The Fadal -Glentek problem,Help,comments?

Hello to all,'hope bussiness is good.Here we go,I have a VH65 rotab with a dead Glentek 4020 motor,broken magnet.Fadal wants to sell me a new motor for about 1800.00 and the same thing will happen again,as these motors are crap.Glentek's position is that its a fadal and thats your problem.
A dc servo is a dc servo,if the specs from one manufacturer to another are the same,they should be interchangeable.That being said,foremetioned glentek crap was replaced with a Baldor MT4060.Same specs,built better,it has seals,orings a varnished magnet structure and new its about 600.00.I bought this one on Ebay for 100.
The motor require a step turned on the face and 4 holes drilled and tapped in the front and two 8-32 holes drilled in the back to mount the resolver.Done.All mounted up and plugged in.The motor hunts for postion.Back and forth.
Fadal and Glentek matched the original 4020 motor and Ga 4568a amp.There is almost no adjustment to the bandwith,tach gain and the position loop gain is pot adjustable but fixed with resistors.We added the comp adjustment and the tach gain-still hunts.There is a non Fadal version that has considreable adjustment.
This is where Im at.We are sooooo close to breaking the Glentek hold.The postion loop gain is to low,the motor is to soft.The gain needs to be increased by adding a bigger resistor in front of the amp itself.We have no schematic.Any one know anything about this amp in detail?
Pulling this off will allow you to use ANY mfg's motor on a Fadal on any axis,as all the amps are set.Ill share all the info with everybody if we can pull this off-'need your help.
One more thing,most of us own old,or "cheap" cnc equipment,we get raped for the parts,charging what the market will bear is BULL****.All of us at one point or more have come up with an alternative part or solution.If I put a FREE website up listing all this kinda stuff,would you all contribute?Here's your first beat the man-own a Matsurra with agear driven head?tried to find the "Schaun" motor drive puck? $300. from Methods-made by American Vulcan in Winterhaven FL-$60.00-your turn.....I need your help with the Glentek amp.

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Originally Posted by JR1050

Fadal and Glentek matched the original 4020 motor and Ga 4568a amp.There is almost no adjustment to the bandwith,tach gain and the position loop gain is pot adjustable but fixed with resistors.We added the comp adjustment and the tach gain-still hunts.There is a non Fadal version that has considreable adjustment.
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There are a few manuf. that do this, they find the optimum setting for their drive/motor combo, and then get the drive manuf. to provide them with a pre-set version, probabally to cut costs.
If you can find the schematics for the off-the-shelf drive, it may be possible to re-populate with the adjusting components.
Depending on the feed back type, it is often possible to substute with a later style drives like AMC if you have to.
These come up on ebay regularly, but the larger sizes are rarer.
Al.

Here is what I have seen time and again when spending a dollar to save a dime.

If business is good, then the downtime cost are far higher than the re-engineering time to beat the man....when you can consider him partially beat by going elsewhere to save 30% and have a running machine in short order. The rest is peace of mind that you have not compromised other parts in the system due to an oversight mismatch.

There are plenty of GM4020's available rebuilt for around $1200 w\core exchange. I cannot tell you how many time I have made purchases on ebay similar to your $100 "NEW\NOS SERVO". More than likely the seller has no clue of its history. From the sounds of it, you may have already spent $1200 of your time mounting it and now modifying the electronics trying to get it to work. Which sounds like a far more expensive risk.....

I think everyone can appreciate the effort to post money saving, off the shelf replacements. Minor mod's for mounting is one thing. Altering circuits at the component level is quite another.

In some respects, we can be thankful there are guy's out there willing to prove it can be done. In other respects, I can't help to believe it is a fools game of chance. The caveat here is knowing IF the information comes from a qualified tech.

DC

There is more than one thing at play here.First and foremost Glentek makes crap -period.The magnets shouldnt fall out of a servo with 200hrs on it.If and when they do, a replacement magnet structure should be available-no questions asked.I looked for a core for a year,ALL 4020's have loose/broken magnets.
Secondly,do you make crap parts for your boss,customers,friends?I think not.I dont have a problem forking out 2k to Fanuc,Siemens or Yasakawa for a motor,because they last 20 years.My Matsurras have original 25 yr old motors. 1200 bucks for a rebuilt peice of crap is worse than 1800 for new.The Fadal aftermarket is worse that G&L themselves.When did this country decide to be such nutless wusses-is our greed so extreme we can justify being screwed so we can pass it on?Sounds like you work for Fadal.....Did you get my email?
Al the man is on the right track,unfortuntely,I cant find any schematics for the older Glentek and our boys at GT,arent gonna help.The motors and drives are matched this way to keep us out of it,so we have to give in-be sheep.
Fadal will join K-T,B&S,Cincinnatti,LOdgeandSHipley,Sunstrand,Devlei g,Bullard,Bendix and the GE 1050 if they dont start careing real soon.They are already on their way,Haas is kicking the living crap out of them,Haas by the way switched to with yasnac motors/drives,years ago-wonder why?and no I dont want a Haas.Anybody wanna deal on a Fadal?

That was a word toward the wise, not a rank on you or your efforts. You are correct, I have no idea what else is at play in your situation. But, I do have 20+ Glentek drives in 7 CNC's that are pushing 17-18 years old a not a problem to speak of.

I just replaced a Parvex servo on a Bridgeport for the exact same reasons. It is fairly common when the motors are not sealed well, that coolant\moisture infiltration will desolve the glues they used in the past to bond the magnets. I know, it is inexcusable considering the application and environment. We were down a total of 4 days(2 shifts) which cost us roughly 48hrs of production time on top of the $1950 rebuilt replacement. EMI didn't have them in stock, and if they did, I think the price was around $2400. They never did return my call while they were searching for other sources. That contributed to one of those lost days.

There were a ton of conditions that brought about the coolant issues. The way covers are tweaked and the motor was never designed as a wash down application. I was given the same warning by the rebuilder on the new motor, although they assured me that they remove the magnets and use better glues, Sealed bearings and seal between all mating surfaces. On those terms, I would say that the rebuilt motor should be a better buy that another OEM motor without these improvments.

Your circumstances must be different. I just can't imagine me still dinking around with unknowns, while several people are standing over my shoulder wondering when the dang thing is going to be making chips again. On a hobby mill maybe, but when a beast of burden in business becomes a problem, you do your best to keep pace with its faults or replace the thing with something more reliable.

IMHO Fadal's were built for economy not longevity. Even with that, there may have been conditions that induced this failure. Meanwhile you have a down machine and no ETA on running anytime soon. My original response was in relation to saving money, yet spending more down time and risk to achieve an unsure thing. In the end, you may have been better off spending 3-4K for a compatible motor and drive and be done with it.

I can still wish you the best of luck with it. We all love a story with a good ending and only the bad guy gets hurt.......just don't be that guy! Been there, done that, didn't like it one bit! LOL!

Yes, I too must also agree with Al. The thing that doesn't make much sense here is that the OEM must purchase a custom board. That is where the conspiracy trap begs the question. Wouln't a stock board that has a wider application range and quantity sales be the better buy?


DC

It is indeed a problem. Glentek's products are not bad but it appears they are not backing up this particular OEM very well. We had a similar problem and contacted uptime cnc (www.uptimecnc.com). They were very helpful, suggested an alternate and it worked.

SAM makes a sort of equivalent sold by K-mac parts. The problem is that their equivalent either requires more power or has less power than the Glentek. I have 3 to replace here and its not going to be cheap.


You would think a competent guy could rebuild one in his spare time. Our 3 on various machine are EXTREMELY LOUD and sound like grinding and squeeking anytime they move.....its a bummer :(

I don't if it is SAM. the loudness is probably due to resonance at some levels and has to do with it being tuned properly. might be worth a try over at uptime.

How do you tune a Glentek?

Sorry but I didn’t read all of the responses so this might have come up already. Glentek supplied both the drive and motor and if I am not mistaken the drive was proprietary. Weather this was deliberately done to lock up the business or not is a subject for debate but the net result was the same. If your early Fadal came with Glentek motors you were stuck with them.
We have 5 VMCs and this has been a reoccurring problem from the outset so we simply started keeping spares motors in stock. For a number of years my company supplied Glentek with all of the resolver couplings in the Fadal motors and this would get us exactly 0 favors. We had to go through Fadal for new or have them rebuilt.

Someone should find a and put together a rebuild kit for these.

Thanks to you all for your input and Warren at UPtime is a great guy.I actually ended up buying a SEM motor from KMAC,and it is down on tourqe.I defence of Kmac, it is bolt in replacement and their service is very good.Considering it comes with the tach and resolver,it really not that bad of a deal.It will probably be returned.
This is what I ended up doing,I bulit a fixture to hold the original broken Glentek magnet in place and glued it back in with epoxy.It was reassembled and is working.After checking the BEMF,it is down on torque,probably due to some magnet loss.The amp required the pos loop gain to be cranked.
The Glentek amp is not so much propreitary,as it is special built for Fadal.They have it fixed so you cant add the missing adjustment pots,as it totally upsets the tach gain.The Baldor motor had a different armature inductance,which was the root of the problem.I will keep an eye out for another amp,as Al suggested.
I cannot agree that Glentek builds quality(or Fadal for that matter).It seems stupid at this point to put together a replacement DC,brush sytem when AC is s much more effecient and prevelent.Fadal,in their infinate wisdom,didnt have any provision for encoder feedback in their old controls.Im not sure a resolver will work with an AC motor.Fadal also didnt beleive in limits either....
Servo motors are used in every thing from tread mills,to printers to the biggest and gnarl'st metal cutting machines.They not are rare or magic,and the only reason in a machine tool application they are so expensive,is because the OEM's are charging what the market will bear.
We may all be in competition with each other to some extent,and Im sure some of us dont like each other....but we are in this business and trade together.Its to everyone's advantage to take a stand over getting raped for repalcement parts.
A last thought about Fadal,a 4020 is about 80 grand with a CNC88 control,thats about 1500 bucks a month.The machine should not need to be rebuilt in 3-5 years.I understand a 40 inch Matsurra is about 250 grand,which is overpriced,you get what you pay for,and the Decauusins knew that,as motors amps and boards were TRADE IN prior to G&L.Next new machine,how
about a ZPS or a TV series Supermax.....

Wow down on torque :(

Resolvers are not all that uncommon on AC servos. Baldor supplies them as a standard part of their product line and we use a few here in a couple of our custom machines. For our application I'd rather have had encoders, but at that time I was not driving the boat.

Bob J