PinBall Machine -2.0/1

PinBall Machine -2.0/1

Sep 09, 2020

James Laumeyer

This was my first week taking over the pinball machine from where the previous intern left off. To start off I had to get my bearings about what the state of the machine is, what was wrong and what still needed to be done. Then, I had to assess how to fix the problems at hand and create the components that are still needed to make this a fun and functional machine.


To start the things that were found to be problematic were that the left flipper would walk up in time as it would actuate, the relays on the bumpers would weld themselves shut, upon fixing the bumper relays a new problem showed up where the bumpers would chatter on and off, and the final issue is that sloppy wiring lead to bare solder joints where wires were connected causing a mild safety hazard.


To rectify these issues the following steps were taken. First the flippers where an easy fix a locking screw just needed tightened up a little further. The bumpers were a little trickier, first I had to replace the lower amperage relays with higher amperage relays. Upon doing so the bumpers would not actuate, upon further inspection this was found to be due to the yellow and red wires being flipped between the two types of relays. This was an easy enough fix as I used bullet connectors so I just swapped them and capped the ones that were no longer in use. Upon resolving this issue a new problem arose, the bumpers were chattering upon further investigation and consulting with r/electricalengineers on reddit the issue was found to be that one of the reed switches was missing a flyback diode causing electrical interference to trigger the relay with the slightest disturbance. Once this was diagnosed as the issue the solution was very simple, simply add a flyback diode. Upon fixing these issues the machine now works as it was intended. 


Now the last problem of shotty wiring appears to be nothing more than a symptom of a bigger problem, that problem being a poorly laid out project; skipping the plan phase and jumping straight into the create phase. However I have time on my side and it is my intention to build a safe, reliable and fun machine through the process laid out below.


 As a result the mess of wires underneath of the machine leaves little room to add more components, such as a spinning motorized wheel, kickout hole, or other items. In order to fix this and the faulty legs in one go my plan is to build an actual pinball box like every other pinball game has, where there is enough room to easily access the components and replace broken or misbehaving components. To accomplish this my plan is to design the box and new playfield including all of its components in Solidworks before going off and building this machine the right way, while drawing from the original prototype using what works and revising what doesn’t.


Thus far I have worked towards this end goal by looking up the specifications of a standard pinball machine and designing a box that fits these requirements. Additionally I have identified on a few systems that would possibly make for a good lifting mechanism to get under the board. So far I have narrowed it down to two candidates: one that uses a guided roller system to slot the board into place and another that has bars that come up and slot into groves on the board holding it up. At present I am waiting to see how the rest of the components shake out to see what sort of mechanism would be best for this particular machine.


Furthermore I have designed a launching mechanism for both the main launching mechanism and the side trap like in that windows XP 3D pinball game. I decided to go with an electrical launching system as opposed to a simple mechanical launching system as this will allow for the automation of a multiball mode in the game. Initially I had planned to just use a pushing solenoid as the launching system but this was decided against as the small metal end would damage the balls in time leading to premature wear, additionally the pull solenoids are smaller and more powerful than their pushing counterparts. As seen in the rendering below I went with a system where the solenoid is actuating a lever so that when the system is activated the lever shoots forward flinging the ball toward its desired path. There are a couple edits that still need to be made to allow for proper clearances of retaining pins and such but on the whole this is what the final mechanism will look like.