Motor And Gearbox For My Millmaster

[razz]

Just thought I would post a couple of pics of the motor for my Millmaster (when it arrives) no slur on Brissybrew either.
Last year a mate gave me a washing machine motor (stuffed) with the right angle drive and gearbox on the end of it. I had a 2hp garden shredder which I had superceded. I put off trying to put the two together because I couldn't find a suitable coupler on the market. My FIL, who is a retired engineer, said I should use a flexible coupler. "What's that?" I said, "Abit of rubber hose" he says. So there it is, so far I've spent about $20 on the hardware to get them together including the 1\4 inch bolts and aly tube. The motor is 2hp, 2840rpm, the gearbox is a 15:1 reduction. This gives me, in theory, 6.2Nm of torque @ 189 rpm. All I have to do now is get my mill and use a piece of smaller hose to get the two shafts together, they're both 13mm diameter. I do need to work out how I will mount the mill in front of the gearbox.

View attachment 17045

View attachment 17046

 

[AUHEAMIC]

Looks the goods. By my calcs you will get 75Nm of torque less gearbox efficiency.

 

[razz]

Thanks Peels, I used an online calculator to work out the torque. Not sure what I did wrong, anyway that will give me loads more torque than I need.

 

[BrissyBrew]

Thanks Peels, I used an online calculator to work out the torque. Not sure what I did wrong, anyway that will give me loads more torque than I need.

I will be interested in how your "flexiable hose connector" wears especially on start up. Cheap to replace though.

 

[hando]

Looks the goods. By my calcs you will get 75Nm of torque less gearbox efficiency.

How did you calculate that? :huh:

 

[newguy]

How did you calculate that? :huh:

This online calculator will give the motor's torque in ft-lbs. The 15:1 gear reduction will result in a torque increase of 15x. Finally, this calculator will convert the resulting torque in ft-lbs to N-m.

 

[oldbugman]

Dont forget to allow for slip within the electric motor.

 

[AUHEAMIC]

How did you calculate that? :huh:

Formulae-
Horse power (Hp) multiplied by 0.75 = Kilowatts (kW).
Input speed divided by gearbox ratio = output speed.
Torque = Power multiplied by 9550 divided by speed.

In this case we have a 2 horse power (Hp) motor running at 2840 revolutions per minute (rpm) and a 15:1 gearbox ratio.
2Hp multiplied by 0.75 = 1.5Kw
2840rpm divided by gearbox ratio 15:1 = 189rpm
So
1.5Kw multiplied by 9550 divided by 189rpm = 75.8Nm

The above figure does not take motor or gearbox efficiency into consideration.

 

[razz]

Now I know where I slipped up. I converted 55 inch. lbs instead of 55 ft.lbs. Thanks for the prompt newguy.