I have slowly and carefully been working through my first playfield swap on Space Shuttle, with a new CPR playfield. I studied vid1900's guides on playfields and mof's guide on playfield swaps and many other threads and videos on swaps, so understood the techniques involved. But sill messed up. Need some advice. All had been going really well until I went to reinstall the wire ball guides, where I have now managed to significantly chip the new playfield twice. I’m just sick. I’ve worked on pinball machines for years and this is incredibly discouraging.

The CPR playfield has pre-drilled 1/16” holes through the playfield for the ball guides. The ball guides themselves are 3/32” diameter. As suggested, I widened the existing holes to 5/64”, just smaller than the ball guides, and drilled the top of the holes to 7/64” (just wider than the ball guide) to avoid contact with the clear. Great. But I already knew I was going to hate this next step of hammering the guides in (and yes I do have the proper soft face hammer).

I hammered in the first small 1” ball guide successfully, though it seemed to take more hammer force than I expected. It looked good and I was feeling confident.

But on the second one, again it seemed tough to go in (recalling a bit too late that vid's guide noted that something was wrong and to to stop if it wasn't going in easily) and I managed to get it bent at an angle and it chipped it chipped a good size piece (easily 1/8” around) of the paint off right next to the hole. Disaster! Fortunately I’d intentionally started at a place where it was under a plastic and wouldn’t be visible to the player, but still my perfect playfield was messed up.

After calming down a bit, I straightened the now-bent ball guide. I widened the holes for that guide to 3/32” and reinstalled the guide with a drop of glue in the hole, as at that hole width the guide wasn’t fitting particularly tight. The playfield chip had mostly come out in one piece and as I mentioned was not in a visible place, so glued it back into place. Was still obviously a chip but life would go on.

Moved on to another ball guide, a curved one. Hammering on the corner edge of the ball guide and getting both ends initially set was tricky. It’s not like hammering a nail. I thought it was going ok but once again managed to hammer one end crooked and again a sizeable chip of paint came off next to the hole. This time in a more visible spot. Makes we want to just give up. Maybe I’m just incompetent at hammering, or maybe the playfield holes are just slightly off what is needed for the ball guide legs to remain straight, but either way it’s a disaster. Is there a particular technique to installing these guides to keep the legs straight?

My thought on path forward is to go ahead and drill all the ball guide holes to 3/32”, which naturally dramatically reduces the hammering force required, and use a drop of glue in the holes to set the guides. Maybe not ideal but would seem to reduce the risk of further pf damage. Open to other ideas? And commiseration. At the moment I don't want to touch the dang thing.

I do think that using a reamer or countersink bit might have minimized the damage. The frustrating part is that I did pre-drill and widen all of the wire-guide holes. Even with 5/64" holes it seemed very tight. I like your idea of a 'test tool' for the wire-guide holes. I also keep thinking there has to be a technique/jig that would make it easier to keep the legs straight. Hammering in the wire guides seems deceptively simple, but until they are half way down in the hole it's tricky. I've been thinking to drill the wire guide holes part way at 3/32" so they'd get aligned more easily and then still have the bottom part of the hole for grab.

As update - I was able to install the rest of the ball guides without issue. After some experimentation, the process that I adopted that worked for me for these 3/32" guides was:
* file the ends of the ball guide legs to bevel them a bit (there's a reason nails and screws have pointed tips)
* as outlined in Vid's guide, drill the holes to 2mm using a 7/64" bit; then pre-drill the holes all the way through with a 5/64" bit
* drill the hole part way through from the top with a 3/32" bit (allows both ends of the guide to easily get aligned straight)
* apply a drop of glue from the bottom of the hole
* hammer in the guide

With this, the hammering process was simpler and with much less stress on the playfield (and me).

Randy