[Don Peterson]

Is a schematic diagram available anywhere for the HobbyCNC 3 axis 4AUPC Chopper Driver Board Kit? I have a data sheet for the Controller/Driver chips and want to see how it's set up.

Also, Is there any simple software to get a system going? I just need to do some stepping and direction control to test out the by router hardware and the controller.

Thanks

Don

[HobbyCNC]

Is a schematic diagram available anywhere for the HobbyCNC 3 axis 4AUPC Chopper Driver Board Kit? I have a data sheet for the Controller/Driver chips and want to see how it's set up.

Also, Is there any simple software to get a system going? I just need to do some stepping and direction control to test out the by router hardware and the controller.

Thanks

Don

No schematic is available nor is one needed for assembly our our driver board kit.
TurboCNC is free and easy to setup.

Dave Rigotti
HobbyCNC.com

[rippersoft]

Don,

I can say that building the board is very easy and using turbo cnc is also easy. I have a INI file for turbo cnc if you are interested. I can also help you with getting the electronics up and running. Everything I did with mine was by trial and error. Much was learned.

[Don Peterson]

Yes, thank you. I just downloaded a copy of TurboCNC and was planning to use that as a start. The main project here is the hardware for the X-Y-Z table. I'm a "EE" and as you might guess, my mechanical skills are not what they could be.

I have purchased the controller board already and have downloaded a copy of the datasheet from Alegro. I can see that the controller IC's could be configured in the application in a couple of ways. I was curious how the designer of this particular board implemented them. I guess they don't share the schematic. I realize that it's not "needed" to get this to work, but it would certainly be nice to have. I'll just have to create my own from the PC board. I wonder if they would be "rattled" if I shared it with others here on the forum???

A copy of the .INI would probably save me some time in setting things up. My email is [email protected].

Thanks again...

Don

[anoel]

Oh, sharing current production schematics from respected guys trying to make a living in the hobby world (any hobby not just this one) is pretty uncool...

Dave is making a product available for very reasonable $$$. let him keep his niche...

But if you can derive your own application from the application notes from Allegro then that's all cool. Because that's your own work. Just don't post reverse engineered work becuase that's someone else's.

[Don Peterson]

Well, if that's how everyone feels, then I'll respect that. The intent here was not to re-create the wheel. The way that I look at it, it's "soooo" much easier to just buy the board (or kit) than to try to go through all the effort of re-designing a PC board. Most electronics that I'm used to dealing with has always included a schematic. For us electrical engineers, it's just a basic road map of the electronics. But I guess I'm in a different world now...

That's why I made the statement; "I wonder..."

For myself, I'd still like to have one.

Don

[philba]

I am probably not in the majority around here but I like to see the schematics of devices I purchase. In particular, I like to understand how things operate in more detail that most user's guides.

I agree that the hobbycnc board represents a good value for the money as the driver chips (sla7062m) are moderately hard to come by and somewhat expensive. I think you'd be hard pressed to buy the components and a PCB for a lot less. I wanted to go a different direction (modular design plus isolation) so the 4AUPC doesn't work for me.

If you get the allegro sla7062m's datasheet, you will see a circuit diagram that is probably pretty close. The datasheet will tell you about the workings of the chip which pretty much does it all. It's a nice chip in many ways, I just wish it was easier to buy.

Phil

[Don Peterson]

I called Alegro directly and they recommended a distributor that did not have a minimum (or it was low enough it didn't matter). I bought an additional 6 pieces to have as spares just in case I burn out one of them. Seems like I paid around $6 - $8 each for them. I can't remember exactly, but for only 6 pieces it was not bad. You may want to call Alegro and ask for a distributor that carries their parts.

I agree with you about having a schematic. You never know when you may want to just check out what's going on in the circuit. If you have an unusual problem, it sometimes helps.

Don

[philba]

don, I got some through a group buy a while ago - around $8. If you could find the name of the disti, I would be greatly appreciative.

edison (great screen name...) - Nice design, I like the way you allow source or sink for the optos. nice touch.

I have a couple of questions - no low pass on step and dir. Are you relying on the optos to form essentially a low pass filter? They (h11L1) are pretty fast optos so noise below 1 Mhz (maybe more like 2-5 mhz) would pretty much pass through. the schmitt triggers help there though.

Also, how well does your sync circuit work? It looks similar to one that I had played with (using cap decay for timing). I also tried using a cheap PIC which allows for reasonably good timing but the data sheet seems to say that there are cases where you shouldn't use sync (certain step angles, iirc) so I bagged it from my design. The PIC could, in theory, track the step angle but that was getting complex - I may still go back to it. It is interesting that you also use the sync signal to feed disable I wonder if you even need to worry about sync input to the 7062.

[Edison4]

philba,

As you mentioned, I'm relying on the schmitt triggers to provide some noise immunity. A low pass filter with the wrong cutoff could accidentally limit the step rate.

About the sync signal: The first part of the data sheet is pretty clear - SYNC should be low when CLOCK input is active (high) and should go high when the CLOCK signal has been low (after a time delay). My circuit follows these rules & works just fine.

The confusion with the sync signal comes from the following: "NOTE - The use of this function except at 0, 70.7, or 100% Itripmax (half-step positions 0 through 8) is not recommended."

After much contemplation on that sentence, I have decided that what it means is:

CONTINUOUS synchronization operation (a logic high on sync input) is not recommended during normal stepping (except at 0, 70.7, or 100% Itripmax). That is why the data sheet is suggesting that the additional circuitry should be used to switch the synchronous mode on and off.

DW

[ssmt21]

philba,

As you mentioned, I'm relying on the schmitt triggers to provide some noise immunity. A low pass filter with the wrong cutoff could accidentally limit the step rate.

About the sync signal: The first part of the data sheet is pretty clear - SYNC should be low when CLOCK input is active (high) and should go high when the CLOCK signal has been low (after a time delay). My circuit follows these rules & works just fine.

The confusion with the sync signal comes from the following: "NOTE - The use of this function except at 0, 70.7, or 100% Itripmax (half-step positions 0 through 8) is not recommended."

After much contemplation on that sentence, I have decided that what it means is:

CONTINUOUS synchronization operation (a logic high on sync input) is not recommended during normal stepping (except at 0, 70.7, or 100% Itripmax). That is why the data sheet is suggesting that the additional circuitry should be used to switch the synchronous mode on and off.

DW

__________________________________________________ ___________

Can you please share available information for the subject matter I have recently bought 2 nos of second hand machine without documentation.
Condition of the machine is good and we need support on documentation side.
Detail of the machine are as below-
EDM machine
Make - ELTEE PULSITRON
Model - EP 30
Sl. No. 0721 & 845
Volts - 210/230/250/460
Ph. 3
Cycle - 60
KVA – 6

Tarun Sharma
[email protected]

[ssmt21]

don, I got some through a group buy a while ago - around $8. If you could find the name of the disti, I would be greatly appreciative.

edison (great screen name...) - Nice design, I like the way you allow source or sink for the optos. nice touch.

I have a couple of questions - no low pass on step and dir. Are you relying on the optos to form essentially a low pass filter? They (h11L1) are pretty fast optos so noise below 1 Mhz (maybe more like 2-5 mhz) would pretty much pass through. the schmitt triggers help there though.

Also, how well does your sync circuit work? It looks similar to one that I had played with (using cap decay for timing). I also tried using a cheap PIC which allows for reasonably good timing but the data sheet seems to say that there are cases where you shouldn't use sync (certain step angles, iirc) so I bagged it from my design. The PIC could, in theory, track the step angle but that was getting complex - I may still go back to it. It is interesting that you also use the sync signal to feed disable I wonder if you even need to worry about sync input to the 7062.

__________________________________________________ _______________

Can you please share available information for the subject matter I have recently bought 2 nos of second hand machine without documentation.
Condition of the machine is good and we need support on documentation side.
Detail of the machine are as below-
EDM machine
Make - ELTEE PULSITRON
Model - EP 30
Sl. No. 0721 & 845
Volts - 210/230/250/460
Ph. 3
Cycle - 60
KVA – 6

Please quote price of documentation available with you.

Tarun Sharma

[der_fisherman]

There is a new kit for stepper motor drivers using the sla7062m chips, all the chip's features have been used.
Kit is under 19 UK Pounds Sterling (less than 30 USD?) for one PCB.
Has opto isolation, up to 1/16 microstepping. 10-44 volts at up to 3 amps...
www.magenta2000.co.uk
Regards
der fisherman