10 replies to this topic

[Phazer51]

I finally got around to installing the second to last element of my 6 year cabinet project, a mechanical potentiometer plunger (that uses the original 1976 WIlliams plunger that came with the original gutted cabinet).

 

I tried out two different potentiometers and calibrated them with the Pinscape Controller tool to see if they worked before I ever mounted them on my plunger.  They seemed to work.

 

Now that I've got my potentiometer mounted on the plunger, I used Pinscape Controller to calibrate the plunger.  It seems to calibrate alright:

 

 Plunger Calibration.JPG   59.88KB   15 downloads

 

Asssembly mocked up on a piece of 3/4" particle board as a stand-in for my cabinet:

 

 Plunger side view.jpg   80.77KB   12 downloads

 

 Plunger top view.jpg   105.27KB   7 downloads

 

 Plunger assembly sitting in front of cabinet.jpg   83.55KB   6 downloads

 

BUT...when I try to play any VP tables, the plunger acts as if it is beyond the "park" position.  If I do nothing, the ball just bounces up and down the shooter lane.  If I pull the plunger back a small amount, the ball settles down, I can fully pull the plunger, and I can shoot the ball.

 

On this table, it even shows the plunger extended too far:

 

 Plunger position in VP.jpg   133.85KB   7 downloads

 

I've tried re-calibrating many, many, times.  I keep getting the same results.

 

Is there any way that I can adjust where VP detects my plunger in order to move the parked position?

 

I don't want to drill into my cabinet and mount this plunger assembly if I cannot get it to work properly, first.

 

As always, any assistance is appreciated.

 

Cheers.

 

Edited by Phazer51, 29 September 2019 - 02:48 AM.

[mjr]

It looks to me like the problem is in the calibration.  See the little purple "Park" arrow in your calibration screen?  It's at 189 out of 65535, or approximately 0.3%.  

 

The normal resting position would be more like 16%.  

 

And when I look at your picture of the plunger you included, which I assume is showing the resting position, it looks to me like it's in that range.

 

When you bring up the raw sensor viewer window, what does the green bar look like when you let the plunger just sit there?  Is that also reading around 189, or is it more like in the 10000 range?

[Phazer51]

It looks to me like the problem is in the calibration.  See the little purple "Park" arrow in your calibration screen?  It's at 189 out of 65535, or approximately 0.3%.  

 

The normal resting position would be more like 16%.  

 

And when I look at your picture of the plunger you included, which I assume is showing the resting position, it looks to me like it's in that range.

 

When you bring up the raw sensor viewer window, what does the green bar look like when you let the plunger just sit there?  Is that also reading around 189, or is it more like in the 10000 range?

 

Thanks for the rapid response, MJR.

 

I rechecked my potentiometer and realized that I was only getting a change in the Z-axis over less than half of the travel range.  I made sure I had a linear potentiometer.  Then, I swapped the two non-power leads on the slider.  I got better resolution and change in the z-axis over the entire range the slider.

 

I recalibrated the plunger and got this:

 

 Plunger calibration 2.JPG   53.96KB   7 downloads

 

The ball still bounces off of the tip of the plunger in the rest/park position.  If I pull back on the plunger about 5 mm, the ball settles down appropriately in the shooter lane.

 

I can try putting in a few more washers as spacers to force the slider back a bit when at rest (after calibration).  But, I'd have thought that there would be some kind of software fix for this.

 

I'd post the "raw sensor" information that you requested, but I don't know where to find the raw sensor viewer window.

 

EDIT:

 

I added three washers in front of the slider handle and I got this (which seems to work):

 

 Plunger calibration with 3 washers.JPG   54.54KB   7 downloads

 

I find this to be an inelegant solution. Plus, if I need to recalibrate, I'll have to remove the plunger e-clip, remove the washers, recalibrate, and then replace the washers, and then replace the e-clip.

 

 

Edited by Phazer51, 28 September 2019 - 08:23 PM.

[mjr]

> I'd post the "raw sensor" information that you requested, but I don't

> know where to find the raw sensor viewer window.

 

I'm just talking about the exact sensor viewer window you've been posting pictures of.

 

There must still something wrong with your calibration, because the whole point calibration is to make it so that the "software" rest position is the same as the "hardware" rest position.  

 

The "hardware" rest position is where the physical plunger sits when you're not moving it.

 

The "software" rest position is the zero point in the joystick axis that VP is reading.  When the software readings zero, the VP simulated plunger is at the starting line.

 

So if it's properly calibrated, the two should be in sync:  when you're not touching the plunger, the joystick axis should read zero.

 

Make sense?

 

So the next thing to do would be to open up the Windows joystick viewer ("Set up USB game controllers" -> Pinscape Controller) and see what it's reading on the Z axis when you're not moving the physical plunger.   Does it read zero?

I should also mention one of the most common problems that people have with both plunger and nudge - the Windows "Set up USB game controllers" calibration.  You should make certain that's reset to defaults.  Open it up again, go to Pinscape Controller, click the Settings tab, and click Rest to default.  And then be sure never to click the Calibrate button there.

[Phazer51]

I should also mention one of the most common problems that people have with both plunger and nudge - the Windows "Set up USB game controllers" calibration.  You should make certain that's reset to defaults.  Open it up again, go to Pinscape Controller, click the Settings tab, and click Rest to default.  And then be sure never to click the Calibrate button there.

Ahhhhh....that's interesting. I did use Windows 10 calibration for the Pinscape Controller at some point. I'll reset that and report back.

[Phazer51]

Okay, Mjr.  I reset Pinscape Controller's Winows 10 "game controller settings" to "default" in the control panel.

 

I still get this after calibration with the plunger at rest:

 

 Plunger calibration after resetting WIndows 10 settings.JPG   54.25KB   8 downloads

 

BUT...NOW the plunger works properly!

 

Thank you, again.

 

It appears that Windows 10 was screwing with my calibration through the Pinscape Controller Tool.

Edited by Phazer51, 28 September 2019 - 10:15 PM.

[mjr]

Well, your park position is a little far forward from where I'd want it, but otherwise you've got it right.  When it's at rest, the green bar should be parked right at the purple arrow showing where the calibrated rest position is.  And it looks like it is, so that much looks good.

 

Does it still bounce the ball around on the plunger now that you deleted the Windows calibration data?  That calibration stuff actually makes a huge difference with this because the old calibration data was making Windows wildly exaggerate little random jitter on the forward side of the park position.  There might still be some jitter, but Windows shouldn't be magnifying it massively any more now that you've deleted the cal data.

 

[EDIT] I see that you edited your post and already answered the question - glad that did the trick!  At least the above might be helpful by way of explanation.

 

The forward position is just a function of where the pot is situated relative to the plunger.  This won't be a problem in software - the reason I'd want it a little farther back is purely for mechanical reasons.  Specifically, when you push the plunger all the way in as hard you can, does that push the slide beyond the limit of the pot?  You're going to break the pot if so, because every time you do a pull-and-release, it's going to bang the pot slide against its limit, and that's going to bend something eventually.  You want it so that the pot slide will never hit the front limit.

Edited by mjr, 28 September 2019 - 10:22 PM.

[Outhere]

If you're still having problems with it not being real stable when it's in neutral I think I had to set my Jitter filter at 1000

[Phazer51]

Specifically, when you push the plunger all the way in as hard you can, does that push the slide beyond the limit of the pot?  You're going to break the pot if so, because every time you do a pull-and-release, it's going to bang the pot slide against its limit, and that's going to bend something eventually.  You want it so that the pot slide will never hit the front limit.

 

That is one thing that I actually considered before installing the pot on my base.  I left a safety margin so that when the plunger is forced forward as far as it can go the pot never reaches the end of its forward travel.

 

Your assistance has been fantastic.

 

Thank you, MJR.  After applying your solution, I hacked into my cabinet and installed the plunger....

 

 plunger mounted.jpg   74.56KB   5 downloads

 

 cabinet with plunger (2).jpg   172.03KB   5 downloads

Edited by Phazer51, 29 September 2019 - 03:01 AM.

[whynotpizza]

Side question...

 

In this setup using a potentiometer plunger, how do you keep the player from "rotating" the knob on the plunger and getting the sensor our of alignment with the board below it?

[LynnInDenver]

Side question...

 

In this setup using a potentiometer plunger, how do you keep the player from "rotating" the knob on the plunger and getting the sensor our of alignment with the board below it?

 

My understanding is that you make it so that the plunger rod rotates freely inside the sleeve attaching it to the potentiometer slide. On my build of the Nailbuster mouse plunger, it's the same deal, the plate over the mouse is held in a rail setup like a potentiometer slider, and is "sleeved" around the plunger rod so that can rotate freely.