I have an older Epilog Summit laser engraver that I have been converting over to something I can support, instead of the Windows 3.1 software that it comes with.   I replaced the control board with a set of Gecko G320x and the up/down with a normal servo as it didn't come with an encoder as the Summirt was manual focus.   All that works and I can zip around at astounding speed.

On to the laser.

My end goal is to cut out shapes from .125 acrylic, some with a little text identifying marks.

Is this as simple as using an output pin as Spindle Motor output and setting the minimim to 2% to get that trickle the Syrad laser needs?

Will a simple G1 move cut a line if it's prefaced by the M11P1 commands?

Will a simple G1 move cut a line if it's prefaced by the M11P1 commands?

Yes it will - but you will also have to have a G0 or G1 movement following the M10P1 to turn the laser off at the end of the line.  

With regard to the tickle pulse I have concluded it is better to use a separate tickle pulse generator (I have described a typical circuit here http://www.cooperman.talktalk.net/files/28.htm).

Hope this helps,

Tweakie.

Is there a low cost PIC programming package?   That is one of my issues, I don't see doing much PIC programming (I could be wrong) so I hesitate to purchase a entire setup.  I see the ones on EBay for $10, will those work?

I like the idea of a separate controller.  Gives me something to put in the slot where the existing control panel is.   Since I already have a laser engraver, could I use that to cut the board?

I wasn't suggesting you build the whole controller, just the tickle pulse generator. 

However, a lot of people have built my laser controller now and it seems to be successful - I certainly don't have any problems with it.
My PIC programmer is years old and I can't even remember what type it is but I think any PIC programmer would be OK as long as it is capable of HS (20Mhz) mode.

Unfortunately PCB's cannot be laser cut and mine was intended to be isolation routed. If you were to acid etch the PCB please remember to leave all the background copper as this forms an important GND plane.

My recommendation, if you decide to build the controller, is that you do get a complete PIC programming package which will allow you to change the software, if necessary, to suite your particular current or future needs. It's all good fun as long as you can find some way of justifying the expense. 

Tweakie.

Looks like a PIC programmer is in my future.   Not that I really need an excused to purchase more tools.

Do you have the schematic/artwork for the simple tickle pulse generator?   I should start with that first and go from there.

I was hoping the "Minimum PWM" in Mach was some sort of trickle pulse and I could use that to at least test this thing.

Sorry, the PCB layout for the tickle pulse generator may take me some time to find (it was a long time ago and it is on my PC somewhere) but the circuit is simple enough so you should not have too much trouble to lay out your own PCB.

The problem with using the Mach3 PWM is that the tube's tickle pulse requirements are a PRF of 5kHz with a pulse width of between 1uS and 1.5uS. If the pulse width is too great then the tube will lase and this defeats the object of the exercise. There is probably a way this could be achieved from Mach3 by using the Charge Pump (Laser Standby) but I have not fully investigated this possibility.

Tweakie.

Rather than get into PIC programming, could I do something with an arduinio?  Those I have and am pretty familiar with programming those.   At least something to get me started.

Sounds like a great idea, I think the Arduinio is ideally suited to the task.

Tweakie.