Measurement Systems 3" Trackball and RAM Optical Instrumentation Controller

Rayndalf

14 Oct 2020, 08:44

hellothere wrote:
26 Sep 2020, 03:25
Yasu0 wrote:
25 Sep 2020, 01:46
There is an orbit "mouse" for $175 shipped on the bay.. very cool vintage pointing device.

Skill level required and dollar level required to get it going both too high for me.

272688588455
I guessed at "former military use" and I was right.

4" L x 2.3" H x 4" wide. Trackball is 3.328" diameter. That's pretty big.
I saw mention of a Measurement Systems trackball in the great finds board, and being who I am I spent the next few hours comparison shopping. After purchasing a completely different device (A RAM Optical Instrumentation control panel), a seller of a significantly cheaper Measurement Systems ball tempted me with a small discount. I was powerless to resist.

The listing quoted the size as 2.5" in diameter and the housing featured buttons. The ball I received was 3" like the other listings.
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The ball is massive compared to the Compaq 11800

The build quality of the device is the real appeal. The lower shell is welded aluminum, the top plate is a machined casting, the buttons "plate" is machined, the switches are massive, click, and seem to have lights to illuminate the white buttons. The mechanism is also different from conventional track balls as it uses servos(?) or some other sealed component instead of spoked wheels and optical encoders.
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A brass plate is installed between the top assembly and the PCB with screws and plastic standoffs.
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The ball spins on a total of 6 bearings, which are tightly screwed down, but it is possible to clean some debris off them from the other side when the ball is removed. Some lubrication and or new bearings would likely make it even better.
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The ball is uncomfortably tall when placed on a desk, and the top of the housing features threaded holes and the button assembly and retainer ring have pronounced ridges, so I believe this module was designed to be installed inside of a desk similar to modules installed into some arcade machines. I am not sure what protocol this device uses (only some of the pins on the connector are used, so it might be serial or something completely proprietary. In any case there is more than enough space to hand wire the components to a teensy or internally convert it.

If I successfully convert it or drill some holes in my desk I'll proudly share the results.

Sorry for the false advertising, I'll take some better pictures of the RAM Optical Instrumentation controller tomorrow.
Last edited by Rayndalf on 14 Oct 2020, 09:06, edited 6 times in total.

Archie

14 Oct 2020, 21:12

Rayndalf wrote:
14 Oct 2020, 08:44
The mechanism is also different from conventional track balls as it uses servos(?) or some other sealed component instead of spoked wheels and optical encoders
Actually, no difference here. They're the same quadrature encoders, just in different (sealed) form, like this:
https://www.bourns.com/products/encoder ... l-encoders

You've got an interesting model: my 2.5" Measurement Systems XCL-250 trackball uses 3 bearings, not 6...

Rayndalf

15 Oct 2020, 09:40

Honestly a 2.5 inch ball sounds like a good size, 3 inches is extremely entertaining, but could be a pain in daily use. The button caps are all brittle and the clips that hold them are cracking (probably fixable), but the switches are backlit and stupidly tall for the amount of travel.

The encoders being sealed makes sense since most of the design (brass plate between the ball and PCB) is designed to prevent ingress of water or dirt. It's bizarre to me that the internal wiring is tied down with finely braided cord (like dress shoe laces) complete with a slightly oily/waxy texture.

Did you manage to get yours working? I'm hoping it's serial, but if it's something else it should still be doable.

Archie

15 Oct 2020, 10:26

Rayndalf wrote:
15 Oct 2020, 09:40
3 inches is extremely entertaining, but could be a pain in daily use.
-snip-
the switches are backlit and stupidly tall for the amount of travel.
Depends on particular use case, I believe. Trackball of such size/shape probably was never intended to be used as a pointing device for computer GUI control.
It's bizarre to me that the internal wiring is tied down with finely braided cord (like dress shoe laces) complete with a slightly oily/waxy texture.
It was military/industrial standard for ages. Cables were prepared by dedicated worker and passed to the assembly line in "ready to solder" state, with appropriate length for each wire.
Did you manage to get yours working? I'm hoping it's serial, but if it's something else it should still be doable.
Mine have quadrature output (raw signals from encoders & switches), and works just fine. Conversion to USB and review on my blog is scheduled for this year... :)

Rayndalf

15 Oct 2020, 11:01

Judging by the raised lip around the ball and buttons I'm fairly confident it was meant to live inside a metal "desk" that has matching holes, probably a radar system (I was surprised to learn that trackballs were around as early as 1946 for exactly that purpose). I guess I still want to get it working with a modern computer, it might be a piece if history, but it has years of life left... and it reminds me of those arcade golf or bowling games.

I know tie downs were extensively used in analog synthesizer montrosities like the Yamaha CS-80, but the frequency (and precision) of the tiedowns impressed me (I guess softer tiedowns won't cut into wires if the device vibrated).

Do you mean replacing the controller with a microcontroller or reading the outputs at the plug? (I gotta make sure I get the backlighting works)

I'll patiently wait for a writeup before I break anything.

Any idea what to do about the disintegrating roller foam? I'm thinking glue or doublesided tape and a strip of similar foam I got in a headphone box, but it have a seem so I wouldn't be perfectly circular.

Archie

16 Oct 2020, 09:57

Rayndalf wrote:
15 Oct 2020, 11:01
Do you mean replacing the controller with a microcontroller or reading the outputs at the plug?
In case of quadrature output, there's no controller in device typically - so I'll have to add one.
Any idea what to do about the disintegrating roller foam? I'm thinking glue or doublesided tape and a strip of similar foam I got in a headphone box, but it have a seem so I wouldn't be perfectly circular.
I've ordered thing like this:
https://www.aliexpress.com/item/33011627135.html

Rayndalf

16 Oct 2020, 19:09

Mine seems to have a few chips inside, but they might for be the buttons, guess I need to break out a voltmeter.

That's a good idea for replacing foam. Did you use one with an opening that size (8 mm) and stretch it over the roller or would something closer to the roller size work better?

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JP!

16 Oct 2020, 20:11

My trackball just arrived. It is so comically large in person though. My hands are minuscule in comparison. I tried getting the bearings freed up (5/6 so far) and will clean the ball with some isopropyl alcohol. A bit of cleaning, new bearings and fresh grease this thing should be decently smooth. Not sure how practical this will be on a modern system though if it can be converted.

Also my trackball has a bit of wear and small gauges from the seized bearings. It looks like 3'' replacement trackballs are available but of course not cheap.

Rayndalf

17 Oct 2020, 00:21

https://usamagictricks.com/contact-jugg ... 37458.html
I was thinking about getting a ball like this (or maybe an interesting natural stone). The mechanism is optomechanical instead of using a mouse sensor, so it will work even if I backlight it (I'm worried about the foam gripping it though).

The bearings should be replaceable/serviceable but they were screwed down tight (and I don't have a screwdriver big enough to rotate that tight without damaging it).

Edit: Also it might be tacky, but replica Dragon Balls from the franchise of the same name are sold in the 76mm size for even less.

Rayndalf

17 Oct 2020, 00:40


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JP!

17 Oct 2020, 02:20

Rayndalf wrote:
17 Oct 2020, 00:21
The bearings should be replaceable/serviceable but they were screwed down tight (and I don't have a screwdriver big enough to rotate that tight without damaging it).
The bearings will pop right out on their own sort of. No need to unscrew anything. If you rub a ball bearing a while it will loosen up. Once you have one rolling free enough take a magnet and you should hopefully see the ball bearing lift up a bit Well at this point you should be able to pry the bearing out if you have long enough fingernails. I was able to pop most of mine out.

Archie

17 Oct 2020, 12:58

Rayndalf wrote:
16 Oct 2020, 19:09
Mine seems to have a few chips inside, but they might for be the buttons, guess I need to break out a voltmeter.
The only quadrature trackball with microcontroller I'm aware of is DT-225 where Microchip PIC16C55 is used for axis rotation, pulse rate (i.e., sensitivity) change, and button function handling. In your case, pictured Intel 8031 with separate ROM chip have way too much power for simple operations, so I'm pretty sure it provides some complicated protocol output, most likely serial.

BTW, identical controller is used in my Fulcrum Trackball Plus, where it's capable to emulate almost anything:
https://forum.trackballs.eu/viewtopic.php?f=17&t=83
That's a good idea for replacing foam. Did you use one with an opening that size (8 mm) and stretch it over the roller or would something closer to the roller size work better?
We have to experiment, I think. In my case, original foam is still provide enough contact (sensors have good bearings, and rotate essentially without resistance), and foam mentioned above isn't arrived yet. Probably, I'll cut it into the rings of appropriate size; let's see...

Rayndalf

Today, 05:30

Archie wrote:
17 Oct 2020, 12:58
Rayndalf wrote:
16 Oct 2020, 19:09
Mine seems to have a few chips inside, but they might for be the buttons, guess I need to break out a voltmeter.
The only quadrature trackball with microcontroller I'm aware of is DT-225 where Microchip PIC16C55 is used for axis rotation, pulse rate (i.e., sensitivity) change, and button function handling. In your case, pictured Intel 8031 with separate ROM chip have way too much power for simple operations, so I'm pretty sure it provides some complicated protocol output, most likely serial.

BTW, identical controller is used in my Fulcrum Trackball Plus, where it's capable to emulate almost anything:
https://forum.trackballs.eu/viewtopic.php?f=17&t=83
That's a good idea for replacing foam. Did you use one with an opening that size (8 mm) and stretch it over the roller or would something closer to the roller size work better?
We have to experiment, I think. In my case, original foam is still provide enough contact (sensors have good bearings, and rotate essentially without resistance), and foam mentioned above isn't arrived yet. Probably, I'll cut it into the rings of appropriate size; let's see...
Only 5 of the pins in the connector in my ball are actually connected to the controller (which is consistent with integrated balls which eventually terminate to a 9 pin plug and use serial).

Similar to your Fulcrum ball (I love that chunky bezel, it reminds me of chording keypads like the BAT), the connector has a total of 15 pins instead of the 9. Hopefully it still uses a standard serial protocol (and isn't relying on a strange pin for additional power). I really need to get a decent serial to USB converter, I have too many boards with serial balls or track points that I need to get working.

Are you familiar with any smaller active serial converters that could be installed inside a device so that the keyboard + trackball connections could be internally converted and combined using a small USB hub so the whole thing would only use 1 USB port? I wonder is a promicro could serve as an active PS/2 converter and a serial converter as the same time (and remove the need for a USB hub as well).

I look forward to hearing if the foam is the right size. Luckily pop-filters are probably the cheapest source of foam I can think of.

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