Stepper motor bearing replacement

[gerald_d]

This morning, on start-up, one side of the gantry had a rough/erratic motion. Aha, been there 3 times before, must be the driver again.....

Loosen turnbuckles and drop motors away from racks, swop leads to confirm....No, the problem stays with the one motor. Visions of a $300 and 2 week repair job. Remove motor from SB and find it impossible to grip pinion and turn by hand. Check a good motor and relieved to find it turns fairly easily. Definitely a bad motor. Total relief!

Open motor (marking all parts first) and find a very simple construction with one very stuck bearing. Sean is out shopping for 8 new bearings....

[gerald_d]

Well, two hours ago the motor was running again.
I don't think we would have had such a short down time with a Thermwood or MultiCam. I would even be a bit nervous of opening an AlphaStep motor.

What caused our bearing to fail? It was fine sawdust getting past the shields of the NTN bearings (6002Z). The grease inside had formed a paste with the sawdust and that congealed with last night's exceptionally cold weather (50F). The back bearing of the motor still had perfect grease in it. Knowing that these bearings run at low speed below temps of 200F, I fitted a pair of sealed bearings (6002RS) from SKF. (The NTN brand has never appealed to me).

This weekend will see all the other bearings in the remaining motors replaced as well. Plus blowing out dust that had entered via the unsealed wire/cable entry hole.

[stevem]

Gerald,

Disassembling stepper motors will demagnetize them and reduce their torque by a substantial amount. Compare the torque required to spin the repaired motor by hand against the torque required to spin the unopened motors.

[ron brown]

Gerald,

I have been told not to open a stepper motor without the "special devices" to keep the magnets at full strength. It might have been salesman hype as I cannot see how a good magnet would loose power from a short open time.

It might be worth a little research before you opened 4 more motors.

Ron

[gerald_d]

Thanks for the warning guys....I will do some more homework first.

[gerald_d]

Phoned Oriental Motor in the UK and the guy promptly told me that I have killed the motor. Searched the www and found some references saying that 50% of the torque would be gone.

Did some practical "tractor pulls" with a fisherman's scale while running the x at 1.5" per sec. The "good" motor on the x pulled up to the scale limit of 80 pounds. The "destroyed/scrap" motor on the other end of the gantry pulled 60 pounds fine, but at 70 pounds it lost the odd step. So there is still plenty of life left in it!


Have any of you guys tried to hold the gantry back while it is running? It is almost scary how much 70 to 80 pounds really is. Makes you understand how the SB can snap 1/2" bits......

Oriental Motor UK says to dump the motor when the $6 bearings go faulty - they do not repair motors.

How did the dust get past the shields? Maybe an erroneous attempt to blow dust out of the motors by aiming a blowgun at the hole where the wires come out? A lot of dust did enter that hole, that is for sure - now we will look at ways of sealing the motors better against dust.

[harold_weber]

I looked through my notes taken in 2002 when the Oriental Motor rep spoke at the first ShopBot Jamboree. The rep said:

1. You will lose 50% of the torque capability when you re-assemble the motor.

2. They magnetize the rotor AFTER they assemble the motor at the factory.

[gerald_d]

It is possible to change the bearings without sliding the rotor out of the stator - I don't know if this will improve matters.

It might be that any contact between rotor and stator already de-magnetizes it - this is impossible (maybe not) to avoid while changing the bearings. (The rotor is the magnet)

[mikejohn]

Gerald
Just out of interest, did they quote you the price of a replacement motor?

.............Mike

[richards]

Oriental Motor (USA) posts prices on their site. The PK296 frame size motor - without controller - is in the $150 range (NOT THE ALPHA MODEL). Just read the model number from the motor on your machine and look it up on their site.

[gerald_d]

Our motor is early PRT (circa 2000) which was rather beefy and has no gearbox. The exact model no. is not with me here at home, but their website had it $205. Then we have their SA "agents" who also want a "commission" and we are probably looking at $250 to $300. There are other brands in stock locally and I'll shop around first.

I am not sorry at all that I did open that motor in ignorance this morning, because the only other option is to buy a new motor in any case. I will probably do a bearing change on the other x-motor on the weekend, this time being very careful with the handling of the rotor, and not moving it axially out of the stator.

[Brady Watson]

Takes a very steady hand...Don't touch the sides!!!


3972
3973

[gerald_d]

Hey, where did you get that pic? I think that site could have some useful info?


Okay, I realise there is an element of Brady's famous pic manipulation, but do you know what really affects the magnetism - is it the touching of the stator, pulling it out, or both?

[Brady Watson]

Gerald...I'm not sure if Milton-Bradley distributed it or not over there...but growing up we had a game called 'Operation'...Even though you knew if you 'touched the sides' the buzzer would go off...It still jolted you with the horrible noise it gave off!

I think the prime concern when removing the rotor is being careful not to scrape the magnets. You may find that section 14.18 on this page (http://straylight.cso.niu.edu/repairfaq/REPAIR/F_appfaqh.html#APPFAQH_015) helpful, but I haven't found the reason WHY it becomes demagnetized upon removal.

-Brady

[gerald_d]

For my own reference (http://www.orientalmotor.co.jp/cgi-bin/WebObjects/UPOMStep.woa/wa/F3?typeNameId=1&modelName=PK299-01AA&seriesId=2PK&frameSize=85)

Brady, thanks for looking that up. That section 14.18 is an overkill, since there are no brushes in a stepper motor. No bent tabs, no commutators, nothing to set or adjust. The construction of the motor is extremely simple - nothing finicky or sensitive at all, until you read that you have messed up the magnetism. I must say that I did pull the thing apart slowly and carefully, and I was very careful to put the permanent magnet rotor down on thick cardboard (at my steel workbench). Also moved the bearings gently, with no hammer blows - everything slipped apart and together with minimum force. That is probably why I still get nearly 70 pounds pull out of it.

If I hadn't posted about it and read the responses here, I would have thought everything is just fine. The SB is now smooth and strong, whereas early this morning it was a dead duck.

[Brady Watson]

Oh cool...so you got it back up then?

[gerald_d]

That's what my second post in this thread said.


Here (http://www.machinedesign.com/ASP/viewSelectedArticle.asp?strArticleId=57968&strSite =MDSite&catId=0) is an interesting article - the picture could very easily have been of our motor.

"Magnets: Magnet materials for hybrid steppers each exhibit their own special qualities, advantages, and disadvantages. Application requirements determine which magnet material is right for the job.

AlNiCo magnets offer stable strength during changes in temperature, but can become demagnetized if removed from the assembly. Alternatively, most hybrid steppers use neodymium-iron-boron magnets. These magnets are stronger than AlNiCo but their strength varies more over extended temperature ranges."

[gerald_d]

Reading some more articles tonight, it would seem that AlNiCo magnets are the ones most susceptible to being de-magnetized by "bad" handling.

"Neodymium-Iron-Boron magnets are state-of-the-art group of recently developed magnetic materials in 1980's, with magnetic characteristics far exceeding those of the Alnico and Ceramic/Ferrite types."

From para 12.0 of this site (http://www.magnetsales.com/Design/DesignG_2.htm#handling): "Materials with low coercive forces such as Alnico 5 must be carefully handled and stored when received in a magnetized condition. When stored, these magnets should be maintained on a "keeper" which provides a closed loop protecting the magnet from adverse fields. Bringing together like poles in repulsion would lead to irreversible, though re-magnetizable, losses."

I am starting to think that "touching the sides" is okay - just don't pull it out! (Even with AlNiCo) If you do pull an AlNiCo across opposite poles, then you are in more trouble than doing it with Neodymium-Iron-Boron?

[bleeth]

Great info and research into the problem guys-I can't help but ponder the many lines of postings about keeping dust and grit off the rails and pinions and now seeing a machine down due to dust in the motors is a bit of a surprise. I've had all manners of woodworking tools die for lots of reasons but no decent motor was ever considered toast because of a burnt or impacted bearing. I will be checking out my motor nos. tomorrow. The logical continuation of the thread is:
1) What will help prevent this without stifling the motor?(Anyone have a mental picture of a stepper motor dust bag?)
2) Are later models more repair friendly or better protected?
3) Do you know how long it takes to get your closest stepper motor replacement so you have the least number of torqued off clients?
4) Although having a four year old motor with the kind of abusive environment we work in go bad is obviously not totally unexpected, is there maintainence or inspection procedures that can help avoid it happening as a surprise?
5)And although we know that this one doesn't apply to Gerald: After several days of no use there have been times when I've cranked up my spindle and watched it spit garbage (a polite word for publication replacing the phrase in my thoughts) up in the air and therefore I am led to thoughts about rebuilding it due to a couple of errant wood chips. Tomorrow it gets a hood.

Dave

[mikejohn]

Is this a 'one-off' for Gerald, or have others experienced a similar problem?
Gerald shuts his ShopBot in a room, vents the air (and dust) outside, cleans up the sawdust on a regular basis. Does this mean he's more likely to meet this problem than others using a dust shoe?
It seems to me the economics are not so much in the price of the motor (although over $200 is still a lot of beer) than in the down time of the machine.
If this is a possibility that can happen to everyone. is it worthwhile keeping a spare motor in stock, or are replacements easy to come by?

Looking at the schematic of the motor shown linked above, an interesting problem to remove both ends without touching the rotor to the sides!

.............Mike

[Brady Watson]

Mike...a 'bad' motor is a very, very rare case.

Stop worrying and start crankin' out 'Alberts'...

-Brady

[gerald_d]

Dave & Mike, the basic things that I will change for a start:

- Seal the wire-entry point into the motor against dust (our motors have a 6-7mm hole that the wires pass through - later motors might be sealed). Probably use putty, won't use a "silicon rubber" in case it is acidic.
- Ban the use of a compressed air blowgun against the motor - particularly the shaft neck point and unsealed wire entries.
- Will remove pinion gears and fit V-Rings (http://www.anyseals.com/v-rings.htm), probably packed with grease before sliding the ring on.


3974
Will use profile 2nd from left
Still planning to replace more bearings this weekend - I have decided that our particular brand/construction of stepper motor is not so sensitive to de-magnetization. The only other choice is to wait till they seize-up completely - which is obviously the worst choice. But will also do a little more research first.

[bleeth]

Interestingly enough the model number on my motors (A6497-9412-KTG) Don't correspond to numbers on Oriental Motors site. There is another number that starts SB and I wonder what that means? The wire lead in on mine looks fairly unsecure also. Plumbers putty maybe?
Gerald-Was it the bearing at the shaft end that went down or the one near the wire?

[gerald_d]

The bearing at the shaft had the grease caked (cemented) with dust. The bearing at the wire end was in perfect (new) condition. My theory is that someone had occasionally tried to blow the dust out of the motor by high-pressure blowing into the wire hole. If you blow air in there, the only place that the air can escape is via the bearing on the output shaft end. The bearing shields are not airtight and I think high-pressure dust was injected into that bearing from the wire hole. (There was also a lot of other dust inside the motor, between the windings and between the rotor slots.)

[ron brown]

IIRC, ShopBots motors from the PRT on are custom motors with taper-hobbed gears. They are not a stock Oriental Moror although they do use "standard" parts.

Ron

[bleeth]

Sounds like a combination of small bits of dry dust getting in the wire aperture and "goo" migrating up the shaft and past the packing bearing/seal. If your 5 year old machine with the heavy use you give it is repairable with new bearings (Like you I heavily prefer SKF)or even needed new motors it's not a bad deal as long as the motors are replaceable without re-inventing the wheel.
On the other hand Gerald, maybe it's an excuse to upgrade your machine with alpha and spindle! (Look how easily I can spend your money for you!!!)
On a real note though, now that SB is only making alphas and if we PRT owners do need a motor replacement what is the deal? Are they still available and at what cost? Are you there Ted?

Dave

[mikejohn]

Dave
Gerald has had a bad week, mentioning Alphas and spindles will ruin it completely for him


...............Mike

[gerald_d]

Hey Mike, you are building this image of me being a hater of Alphas and spindles, which isn't true at all. They are in a class by themselves regarding performance, price and "repairability". I simply have a habit of defending my choice of the particular class of machine that we have.

[mikejohn]

Sorry Gerald, only leg pulling

[gerald_d]

I fully understand that Mike, but often the "other side" takes us very seriously

[rjguinn@optonline.net]

Gerald,
Was the motor running much hotter than normal when you 1st noticed the erratic behavior? A tech at Oriental Motor told me the grease will start to break down at 184F (84C). Could the motor have been running at or above this temp?
Jeff

[gerald_d]

Hi Jeff, those motors are always pretty hot, probably about 60C. Never as much as 100C (212F) boil point of water. The catalog from SKF says that one starts to look for special bearings at over 230F - below that is normally okay. But the main point is that the second (back) bearing was still perfect, so this is not a temperature issue.

[ted]

Hi Guys,

Wow! You've really gotten into these motors! I've certainly messed up a few myself.

Anyway, yes we do have all the standard ShopBot motors in stock. Our prices are either the same or lower than Oriental's; it depends on the model. For some motors, we also have some used motors (6 months or less use; from upgrade programs).

The tapered-hob, low-backlash gearhead motor (A6497-9412KTG) that is on most PRT's is a ShopBot special that Oriental made for us. It has both a good gearbox and a tight stress-relief connector for the wire exit. We have these at $375. You could also substitute Oriental's less expensive PK296-SG3.6 and would only suffer slightly greater backlash.

I might point out, that generally these motors do not fail. We have had very few problems with them over the years and are very impressed with Oriental's quality control. (I'm inclined to agree with Gerald that too much air-blasting around the few openings may not be a good idea.) There are many less expensive motors, but we have not found any with the same quality bearings and gears, and believe me we have been looking.

FYI. We have a handful of other interesting motors around that are available very slightly used (as in we have just played with them in development here).
FOR PRTs -
==> TH gearheads: 7.2:1 & 20:1
==> Planetary gearhead: 25:1 (one awesome indexer motor)

FOR PRTalphas -
==> TH gearheads (new): 7.2:1 & 10:1
==> Planetary gearheads (new): 25:1 (a FAST awesome indexer motor or other robotic positioner)

Give Gordon or me a call if you have an interest in a good deal on any of these later ones.

-Ted

[gerald_d]

Hi Ted, thanks for that post. You said "......motors! I've certainly messed up a few myself.". Since I am venturing down this path, I am curious to learn if you had some that survived after opening. Or would you also go along with the terse advice "Don't touch!"?

[Brady Watson]

Gerald,
I know you addressed the question to Ted...but I am a firm believer in, "If it ain't broke, don't fix it"

Use your test gauge to measure pull of the other axes...if they are fine, then just leave them alone.

-Brady

[gerald_d]

Brady, a pull test will be no indication of imminent bearing problems. That first bearing jammed up with no warning of loss of power. One day it was working fine (heavy hardwood cuts), the next morning it was putting a huge load on the drivers. (The SB even lost its connection under this overload - twice). I would rather weaken a motor than put the control board through that strain again. I am the type of person who replaces the bearings on both sides of my car when one side has jammed up and nearly caused an accident.

[dvanr]

Gerald,

Gerald said, "This morning, on start-up, one side of the gantry had a rough/erratic motion. Aha, been there 3 times before, must be the driver again..... "

Has that all been fairly recent? (last 12 months) At startup or during a heavy cut?

I'm wondering if a blown driver is a precursor to a motor seizing.

[gerald_d]

Click on the pictures for bigger views:


3975 (http://www.scapenotes.com/notes/messages/2020/4648.jpg)
1. Mark orientations and clamp in vice.


3976 (http://www.scapenotes.com/notes/messages/2020/4649.jpg)
2. Measure pinion location and remove pinion


3977 (http://www.scapenotes.com/notes/messages/2020/4650.jpg)
3. Remove 4 long screws (very little force needed)


3978 (http://www.scapenotes.com/notes/messages/2020/4651.jpg)
4. Gently pull off end-cover


3979 (http://www.scapenotes.com/notes/messages/2020/4652.jpg)
5. See dust build-up inside cover - blowing in there would be bad.


3980 (http://www.scapenotes.com/notes/messages/2020/4653.jpg)
6. See dust on bearing shield


3981 (http://www.scapenotes.com/notes/messages/2020/4654.jpg)
7. Pull off bearing - only slight force needed.


3982 (http://www.scapenotes.com/notes/messages/2020/4659.jpg)
8. Gently press on new bearing in drill press


3983 (http://www.scapenotes.com/notes/messages/2020/4656.jpg)
9. x(left) and y(right) bearings with shields removed


3984 (http://www.scapenotes.com/notes/messages/2020/4657.jpg)
10. Tools needed. Hooks of puller thinned down

[gerald_d]

Dick, the drivers blew while nothing was cutting - it doesn't look like "overload" has caused them to blow, so far.....But I do plan to avoid overloads. One of the blown drivers was on the y-motor and you can see that motor still has good grease.

I only changed front bearings today, having seen in the first motor that the back bearing was perfectly clean.

Next week will tell if the 3 motors opened so far will take the punch - there is heavy Chinese restaurant screen job coming up.

[ron brown]

With the new motors being gear driven, the bearing having the most potential for dust collection will be attached to a gear, not a stator. Damage to magnetic field may be avoidable with gearbox motors.

Ron

Nice job of showing your procedure Gerald - thanks

[gerald_d]

I think that I had no degradation of the magnetic field - that is what the motors feel like, compared to the un-opened z-motor. The "tractor pulls" will be on Monday - it is a two-person job.

Sealing the outer bearing against dust appears to be absolutely essential - the standard "shielded" bearings are simply not sufficient. Adding a V-Ring is so simple, so cheap and will be so effective - they cannot do any harm. Prevention is better than cure. (The BWC V-Rollers are "sealed" as opposed to only being "shielded" - they run about the same distance as the motors, and I don't expect to see dust inside them).

Why such a big difference in the amount of dust inside the x-bearing versus the y-bearing? The x-motors run much further, they are lower down, they are line-of-sight of the cutter (our x-rails are on pedestals).

We think that the z-motor's bearing should still be very clean, so we are keeping that one as a non-tampered reference motor. But it will get a V-Ring, like all the others.

[rjguinn@optonline.net]

Gerald,
My original question about increased temperature was asked because I am trying to determine if most driver board/motor failures start with a substantially increased motor temperature.I installed aluminum heat sinks at top of each motor with 70C thermal switches to eliminate related problems. Any ideas why I can't view your photos? Also, do you have any photos of your V ring installation & recommended sizes?
Thanks,
Jeff

[gerald_d]

Jeff, I very much doubt that driver board failures are in any way linked to motor temperatures. 70C feels pretty hot to the hand, but it is relatively cold for stepper motors. (I would say that 100C is where the motor can really be called "hot")

No idea why you can't see the photos - anyone else have a problem too?

V-Ring (or V-Seal), profile S (or A), size 13mm (or 1/2"), they stretch to fit over the shaft. Will do photos of this later. This page (http://www.argensold.com/vrings.php3) might help for the time-being. Also this page (http://www2.chicago-rawhide.com/v_rings.htm) - What I call profile S is called VR2 and my profile A is called VR1, but this is not critical.

[billp]

Gerald,
Nothing but descriptions, NO pix...

[fleinbach]

I see them ok

[fleinbach]

Jeff and Bill

Did you Try clearing your cookies and old Internet files. If not go to Tools, Internet Options then select Delete cookies and delete files. Then try and see if you can get the pictures.

Try this link to the pictures.

http://www.scapenotes.com/notes/messages/2020/4648.jpg

There are 10 pictures, just substitute 4648 being the first all the way to 4657

[gerald_d]

Frank the hacker


If some of you can't see pics on this Forum page, that is a problem beyond my control. You should at least see a blue frame which you can click to see the bigger photos hosted on my sites.

This morning I added some more comments at my site and you can see the whole page here (http://www.scapenotes.com/notes/messages/2020/4604.html).

[fleinbach]

I wish!

[gerald_d]

Sean has run the SB hard today (12 hours, 10mm bit through 30mm hardwood) and no problems with the 3 re-built stepper motors.


The one-year-old Makita router needed its first bearing change though.

[bleeth]

Good job

[gerald_d]

This video (http://www.mechlift.com/ShopBot4.mpg) might explain the dusty conditions (3MB, mpg, no sound).

[evan]

Do you worry about spark and the potential of fire?
If the Fire Dept saw that in my shop I'd be shut down. But they are very vigilant here, visiting a couple of times a year.

[gerald_d]

Everything is well grounded, and you can see a fire extinguisher plus E-stop (stops fan as well) right by the door. That amount of dust is unusual, but is still less than running a thicknesser for an hour or two. I think there is more chance of fire in a ducted extraction system with closed bins/canisters.

[evan]

You're pbobably right. As you say (in many post)the key is grounding.

[mikejohn]

Gerald
You have solved the height challenged Dan Dunn's short table problem.
Simply let the sawdust and shavings raise the floor level

Nice video, liked Lord of the Rings III better though.
...........Mike

[gerald_d]

Re-magnetizing of stepper motors....

Copied with permission from a post on another forum: "Rare Earth Magnets are very difficult to demagnitize, disassembly should not present a problem. The older Alnickel magnets are another story. They could sometimes "loose it" and even reverse their field for no apparent reason. You never want to disturb an assembly with Alnickel. Ceramic Magnets can be quite forgiving, I don't know if they are used much in motors though. In any case, it's good practice to use slow deliberate movements when assembling/disassembling any magnetic device.

Many Step Motor designs are magnetized along the axis, while fully assembled. One way this is done is with a few turns of 000gage wire (about 0.5" diam.) wrapped around the motor. A very short pulse of several thousand amperes is applied."

Apparently this company (http://www.servo-repair.com/magnetize.htm) does re-magnetizing. ($150 for a batch of 3 motors)

[dhunt]

UNUSUAL (Near Side) X GANTRY VIBRATION.

Yesterday,while cutting a length of ornate Victorian gingerbread facia board, suddenly the ShopBot 'loses it' in X direction, accompanied by unusual shaking and vibration.
Pause. Check everything.
It hasn't jumped the tracks, everything's tight and okay.
Resume the cut-file for a short while: same problem. Pause again, this time Quitting the file entirely.
Turn everything off.

After several elimination processes, it is deduced that the vibration is happening when the near-side X-motor is engaged,
and NOT happening with the far-side X-motor.

Freeing the near-side X motor from the cogs, we try to turn the shaft of the motor to discover it is very stiff and difficult to turn.
Comparison with a spare motor, and with the far-side X motor only confirms this difficulty turning the shaft.
We freak out, assume a dead motor, and order a new one at "a mere $375" !

This morning now, we replace our 'dead' motor with our spare wot's been hanging around here for 4 yrs., awaiting its moment of glory.
We discover that the shaft on yesterday's 'dead' motor is now turning as sweetly as any other! Resurrection from the dead! - It's a miracle!

We also notice that it has not been meshing fully(breadth for breadth) with the 8ft.length of cogs
and there is now some degree of thin-ness to the individual teeth on the small round cogwheel affixed by Allen screws to the motor shaft, and some taper,too.

Okay, in the interests of doing a thorough replacement job, we decide not to simply replace the worn cog wheel onto the newly resurrected 'dead' motor, but to reassemble with the brand-new spare and its brand-new cog-wheel.

Everything's fine, we take the big X-gantry right to the end of its rails where we make sure we're re-engaging both X-motors at the same point,
and gently push the X-gantry to discover we've cured absolutely NOTHING.
The same darned vibration is STILL there.

SO...
It wasn't the 'dead' motor?
It wasn't the worn cog-wheel on the 'dead' motor?

Running our fingers along the underside of the 8ft.lengths of gear cogs proves nothing other than they're okay.
No visible detectable problem that would cause vibration running it dead, far less alive!

Does anyone have the number for Unsolved Mysteries ??

[marshawk]

It sounds like you lost a driver.

I can't remember...do you have a PRT or an Alpha?

Chip

[dhunt]

PRT 96 (4ft. x 8ft.) installed late Feb,2001

Yes.. another guy emailed privately, to say much the same thing.
My first reaction was that the problem was something mechanical

[ted]

Hi David,

Yes ... as Chip suggests, it sounds like a driver has blown out. Generally speaking, we very rarely have motor failures (maybe 6 in 16,000 over the last 8 years). The technology is relatively stable and OM makes a great motor.
Thus, it is more likely the driver, or a problem with a cable or connector.

The reason the motor may feel hard to turn is that if its coils are shorted (perhaps by a bad drive or cable), it will become difficult to turn (e.g. on your spare motor, put a screwdriver across the pins in the connector and then try to rotate the motor; you'll see it turns harder).

If you are lucky, you may just have a stray wire in one of the connectors in the wiring between the control box and the motor (or some debris) that has become loose and is shorting.

To evaluate the driver: with the contol box turned off, swap the motor cables for the X axis at the control box (remembering that unplugging a motor with the power on is one of the best ways to blow out a driver). Then test again. If the bad motor now runs fine, and the good motor is bad, your problem is the driver.

If you have a PRT with straight-drive motors (like Gerald's pictures above) we will need to send you a new IMS driver for your control box. These can be a little tricky to put in ... so have a chat with us about it.

If you have a more recent PRT with gearhead motors, and you do not have a second Z, then you already have a spare drive (the accessory channel) on the board which we may be able to use for the X axis. Just move the motor cable from the bad drive to the Acc channel, and set both of the dip switches on that channel to #1, so that it will function as a X axis. Give us a call if you'd like us to prompt you through the process.

I just noticed that you have also emailed us, so I will respond to your email a little more extensively.

-Ted

[dhunt]

Many thanks to those who wrote to suggest it was a blown driver,
coz that's exactly what it was!

Luckily we had a spare driver or two, here on our small Caribbean island,
so we swapped in a replacement, and The Thing runs just fine now!

[gerald_d]

Just wanted to drop back into this thread and say that those "re-built" steppers are still going fine! I don't think that the procedure harmed them in any way. The z-motor of that machine will have a bearing replacement this weekend.

(PS. The bigger versions of those pics are gone - I don't own that website any longer)