Hmmm
Thinking about giving up on my CNC dreams, managed to fry another Mega and have no idea this time how, switched everything off to adjust belt tensions, back on again and nothing, nada, didn’t even touch the controller.
Cant connect to the Mega via Arduino or Pronterface, at least I knew what I done with the other Mega by frying the 5v regulator, this time no idea.
Can the Ramps be connected to an UNO, still got one of those and a couple of Nanos Kicking about.
When doing this did you move the steppers to test belt tension? If you move them too fast they generate power and this can pop the drivers on a ramps board. but should only effect the drivers.
That should be “safe” homing a feature that picks up the Z axis a bit and then moves in case it is sitting on the material or table. You can turn that off in the firmware if you don’t like it but it has saved me a few times.
Hi Ryan
I didn’t move them fast enough to activate the LCD screen but all the drivers are ok, its the Mega that has fried.
I like the idea of Safe homing but its moving my Z axis down not up, which at first I would assume my Z motor plug is the wrong way around but in normal operation my Z axis goes down when its asked to. I will have a look for the setting in the config.
Just spent the last 2 hours trying to rebuild my Gantry as its putting a lot of pressure on the Stepper motors trying to keep it square, autosquaring is great but better fixing my gantry first.
Yeah your gantry needs to be close. It should be really close and is used more for straightening the whole system. The larger machines all 4 rollers can kind of twist in the frame and is ideal for those sort of things.
Hi Ryan
I am glad I spent the time to fix the gantry, everything seems more fluid now and there is no struggling or skipping when trying to auto square and home.
At the moment I am running of a faulty Mega (5v Regulator is blown) As long as I supply power to the Ramps and supply my Arduino a supply voltage, USB at the moment, can you see any issues using it like this until I either fix my Mega or get a new one?
Nope nothing wrong with that at all.
Hi
My Dremel bits are not going to be here until the end of the week and want to do some detail work testing that the pen isn’t accurate enough for, I have an endurance 3.4w L-Cheapo Laser with PWN attached to my 3D Printer, how easy is it to connect a Laser to the ramps board?
Hi Ryan
Thanks for the reply, will look at it tomorrow, the only issue I may have is my MPCNC PSU won’t run all the steppers and the laser, I know the ramps board has spare PSU points that is used for the D8 and D9, which I will attach my laser as mines is a 12v 3a laser, can I connect a second PSU into Ramps or should I just directly power the laser?
I don’t really understand the question.
In those instructions it explains all of that, you will not use d8-d10 you will remap a new pin. As for power supply it depends on what one you have, the rating of the laser is not the rating of the power supply you need. A 2A laser needs a much larger power supply to drive the driver and the current gets converted so you have loses all over the place.
Douglas,
The laser gets power from the driver, which has its own power supply. That’s where the current comes from. The logic for when to turn it on and off and at what power is what you use the Arduino/Marlin for. That’s why you don’t use D8-D10. At least that’s how I’ve seen it done, and that’s what’s in the guide.
Dang it is so much more clear when you explain it. I should have payed more attention in English classes.
Hi Ryan
sorry the document you supplied had me a little confused as the main reason for remapping the pin is that the laser used has a 5v TTL and D9 outputs 12v.
From what I have read on the endurance laser specs is the driver they are using requires a 12v TTL so remapping would cut the power in half for the laser.
It’s late and I may be misreading things, so I will give all the documents a good read in the morning, and apologise if late night reading is confusing me 
Damn didn’t notice the last 2 replies before posting, sorry Jeffeb3, wasn’t ignoring your post, here is the document for my laser page 27 see if it clears anything up.
With a 12V TTL , you can wire it up like in that manual (cool that it covers MPCNC).
As for where the laser gets it’s current, I’d have to see the schematic for the driver. But if it’s really just a 12V TTL, and it is also connected to a power supply, then the amount of current coming from D9 should be minimal, so you wouldn’t need more current to drive it.
Ryan, I failed all my English classes. Sometimes it just takes someone to say it differently.
Hey guys.
I failed English and I am British, lol
Spent all day trying to get my damn laser working.
First issues was my fault, designed and printed a mount for my laser for the MPCNC then realised had no way to focus the laser when mounted. oh my design choices the joy.
Hooking up the laser and getting it to work not an issue, using DFX2GCODE works great for basics and cutting no issues there.
Engraving on the other hand using Image2Gcode, just cant get it working, tried lots of different settings from laser power to feed rates and most of my tests just end up black with the faintest hint of the drawing, stuck a volt meter on the D9 terminals and the voltages are varying depending on the image, tested laser by varying the output using the M106 S and the strength of the laser varies depending on the number from 0 - 255 I put in.
So I just cant figure this out, I have attached the image been trying to burn.
[attachment file=44143]
I have also attached my Gcode for the image, maybe its a setting issue I have not done or is not correct.
Try starting with some basic vector graphics. Solid lines. That way you can verify it turns on and off and how much power you actually need at what speed. Going straight into etching isn’t easy.
Hi Ryan
It works fine with basic Vector images / outline images. and it works great with just black and white images, it just seems to be etching or PWM control, just in case even tried connecting it like the instructions you gave me but that just resulted in the same just with half the power.
Need to do some more testing with the driver itself, I know the terminals on the Ramps are varying the voltages for PWM, just wondering if the laser driver is, could be a wiring issue on my laser module as I have never tried engraving side with it just the cutting or basic vector drawings.
One thing I have noticed and it just might be me being stupid with no real knowledge of electronics but if I stick my meter on the + and - on the D9 terminal on Ramps and adjust the fan speed it adjusts the voltages being read.
If I put my meter between D9 + and the Ramps common ground the voltage never varies it reads 12v all the time even when I adjust the fan settings, is this normal?
Where are you reading “common ground”? Can you take a pic of the wiring? Especially the green power connector. Maybe you need to tie the grounds together on the green plug?
Hi Jeffeb3
Sorry not at home at the moment so can’t get pic.
I have the power supply plugged into the 5A ports on the Green Connecter, nothing in the 12A side, I assumed common ground would be the negative on the 5A side, again not great with electronics but learning everyday so apologies if I am wrong.
