Stepper motors

edwardrford
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Re: Stepper motors

Post by edwardrford » Wed Apr 18, 2012 8:16 pm

So, I've tried drilling out a 5mm pulley to fit a nema23. The results are so/so at best. You'd think it would be easy to bore out the original hole and keep everything concentric, but it ends up that it isn't that easy. (at least for me it wasn't)

After many screwed up pulleys (or so/so pulleys as I like to call them), I've resorted to just buying new ones when the situation arises. They run about $5/each and in my opinion, it's worth the price.

-Edward
Shapeoko 1 #0 - a couple of upgrades.
Shapeoko 2 #0 - a couple of upgrades.
Shapeoko 3 #2 - Stock

kargofab
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Joined: Tue Apr 10, 2012 12:30 am

Re: Stepper motors

Post by kargofab » Thu Apr 19, 2012 1:05 am

Hi Edward,

So are you saying there's a larger bore pulley that'll work?? Do you have a pointer to the part?

Thx.

-m

RedOko
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Location: TX

Re: Stepper motors

Post by RedOko » Thu Apr 19, 2012 1:15 am

Its actually a 1/4(.250) inch diameter.

http://store.makerslide.com/index.php?m ... ucts_id=16
Luis
aka "RedOko"

edwardrford
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Re: Stepper motors

Post by edwardrford » Thu Apr 19, 2012 1:43 am

RedOko is correct, it's 1/4" pulley for a nema23.

You can find them here as well: https://sdp-si.com/eStore/PartDetail.as ... roupID=218

That's a great site btw for lots of stuff: belting, pulleys, hardware, shafts, bearings, etc.

-Edward
Shapeoko 1 #0 - a couple of upgrades.
Shapeoko 2 #0 - a couple of upgrades.
Shapeoko 3 #2 - Stock

sea2stars
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Joined: Mon Apr 09, 2012 9:54 pm
Location: Cromwell, CT

Re: Stepper motors

Post by sea2stars » Thu Apr 19, 2012 2:28 pm

Nice link.

I bought some metal ones from these guys in NY though;
Quality Transmission Components

RedOko
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Location: TX

Re: Stepper motors

Post by RedOko » Thu Apr 19, 2012 2:53 pm

In order to have a nice hole for these thing, I recommend reaming it out after drilling it a bit undersized. This is basically a 2 step operation and better performed in a rigid drill press. A 1/4" drill bit will almost always create a hole bigger than 1/4".
Here is a nice explanation on the topic in case you need to do a lot.

http://awtarlab3.engin.umich.edu/wiki/i ... ing_a_mill

Personnally for a few timing pulley it will be a lot cheaper to just buy new one, and just save those in case you come across metric sized stepper.

Nema stepper motor mounting hole location are the same for metric and inch. Just the size and thread differ, for the shaft they either have 5mm or 1/4inch diameter shaft for the Nema 17 and 23. The motor I'm using is actually a mix of 4-40 thread for the mounting with a 5mm shaft. :o
Luis
aka "RedOko"

nogthree
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Re: Stepper motors

Post by nogthree » Thu Apr 19, 2012 9:39 pm

Just a tip, if you're trying to bore out the pulleys you're better off doing it in a lathe. The original pulleys I had were for Nema17 spec shafts and I had to bore them out, doing them on a lathe keeps them centred perfectly.

Just don't do what I did and bore it out with a metric drill instead of the 1/4 in one :oops:
- Brendan Halliday.
ShapeOko Wiki Userpage

CptanPanic
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Joined: Tue Apr 10, 2012 3:14 pm

Re: Stepper motors

Post by CptanPanic » Fri Apr 20, 2012 11:35 am

So to upgrade x/y to nema23, all you need is new pulleys?

Aaron Seltzer
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Joined: Tue Apr 10, 2012 4:33 am

Re: Stepper motors

Post by Aaron Seltzer » Fri Apr 20, 2012 1:18 pm

CptanPanic wrote:So to upgrade x/y to nema23, all you need is new pulleys?
Nema23's attach with M5 not M3 fasteners. Not clear if either are included in the kit.

edwardrford
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Re: Stepper motors

Post by edwardrford » Fri Apr 20, 2012 1:40 pm

The kits from inventables will include the correct M3 fasteners to connect the standard nema17 motors. If you're going to use nema23 motors then yes, you'll have to get the M5 bolts to mount those motors.

If I recall correctly, M5 x 16mm socket head cap screws will work great. When you mount the motors, run the bolts from the inside out (backwards from what you would think). So the nut is on the outside of the motor and the bolt head is on the inside of the plate. This gives enough room for the belt to clear.

-Edward
Shapeoko 1 #0 - a couple of upgrades.
Shapeoko 2 #0 - a couple of upgrades.
Shapeoko 3 #2 - Stock

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