How to find shaft diameter on stepper motors?

Technical Motors
1

I need to buy stepper motors for a hobby CNC machine I’m planning on making. Most of the motors I’m seeing are have a rating like “NEMA 23” for instance, but don’t list the shaft’s diameter. Is there a standard, where each NEMA rating coincides with a set shaft diameter?

Thanks.

2

NEMA 23 steppers usually have 1/4 inch diameter shafts.

See this example. The drawing is about halfway down the page.

Yes, there are standards. This one is a good place to look first.

3

^+1

Any motor with a NEMA number has a set of standard dimensions associated with it. Good luck with the CNC machine! Don’t forget your anti-backlash gear drives.

4

You’ll find additional links in your previous post on this issue: http://www.chiefdelphi.com/forums/showthread.php?t=86191

5

The NEMA23 motors you’ll probably be using (less than 380oz/in torque) all have .25" shafts with a flat. To properly connect them to your leadscrews which I expect you to be using, you’ll need the assistance of these handy connectors. We use the L-type connectors and they’re excellent.

http://www.lovejoy-inc.com/products/jaw-type-couplings.aspx

Here is an exploded view of how to couple the NEMA23’s with the leadscrews by using the lovejoy connectors.

http://www.cncrouterparts.com/product_info.php?cPath=24&products_id=58

Our team used this method (and the parts from that website) when creating our 4’x4’ CNC routing table. It works excellently and we use it to manufacture a very large portion of our robots parts now.

You can see a picture of our router and some information on it at our thread about it here http://www.chiefdelphi.com/forums/showthread.php?t=79401&highlight=cnc+router

If you want more pictures of our router, you can see them in the media section of our website d5robotics.org, otherwise you’re welcome to PM me with any questions on your build. Also, cnczone.com is a GREAT resource. Their homebrew CNC router section can be found here http://cnczone.com/forums/forumdisplay.php?f=48 and their CNC mill section can be found here, with examples of conversions of common CNC mills like the Sieg/Grizzly micro/mini/small mills http://cnczone.com/forums/forumdisplay.php?f=20

Good luck with your CNC builds, it’s difficult work and planning, but once finished, you get a highly rewarding result.