that, but it is going to test my newly learned CAD design skills. I’ll post back more later about it.

I will say that I was initially reluctant to get a 3D printer because I was worried I would get too distracted and it would take time away from this project. And, in fact, I did fall into that 3D printing rabbit hole for a few weeks. However, now that I have a feel for it, it is truly enabling. If I have an idea, I don’t need to worry about finding miscellaneous parts to make it happen. I just make my own parts. Ultimately, I can move faster with it. I don’t think I could conceive of this project without one anymore.

Oh, yeah. This will be great for other things. I’ve been doing a bunch of electronic projects. In the past, just finding a housing in the size I wanted was a challenge. For example, for a game I made, I needed a couple of handheld buttons. I found a rectangular plastic housing on Amazon, drilled holes in it, and then filed the holes to get them large enough for the buttons. No more! Now, I just make what I need.

Well, here's my idea for the replacement for the left ramp. I have no idea if this will work, but it will be fun to try. Left Ramp (resized).JPG

There will be a little support on the overhang to the right, but I don’t think I need any elsewhere. Will try printing tomorrow. This was all a bit of guesswork as I was designing it. We’ll see . . . .

It works! Feeling pretty awesome right now!

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The ramp is supposed to represent the character Haku in his spirit form, and the wireform will snake back to the right return lane.

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One thing that I didn’t think about is that the exit from the ramp heads slightly up the playfield. I should have angled it down. However, the ball comes out with enough speed that if I make the wireform turn down right at the exit, it should be fine. I could also try redesigning it if it becomes an issue, but I think I’ll be fine.

It would be great to actually try to mold the face of the Haku dragon spirit around the entrance to the ramp, but I don’t have the skills for that. I may try to decorate it in some way with his image though.

Thanks all. It was fun to design.

Hey, you want to be my art designer?

Took a stab at designing the left ramp today. It is too big to print on the Ender 3, so I had to split it into two parts. Again, this is all new to me, so this is a bit of trial and error. Will try to print it over the next couple of days.

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This did not work out as planned. First, I messed up and somehow got way off on the dimensions for my right ramp. The one I printed is far too large.

On top of that, while the bottom section printed perfectly, the top section’s walls are not sticking together well and are spongy. There is also some layer separation. The top section is an odd shape with the ramp curving up and then down as it goes around the bend. Because of the way it is shaped, it was printed entirely on supports with the walls at an angle from the z axis. I wonder if it is just hard to print, or if I have some under extrusion that is manifesting itself because of the difficult shape.

Regardless, I need to recalibrate and try again. Finding out your print is bad at the end of a two hour print is frustrating. Finding out it is bad at the end of a 25 hour print is exceedingly annoying.

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That’s a really good idea. I didn’t realize that a lot of ramps are flat.

One issue I have is that the back part of the ramp travels horizontally across the back of the playfield, so it has to angle down, otherwise the ball might get stuck. But, I could probably have the right side of the ramp raised slightly higher than the left to make that happen.

Do you think the weird curves I was trying to do could have led to my soft, separated wall issue?

I’ve been printing at 210 with this filament for a while now so don’t think it is a heat issue. And, it seems to have started happening mid print. I’ll check those other things. Thanks all.

Attempt number 2 to make my right ramp went much better. I cleaned the nozzle on my 3D printer and tightened the gears. I also redesigned the ramp, following the suggestion of toyotaboy to print it flat. I was wondering how best to loft it at an angle when I noticed that one of the ramps on one of my pins had these slotted grooves in the side so that it could be mounted to a straight post at an angle. I thought that was the perfect solution, so I added that to the ramp. I also was much, much, much, much more careful about measuring the dimensions this time. And, since the back of the ramp lies flat across the back of the playfield, I arced it along a curve so balls can't get stuck there. It was just slightly too large to print with the ramp flap, so I took off the ramp flap and printed that as a separate piece.

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Next step will be to mount it to some posts and do some more work on the rails.

Yeah, because that’s an area of horizontal travel, that curve is solely there to prevent a slow ball from coming to rest. Typically, the ball just travels along the back wall as expected.

Pretty slow progress as of late. Life's getting in the way. But, I was able to mount my right ramp, and finish and mount the wireform off of it. I had to make a custom starpost that had the indent for the rubber ring a bit lower to accommodate my smaller ball. I attached it to the playfield through a t-nut and hooked the end of the wireform onto it. Works pretty well. The wireform still needs a bit of work. Really fast shots will fall off around the bend -- easy fix with another side rail. And slow shots can get caught at the lower part of the entrance to the wireform. That will be a bit of a harder fix, but I think I can reconfigure it.

I also ordered some servo motors to try out my idea for gates around the inner orbit. I should get those this week.

Still need to make the wireform for the left ramp. Will probably start on that tomorrow.

Here's a few pics including a video of me trying the ramp by hand.

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The more I play with it, the more I realize the left ramp could be a lot better. It takes a near perfect shot to make it through the loop. Most shots get rejected. I have to decide whether I'm ok with that -- some games have such a shot that you need to nail perfectly -- or whether I want to redesign it.

It’s weird because when I first tested it, it worked for the most part. Maybe I just got lucky. But now it is rejecting more than it is letting through. I’m tempted to make the bottom a bit longer and the tube diameter a bit wider to see if that will help. I’m debating whether to try that now or work on other areas of the table and come back to it.

Honestly, though, this table is pretty brutal and unforgiving. The ball moves really fast, and it is hard to react in time. Very different than full sized. The flippers are too powerful on the middle shots, but if I turn them down, the wide shots become difficult. That inner loop just chucks the ball back at you. I haven’t played Munsters, where these flippers are used on the lower playfield with a ball the same diameter as mine, but I can’t imagine players can keep the ball in play on that lower playfield for long.

All in all, this is meant to be a fun experiment / learning experience. We’ll see how playable it is when I’m done with everything. There may be only so much I can do at this scale.