Hard Drivin' steering issue

Dan

New member
Joined
May 26, 2011
Messages
20
Reaction score
1
Location
Wimborne, Dorset, United Kingdom
My Hard Drivin' has developed an annoying little issue with its steering - when playing the game (or when it's running in attract mode), the steering wheel constantly twitches, like the FF motors are pulsing slightly. It's not a huge issue at the moment, but it's gradually getting worse and will start to impact on playability soon I think.

As far as I can tell the main parts of the steering are:

FF motors
Steering pot
Motor Amplifier PCB
Optos

I haven't a clue where to start troubleshooting though, and the operators manual isn't massively helpful on this issue. Anyone have any experience, or thoughts, of where I should start? Also to try and eliminate stuff, if anyone has a spare motor amp PCB I could borrow to swap temporarily then it'd be mucho appreciated. It's the one with two large blue caps on it, as below.

thanks :)

Danny

amp.jpg
 
Not overly familiar with the workings of this particular game, but when the steering pot went bad on my Rush, when you would drive it, it was difficult to keep the car driving in a straight line. The car would constantly be hunting back and forth....not sure that is your issue though?
On that steering pcb, what drives FF motor? There should be some kind of power transistor on a large heat sink....or maybe 2 of them? That would be the first thing I would look at???
 
I would clean (if possible) or replace the steering pot first. In my experience it seems that when you have a "twitch" in the force feedback it is because the pot is acting as if it is jumping back and forth between two values that it is sending to the FF board and the FF is trying to correct for it by moving the motor left and right to re-center the wheel constantly.

Quentin
 
Thanks for the replies guys, what you said about the steering pot makes sense when you put it like that. I think I have a spare pot that came with the game, no idea if it's for the steering but I'll have a look at the weekend.
 
You are correct that it has no optos, first try going into the srvc menu and sending sine waves to it, my guess is it's more brush wear on the motor vs. a faulty pot. By doing different testing you can determine this. If when sending current it still twitches it's the brushes. Since you would be sending power directly vs. just playing the game it helps determine the real issue. You can also set the intensity of the feedback in one of the menus, perhaps turn it down a bit as it should help reduce the twitching.
 
Yep, it's a cockpit version. I had no idea that meant no optos.

After looking at the steering fault-finding flowchart in the manual I did try a square wave test, but wasn't really sure what I was meant to be looking for. I remember the steering didn't twitch at all though.

Anyway I'll try the same with a sine wave test later. So based on what's been said above, if the steering doesn't twitch during the sine wave test then it's more likely the pot than the brushes?

Really appreciate all the advice by the way :)
 
You could also try looking at the readings that display on the screen for the pot and when turning the wheel manually see if the readout twitches indicating a bad pot. There are 2 displays, the bar type indicator on screen and the location readout (2F,2E,etc...) you will know what I mean when you see it. It would flip between numbers back and forth if there are worn areas on the pot. You could also check the physical connection (solder) on the pot, perhaps it's loose and the wires are only marginally connecting causing incorrect readings. I know you can also adjust the output voltage on one of the screens to the motor, perhaps it's a voltage issue and the board is continually correcting for that.
 
Last edited:
Right, I finally had a chance over the weekend to remove the dash/steering assembly (holy cr@p it was heavy, mostly due to the that hoofing great FF motor I guess).

Now I know what the pot looks like, I checked the bag of spares that were tucked away in the back of my cab and there are two spare steering pots in there, which is cool. They both look unused too.

So, I'm gonna try and swap the pot over during this weekend. I have the instructions in the operators manual and it doesn't look too complicated, but if any of you guys have done this before and know of any tips or common pitfalls I should look out for then it would be much appreciated. :)


DSCF5370.jpg
 
Just remember to center the pot before installing (make sure you turn it until it stops then back to locate the center, I think it's a 10 turn, but I may be wrong... if it is it would be turned back 5 times to center from a stop) Afterwords remember to go to the service menu and set the limits (where is asks to turn wheel full left, then right) so it will be properly calibrated.
 
Last edited:
Just remember to center the pot before installing (make sure you turn it until it stops then back to locate the center, I think it's a 10 turn, but I may be wrong... if it is it would be turned back 5 times to center from a stop) Afterwords remember to go to the service menu and set the limits (where is asks to turn wheel full left, then right) so it will be properly calibrated.

Yep it's a 10 turn pot. I would have thought it should be centred too, but in the manual it says to turn it all the way anti-clockwise, then turn it clockwise just a little (15 degrees), so who knows... :D

The bit I find a bit confusing is, once you've installed the new pot, it says to check the wheel stops turning in both directions before the pot does. But I can't see how you could tell whether the pot would would still be able to keep turning, without disconnecting it again. Hopefully will all become clear when I actually attempt it anyway.


Following this with great interest as I probably have to do it too. Replacing a pot cant be that hard. Can you take a close-up picture of the spare pots ?

That's what I figured too, it can't be that hard, it's just the bit above I'm unsure about. But I'll post some step-by-step notes with pics when I have time to try it out, hopefully this weekend but not sure yet.

Here are the spare pots that I found inside my game, with a British penny for size comparison (~ 2cm diameter):

IMG_0940s.png


High-res version of this photo here: http://i1176.photobucket.com/albums/x322/dannyboyy75/Hard Drivin/IMG_0940.jpg


Going slightly OT here, but I also found these spare parts inside the game, I have no idea what they are though. Any ideas? :)

http://i1176.photobucket.com/albums/x322/dannyboyy75/Hard Drivin/IMG_0941.jpg
 
Yep it's a 10 turn pot. I would have thought it should be centred too, but in the manual it says to turn it all the way anti-clockwise, then turn it clockwise just a little (15 degrees), so who knows... :D

The bit I find a bit confusing is, once you've installed the new pot, it says to check the wheel stops turning in both directions before the pot does. But I can't see how you could tell whether the pot would would still be able to keep turning, without disconnecting it again. Hopefully will all become clear when I actually attempt it anyway.


They probably mean to turn it just a tad and when you install it have the wheel turned the same direction, so basically don't center the wheel when installing so you can check that it stops before the pot does. Kinda confusing I know, but I think it will make sense when you install it.

The other pic is of the motor brushes. While you have it out, you should check the ones in the motor now and perhaps install the new ones if they look worn. The 2 on the right look new, so they would last probably another 30 years...
 
Last edited:
Ah, so those are the brushes. Not so OT after all then. I guess there's no harm in me installing the 2 new looking ones while I've got the steering assembly out then - hopefully between replacing those and the pot it will sort out the twitchy steering.
 
Thanks for the pics !!!

I never saw a pic of the CP out like that so that is already good to see, doesn't look as scary as drawings ;)

Ezcellent pic of the pots.
They are Spectrol 534 pots. I found them for sale locally at my favorite parts supplier, RS online:
http://nl.rs-online.com/web/c/passi...4886244&lastAttributeSelectedBlock=4294956758

The cheapest one that doesn't have a picture actually has a link to the original Spectrol datasheet. It looks like Vishay acquired Spectrol as the datasheet of the Vishay 534's says Vishay Spectrol. They also changed the color. Good to know I can order them, relatively affordable, no shipping costs :)

Checking the datasheet Atari chose the sturdiest one, rated at 1.000.000 turns.....

Never knew the brushes looked like that. Do they fail often and how do I notice ?
 
Last edited:
Last edited:
My Hard Drivin' has developed an annoying little issue with its steering - when playing the game (or when it's running in attract mode), the steering wheel constantly twitches, like the FF motors are pulsing slightly. It's not a huge issue at the moment, but it's gradually getting worse and will start to impact on playability soon I think.

As far as I can tell the main parts of the steering are:

FF motors
Steering pot
Motor Amplifier PCB
Optos

I haven't a clue where to start troubleshooting though, and the operators manual isn't massively helpful on this issue. Anyone have any experience, or thoughts, of where I should start? Also to try and eliminate stuff, if anyone has a spare motor amp PCB I could borrow to swap temporarily then it'd be mucho appreciated. It's the one with two large blue caps on it, as below.

thanks :)

Danny

amp.jpg

YO DAN :) welcome to IAM/KLOV :)

from a Fellow DAN and Retired Arcade tech...here's some info that Might help ya...if you still keep having problems with Hard Drivin'..just keep yellin on the Forums...some of us will get ya squared away sooner or later :D

anyhow try this...one of the builders for atari has stuff posted on his site that is sometimes useful :)

http://www.jmargolin.com/schem/schems.htm


Good Luck :D



END OF LINE.


Daniel.
 
Thanks for the pics !!!

I never saw a pic of the CP out like that so that is already good to see, doesn't look as scary as drawings ;)

Ezcellent pic of the pots.
They are Spectrol 534 pots. I found them for sale locally at my favorite parts supplier, RS online:
http://nl.rs-online.com/web/c/passi...4886244&lastAttributeSelectedBlock=4294956758

The cheapest one that doesn't have a picture actually has a link to the original Spectrol datasheet. It looks like Vishay acquired Spectrol as the datasheet of the Vishay 534's says Vishay Spectrol. They also changed the color. Good to know I can order them, relatively affordable, no shipping costs :)

Checking the datasheet Atari chose the sturdiest one, rated at 1.000.000 turns.....

Never knew the brushes looked like that. Do they fail often and how do I notice ?

Well I changed the pot at the weekend and it made no difference, so I guess the problem in my case must be the brushes. If you have trouble finding the right pot I can send you the one I took out of my game, as there's obviously nothing wrong with it. All I would ask is that you pay the postage costs.

The pot was actually quite easy to replace. The hardest part is manhandling the dashboard/steering assembly as it's so heavy, especially doing it on your own. I haven't linked the photos directly into this thread as it'll get huge otherwise, so have just used url links instead.

* Remember the motor and motor amp board handle 120V, so make sure the game has been unplugged for at least 5 minutes beforehand! *

1) You have to start by removing the two bolts on each side of the game:Pic 1

2) Then remove the two Philips screws in the front of the dash assembly (no pic for those as you can't miss them). EDIT: Also remove the cover under the dash (2 Philips screws). I forgot this as it was already removed from my game.

3) Next you disconnect four wiring harnesses in the back of the game. On the left side is the right speaker connector: Pic 2

4) Then on the right side, the 3-pin and 9-pin connectors in Pic 3, followed by the 6-pin connector on the motor amp board (below the blue caps) Pic 4

5) Now reach into the space behind the pedals in pics 3 and 4, and undo the two nuts highlighted in Pic 5. The bolts will drop down into the cockpit area at the front. N.B. I also had to unscrew the bit of wood with the transformer bolted to it in Pic 3, to allow me to access the nut on that side.

6) You can then sit in the seat and slide the dash assembly out onto your lap (did I mention it's heavy :) ) . Also take care not to scrape the side panels as it's a very tight fit.

7) Once it's out, turn the wheel all the way to left and make sure it stays there. Next, loosen the little grub screw that holds the pot in place using an allen key (I think I used a 9/64" one), then undo the nut that holds the pot bracket in place - Pic 6. Note the pot bracket will flip over when you do this as it's under tension from a spring.

8) Now remove the pot, desolder the 3 wires and solder them onto the new pot (red at the top, nearest the shaft, then the clear wire, then black).

9) At this point, check again that the steering wheel is still turned left as far as it will go. Next turn the pot all the way anti-clockwise, then turn it back a little way clockwise (about 15 degrees will do) and refit the pot, making sure the pot bracket is flipped back over once so there's some tension on the spring (you'll see what I mean when you do it), and tighten the nut and grub screw.

N.B. While I had the steering assembly out, I also took the opportunity to spray some WD40 onto the key switch assembly as it was quite stiff. It turns much more easily now.

10) Slide the dash assembly back into place, making sure you've fed the wiring harnesses back through the holes on each side. Refit the two bolts on each side, the two philips screws in the front of the dash, and the two nuts & bolts behind the dash. N.B. If working alone, I found it easier to refit these last two while lying in the cockpit, so that you can hold each bolt in place and then screw the nut onto it, to stop the bolt dropping down again. Then you can tighten them properly from the rear of the game.

11) Lastly, reattach the four wiring harnesses, and the wooden transformer mounting from Pic 3, if you had to unscrew it. Job done :)

Oh, and don't forget to run through the 'Set Controls' setup when you power the game up. ;)
 
Last edited:
They probably mean to turn it just a tad and when you install it have the wheel turned the same direction, so basically don't center the wheel when installing so you can check that it stops before the pot does. Kinda confusing I know, but I think it will make sense when you install it.

The other pic is of the motor brushes. While you have it out, you should check the ones in the motor now and perhaps install the new ones if they look worn. The 2 on the right look new, so they would last probably another 30 years...

Well it looks like it must be the brushes in my case, as it's the same with the new pot installed. I ran out of time to look at replacing those at the same time though - did have a quick look but it wasn't obvious how to get inside the motor as it looked like the inspection panel was held in place by rivets. I'll have a closer look over the next week or two though.

Out of interest does anyone know if there's a way to test which brush(es) are faulty?
 
Back
Top Bottom