Using T2Laser to engrave on Cylindrical Objects

[SteveK]

Thank you Sir!!

Steve

[Wheelz]

Had wanted to set this up a while ago but I didn't realise it was so easy and inexpensive.
I'm assuming the nema 17 stepper is the same as those supplied for the X&Y?
If I choose to use the Y axis, do I just plug one of those directly into the rotary stepper and leave the other disconnected? Or is there another connector on the board I need to use?
Thanks.

[ThothLoki]

Had wanted to set this up a while ago but I didn't realise it was so easy and inexpensive.
I'm assuming the nema 17 stepper is the same as those supplied for the X&Y?
If I choose to use the Y axis, do I just plug one of those directly into the rotary stepper and leave the other disconnected? Or is there another connector on the board I need to use?
Thanks.

Yes, I used the same NEMA17 motor as the ones on the engraver (actually used it from a broken engraver I had).
to use the Y axis, you simply unplug the Y motors and plug in the rotary. Test it out first to make sure you are using the correct Y plug. The two on the board will turn opposite of each other, so make sure the on you plug in makes the rotary turn the way you want otherwise you will get a mirrored image.
As a side note, when you are using the Y axis, keep an eye on your rotary stepper motor and make sure it does not get too hot. That stepper driver is set up to run two motors so it will be pumping out more current. If you rotary motor gets hot, you will need to adjust the current.

[Wheelz]

If you rotary motor gets hot, you will need to adjust the current.

Thanks Loki,
If I do need to adjust the current, Where would I do that?
Cheers,
Pete

[Zax]

Yes, that's the pot to adjust current limit but it should be OK. Yes the motor will be getting more current than when there's 2 motors but it can take it (you just get more torque).

[Wheelz]

I just did a quick calculation, the Nema17 with 1.8deg steps will produce minimum arc lengths of 0.786mm on a 50mm dia. part. Has anyone researched a motor with a finer step? And would it be compatible with the driver and/or software?

[ggallant571]

The A4988 stepper motor driver chip is typically jumpered for 16 micro step so the more realistic number is approx 0.05 mm. If you need more you can get driver chips with much higher micro stepping, motors with 0.9 degree steps, and or mechanical gear reduction.

[Wheelz]

The A4988 stepper motor driver chip is typically jumpered for 16 micro step so the more realistic number is approx 0.05 mm.

Ah yes, the micro steps. Ignore my previous post. I think I'll be fine! 
Thanks mate.