Hurco MB1 retrofit

[swafrep]

Hello everyone, new member here getting ready to take on a Hurco MB1 mill retrofit. I've read just about everything on the web that I could find and not much is out there on these mills. This was a perfectly good running machine until the controller started to systematically fail and let it's smoke out! I have a few basic questions and would appreciate any and all feedback that I can get.

I would like to retain the stock Electrocraft DC servos and Max400 drive amps. Can I use something like a Rutex R2040 per axis to convert step & direction to +- 10volts?

As far as motherboards go, I like the features of the C-11 from cnc4pc. Does anyone have any experience with this product or other recommendations?

I look forward to hearing from everyone soon.

Thanks.  

[Hood]

No experience with the Rutex so cant advise on them but if I were to be doing a machine that had analogue amps I think I would go the extra bit and go with the DSPMC from Vital Systems. Again no experience of that but have heard nothing but good comments and it will allow you to use high count encoders if that is what your motors have already.

Similar with the CNC4PC,  no experience but  I  prefer to have a basic breakout as I feel the more things that are  on a board then the more problems you can potentially have.

Hood

[swafrep]

Hood,

The machine is currently buried with stuff in the corner of my brothers' shop so I won't have an opportunity to clear a path around it and pull one of the servos out to study it until this weekend. Based on the documentation of the drives that are currently in the machine,

Peak Motor Current                                    +-30.0 Amps
Max Continous Motor Current                       +-15.0 Amps
Motor Supply Voltage                                 30-120VDC

Is it worthwhile trying to retain the original analog drives or should I ditch them for newer ones that already accept step & direction? I dont mind sacrificing some feedrate speed if its going to simplify and streamline the conversion process. Keeping the cost low would be nice too!


Thank you in advance.

[swafrep]

I left work early today to see if I could read the nameplate on one of the servos. Here's what I found:

Electrocraft

model E26-2
pt# 727-902-0767
build date 08/1991

I also pulled the rear cover to see what type of encoders are in this thing.

BEI industrial encoder divsion

model E25BG-4R-1000-ABZ-7406R-LED-SC6-S
pt# 924-01029-754A


Does anyone have the specs for these servos? I was able to find specs for the encoders online but I have no idea what I'm looking at as far as resolution goes!

[Hood]

Will see if I can find the specs, may have them here if not will search Rockwells site.
 Should be good drives and not old so should be good, Industrial drives are almost bullet proof.

The encoders look like they are 1000 line from the specs, that means 4000 counts per rev as far as Mach is concerned.
 If you use the Rutex StepDir to analogue converters you will either need to use electronic gearing (if they have such a thing) or go with a SmoothStepper or be satisfied will slowish  rapids. Electronic gearing is not great in my opinion, SmoothStepper is good but I have seen very little info on the Rutex converters so cant say on that.
Hood

[Hood]

oops just realised thats the motors, any idea what drives?
Hood

[swafrep]

Hood

The Drives are:

Hurco MAX-400
PWM servo drives

I do have full documentation on these drives and most of the machine. Did you notice the build date on the servos? Possibly upgraded since the mill was built in the mid 80's?

I have to get some pictures up soon!

Thanks

[Hood]

Electro-Craft did Max series amps, so thats probably the same. Do you have the manual as a pdf? if so can you attach please.
Sounds like it has had new motors at some point which can only be a good thing
Hood

[swafrep]

Everything I have is on paper. When I get home from work Tonight, I'll try to scan the manual on the drives and send it to you.

Based on some of the other MB-1's inner workings that I have seen on the web, I believe this one has had it's share of upgrades. Probably due to the fact that it was owned by a large defense firm here in the states.

[Hood]

Never had Electro-Craft DC drives but I do use Allen Bradley and Giddings and Lewis AC drives and they are rebadged Electro-Craft drives and are top notch, so it may well be worth keeping yours. The good thing about that is the motors and drives will be well matched and you will get the best performance that way.
Hood