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Keith Matthews
September 20th, 2016, 05:00 PM
Hi All,

This week I got super bold and decided to have a crack at Aligning the internal drive of my 1571 using the Free Spirit Software 1541/1571 Alignment package.
At first I checked my 1541-II and my external 1571 and they came up as satisfactory, so I moved over to the internal drive.

It is the Newtronics early model with the Alignment screws underneath.

It was not working at all and I know it has a bodgy latch where the pin drops back, so I check it first and put it back in place, then I got it to work about 30% of the time.
Anyhow I followed the Free spirit instructions and adjusted the stepper which needed to go all the way back to the end of its travel in order to get SATISFACTORY on all tracks. The zero stop test failed but the instructions said that was normal due to the electronics.

I put the C128 factory diags in and it PASSED a few times then the day got cold and rainy and the drive became slowly worse.

So I pulled it apart again and tried again, now I can't get it to Align SATISFACTORY on all tracks and remain consistant.

I am guessing this means that the belt is stuffed/stretch with age! 8-(

Do any of you have a brilliant solution. I would dearly love to get my old girl working again, as she has meant so much to me over the years. :D

Failing that, Do we know of anyone that reconditions drives or sells them. P.S. I am in Australia. 8-)

Or does anyone have a C128D they are scrapping for parts?

Thanks so much for any assistance. 8-))

KC9UDX
September 20th, 2016, 06:12 PM
It sounds sticky to me. If so, I'd disassemble and clean it, lubricate as necessary (don't spray WD40 in and call it good).

Keith Matthews
September 20th, 2016, 06:37 PM
It sounds sticky to me. If so, I'd disassemble and clean it, lubricate as necessary (don't spray WD40 in and call it good).

Hi, Thx for the reply,

Yep, i forgot to mention that I have given it all a good clean with ISO and put 1 drop of Silicon lube on each of the rails like in the old days 8-).

I guess the brass idler wheel under the latch asm could be binding, I didn't dissemble it that far. 8-). The stepper motor is hard up against the end of its adjustment.

Druid6900
September 20th, 2016, 07:44 PM
What model Newtronics drive is it? I have several on my site and it may be easier to replace it at this point then try and undo years of wear and tear.

One thing you should check, if the diagnostics allow for it, is rotational speed. Monitor it for a while and see if remains constant.

Something else you can try, if the belt has stretch, is something called Rubber Renue. It's available at electronic parts suppliers and it will, as the name implies, "renue" the belt surface and if you take it off and soak it for a bit, will actually shrink the belt somewhat. I think it's just pure acetone, to tell you the truth, but, don't use nail polish remover type acetone as it has additional ingredients that wouldn't be that good for the belt.

KC9UDX
September 20th, 2016, 10:21 PM
As far as I know, Rubber Renue is peppermint oil and Xylol.

Acetone will certainly not do good things to a synthetic rubber belt. It may completely dissolve it.

Long before I knew about Rubber Renue, I used MEK and mineral oil, just from experimentation. I started with mineral oil, and added isopropyl alcohol, then went on to MEK and mineral oil. I don't recommend this. It takes a lot of practise to get it right. Rubber Renue works much better. Don't spill it.

rittwage
September 21st, 2016, 04:46 AM
To rejuvenate rubber rollers on old printers, we used to use brake fluid (from the auto parts store). I am not a chemist and maybe we were just lucky, since I don't know the ingredients or where we got this pointer. It usually seemed to fix it, though.

I haven't tried it on a little thin belt, though... just adding to the conversation.

KC9UDX
September 21st, 2016, 04:49 AM
Good grief! I don't doubt you. But I know that brake fluid turns normal (non-brake) rubber hoses into slime.

rittwage
September 21st, 2016, 04:54 AM
Good grief! I don't doubt you. But I know that brake fluid turns normal (non-brake) rubber hoses into slime.

It shouldn't... I think it has some kind or rubber preservative in it. That's why it doesn't dissolve all the rubber seals in an old brake system in your car!

I think most petroleum or silicon based stuff will soak into rubber and swell and soften it, but it can't "repair" it. A new belt is best of course... any fix like this would be temporary.

EDIT: I looked it up and it seems to be a common trick. There are lots of videos about people soaking old rubber motorcycle parts in brake fluid to get them flexible again.

KC9UDX
September 21st, 2016, 05:08 AM
Well I can tell you that I've used "vacuum lines" (EPDM?) for decades for bleeding brakes. It doesn't happen immediately, but they always turn flimsy and fall apart eventually. Granted we're not talking about subjecting a belt to brake fluid for extended periods, so maybe it works.

I always expected that the rubber in brake systems was some other specific kind of rubber meant to handle it.

Brake fluid also dissolves dried POR-15, whatever that stuff is made of.

Keith Matthews
September 21st, 2016, 04:42 PM
Hi Druid,
Thanks for the reply 8-)
The rotational speed seems nice and steady at 320 RPM +/- 1 RPM which is within the specs given by the Alignment SW. So at least that is still good 8-) It is a direct drive type of unit. I'll attach some photo's 8-)
I think it is the Stainless steel Head drive belt that has become out of spec over the 30+years or so and that is why I am at or beyond the Alignment capability. Just my guess though. 8-)

It is a Newtronics D502 (Which is and Mitsumi Mechanism I Guess, See Photos) 8-)

Thanks.

3330033301333023330333304

KC9UDX
September 21st, 2016, 07:32 PM
The only thing that steel strip can do is stretch, and stay stretched. If it did, you would need to perform an alignment once.

But it probably didn't. If the linearity is incorrect, something is binding, causing the motor to skip a step, or, something is just loose.

Druid6900
September 21st, 2016, 07:46 PM
Hi Druid,
Thanks for the reply 8-)
The rotational speed seems nice and steady at 320 RPM +/- 1 RPM which is within the specs given by the Alignment SW. So at least that is still good 8-) It is a direct drive type of unit. I'll attach some photo's 8-)
I think it is the Stainless steel Head drive belt that has become out of spec over the 30+years or so and that is why I am at or beyond the Alignment capability. Just my guess though. 8-)

It is a Newtronics D502 (Which is and Mitsumi Mechanism I Guess, See Photos) 8-)

Thanks.

3330033301333023330333304

No, I don't think I'm going to be able to help you out. All I have is a couple of D509s and I don't think the firmware is going to be happy with a 1.2 MB drive.

320 RPM? Well, trust Commodore to have a rotational speed 20 RPM faster than anyone else....

I've seen the head step band break, but, I've never heard of one stretching.

rittwage
September 22nd, 2016, 04:13 AM
The RPM should be 300, as near as possible. I don't know what tool would say 320 is correct...

Pet Rescue
September 22nd, 2016, 07:13 AM
Hi that steel belt does not look quite right.

Here is a picture of one online:-

https://ist.uwaterloo.ca/~schepers/CABLEPIX/1571/pic10.jpg

Just noted that the carrier looks too far back that's why the steel belt looks slack.

geoffm3
September 22nd, 2016, 12:07 PM
The top head isn't "sprung" is it? When the latch is left open or closed with nothing in the drive it tends to fatigue the spring steel hinge on the top head carrier and then they will suffer from lack of proper tension of the media.

Keith Matthews
September 22nd, 2016, 07:57 PM
The only thing that steel strip can do is stretch, and stay stretched. If it did, you would need to perform an alignment once.

But it probably didn't. If the linearity is incorrect, something is binding, causing the motor to skip a step, or, something is just loose.

Thanks,
Yeah perhaps the belt is not riding flat. I might strip it further this weekend. I cant make it any worse 8-)

Keith Matthews
September 22nd, 2016, 07:59 PM
No, I don't think I'm going to be able to help you out. All I have is a couple of D509s and I don't think the firmware is going to be happy with a 1.2 MB drive.

320 RPM? Well, trust Commodore to have a rotational speed 20 RPM faster than anyone else....

I've seen the head step band break, but, I've never heard of one stretching.

I think the 320 RPM is something to do with the PAL version of the C128D machines, because the Free Spirit Documentation says that people in Australia, NZ and Europe can expect a reading of "Too High" and 320 RPM, but that that is correct for PAL Countries. ?

Keith Matthews
September 22nd, 2016, 08:01 PM
Hi that steel belt does not look quite right.

Here is a picture of one online:-

https://ist.uwaterloo.ca/~schepers/CABLEPIX/1571/pic10.jpg

Just noted that the carrier looks too far back that's why the steel belt looks slack.

Thx for the Pick, I'll compare it on the weekend 8-)

geoffm3
September 23rd, 2016, 06:13 AM
I think the 320 RPM is something to do with the PAL version of the C128D machines, because the Free Spirit Documentation says that people in Australia, NZ and Europe can expect a reading of "Too High" and 320 RPM, but that that is correct for PAL Countries. ?

That seems plausible if their code is using the CIA TOD counter and not accounting for the 50/60Hz thing.

To OP: do you have a second drive? If so, you might try doing a disk copy from one drive to the next. If only the alignment or rotational speed is off the copy should pass and work in that drive. That would rule out some other mechanical issue.

Keith Matthews
September 26th, 2016, 08:07 PM
That seems plausible if their code is using the CIA TOD counter and not accounting for the 50/60Hz thing.

To OP: do you have a second drive? If so, you might try doing a disk copy from one drive to the next. If only the alignment or rotational speed is off the copy should pass and work in that drive. That would rule out some other mechanical issue.


Well, I spent about 4 hours stripping the drive right down, cleaning everything and building it again, then had similar issued except this time, although the range of movement was more in the centre of the Alignment area, no matter how hard I tried I could not get a stable alignment between the upper and lower tracks. And every time I got very close and locked gently locked off the screws bam, it was out again. So I am beginning to think that without an oscilloscope to see what is really going on i am screwed. 8-(

I Think I am just going to just have to Beg around the forums for anyone that is scrapping a C128D or 1571 to consider selling me a D502 Newtronics Mechanism. Assuming they are the same world over. They are rare as hens teeth in Australia, and when they do come up on ebay they are very overpriced. 8-(

On a good note though, the rest of the weekend was successful getting my other 1571, 1541-II and 2 older classic 1541's working in perfect alignment. 8-). Although 1 of the older 1541 seems to have a heat issue, as when it is on for a while the logic goes screwy 8-)

If anyone here sees a 1571 or C128D going at one of the VCF events, please keep me in mind way over here on the other side of the world 8-)

;)

KC9UDX
September 26th, 2016, 09:24 PM
The 1541 likely has bad RAM.

Since you have a 1571, assuming they are the same mechanism, in your shoes I would swap stepper motors and see where the problem goes.

Keith Matthews
September 27th, 2016, 11:09 PM
The 1541 likely has bad RAM.

Since you have a 1571, assuming they are the same mechanism, in your shoes I would swap stepper motors and see where the problem goes.


Yeah I guessed RAM or some other chip that is lifting out of its socket with heat. I'll pull all the chips and re-seat them on the weekend 8-), I have some freeze spray so i can also try that on a few chips to see if they come good when cooled. 8-)

I'm a little hesitant to pull the stepper out of my good 1571, seeing as its working so well at the moment 8-). But thats a good idea. Ive pulled the power int the internal drive for now and I'll leave it off until I get a replacement I rekon 8-)

Thanks heaps for your advice. 8-)
:)

Keith Matthews
October 13th, 2016, 05:51 PM
Hi Matt,

I took the plunge and decided to migrate my good working 1571 mechanism from the good external 1571 drive I have into my trusty 128D so the old girl would be a fully working unit.

The external unit also had a D502 Newtronics Mechanism in it so I thought you beauty direct replacement .........nah!!!

The Cables were exactly 2 inches 2 short!!! (Except for the head cables)

Anyhow I made up 3 extension cables and yipee, now I have a working 1571 inside my C128D.
338133381433815

So Now I just need to fix the External 1571 8-)

hehehehe

geoffm3
October 13th, 2016, 07:15 PM
Hi Matt,

I took the plunge and decided to migrate my good working 1571 mechanism from the good external 1571 drive I have into my trusty 128D so the old girl would be a fully working unit.

The external unit also had a D502 Newtronics Mechanism in it so I thought you beauty direct replacement .........nah!!!

The Cables were exactly 2 inches 2 short!!! (Except for the head cables)

Anyhow I made up 3 extension cables and yipee, now I have a working 1571 inside my C128D.
338133381433815

So Now I just need to fix the External 1571 8-)

hehehehe


Did the head carriage assembly glide smoothly on the rails by hand with the power off?

Keith Matthews
October 13th, 2016, 09:17 PM
Did the head carriage assembly glide smoothly on the rails by hand with the power off?

Hi Geoff,

Yep,

No problems with motion that I can see on the bad unit, but stuffed it I can get ant sense out of my attempts to perform alignment:confused:.

geoffm3
October 14th, 2016, 11:25 AM
I imagine if it moves freely, AND doesn't wiggle while attempting to move the head carriage whilst also preventing the stepper wheel from turning then the band is okay. Could the wheel be slipping on the shaft of the stepper motor perhaps?

Keith Matthews
October 17th, 2016, 12:43 AM
I imagine if it moves freely, AND doesn't wiggle while attempting to move the head carriage whilst also preventing the stepper wheel from turning then the band is okay. Could the wheel be slipping on the shaft of the stepper motor perhaps?

Hi,

Not that I can tell. 8-/
The problem I see now, is that no matter where I locate the stepper, If the Alignment software is between tracks (ie. 18.5) it say's EXCELLENT, At Half Track, and when I step to a track (ie. 18 or 19) I get NEEDS Alignment, and no Blocks read. As if the heads were not reading. But if that were the case how would it know when it was At Half Track when at 18.5.

Very weird. Really need to get an Oscilloscope, and follow the 1571 Service Guide at this point I think. Or just throw in another D502 Mechanism, if I can get hold of one. 8-)

8-)