Sounds cool. Are you making the Y axis end plates taller? I was thinking about doing that so I could put longer material in from the sides.
Nope, I’m going to have them come up only to the top of the flat part of the rail. Imagine the end plate, just more square and cut off between the top two holes.
Oh, I see. BTW, do you see any problem extending those plates 1" taller and raising everything that much higher off the waste board?
I don’t think it needs to be dead accurate. The only reason I’m checking it now is with me new spindle I was seeing some issues. Like @RobertA_Rieke said, if it’s not broke don’t fix it.
I went and tested the belt tension of current setup and at 1 inch it was reading 0lbs! Up until now, it was working just great!
@JeffParish @AngusMcleod I don’t see any problem with taller endplates, but I would hesitate to use aluminum instead of steel I chose to use aluminum for the mid-line supports, but I would be a little concerned that aluminum endplates would add a bit more flex, especially if they are only 1/8" thick and unsupported. Maybe if they’re 1/4" thick, or if there are a couple vertical ribs attached to them. Sure would be nice to have another inch of cut depth though…
@Rusty Holy crap, 0 pounds??? No wonder my 6 pounds snapped!
You have have to finish your build first! How’s it going?
To check the belt tension, the so called “deflection method” :
Easy to do, and for a 6 mm belt suggested force is 2 lbf per inch of span to get 1/64" deflection.
More details about timing belts, installation and tensioning here:
http://sdp-si.com/resources/beltdesignsuggestions.htm
-Hermann-
Robert, I have watched your videos on belt tension and followed your comments here in the forum. What is your latest recommendation for belt tension? The last I saw, it was about 3.5 pounds. Thanks.
I’ve dropped it down to about 3.2 pounds, but that was more to make my small (<3/16") circles perfectly round. Larger circles were still pretty much perfect at 3.5 pounds.
What about the higher belt tension affects roundness carved circles?
Thanks.
Actually, its 1/64" of deflection per inch of span, with a 2 pound force. The test-force is always two pounds in this method, for any length span. Which is an important difference! 
I’ll have to try this procedure! I keep breaking belts. I’m guessing because they’re to tight.
My theory is that the steppers don’t build up enough torque to move correctly when the belt tension is too high. For instance, going clockwise from the 12 o’clock position, if the Y belt tension is too high then the bit would move quite a bit in the X direction before moving Y, causing it to seem more like an oval pointing at the 3/9 o’clock positions.
Just a guess, but it seems to make sense.
I upgraded to 269oz-in NEMA steppers on x and y stage a few weeks back. Now I can run with a bit more v-wheel pressure and belt tension and never loose steps, which is really nice. However, these brutes ripped the teeth right off the 6mm belt when the bit crashed hard into a clamp.
So many tradeoffs.
X-Controller.
I’m running into that problem right now. the xaxis belt is rubbing on the motor pulley on one side.
Is here a way i can i adjust this now?
You should be able to move the pulley in and out on the shaft a bit to align it. You need to make sure the belt is sitting in the middle of the rollers though.
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Hi Guys
my belts were tensioned with a fishing scale then a guitar tuner to get them exactly the same,
I got the idea from the instructions saying "taut like a guitar string)
G
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Thank you. I loosened the xaxis belt, took 4 screws from back of xaxis motor, and was able to adjust it. Think it fixed my xaxis slipping problem.
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