MechMate CNC Router Forum - Reduction Drive by belt - a collection of various designs and how to build your own.

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- - Reduction Drive by belt - a collection of various designs and how to build your own. (http://www.mechmate.com/forums/showthread.php?t=366)

Dale

I bought 15T T5 16mm pulleys with 12.7mm bores along with 45T T5 16mm pulleys for my 3:1 boxes. The 45T's are only 8mm bore so I will need to make mine bigger. I might still get some 44T as I can get those in 12.7 as well, that would reduce my ratio to 2.933333. All these are from AusXMods here in Aus, for the 4x 15T, 4x 45T and 4 suitable belts it all came to $102 including shipping.

I doubt you will get the 10T bored to 12.7mm to suit your motors, you'll need to increase the tooth count.

@Bruce Thanks for the tip!

Why not go the extreme with GT2 timing belt & pulley. you might be able to get 8:1 ratio if you don't mind fat & clumsy look.

Quote:

Originally Posted by Greg

Michael

These are a couple of pics just to give you more ideas.

I don't have any drawings. And this is obviously not a mechmate.

Same principals apply though. Keep the relationship between the pivot and the pinion shaft no more than 45 degrees from horizontal. I would make it less if I was starting again.

I see the weak point of other designs to be the pivot mechanism. Any slop here goes straight to backlash.

Whenever I drill a hole and put a bolt or shaft through it, it usually ends up with about 3 to 5 thou slop. Then the rapid back and forth of the axis will increase this with wear.

That's why I put bearings on the pivot and made them a firm fit in their housing and on the shaft.

Also be careful in your belt selection. Mine are T5 and the "cog" on the belt is smaller than the "groove" on the pulley.

So far this has not showed up in accuracy but this is not a good place to start. http://www.mechmate.com/Forum/clipart/happy.gif

http://www.mechmate.com/Forum/messages/12/3686.jpg

http://www.mechmate.com/Forum/messages/12/3687.jpg

Greg
I have just finished reading all of this thread and I am veruy interested in the machine pictured in these photos
Thank You
archie

Aluminium Pulleys on belt drive

Hi, has anybody built belt reduction gearboxes using aluminium timing pulleys? If so how has it worked out? I was looking at steel ones but the aluminium seem to be more readily available and with a wider choice.
Also I was going to go for a 15 tooth to 60 tooth pulley arrangement but most of the 15 tooth pulleys I have found would not be able to be drilled out to fit the 14mm shaft on my stepper motors and still take a grub screw. Any suggestions?

with 14mm shaft on stepper motor you have to go to 20 tooth T5 pulley , so its 1:3 because the largest is 60 tooth pulley for T5

No problem with aluminium pulleys I use them all the time for belt drives

All of mine are aluminum pulleys. I have a 7 to 1 ratio with my largest pulley custom made from a gear maker out of Massachusetts. No issues with wear.

Thanks for the feedback. Does anyone have any preference over gear profile? Lots of people seem to use XL or T5 but I have seen references that GT2 is better at minimising backlash.

I use sometimes HTD 3M belt and pulleys with conical axle grip .

GT2 seems compatible profile with HTD . its just matter of cost they are a bit more pricey

Belt Drive update

Quote:

Originally Posted by Castone

Here are some pics again. The belt drives can be built pretty easy . I would recomend having the stand offs made on a lathe but everything else can be done with a hand drill as I made mine with nothing more than a hand drill just to see how well they would work. I have sold about 20 sets of these have not had any bad feed back so far. If anyone needs the drawing or a parts list just PM me.

I put these belt drives on my machine in late 2009 I use my machine every day and cut a wide range of products, today 3/9/2019 is the first day I have had to do anything with my belt drives as I broke a belt today and came on here to find my old part number to reorder some more belts. Thankfully my parts list was still posted so if you're ever wondering if these will hold, don't as they hold up great. Also thanks to the Mechmate site for still having my post up.