So, looks like the coil itself on one of the flippers is shorted, and compounding the bad news, when checking the resistance on the other coil, I discovered that it’s also shorted out some of the windings, and will likely burn itself out in short order.
I guess time to buy some new coils…
do the coils have the # on them?
i may have some spares…
SFL-23-600/30-2600
I believe this is the part. (it matches what was originally in Comet, too).
Thanks!
IT LIVES! or at least flips.
John’s Jukes turns out to have relatively reasonable pricing on coils, so I picked up a replacement coil locally.
Installed the replacement for the shorted one, tested the resistences, and it appears equivalent to the one in the existing flipper, so that’s good news.
With that installed, flipped it over, connected the power, and started testing: (apologies for the vertical videos)
testing the flippers:
testing the slingshots:
So far so good! Both flippers and the slings are able to throw the ball to the top of the table, but not too much.
I built a bit of a temporary “rear wall” out of some scrap acrylic and wood that was lying around - lets me test the single side.
then started gluing some additional parts on, and testing how it shot:
One of the flippers ( the one with the new coil…) is weaker than the other. As both appeared to have similar resistances, I suspect this is due to the end of stroke switch being finicky.
I’m also looking forward to some high amperage connectors I ordered showing up - currently setting up the table to test requires soldering some wires together!
Next step is more layout tweaking, and once I get positions I’m happy with, putting them into the CAD model.
Could also be due to the plunger or its sleeve in the coil…
The plungers tend to get mushroomed a bit on the bottom from hitting the stop and the sleeves wear out…
Can’t remember if those were all new parts or not…
Looking awesome @jon. I like that the balls go down all three of the lanes next to the flippers. I was worries that the gutter would never get used with the bumpers on the wall.
So this is what I was thinking for the center “wormhole” trap/multiball hole
Here’s the onshape file for those who want to give it a twirl:
Essentially it consists of an acrylic tube, with an elevator that rides along a slot in the side of it. The elevator would be attached to a belt driven by a stepper motor, much like the Tinkerine belts in my mind. The elevator would start near the top, there would be a microswitch at the top that would read when a new ball has entered the tube, and would tell the motor to drop down 1 unit (the standard ball height). That way you reduce the amount of impact from incoming balls, and once the tube is filled (this mockup is 20 balls high for a height around 50cm, so could be bigger depending on the space we’ve got available) it’ll reverse the elevator all the way up and spit all the balls back onto the field.
The elevator design can be optimized to make sure that at it’s peak it’s flush with the table surface, in order to close off the wormhole when not in use, maybe while the multiball mode is running. Also it would need some fiddling to make sure it doesn’t hit the upper belt wheel once we know what to use.
I’m still a bit worried about the strength of the stepper motor, 20 pinballs is 1.6 kg, so I’m not sure whether it will have the torque to move that much?
Fibertek has Acrylic rods, so we can even see the pinballs in the tube, I’m not sure where to get the motor, switch, drive belt or wheels, buuut you guys do, so direct me!
Yeah, it would be better to have the tube closer to horizontal, with a curve to push only the balls at the top vertically. Neat idea though!
I’d have no clue how to make that tube though, without buying something flexible or printing something ourselves, and then it would take more engineering to figure out the curved elevator belt setup too (not impossible) I like the idea of having a clear tube though, we could have a window in the side of the machine to show off the innards.
I think this would be a great task for a 3D printer! (the curved part of the tube)
Tonight we tested to see if the flippers, slingshots and coils would effect the WS2812 LED strips that we are planing on using for the table. There was no visible effect on the LEDs.
My next task is to do some demo cuts with the Shopbot for the LED pockets in the playing field.
The image below is a cross section of the plywood.
On my front, Connectors finally came in, so am able to setup the test playfield without soldering/desoldering it each time.
I think I’ve resolved the "different flipper strengths issue - I had missed transfering a plastic sleeve from the center of the coil to the one that I replaced, so there was added friction.
@SDY and @packetbob raised some concerns with my power supplies not being up to snuff. @SDY’s offered to lend a large transformer, which will at the very least let us confirm that.
I’m continuing to tweak the layout.
“…Option 1 is a more genital curve…”
Steven’s got lots of balls to claim that, LOL!
I pulled the transformer out of storage at my work, will try to connect one before the weekend and see what kind of DC I can generate, both voltage and current wise.
SDY
The pull in coils are around 3 Ohms so at 48 Volts that is a 16 Amp load (till the end of stroke switch kicks in the holding coil and the resistance jumps to around 60 Ohms (for a more manageable 0.8 Amp)…
Your power supply was rated at 7.5 Amps I think…
The switching power supplies probably don’t like what will probably appear to be a dead short for whatever protection circuit they have…
Perhaps adding a capacitor bank to handle the initial spike may help…
Or ditch the switchers for a simple 48 volt transformer with bridge rectifier that can dump out the needed current…That’s all the game had originally…Just a 100 uF filter after the rectifier…
I have some heavy duty rectifiers if you go that route…
But it will be heavy… Bunch o caps may be much lighter…
Only 5 amps? Allright, my transformer has been tested and running the appropriate winding at 120Vac, I get about 65Vac out of it, which when rectified should be about 50Vdc. The capacitor bank is 5 X 2700uF/200V, individually wired so as to lose only a minimum via resistive loss. The transformer VA rating is 750, 'should be more than OK.
That’s a piece of art!
awesome!
Spent some more time on tweaking the playfield layout. Here’s where we’re at (the center and right side) :
Highlights -
on the whole I’m pretty happy with how it shoots - I think I will start to translate this back to the CAD model, and it will be mirrored for the left side.
I will be dropping off the basic power supply tomorrow, Tuesday. I might add some work to it (it could use some blue LEDs… And an analog meter to indicate the state of charge of the capacitors… "Scotty! I need more power! “Keep your shorts on, Kirk, them flippers were abused, them flippers will have to wait 637milliseconds!”). It is mounted on a steel shelf, along a couple of fuse blocks, and I am bringing another identical shelf if you care to use them for all the different supplies you might be using in the machine.
