Welcome to GD Drives & electronics forum!

[Xerxes]

CNCadmin was kind to create very own forum for us Thank you!

We are Granite Devices Inc. which has roots on this forum. In the beginning there was a project to create industrial quality AC/DC servo drive for affordable price. The project succeed and now there is a company whose purpose is to
manufacture and develop these drives further.

From this site you can find more details and specifications about our products:
http://granitedevices.fi/

To take a closer look on the first projects & history, plese see the threads:

- New sinusoidal AC servo drive development
- Ordering industrial made AC servo drives

I welcome everyone to join discussion on this forum. Hopefully we see discussions about user experiences, questions, future suggestions etc! :-)

Best regards,
Tero

[buckie555]

Tero,

Firstly congratulations on bringing your product to market. It's no mean feat to do so and I know that there have been a large number of people watching your thread develop with considerable interest. I truly hope all your hard work pays off and wish you the very best of luck. If the drive is half as good as it appears then it's set to be a spectacular success.

Now onto business. I'm in the process of retrofitting a cincinnati VMC and would like to use your drives for the x, y and z axis'. I'm planning on keeping the existing fanuc red cap motors but ditching the triple stack fanuc drive. The x and y axis motors are 144V 6A and the z axis is 144V 11A continuous so I believe your drives should be a good fit for them. All three motors are circa 1990 and have fanuc pulse coders which I believe contain regular differential quadrature encoder lines as well as tach info that the original drives used. Anyway I'll be using just the encoder signals.

I have a couple of questions:

From your testing experience do you believe your drives will be a good fit for these?

Is the dc that you inject on startup to ascertain the rotor alignment likely to damage the motors? How much voltage and what current is injected?


I'm also wondering whether I could use your drive for driving the spindle which is also a fanuc servo motor albeit much larger. I believe it's rated at 10kW. Now I realise that really I should be looking at a much larger drive but I don't want to splash out on a fanuc drive and I don't want to remove the motor and replace with an induction motor and vfd since I would like to accurately control the motor speed and position for tapping and orientation during tool changes. I'm thinking that with some heavy cooling I could squeeze 2kW or so out of the drive. I realise that I would only be using a fraction of what the spindle motor is capable of but at this moment in time it would be enough power for me and could be a cost effective solution.

What do you think?

Finally I know you mentioned looking into accepting credit card payments in the future and I can understand completely your reservations regarding paypal. Have you looked at google checkout. It looks as though it could be quite an elegant solution for you.

And finally,

I have some slight concerns regarding the reliability of the drives given that as yet they have no proven track record. I was wondering and I'm sure some of the other members would be interested to know your return, support and warranty policy.

Looking forward to your comments and once again very well done indeed.

Neil Buck

[Xerxes]

Hi,

I guess those are AC servo motors, aren't they? Indeed they sound like a pretty good match for this drive. At least one user has already done some testing for Fanuc servo with Fluxeon and has success so far.

User can configure precise DC current limit for start-up. If you keep that current below motor's peak current, there is no danger of damage. Motor aways sees the voltage of power supply which is not a problem since typically motors can survive much more than their rated voltage.

Is this spindle motor permanent magnet motor? If yes, then it should run with this drive, but I guess the current/voltage ranges are not a very good match in 10 kW power range. Do you have any specs of the motor? Output cabability of the drive can't be exceeded no matter how powerful cooling you are using. The maximum continuous output of VSD-A is about 1600 Watts but utilizing it completedly would require a perfectly matching motor and maximum allowed supply voltage.


The Google Checkout looks very interesting! Thank you for pointing this out. We probably try it some day.

--

We give 12 month full warranty for defects and cases where failure happens withing specifications (i.e. not overtemperature/overvoltage/miswiring failure). We have 12 month warranty from our subcontract manufacturer for electronics so giving such warranty is not a problem for us. Repair needs are minimized by testing every drive thoroughly before shipping.

No customer is left alone with their problems. We do our best to ensure that every drive gets running as expected. If there is no way to make them work (i.e. some strange incompatibilitiy with certain motor), then we probably decide to refund even after the law enforced return period.

I believe that keeping customer happy is they best way to success :-)

[buckie555]

Tero,

Thanks for the info. You've reassured me, particularly regarding the dc start-up current. Yes the spindle motor is permanent magnet. Sounds as though I would be better off finding an alternative for that though - 1600Watts is a little low for what I need. I'll certainly be ordering 3 for the axis drives though.

Thanks again and I'll be in touch,

Neil

[kmcwhq]

This is -very- interesting, as I have a Hardinge Conquest 42 CNC Lathe that was used (very little) in an R&D application and has never cut chips. I got it about 7 years ago in pieces, with the Fanuc 0T control, drives, Red Cap motors, etc.
I have been waiting for a low cost cnc retrofit for it, (Found! MACH III) and low cost drives for the (what Fanuc calls) "special" motors.
Found now also!

buckie555, please post your progress and performance in using these drives to run the Red caps....

Thank you
dk

[buckie555]

dk,

The machine only arrived last week and I'm still in the process of getting everything together that I need. I was planning on using the fluxeons to drive the redcaps but I had a bit of luck and was able to get hold of the interface diagrams for the triple stack fanuc servo drives that I have and the fanuc spindle drive. Both take analog voltage references for the velocity control so should be quite straightforward to interface to. There's a bunch load of handshaking that's also taken care of by the existing siemens control but I believe I can replicate this using macros in Mach3. However if this doesn't work out then the fluxeons are most definately my plan B

The redcaps I've got have a & b standard quad outputs as opposed to the proprietary binary protocol that some of the later ones used. I know that the drives and motors are fully operational as I'm able to run them with the existing control. At the moment I'm playing with GREX and mach3. My aim is to get the Mach3 GREX combination working offline before finally hooking it to the axis and spindle drives. I've had plenty of experience with Mach3 on other machines but this is my first attempt at using the GREX. I intend to configure Mach3 to handle the complete tool change cycle as well as all the safetys. I was planning to order pixies to bridge the gap from GREX to the drives but I might even roll my own. I need this machine to be cutting chips yesterday so I plan on having the conversion complete in 4 weeks. I may well be pushing the limits of what Mach3 and GREX can reliably do but hey it's going to be a fun ride. I'll be devoting some time to the safety features. I love Mach3 and have used it daily for the last 2 years commerically but I have had occasions where it's done some pretty wacky things. I don't plan on taking any risks with a 4 tonne VMC with a 15hp spindle.

Cheers,

Neil

[Lemo]

I would like to know if the drives also work for the
KL34-180-90 90V motor from
http://www.kelinginc.net/ServoMotor.html

I would LOVE to buy a stack of those drives.

I read that the drive can 'only' supply 10-12 Amp. peak when I understand it right. So.... what happens when all the existing motors throw in the reverse gear and gulp down all the current they can get? Do they blow a fuse? Is the peak current of the drive higher? Is 10-12 Amp the peak current? Does it cap at a higher peak current like the Gecko drive (20Amp).

And if the Keling motor does not work.... which other comparable model would be a match?

Cheers
Lemo

[Xerxes]

Lemo, that Keling motor works fine, we have at least one case using the same motors. A simple differential line driver circuit may be needed for encoders if they are "single ended" type.

Unlike most of the lower cost drives, VSD-A has active current regulation so in practice it is indestructable by driving motor in any imaginable way. Try reversing directions or crash it to hard stop at full speed, no smoke will come out (not from drive, motor or fuse) since current gets clamped to user specified maximum value. Drive has 12.5A peak current limit but I'm planning to inrease it to 16A for short peak loads. Upgrade to 16A can be done with software to every sold drive by user.

All these current limits are in software only. It means that for example 12.5A is the highest current that drive is willing to output. It is nowhere near breakdown level (output has 20A continous rated parts).