How to connect 2 shafts?

I have a barley crusher that has a 3/8" shaft.

I have a 177 RPM motor that has a 1/2" shaft....

I am building a grain mill and need to couple these two shafts together. Any idea how?

I would imagine some sort of coupler that has 1/2 smooth on one side and 3/8 on the other but I have yet to find such a beast.

its called docking.

no wait, that is something else.

no clue, sorry.

You'll need to buy a shaft coupling if you want to connect directly shaft to shaft. McMaster-Carr carries the size you need for $42. You can shop around with other industrial supply companies. Its rated for 4000rpm at 540in-lbs.

http://www.mcmaster.com/#catalog/117/1162

What most people on here seem to use is called a jaw coupling or possibly a spider coupling. You can get them from McMaster if you are in the US, or Fastenal if you are in Canada. Here are the part numbers:

3/8" Hub (For Mill) - Fastenal: 0439466 - McMaster: 6408K123
1/2" Hub (For Motor) - Fastenal: 0439470 - McMaster: 6408K712
Spider Insert - Fastenal: 0439459 - McMaster: 6408K73

Mine have yet to show up, but I got the McMaster part numbers from another post on here somewhere, and the Fastenal ones I think are for the same parts.

I used this brand to connect my Barleycrusher to a gearmotor:

http://www.lovejoy-inc.com/

I used model L090 lovejoy couplers. Each model comes in different shaft sizes, and can be slotted for a key or screw tightened. Spider couplers are also a tag forgiving of misalignments.

I've connected shafts with pulleys and belts, or old bike sprockets and chain. It's cheap and easy and it works. If you don't want to change RPM, then use same diameter pulley or same amount of teeth on sprockets.

I would go with pulleys and a belt, if your motor rpm is 1725 which is standard that would be really fast for the grain mill so you can slow it down with a larger pulley on the mill

The simple way is with the jaw coupling. The L090 will work, but is overkill. I would use an L075 at half the price. The advantage of pulleys is that you can tweek the driven speed. Stay away from sprockets. If your in the US you should be able to get one at a local IDC authorized distributor, or pm me.

The part numbers you need are:

1-3419-C 3/8" L-050 JAW COUPLING HALF 2.85
1-3419-E 1/2" L-050 JAW COUPLING HALF 2.85
1-3419-X BUNA-N INSERT FOR L-050 JAW COUPLING 1.70

Those I got from Surplus Center, which I think is where you got your motor from.

M_C

Awesome! Thanks so much for the responses! I ordered them this morning from McMaster! No more hand cranking or screwing around with the drill for me!

Misplaced_Canuck said:

The part numbers you need are:

1-3419-C 3/8" L-050 JAW COUPLING HALF 2.85
1-3419-E 1/2" L-050 JAW COUPLING HALF 2.85
1-3419-X BUNA-N INSERT FOR L-050 JAW COUPLING 1.70

Those I got from Surplus Center, which I think is where you got your motor from.

M_C

Click to expand...

I wish I'd thought of this. I ordered my motor from them and it showed up 6 days later. I bought the couplers locally and I'm waiting 10-14 more days for them to come in now.

toolboxdiver said:

I would go with pulleys and a belt, if your motor rpm is 1725 which is standard that would be really fast for the grain mill so you can slow it down with a larger pulley on the mill

Click to expand...

His motor is 177rpm ... I'm assuming its the $40 surplus center motor.

Just wanted to thank everyone! I built my new grain mill this weekend. Fired it up and ran some grain thru it. crush looked great.

It runs nice and slow 177 rpm. Could not be more pleased!