Ultimarc U-Trak "sensitivity" problem

[Cynicaster]

Just yesterday I finished wiring up the control panel on my first MAME cabinet.  To my utter surprise, everything worked the first time I plugged it in.

For a trackball, I'm using an Ultimarc U-Trak.  It's a really nice and convenient product from an installation standpoint but I'm not crazy about the way it's performing.  It's passable on Millipede and any game where you're rolling the ball in small and controlled spurts, but for games that involve more "spirited" rolling and quick changes of direction (like Marble Madness--or at least the way I play Marble Madness), not so much. 

Through experimentation I've determined that, for whatever reason, the ball works great when moving up and left, but down and right are extremely sluggish in comparison.  For example, if I put the mouse cursor on the far right of the screen and give a solid swipe on the ball to the left, the cursor zooms across the screen no problem.  But, if I start at the left of the screen and give a similar swipe to the right, the cursor only moves about 1/4 of the way, so it takes me 3-4 swipes to move left to right across the screen.  Similar situation applies for up vs. down. 

It almost seems to me like the ball is losing traction on the rollers or something... but if that were the case, why would it only be 2 of 4 directions?  I can't see it being a case of the rollers or ball being dirty because it's brand new (not to mention, I checked it for signs of dirt and grime before I installed it). 

Any ideas or similar experiences?  Any help would be appreciated.

Thanks
Matt
 

[scream1973]

Email Andy and he should be able to help you out.

[Cynicaster]

After fiddling around with the U-Trak a bit more, I've got a theory about what's happening.  There appears to be a bit of "slop" in the trackball--like when you do a full swipe the ball "jumps" a bit in the housing.  It's not much, but it's enough that you can hear it.  So when the ball jumps it probably results in only a fraction of the swipe being translated from the ball to the roller.  To me, such a "mechanical" issue is the only way to explain why things would work fine going left but not right, since both horizontal directions are handled by the same encoder.  Dang it, I was really hoping it was just a problem with settings...

[yotsuya]

After fiddling around with the U-Trak a bit more, I've got a theory about what's happening.  There appears to be a bit of "slop" in the trackball--like when you do a full swipe the ball "jumps" a bit in the housing.  It's not much, but it's enough that you can hear it.  So when the ball jumps it probably results in only a fraction of the swipe being translated from the ball to the roller.  To me, such a "mechanical" issue is the only way to explain why things would work fine going left but not right, since both horizontal directions are handled by the same encoder.  Dang it, I was really hoping it was just a problem with settings...

I had the same issue at first, but I think you just need to break it in. Over time, I've noticed mine has gotten smoother. Either that, or I compensate for that jump by using the ball differently.

[markronz]

I recently had an awful time getting my trackball to work.  You can check out my post and see if it might be of some interest.  The solution I suppose is part software, part mechanical.  

You can try these types of fixes to turn off mouse acceleration:
http://kaioa.com/node/68
http://www.tweakxp.com/article36785.aspx

If the sensitivity numbers don't match, you could also notice a slower response in a certain direction.

Something else that software you could consider is to check out your default MAME config.  You want to make sure that your trackball settings are right.   You only want the mousecode_1_XAXIS to be listed once under standard.   You do not want it to be listed under the increment and decrement parts as well.  So something like this would be correct:

Code: [Select]

   <port type="P1_TRACKBALL_X">
                <newseq type="standard">
                    MOUSECODE_1_XAXIS
                </newseq>
                <newseq type="decrement">
                    KEYCODE_G
                </newseq>
                <newseq type="increment">
                    KEYCODE_D
                </newseq>
            </port>
            <port type="P1_TRACKBALL_Y">
                <newseq type="standard">
                    MOUSECODE_1_YAXIS
                </newseq>
                <newseq type="decrement">
                    KEYCODE_F
                </newseq>
                <newseq type="increment">
                    KEYCODE_R
                </newseq>
            </port>

To illustrate my point better, this configuration would be WRONG:

Code: [Select]

   <port type="P1_TRACKBALL_X">
                <newseq type="standard">
                    MOUSECODE_1_XAXIS
                </newseq>
                <newseq type="decrement">
                    MOUSECODE_1_X_NEG_SWITCH
                </newseq>
                <newseq type="increment">
                    MOUSECODE_1_X_POS_SWITCH
                </newseq>
            </port>
            <port type="P1_TRACKBALL_Y">
                <newseq type="standard">
                    MOUSECODE_1_YAXIS
                </newseq>
                <newseq type="decrement">
                    MOUSECODE_1_Y_NEG_SWITCH
                </newseq>
                <newseq type="increment">
                    MOUSECODE_1_Y_POS_SWITCH
                </newseq>
            </port>

This does some pretty strange stuff if you have your trackball listed in both locations.

Then I guess, like others have said, you just need to break in the trackball as well.   My thread goes over some of what I did to break mine in.   Basically cleaning out the old oil, spinning, adding 3-in-1 oil and spinning more.

Well, I hope you get it to work.   I worked on mine so long it was driving me nuts!  But it works great now!

[Cynicaster]

I had the same issue at first, but I think you just need to break it in. Over time, I've noticed mine has gotten smoother. Either that, or I compensate for that jump by using the ball differently.

Two questions:

- do you have a U-Trak as well?
- when you say you "had the same issue", are you referring to the "jumping" trackball, the actual behavior of the mouse on the screen, or both?

@markronz--thanks for the info, I'll look into those things. 

[yotsuya]

1) I have the U-Trak as well.

2) I had what felt like a jumping trackball. I think I just either subconsciously accounted for it by using the trackball differently, or it may have been how things were mounted. I try not to release the ball as much as I might have when I did when I was a kid, and I think that helps. 

I will say that I opened up the unit and found that one of the encoder wheels was loose to the point that it fell off when I picked it up. I tightened everything up and went from there.

[tsaylor]

Interesting ... I have the U-Trak as well and have the same disappointment (smoother some directions than others, "jumping" like you describe).  It feels pretty loose so I'm planning to open it and see if something needs to be tightened.  I've only tested it a bit on my cardboard control panel mockup, so it definitely isn't broken in yet.  Hopefully it will improve over time.

[Cynicaster]

Hi guys:

I thought I’d post an update to the situation.

My original post was written pretty much based on my very very first impressions of the trackball after assembly of the CP—i.e., maybe a few minutes of “test play” on Marble Madness, Missile Command, and Centipede. 

The following day, I had a friend over and he asked if we could have a game of Golden Tee.  I was reluctant to load up that game knowing that there were issues to be sorted out with the trackball but we tried it anyway.  It worked fairly well and we played about three 9-hole games of GT. 

The day after that, I went back and tried Marble Madness, Missile Command, and Millipede and noticed a major improvement in comparison to the first day.  Marble Madness went from being unplayable to quite fun (I totally suck at it though).  In playing the other two games, I really felt “in control” of what I was doing.  Maybe it was just in my head but the ball seemed to be more smoothly rolling.

I didn’t change anything else in the meantime (software or otherwise) so I’m wondering if it really was just a break-in issue.  Maybe a few thousand turns on the bearings from driving golf balls in Golden Tee was all that was needed.  I’ll hold off on celebrating for now but the signs are encouraging.  Will update if anything changes. 


   

[boardjunkie]

Trackballs are fussy to say the least in MAME. I had problems with not getting the greatest onscreen speed, and when it got close to where it needed to be there was problems with  the players character stopping or reversing direction. This was with a Wico home model trackball hacked to USB via the board from a USB ball mouse.

What I ended up doing was covering every other "window" in the chopper discs and jacking the sensitivity settings way up. Worked great after that.....YMMV.

[AndyWarne]

All arcade trackballs have the same design, the ball rests on the rollers by gravity. So slippage can occur. This is worst when the trackball is very new because the curved ball surface is resting on a flat roller. After a while the roller develops a curve which the ball surface sits into. It should be OK after a while.

Another factor is after a few minutes of use the roller gets a grain on its surface. This is to do with the machining of the metal which affects the surface properties. This grain soon wears away completely.

Andy