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I have an old laser engraver that runs from Windows 98SE and DOS-6. Yup, still works fine but a pain as I regularly have to open it up and unplug and re-seat all the ribbon connectors. Fifteen of them and I tire of that fast.

I am thinking of pulling out all the electronics and installing a TB6600 stepper drivers and Arduino to run G-code. My order of desire is based on price, RAMPS, Smoothie and the AWC708C. I'd actually like to stay away from the AWC as it is closed source and I would be stuck with whatever it has.

With the existing NEMA 17 steppers I can get rapids to 400 mm/s. Will a RAMPS system drive this fast enough? It doesn't have to be that fast, but close to and certainly not below about 200 mm/sec.

I have been searching but cannot find any actual figures achieved. If not then I guess my second option is the smoothie.

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  • $\begingroup$ I can get rapids - Is that a typo? $\endgroup$ – Greenonline Jun 23 '18 at 15:10
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    $\begingroup$ @Greenonline No, "rapid" is CNC terminology. It refers to a non-cutting (or in this case, non-engraving) move. The 3D printing equivalent would be "travel move". $\endgroup$ – Tom van der Zanden Jun 23 '18 at 15:28
  • $\begingroup$ Thanks Tom, yup many CNC machines in the garage. Didn't even know I had written "rapids." $\endgroup$ – LinuxFerLife Jun 23 '18 at 18:10
  • $\begingroup$ Why not either clean or replace the connectors, assuming there's still some slack in the ribbon cables? MIght be a lot simpler than a major electronics + software change. (or, if it's really a loose connector problem, see if there's a way to cable-tie them securely in place) $\endgroup$ – Carl Witthoft Jun 25 '18 at 14:25
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Marlin supports a stepping frequency of up to 40kHz. For a pretty typical setup with 100 steps/mm, this translates to 400 mm/s - obviously, if you use higher microstepping settings or use finer pitched belts you will get a lower maximum speed.

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  • $\begingroup$ Thanks Tom, I want to use the existing mechanical set up so the 2mm belts will have to stay. I suspect I will need micro stepping as the current resolution of the laser is around 0.01mm. It was a high class laser in it's time. So looks like I go with the smoothie then. I might give it a try as I have a spare Mega+RAMPS here that came out of a Delta printer when I put a smoothie in it. :) $\endgroup$ – LinuxFerLife Jun 23 '18 at 18:15
  • $\begingroup$ I do not think you have understood my answer properly. It looks like RAMPs would be perfectly suitable, it will let you hit your 400mm/s speeds (but just barely). The 100 steps/mm figure matches up perfectly with your 0.01mm resolution and already accounts for a certain amount of microstepping. $\endgroup$ – Tom van der Zanden Jun 23 '18 at 18:26
  • $\begingroup$ Tom, thanks again, but I did understand your answer, I just do not like making something that is working at the upper limit. I will be doing some major surgery on the machine so if RAMPS is at the high end to duplicate what I have then it is worth the $60 to get an MKS SBase smoothie board. I have since found that the laser can be pulsed above 40khz so the faster MKS board will give me room to move -- a little. $\endgroup$ – LinuxFerLife Jun 23 '18 at 21:57

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