Interesting develpoment . . .  the Rutex self destructed.

Unlike the Whale  .  which I murdered with my own mistake, the Rutex just exploded for no particular reason. In the process, the PS rectifier was also fried.

The AC line-in fuse on my PS popped off and I was able to track it down to one of the bridge restifiers being shorted. Once I located the problem it was relatively simple to replace. However, on power up, the Rutex oddly was moving the motor continuously in one direction.

I reset the drive and zeroed the encoder and turned the HV back on and  . .  POP!  Fire and smoke from under the Rutex . . . . and . . . the rectifier was fried again. Hard to say who threw the first punch.

The Rutex exploded a MOSFET and has thus far resisted all attempt at repair.

Each drive has an independent fuse on the positive DC power (20A in the case of the Rutex). Despite the exploded MOSFET and the shorted Rectifier, that fuse did not open. I replaced the rectifier again and the mill is back running fine with the two CNCdrive servo drives and a stepper back on the Z axis for now.

I don't know if this is enough info for anyone to formulate a theory about what happened. What I don't understand about the event is how the Rutex somehow *appears* to have fried the rectifier. Is that possible?
 

Update:

I reported the drive burn-out and asked for information about repair on both the Rutex web site and after getting no response, there, also by email directly to Ton Eldridge, the Rutex rep. Thus far no response their either.

An interesting discovery that I made while researching the parts needed for repair, is that the MOSFET controller is an obsolete part. One of these controllers is burned out on the drive along with the MOSFETS.  Mouser has no stock and Newark says that after their stock is gone, there will be no more available. Neither of these major suppliers lists a replacement or equivalent part.

The controller is an ST brand L6386. It would seem there are two conclusions to draw:

1) the well known Rutex 'burn out ' issue is NOT confined to older models or even a single current model

2) it seems reasonable to assume that even the current model drives will soon be unrepairable for lack of available parts once the obsolete stock is used up.
 

Another update on the Rutex drive failure:

I received an e-mail responce from Tom Eldridge,  not as as a result of my official contacts, but as as result of posting here in the Mach forum.

He states in part: "When a customer asks for warranty service, I normally send out the replacement the day I receive the bad drive from them.  If I am comfortable with the customer, I will send out a replacement if they call me right away, even without payment and even before I receive the blown drive.  If you had called me right away, I'd have done that for you too. "

Note: This statement is consistent with reports I read and obtained from Rutex users, as noted in the review. I did not call Rutex. I used only e-mail communication.

Mr. Eldridge goes on to add this condition to the warranty offer: "Normally I would just warranty this for you, but if you put the current setting higher than I recommended and if the drive solder runs are damaged he may only want to warranty them half way...in other words, you would have to pay for half of a drive to receive a new one from us."

Note: The drive is rated at 20A. The recommended setting above which the warranty is cut in half is 7A. This reccommendation, to my knowledge is 'published' only in a single old posting in an obscure Yahoo forum. The drive continues to be rated at 20A in the product literature.

Thus I have apparently voided my full warranty not by attempting to repair the drive, but by using it at it's rated capacity. Fortunately, I have successfully repaired the drive myself, but as others have done, I  will have to 'derate' it and find an use that requires only 7A max.

Talk about the fine print.  20A vs 7A is more like 1/3 of it's rating.

I agree, if that is truly the case then they are deceiving people and everyone should be told that.

Hood

Vladimir, top dog at Rutex, sent me an explanation as to why it is 'OK' to have to limit the current, claimed that this doesn't effect operation because the drive will still somehow provide the max amps . . . . which makes no sense to me and is not consistent with my experience with the product. For me the drive had distinctly different behavior with the amps limited to 7 as 'recommended' by Rutex. I could not get a 3.5A cont, 20A peak motor to accelerate using that setting.

However, setting the drive to it's rated 20A resulted in the best performance of all of the drives by a small margin . . but only for three weeks until poof.

The boss man offered full warranty replacement instead of the half warranty offered by the US rep. Since a refund if the product 'does not meet customer expectations' is part of the warranty,  I asked for that and returned the drive altogether and got a full and prompt refund.

I have decided not to review the Granite drive. I want to make it clear that this is not due to some known failing of that product. The focus of the review is DC brush drives and for that purpose, the Granite is simply too expensive to justify. The eagerly anticipated 'dual DC drive' is now reality, but so it the resulting limitation to 20A per motor, leaving a situation where one can still purchase two competing equivalent products cheaper than one Granite drive. When you include the 'install kit' and the extraordinarily high shipping cost, the drive is simply impossible for me to justify for DC servo use given the alternatives. You mileage may vary.

If a user contemplates using brushless motors, either DC or AC, then the cost of the Granite is more palatable. Granite has only one "universal, I can do everything" product, so for low end application such as stepper or DC brush servo, you still pay for the enormous capability, even though you will not benefit .

So, after several months, thousands of reads and dozens of emails, the review is therefor completed and closed. Vendors can still provide new information or corrections and I will continue to do updates.

Thanks Simpson.

Brett

On the basis of this (and a couple of other) thread, I bought 3 x Dugong drives plus a HD BOB from CNCDrives to retrofit a Bridgeport Series 1 Mk2 Interact.

I've kept the original SEM servo motors which are rated at about 140v, 25A.  The rating put them outside the capabilities of Gecko's which were my first choice.

The Dugong drives have proven to be fantastic.  Unbeatable for the money.  The config software is a bit clonky - but works well enough.  I give them a whole hearted recommendation!

I added AMT102 capacitive encoders set to 1000 counts per rev which the drives multiply to 4000 giving 0.000625mm per count.

I've been using the mill with Mach and the new drives for a month now.  I've been a Mach3 Turn user for a couple of years and never used Mill before.  I felt right at home with it after about 5 mins - brilliant!

To give the Dugongs a real test, I have decided to use one for my spindle drive controller.  The mill has a 5Hp DC motor which is pretty big physically.  I'll add another AMT102 to the spindle then run it with step & direction from Mach.

I'm using a Smoothstepper so I should be able to run it pretty fast.

If they can run a spindle - they can run anything!  I'll keep you posted!

Si

Forgot to mention, the reason I want to try one on the spindle is because the original Mentor2 drive let the smoke out when I started the spindle with the spindle lock engaged.

I would have thought it would just throw an over current error - but the smoke got out first!  I have been quoted $1800 to fix it - so it's going in the trash!

On the plus side, this will leave the whole of the mill running on single phase!

Si

Good to hear 
Hood