Laser Engraver Driver Help

Hey all, I am in the process of making 2'x3' laser engraver. I bought an m140, housing, and G2 from DTR. I plan on doing the 8 bit laser engraving which mean I have to have an analog/ttl driver, but I am having issues getting a hold of a flexmod P3. They seem to be sold out and on back order . I have emails in to both of them to find out when they might be back in stock. From what I have been reading they are out more than they are in so I am not holding my breath.

I am trying to find out what my options are. I can't find any analog/ttl drivers in USA and under $50. I found 1 in Russia that is around $40 shipped but will take a month + to get here or 1 or 2 in the USA but they want $75+.

I can make buy the parts and make a driver but couldn't find a schematic for one with analog/ttl. Should I just buy a standard driver and make a DAC circuit for it? Is there a reasonably priced DAC already made that would work well? This is where I don't know what is best. Any help would be appreciated.

Thanks
Jason

Anyone? I am really unsure on what to do.

There are several competitors to the flexmod, but I am not current on them. Have a look around, or post a thread on Photonlexicon

See the advice in this post.:beer:
http://laserpointerforums.com/f67/445nm-driver-can-fast-switched-92534.html#post1344292

Cyparagon said:

There are several competitors to the flexmod, but I am not current on them. Have a look around, or post a thread on Photonlexicon

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I looked and didn't find much and the few I did find were all over seas because plex is a euro site. I don't want to wait a month for a power supply. I have scoured everywhere and can't find one. This is soooo stupid. I can't believe that the are not flexmods or equivalents in the US.

DistortedDesigns said:

I looked and didn't find much and the few I did find were all over seas because plex is a euro site. I don't want to wait a month for a power supply. I have scoured everywhere and can't find one. This is soooo stupid. I can't believe that the are not flexmods or equivalents in the US.

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Waiting a month is pretty standard for the rest of the world

I think Sam's Laser FAQ has some DIY designs, they may work for you.

ARG said:

Waiting a month is pretty standard for the rest of the world

I think Sam's Laser FAQ has some DIY designs, they may work for you.

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Usually there is always someone in country selling whatever you are after but you will just pay 50%+ more for it depending. I don't know how Innolasers does business they way they do. I can't get any kind of response from them after several calls and multiple emails.... nothing... and the fact their website doesn't say they are out of stock and continue to take orders for stuff they may not get in stock for a month or more. It is just frustrating is all. I have several vendors selling stuff they don't have in stock or are out of stock of the most common things.

DistortedDesigns said:

I don't know how Innolasers does business they way they do.

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I'm not sure who manages innolasers these days, but I know dr lava is involved.
At the bottom of the page there is a search bar, type in "dr lava" You'll see plenty of similar stories.

DTR said:

See the advice in this post.:beer:
http://laserpointerforums.com/f67/445nm-driver-can-fast-switched-92534.html#post1344292

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Hey DTR, I was just about to order more stuff from you... lol I just got my M140 and housings from you two days ago, thanks.

I saw all of the models in that post, unfortunately none are in the US and would be near the end of Feb. before I got them. What I will prob. have to do is get an x-drive or a ttl equivalent for the time being so I can get up and running. Then just order the one I need or wait for a flexmod or just make the analog input circuit for it.

Curious what you are doing for a DAC.

Im using an FPGA/CPLD over here

Zeppelin 1007 said:

Curious what you are doing for a DAC.

Im using an FPGA/CPLD over here

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I don't know yet. I am trying to figure that out. I managed to get a flexmod p3 so that is great. I have been looking at dac's but I don't know what I can use that would be compatible with the software and what software is available. I will start a thread about it so we don't get off topic.

I haven't heard of FPGA/CPLD.

I know exactly what you're trying to do. I'm in the same boat, but, my Flexmod doesnt seem to work. I'm a bit peeved about this.

FPGA - Field programmable gate array. Basically, you design hardware via software.

Theres only one major package out there for this, PicEngrave. But, realistically, any program that will carve a 3D relief based on greyscale can be used. these guys have perfected it in their G-code generation. Takes into account speeds, accel, other machine parameters.

For CNC your DAC needs to understand Up, down, and count. Output 0-5V. You can offset the output with a small opamp circuit, incase it takes some voltage before you actually start getting your grey scale.

Some guys are using the mechanical ones with encoders, I'm not a fan. Just seems like wasted energy to me.

Others are using small IC counters, and that works great! The FPGA approach lets me use whatever bit resolution i want at the output, as well as really having one digital component rather than tying IC's together, adding buffers for signal, worrying about carry, etc etc.

I got all THAT figured out but havent even lit a match with the laser yet lol. Thats my luck! Hell the heatsink i made for it is fantastic too, i may even sell a few. Theyre designed exactly for this and when i'm ready you'll see why.

I'll watch your separate thread. PM me if you need.

I guess I will follow pic engraves dac circuit. Theirs just seemed a bit overly complex.

The older one, with 2 BCD up down's, isnt that bad. The resistor network is required to get the different voltages between 0-5V, and they use 2 4bit counters because its pretty tough finding a single 8 biit up/down.

Its actually easier since the machine steps are the clock source.

If you're stuck let me know. The encoder version is beyond complicated IMO. Just reassign your step/dir to spare I/O in mach3.

My version with the FPGA replaces the 2 counters. Still need the resistor network. Actually would need a double size one at half resistance to do 16bit. I may distribute some preprogrammed chips when all is said and done.

Zeppelin 1007 said:

Curious what you are doing for a DAC. Im using an FPGA/CPLD over here

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FPGAs are digital-only last I checked. How are you getting analog output?

Cyparagon,

They are. I've attached the old suggested schematic from PicEngrave. They use 2 counters and a resistor network. My use of the FPGA was simply to replace the 2 counters. I could also add things like reset, which they have on most counters. But i could even offer some digital feedback via a 7Seg display.

Im leaning towards that because finding 2 counters that are in stock is always a pain in the butt. Atleast with a small FPGA/CPLD, its what, 7$ for a xilinx cool runner?

Distorted designs: i see the authors of PicEngrave are using a newer schematic with a digital pot. I dig it actually. Just soldering SMD is rough.

I chose this over arduino/atmel because of the clock. This design, and FPGA design, the CNC pulses are the clock. With a micro, there's the boot up process with takes x amount of cycles. Then theres the clock syncing issues. Not to mention if i remember correctly Atmel chips "scan" inputs then write outputs serially, similar to a PLC.