Steppers to use in JGRO and using them on future. CNC projects

[Rotax91]

Hey everyone,

I'm building a JGRO. I want to get the electronics ordered. That will be my motivation to actually finish the project I've been doing alot of research of what people use for motors. I see everything from about 200-300+oz steppers. I would like to buy an adequate enough of a motor to use on the JGRO but then also be able to use it on future projects such as the Joe's 2006 or Hybrid. I think I'm pretty much set on getting the electronics from either Keling or cncrouterparts.com Do you feel that 425oz would be too strong for the JGRO? Or should I stick to a max of about 380oz? I don't want to rip the mdf JGRO to pieces but I want to be able to transfer my motors to the Joe's later on.
What do yous think, 380 or 425?

Thanks

[Jason Marsha]

These motors will work very well with the G540.
http://www.kelinginc.net/KL23H2100-35-4B.pdf

Their lower Inductance will make them a much better choice than the 425's. I have 425's in a box at home and I would love to exchange them.

Jason

[Rotax91]

Hi Jason,

Thanks for responding. Glad you replied. I guess bigger isn't always better.

I found the kit with those motors @ Keling. It's $455.. Fineline & cncrouterparts has the same kit for $519 but it's pretty much already wired with DB9 type cables. I think I'm better off spending the extra money and not having to mess with wiring for the most part, except for an estop & maybe limit switches.

http://www.finelineautomation.com/store/show/EL-0007

/tim

[Jason Marsha]

Be sure to use the 381's not the 382's or 387's if possible as the inductance is higher.

Jason

[Rotax91]

That puts me with the Keling kit for $455. The other 2 places are the 380's. Third one down in this link.

http://www.kelinginc.net/CNCNEMA23G540Package.html

[dustin1706]

I am running the CNCrouterparts 380oz kit on mine and it works great. Great service/communication from cncrouterparts.com as well.

I have already purchased the joes hybrid plans and joined the forum there. Several people are running the 380oz with no problems.

[Rotax91]

HI Dustin, I appreciate your input. I'm comparing the 380's to the 381's right now. I do like the fact that you can get the 380's all wired and ready to go.

I did just come across this. It's a more complex wiring diagram for use of the G540.

http://www.homanndesigns.com/EN010_V8.pdf

[Rotax91]

FYI- the 380's are 4.1mH and the 381's are 2.1mH.

Since I'm not a electronics guru, I had to search what exactly inductance is.

"To put this very simply, inductance means that it takes TIME to build a magnetic field in the coil, and larger inductance means that the change from no magnetic field to full magnetic field takes longer than a low inductance motor. Inductance is closely related to how many turns of wire so motors that have finer wire and more turns will have higher inductances. "

[Jason Marsha]

Mariss from Gecko gives us this formula to go by for the max voltage of a stepper.

32*(sqrt(inductance))

The 380's max voltage should be 32*(sqrt(4.1)) = 64.79 volts

The 381's max voltage should be 32*(sqrt(2.1)) = 46.37 volts

Based on the 48 volt PSU the 381's will operate at their full potential.

The kit from cncrouterparts is great as its plug and play and the faster the assembly goes the better.

Decisions, Decisions.