Can't decide what motors to use ???

[scorpio2367]

I'm kinda at a stump when it comes to electronics !!! I can't quite figure out what type of stepping motors I should purchase. I am Attempting to build the JGRO special and I have confidence that I can build it , but not so sure on how to power it all up. I was thinking of using a nema 23 motor with 1/4 inch shaft for the z axis and two nema 34's 1/2 inch shaft for the x and the y axis. I am not sure if it's over kill or even if it's possible to do this, mixing them that is. Any help would be greatfull and any suggestions on what I should use would be usefull also, like drivers ,power supply, etc. I have over 20 years of cnc milling / programing experience but zero experience when it comes to electronics......

Thanks..........................

[Jason Marsha]

The setup I have consists of the Hobbycnc kit with the 127oz/inch motors. I just changed my longest axis over to 5/16-18 allthread after using 1/4-20 for several months. 1/2"-10 acme rod seems fairly popular with the guys.

You can use the motors you suggest but from what I have heard the 200oz/inch motors should serve you just fine for the JGRO machine. After changing the long axis to 5/16-18 I can now jog up to 70"/min without whip, I should have done this from the beginning considering the inside diameter of the skate bearings is just about 5/16".

You can use your NEMA 34's if you want on the X and Y axis along with one on the Z axis as well. The stronger motors will allow faster movements without the steppers losing steps due weakening at high RPM's . It is not always wise to use a weak motor on the Z axis because it undergoes lots of strain, especially if using a heavy router, through the continual lifting and lowering of the router.

I use a 24v transformer with my Hobbycnc kit.
I use Mach 3 to drive my machine.

Jason

[scorpio2367]

Thanks Jason..........where did you purchase your Hobbycnc kit from........by the way i have been reading your post and after reading what your going thru with whip of the 1/4-20 rod I also decide to up the rod size, but I was thinking of going with 1/2-20. What do you think of that size thread for both the x and the y axis's. I'm looking for precise movement's rather than just speed.

Because I have almost unlimited resources working in a machine shop now I have been able to run most of my cnc router parts off on a cnc robo drill....I just program at home what I want the machine to do and when I go to work I just cut it out. So far it's been a piece of cake.....

Thanks for the help.................Mike

[Jason Marsha]

The kit is sold at Hobbycnc.com. Go for the 200oz/inch motors. I have not heard of anyone using 1/2"-20, but there is nothing wrong with being first.

Jason

[scorpio2367]

Thanks for the link, I will check it out.......have you ever heard of anyone using Titanuim for the z axis rails? I found some .750 dia pcs laying around the shop the other day and I thought that they would work great. They are light weight, strong and will never rust, expesive though if I have to purchase them myself. It pays to dig thru the scrap barrel from time to time......lol

[Rance]

[I was thinking of going with 1/2-20...]

Did you mean 1/2-10 or do they actually make 1/2-20?

Rance (learning so much from you guys here)

[scorpio2367]

Yes they do actually make a 1/2 -20 thread rod........you can purchase it on line if you can't find any around you from McMaster-Carr or mabey even mscdirect......anyway they are both online and fairly reasonable on there prices. I deal with both of them almost on a daily basis from the machine shop I work at...............Mike

[scorpio2367]

Jason I did go and checked out Hobbycnc.com they had the 200oz stepper motors there as a package deal for $275.00 plus shipping.......I had to buy the driver board box and power supply else where but at least now I have my complete electronics ordered.......hardware that is - no software yet - still checking them out..........thanks for the link........now my wallet is empty :frown: LOL....................