[Xerxes]

Final board high power testing is going well. I'm running it at 14A continuous and it's not overheating without additional heatsinking (but fan cooled though). 14A produces 100% more heat than 10A since resistive losses raise in power of two.

[Xerxes]

I think I have discovered an way to extract even more incredible speeds from stepping motor (in servo mode). I just broke my previous record (3300 rpm at 30Vdc) and my ears. Now the same setup goes up to 6000 rpm!

I was able to turn same motor only little over 1000 rpm in traditional open loop mode before stalling.

[CNCAddict]

6000rpm!!! The commutation frequency is approaching PWM frequency no?

[Xerxes]

I did some code changes again and now I reached 6975 rpm... it will take time before the firmware can take control of this in normal operation. Now it is based just on a testing code.

7krpm means 5833 Hz commutation frequency while PWM frequency is 20 kHz. Theoretical upper limit for commutation would be 10 kHz.

[JerryFlyGuy]

Tero, can you explain to me a couple things. You mentioned a stepper [above] in 'servo' mode.. what are the results of running a stepper in 'servo' mode. Does it produce the rated torque all the way up the rpm scale like a servo or? At 6kpm, what torque would you be delivering compared to the name plate torque?

Also, will the VSD-A do this as well?

Thanks sir
J

[Xerxes]

Jerry,

Maximum obtainable torque does not increase in servo mode, it is just unstallable and reduces heating. So torque reduces when running fast. However, higher peak torque can be get at low speeds because cooler operation allows overloading just like servos.

VSD-A hardware is not very optimal for steppers which is why such stepper support is not available.

[Jason3]

Hey,

Any hint as to final price yet? I'm saving up...

I like the idea of the limit switches going to the VSD not the BOB. Does the VSD have opto isolators - could I do away with the BOB altogether? Now that idea I like

Regards,

Jason

[Xerxes]

Final price will be similar to VSD-A but exact price is still undetermined.

I just got good news from factory. The first production batch is being manufactured while I type this. :-)

[antichip]

I always wondered why no one made a multi phase drive for steppers. They just seemed like the natural progression.

[Jason3]

Final price will be similar to VSD-A but exact price is still undetermined.

I just got good news from factory. The first production batch is being manufactured while I type this. :-)

Good news!

...can't wait Say the word, I'll send you my money!

Jason

[Xerxes]

I got a message that first 125 units are on the way to us! :-)

I have an USA visit on week 38 that may delay little bit the beginning of sales. If tuning software is ready when I return, the sales can begin immediately. Timo is developing GDtool so the rest is in his hands.

At the point of release, the stepper support will be operating at limited speed. High speed stepper operation needs more work and will be available as downloadable free firmware upgrade when it's ready.

This is how final VSD-E looks like (the one with grey anodized plate). It looks better than prototypes because pin headers are not angled and reaching over board edge. I also milled a prototype of high power heatsink. It is uncertain whether or not it becomes available as an option (depends on cost).

[CNCAddict]

Man, that heatsink design is very sexy. I have a question about using higher voltages with this drive. Is it a matter of replacing a few resistors, and the FET's??? If it is...maybe you could make a few drives with those parts not installed...and sell it as a partial kit. Just an idea for those of us running over 100V.

[Xerxes]

CNCaddict, half assembled drive would probably cost more than fully assembled since it would take more production steps to prevent solder getting into empty component places (two new steps, one for reflow and one for wavesoldering). Also giving warranty for such product would be complicated.

[Xerxes]

Things with VSD-E are a bit late but we are doing great progress. Sales begin in matter of days.

From this site you can see how VSD-E is meant to be installed:
http://granitedevices.fi/index.php?q=vsd-e-install

[JerryFlyGuy]

Ok Tero.. now I'm gonna bug ya.. are you going to sell the fibre optic cables seperate for us VSD-A users? I've been looking for a reasonable solution to seeing the error state on my drives [which are tucked up in a sealed console/cabinet] but haven't found anything which is reasonably priced and simple to aquire..

I REALLY WANT SOME!

Can I buy a set [or four]

J [finger's poised to log into Paypal and send money]..

[Xerxes]

Hi Jerry,

The plastic core fibers are available in many electronic part distributors such as Newark or Farnell.

[JerryFlyGuy]

Hrm.. I must be searching for the wrong thing.. you have a Newark part number?

J

[Xerxes]

This seems to be similar that I used:
Newark Part Number: 16F3288

Strange that Farnell seems to have much better selection on these. Usually it's otherwise around.

[Jason3]

Things with VSD-E are a bit late but we are doing great progress. Sales begin in matter of days.

From this site you can see how VSD-E is meant to be installed:
http://granitedevices.fi/index.php?q=vsd-e-install

That's great news, and good timing for me - the new machine is almost ready for them. I can't wait!

The installation looks good - almost too simple Is there a price/detail on the installation kit yet?

Best regards,

Jason

[Xerxes]

Jason,

Installation kit price should not be much higher than same parts separately from any parts distributor (haven't calculated cost yet). Kit is meant only to reduce part hunting. It includes at least connectors, fibers and installation panel.