Need quick help with 2x72 drive wheel sizing

G

Grayzer86

Joined
Jan 15, 2012
Messages
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I am trying to finish up a build on a NWGS and have a question about drive wheel size. The motor i have is a 1750rpm and i plan to run a step pulley setup on it. With a 4 inch drive wheel that gives me roughly 1750 sfpm at 1:1, 3500 at 2:1 and like 875 at lowest which seems way too slow for anything. Even 3500 seems quite slow to me on the highest step so would i be better off to step to a 6 inch drive wheel? This would give me 5250 at a top speed which seems far more versatile overall. I have also been thinking about running a dual drive shaft setup for more adjustment since i already have more step pulleys than i can use so they are free. Basically my setup would look like this if i double shafted.


III---------( ) this end is drive wheel
l
l
l
III------III
l
l
l
[motor]-----III

This may look stupid but it gets the point across.


Anyway just getting the correct wheel is a lot easier so what do the experts think?
 
Sorry the spacing on my little diagram got screwed up and didn't show up how i typed it so you can just disregard it.
 
Slower is better, IMO. Either one of those ranges you posted will do just fine. You'll have to have a pretty well balanced system to run 5250 without alot of noise and wobble.
 
Ok thanks for the info, I also have the option to go with a 5 inch drive so maybe that will give me the better setup. Still able to slow it enough but give me the extra speed when i need it.
 
If the motor is big enough ( 1HP or larger), and everything is well balanced, and the bearings are all good quality, then the 6" drive wheel will be OK. If the motor is smaller, the build is less precise, or there is any slop in the bearings, then the 4" wheel may be a better choice.
 
Thanks Stacy, i didnt end up ordering yesterday as i was hoping to get a few more responses before i checked again here. The motor is 1hp, 1750rpm, and all wheels and bearings are being ordered from USAknifemaker, as i have not found any other places that will ship to Canada and have the parts i am needing. I have been thinking about different wheel sizes due to the speed issue but also because they seem to always be out of the 4 inch drives when i check their site. I am getting my contact and idler wheels from them but dont want to make two orders and have to pay shipping to Canada twice. Also the shipping and wait time is horrible between USPS and Canada post so i was hoping to get it all in one shot. The last order i did from there took 16 days thanks to Canada post and all it was was a book. My figures show me that at 1:1 4 inch gives me about 1800 sfpm, 5 inch gives me 2290 and 6 would give 2625. What is the optimum speeds these belts should be running as far as sfpm?
 
Grayzer86 said:
Thanks Stacy, i didnt end up ordering yesterday as i was hoping to get a few more responses before i checked again here. The motor is 1hp, 1750rpm, and all wheels and bearings are being ordered from USAknifemaker, as i have not found any other places that will ship to Canada and have the parts i am needing. I have been thinking about different wheel sizes due to the speed issue but also because they seem to always be out of the 4 inch drives when i check their site. I am getting my contact and idler wheels from them but dont want to make two orders and have to pay shipping to Canada twice. Also the shipping and wait time is horrible between USPS and Canada post so i was hoping to get it all in one shot. The last order i did from there took 16 days thanks to Canada post and all it was was a book. My figures show me that at 1:1 4 inch gives me about 1800 sfpm, 5 inch gives me 2290 and 6 would give 2625. What is the optimum speeds these belts should be running as far as sfpm?
Click to expand...

You can buy that keyed shaft at Princess auto and those bearings at TSC and Princess auto, It may save you some shipping weight.

If you look at other grinders like the Bader, Bee, Wilton they come with 6 inch drive wheels
That extra speed can be nice for hogging especially with those ceramic orange and blue belts

But on handle shaping and fine grinding it's really nice to slow it way down


If they are sold out, I would get the 6, but there's no harm in slowing down to the 4 for better control
 
I would get the 6" because faster is more often used than slower.

About the dual drive shaft....don't do it. For low speed-high torque machines, it is a great setup. At the speeds we run grinders at it may shake the bolts out of your machine. I run a system like that to drop my Consew sewing machine to a usable speed.
 
Thanks for the offer Frank, i would totally be interested but i have gathered all the parts so my step pulleys, pillow blocks and shafts are already bought and are all 5/8. Thanks anyway though.
 
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