WildCircuits Laser HackLog

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Re: WildCircuits Laser HackLog

Postby Robin Hewitt » Wed Feb 20, 2013 12:17 am

I got the laser, blew it up, the new tube and PSU arrived yesterday. Now waiting on parts for the chiller.

I am assuming laser PSU control is a simple on/off pulse width modulation because if they restricted the Amps the volts would fall away. The new PSU manual is open to interpretation but it seems that if I omit the pot the laser goes full power and expects me to provide a PWM signal to one of it's enable lines. I think I will start with the pot and see if I have a need to control Wattage on the fly.

I am not au-fait with Python, but I have done machine control with Visual Studio. I spawn off a seperate task to top up the machine buffers and send status reports, that way I can release the processor and avoid "Program not responding" messages.
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Re: WildCircuits Laser HackLog

Postby Praxis » Wed Feb 20, 2013 1:16 pm

I am assuming laser PSU control is a simple on/off pulse width modulation because if they restricted the Amps the volts would fall away.


I am not sure if this assumption is valid; while in a normal system ohm's law would dictate what you say, tubes don't exhibit linear resistance; in fact over certain parts of their range their resistance is negative. You might ultimately be right, but I would verify before working from this assumption.
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Re: WildCircuits Laser HackLog

Postby timogiles » Wed Feb 20, 2013 5:39 pm

Sorry to hear that you had a tube blow up.

I run my tube at 16 to 17mA. 18mA is the highest current you can go to safely. I would suggest always using a POT to control your max power. My controller board does the following:

5V PWM output -> POT voltage divider -> laser PSU input

That configuration gives you 100% power when your PWM duty cycle is 100%. If your controller has a malfunction and the PWM is stuck at 100% nothing will get damaged.
WildCircuits.com
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Re: WildCircuits Laser HackLog

Postby trunner » Mon Jun 23, 2014 3:25 pm

Tim, Sorry to bug you, but I was wondering if you have made any additional progress making this open source? Or if you have posted your PCB and code files anywhere?

I am with Calgary's local hacker space and we are trying to make a drop in solution like what you were trying to do here. Our goal will be to help other hacker spaces around the globe, because a large number of them end up with the K40 or Kiii machines. Because we are all non-profit, money to spend on these projects is non-existent, so a cheep diy-drop in is perfect for us.
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Re: WildCircuits Laser HackLog

Postby timogiles » Mon Jun 23, 2014 6:49 pm

Trunner,

I never got around to tidying up my work on the K40 to the point that I released any code / board files. I believe that I posted enough information that anybody should be able to hijack the motor control signals on the K40 control board and drive them with whatever setup they like. I wanted to make a plug in board that would go in the IC slot of the K40 board, but I couldn't find a method to attach it reliably. For my own implementation I soldered wires onto the IC socket. After thinking about it I decided that I didn't want to release something into the wild that I didn't think was a reliable and that I would have to support. I ended up just making my own control board with A4988 stepper driver ICs that completely replaced the K40's board. I ultimately rebuilt my K40 into a much larger machine (2'x4' work area) reusing the tube and PSU. a while ago my PSU died and a month ago upgraded to a 60W tube, so I guess my laser cutter doesn't have much of the K40 left in it. hmm, now that I think about it, the mirrors are the only thing that are still original!

Anyways, I'd be more than happy to help you on your K40 hacking mission. Do you currently have one? What software are you using (or going to use) to control it?
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Re: WildCircuits Laser HackLog

Postby trunner » Tue Jun 24, 2014 5:19 am

Tim,

Thanks for any help. Well basically I have put together a team of people who will be helping out. I am going to have a few questions for you. For now; I plan to use mach3, but I really want this to be as compatible as possible, so linuxcnc is as important as anything. We have managed to narrow the proc down to one of about 8, the most likely candidate is NXP 80C51 series, it can run up to 33MHz. 32MHz is the closest standard value I believe.

Ideally we would have a chip that can be dropped in place. I need to be clear, the plan is to sell these at the cost of the chip + 20$ and it will be used as a fundraiser for Protospace.ca.

Now all that being said, I still think that we will have to start work with a breakout board. I REALLY want to hear from anyone that has done ANY reverse engineering on the MS10105 USB board, The whole point of what Tim has started here is to make this information public;

**WARNING, TANGENT!!!***
I have been to Omaha hackerspace, Chicago hackerspace, Toronto hackerspace, Edmonton hackerspace, Portland hackerspace and I hear the same thing, over and over, "Had to replace the controller...", Cause lets face it Moshidraw, is kinda ass... Some people like it, I have moshidraw 2014, and while I will admit, it doesnt always crash, it still is poorly designed, especially as it doesn't conform to ANY machining standards for naming. I respect its better than them shipping it with nothing, but I want to make an affordable alternative. Having to drop 400$ on a DSP when you have a perfectly viable solution in front of you is, in my opinion un-acceptable.
**End of Tangent**

I have a K40, ordered several weeks ago, it came in the mail (Canada post football team had there A game on, I had to beat the dents out and then use the CNC mill to fix the gantry.). shipped with moshidraw 2014 MS10105 USB. the board is identical to the one in your photos.

-Jim
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Re: WildCircuits Laser HackLog

Postby Fred » Tue Jun 24, 2014 10:43 am

If you're looking for a drop-in Mach3 (and I assume LinuxCNC) compatible replacement for the whole moshiboard, I can recommend the one from ChrisCircuits.com. To be honest, it's mostly a parallel port breakout for some A4988s and limit switch inputs, so definitely something you could do yourself if you're inclinded to. The big plus of the CC one is that he's gone to the trouble of sourcing the same connectors as the Moshiboard. It really is drop-in and go and reasonably priced.
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