DSP Commercial Controller Support

[baz]

Hi,

A bit of background info, I am building/planning on building both a shapeoko and 2.x. I got one of the infamous TB6560 drivers to play with, but inevitably it has given up the ghost! So now it's time to look for more permanent one.

So my question is, can DSP controllers be used on CNC routers? So is it possible to use a DSP controller on both my laser and router? or have one that can be transferred? 

Many thanks

Baz

[gavztheouch]

I would guess no for the following reasons, someone correct me if these are wrong.

You can't run g code on the dsp

You can't profile in 3D

You cant internally or externally offset for router bit diameter ( There may be an option to offset in the dsp for laser beam width?)

There are prob more, but the main one for me is IF it can't run gcode then you can't use your external tool path generation programs. This would make anything but the simplest profiling job impossible.

[baz]

Thanks Gav

That seems to make sense , I have seen a few Chinese DSP controllers for routers but like you mention, they are not inter-compatible with the Laser ones.

Many Thanks

Baz

[frob]

Hi Baz,
What size / electrical ratings are the motors you want to use ?
Are you sticking with the same NEMA 17 1.6A ones recommended?

Hi,
A bit of background info, I am building/planning on building both a shapeoko and 2.x. I got one of the infamous TB6560 drivers to play with, but inevitably it has given up the ghost! So now it's time to look for more permanent one.

So my question is, can DSP controllers be used on CNC routers? So is it possible to use a DSP controller on both my laser and router? or have one that can be transferred? 

Many thanks

Baz

[baz]

Hi frob,

Yeah I will have Nema 17 1.6 A on both my 2.x and ShapeOko. I have done a bit more research and found out you can get DSP modules for routers, however they are very expensive. So now I am looking into seeing if it is possible to build one, I might be able to use a Arduino or something similar. Not sure atm though.

Many Thanks

Baz

[gavztheouch]

I doubt that it is anything inherent in the DSP. If it were, then I would not expect to see it's effect to be speed-dependent. There may be a difference between how the DSP does acceleration compared to Mach3. You mentioned slow acceleration as a possibility. I would lean the other way. The Y axis has a lot more mass to move around than does the X axis. Overcoming inertia (acceleration or deceleration) could possibly produce different speed-dependent results. Since it is less noticeable with Mach3 and more so with DSP, the algorithm for implementing acceleration may be different.

One other person reported a y-only backlash. Turns out it was the motor couplings he used. When he switched to solid couplings, the issue went away. The springiness in the others was causing the problem on change of Y direction.

A test that may help to determine if it is mechanical or not, would be to make a small test and change the x/y axis (x axis to y drive, etc). If the error stays in the Y axis, it is likely mechanical. If it moves to the x axis, it is more likely the controller.

After tuning my new setup with mach I was getting some nice vectors even at insanly fast speeds way beyond what my laser can comfortably handle it never missed a beat and the y-axis displayed no signs of backlash. I am therefore fairly confident my machine is mechnically free of backlash(<0.05mm) in the y axis. So I tried running it with the DSP and the it failed to reproduce good results even at very low speeds. Is it possibly I have a duff DSP, surely acceleration algarithims cannot be worse in a commercial DSP designed for lasers than mach3 which is not.

I relise there have been a lot of mods made to these 2012 dsp I think I have one of the first new ones, is it worth upgrading the firmware and lasercad software. Lasercad seems to crash on a hourly basis which requires me to restart my pc.

Cheers

Gav

[twehr]

I doubt that it is anything inherent in the DSP. If it were, then I would not expect to see it's effect to be speed-dependent. There may be a difference between how the DSP does acceleration compared to Mach3. You mentioned slow acceleration as a possibility. I would lean the other way. The Y axis has a lot more mass to move around than does the X axis. Overcoming inertia (acceleration or deceleration) could possibly produce different speed-dependent results. Since it is less noticeable with Mach3 and more so with DSP, the algorithm for implementing acceleration may be different.

One other person reported a y-only backlash. Turns out it was the motor couplings he used. When he switched to solid couplings, the issue went away. The springiness in the others was causing the problem on change of Y direction.

A test that may help to determine if it is mechanical or not, would be to make a small test and change the x/y axis (x axis to y drive, etc). If the error stays in the Y axis, it is likely mechanical. If it moves to the x axis, it is more likely the controller.

After tuning my new setup with mach I was getting some nice vectors even at insanly fast speeds way beyond what my laser can comfortably handle it never missed a beat and the y-axis displayed no signs of backlash. I am therefore fairly confident my machine is mechnically free of backlash(<0.05mm) in the y axis. So I tried running it with the DSP and the it failed to reproduce good results even at very low speeds. Is it possibly I have a duff DSP, surely acceleration algarithims cannot be worse in a commercial DSP designed for lasers than mach3 which is not.

I relise there have been a lot of mods made to these 2012 dsp I think I have one of the first new ones, is it worth upgrading the firmware and lasercad software. Lasercad seems to crash on a hourly basis which requires me to restart my pc.

Cheers

Gav

Do you have the 2012 model or the AWC608 (which is newer)? Off the top of my head, I am not sure what version is the latest that works with the 2012. If you have the 608, then for sure you want (and will continue to want) to upgrade to the latest LaserCAD and firmware. I think the current version is 5.95.

[gavztheouch]

Sorry Tim, yes I have the AWC608 not the 2012.

My biggest problem at the mo is, laser cad keeps crashing as soon as I press any button to communicate with the DSP, eg.. Read postion or Download.

If I pull the USB plug from the pc it will say "communication unsuccessful". But the program has become unresponsive at this point. It will not close down so I have to restart my computer.

I have had it working just an hour ago, and I have setup the com ports. Is there anything I have missed.

Cheers

Gav

[twehr]

Sorry Tim, yes I have the AWC608 not the 2012.

My biggest problem at the mo is, laser cad keeps crashing as soon as I press any button to communicate with the DSP, eg.. Read postion or Download.

If I pull the USB plug from the pc it will say "communication unsuccessful". But the program has become unresponsive at this point. It will not close down so I have to restart my computer.

I have had it working just an hour ago, and I have setup the com ports. Is there anything I have missed.

Cheers

Gav

A couple of thoughts....
1. You went back an forth between the DSP and Mach3. Check your grounding on the DSP. It is VERY sensitive to poor grounding. Specifically, you should have an EXTRA ground running from LaserPS ground (case) to Mains ground, to case of DSP and to case of control panel.
2. There were some USB issues with some of the version so of the laserCAD and firmware. Please update to the latest. It may resolve the issue.

FYI - (You probably already know this) If your laserCad is frozen, get the to Task Manager (via ctl-alt-del) and kill the LaserCAD program. If LaserCAD then refuses to load, again in TaskManager, find the LaserCAD Process and force quit it. This is usually faster and easier than rebooting.

[gavztheouch]

Thanks Tim, I shall check my grounding.

FYI - (You probably already know this) If your laserCad is frozen, get the to Task Manager (via ctl-alt-del) and kill the LaserCAD program. If LaserCAD then refuses to load, again in TaskManager, find the LaserCAD Process and force quit it. This is usually faster and easier than rebooting.

I had already tried this, but strangly it still hangs and won't close even from the task manager. It was still churning away after a few mins so I just reboot now. I found another work actually, if you pull the usb out, then press "esc" or/and "reset" then plug the usb back in it sometimes starts working again.

A quick though on firmware and software. Comparing the firmware on the website I appear to be running the latest version, however If I remember rightly when I purchase the dsp the version I am running had not been released publicly. Is it possible there were more tweaks done to the firmware before it was released and I am actually running an older version possibly beta firmware. For software I am now using the current Lasercad.

Many thanks for you help

Gav