Hurco Trackball - I did it now !

[Rich Carlstedt]

My Trackball on my KMb3 has been very inconsistant since I got this 1989 machine. I am helping our local High school, with their recently aquired Hurco of the same vintage, by showing them how to do Conversational programs.
When they got their mill, the trackball was almost non functional, so they took it apart and cleaned it. Its now perfect. They said it was easy
So I thought I could do that on mine.. bad mistake
I tried to be as careful with it as possible and got a lot of crud out, but when reassembled, only the X axis on the right hand screen works.
I disasembled and the pulse wheel is turning, but nothing happens
I inspected the board and see no problems.
I check for continuity on the plug and its OK.
All resistance (No Power !) readings are the same on both the X and Y optocoupler. ( Y works !)
I tried blowing air with a small rubber bulb across the coupler area to see if a spect of dirt blocked the light- no change
The coupler is a TRW OPB3758 (also 8811 ?)
No specification sheets on the web can be found.
TRW does not show that number

I am retired and use the Hurco for fun.
buying a new ball is out of the question
Any thoughts or help ?
Thank You
Rich

[Rick Kight]

Hey Rich

My track ball is not the best also, the foam rubber wheels are bad. I don't know the answer to your problem but Buddy at AMTS will. Here is a link to his web site, he has a forum on it so you might get your answer there, but you can just give him a call he is very helpfull and reasonable also.

http://www.amtsinc.com/

Did you do anything with thee foam wheels? If so what did you do?
Thought about making some new ones but really don't use it that much as I have a PC hooked to the machine and save programs that way. It would be nice to get it working correctly to check program paths in more than the top view.

Have you done any casting lately? I have a few wax patterns ready to go just need to find the time to make a larger casting flask and go from there.

Rick Kight

[Rich Carlstedt]

Thanks Rick for the URL

Well I got into it a bit more.
After cleaning the crude (gently) off the foam wheels, they were too small to reach the ball. no adjustment on lowering the ball (don't want to do that really). I made up some non-abrasive Scotchbrite tires, but they slip (???)
I think the density changes slightly.
I got into the Ball unit again and found that the X couple runs fine and produces +/- 5 volts DC pulses
The Y couple only does -5 volt DC Pulses, so I assume(!) that because it does not go positive, that is the cause of my problem. ( I need Y to be + to move the cursor + on the screen. I claened it again with electronic solvent and no change.
I switched wires feeding the Keyboard circut board, and the X couple would move the cursor vertically without issue. That means the problem is in the Y Couple. I assume it has two infared receptors, and one is not working.
I will ask buddy per your comments.
Anyone here that can shed a light, please do.
Proves once again..if it works, don't fix it


oh Rick
I haven't done any casting for a year. Maybe This March

Rich

[Rich Carlstedt]

Update on my issue. and a possible TRACK BALL FIX
Well, a friend contacted me and gave me his old trackball to part out.
It stopped working because of the foam wheels and rough surface. I cleaned them with electronic
parts cleaner...works really good and no deterioration was observed, but the wheels slip because of wear and a reduced diameter.
The Track ball assembly has 4 housings.
The top two contain the ball (# 1,2)
The next one lower( #3) one has the wheels and encoders along with electrical plug.
The bottom#4 is a cover more or less
I took #2 and marked its underside surface where the encoders touch, and carefully machined off .015 " ONLY where the encoders blocks touched.
Then assembled it and it worked as slick as a new paint job.
What I effectively did was to raise the encoders .015 to get greater impingement on the track ball, to replace the worn surface,

My trackball works like new..
Rich

[Rick Kight]

Good deal Rich

I will have mine apart soon to try this as the only issue mine has is the track ball not touching the foam or just barely touching. Thanks

Rick

[xray34]

Thanks Rick.. Worked for me also..top fix!! :-)

[Exwhyzee]

Hi all:
I wasted a more than a considerable amount of my mechanical skills trying to make my old Hurco 5M failed trackball to work.
Among a number of solutions I tried:
40 to 48 inches of 1/2 inch plumbers teflon tape.
14 to 18 inches of 3M #2 fiberglass tape.
Both worked for a few days or so but not not much longer.
I have developed a permanent software, hardware fix, for real.
Using a modern, laser, track ball integrated chip, I have a complete and relatively inexpensive, circuit board which replaces the fool, foam roller assembly, and is bolted on to the bottom of the existing track ball housing.
The acceleration (ballistics) of the Hurco software is as the original.
I can provide this for under $100. Is there any interest ?
Peter

[skullworks]

I'll bite - at least to get more info.

My KM3P ball feels like its full of gravel - if you can get it to budge.

Greg.

[Rulunney]

I would like info also

[Rich Carlstedt]

I think he is selling the units, not providing the info on how to build it

[skullworks]

Yes, well it does not look like he is trying very hard to sell units...

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