Wanting to Motorize a monster mm-3

[ToastedPenguin]

Just got a mm-3 and I would like to motorize it. I am going to start off building the table for it, not sure of the design yet though. I'd also like to find a CW motor for it at a reasonable price that can get the job done.

Any recommendations on this would be helpful.

Thanks.

 

[SankePankey]

You'll be hard pressed to find a used motor that is the exact torque and rpm that you want (which is over 50 in-lb and 175 RPM). So, most people get garage door motors. Mine is 1725 RPM and 1/3 hp. It is slowed down 10:1 with a gear reducer. That gives me 172 RPM and multiplies my torque to 100 in-lb. I have a lovejoy connector in between the drive shaft of the mill and the gearbox shaft.

The main question is- do you want to slow it down with a pulley system or a gearbox. I wanted to stay away from pulleys. Pulleys are cheaper than a gearbox.

Sorry if I oversimplified. Here are previous posts to check out (albeit I don't think they make this gearbox anymore):

https://www.homebrewtalk.com/f51/motor-size-monster-mill-195335/
and
https://www.homebrewtalk.com/f51/looking-grain-mill-motor-advice-246959/#post2944041
with a vid w/ it in use (about in the middle of the vid).

 

[outside92129]

+1 on SankePankey's suggestion. I too went with a gear box on my mm3, just in case my 2yr old found the plug and switch- those fingers are tiny. Figure $150 for a new Groschopp gearbox and $20 for the coupler, maybe $50 if you go the pulley route. IMHO the gearbox is way cheaper than any hospital trip (and associated guilt). Safer for tipsy or otherwise distracted brewers too.

Over a span of a couple weeks i found a 1/2 HP 1725 RPM motor for $60 delivered on ebay. You can get better prices on lower HP motors, as well as motors that need mounting work. I found a $10 1/2hp sump motor but then punted it off to someone else when i didn't feel like making a mount.

tip- replace some of the key screws/bolts on the mm3 to make them finger workable. When you get a jam in the middle of brew day you don't want to have to go looking for tools.

 

[ToastedPenguin]

You'll be hard pressed to find a used motor that is the exact torque and rpm that you want (which is over 50 in-lb and 175 RPM). So, most people get garage door motors. Mine is 1725 RPM and 1/3 hp. It is slowed down 10:1 with a gear reducer. That gives me 172 RPM and multiplies my torque to 100 in-lb. I have a lovejoy connector in between the drive shaft of the mill and the gearbox shaft.

The main question is- do you want to slow it down with a pulley system or a gearbox. I wanted to stay away from pulleys. Pulleys are cheaper than a gearbox.

Sorry if I oversimplified. Here are previous posts to check out (albeit I don't think they make this gearbox anymore):

https://www.homebrewtalk.com/f51/motor-size-monster-mill-195335/
and
https://www.homebrewtalk.com/f51/looking-grain-mill-motor-advice-246959/#post2944041
with a vid w/ it in use (about in the middle of the vid).

Thanks for the info its helped a ton. Picked up an Emerson 1/3 HP 1725 HP Single phase, single speed motor for $40 so I am on my way.

 

[ToastedPenguin]

+1 on SankePankey's suggestion. I too went with a gear box on my mm3, just in case my 2yr old found the plug and switch- those fingers are tiny. Figure $150 for a new Groschopp gearbox and $20 for the coupler, maybe $50 if you go the pulley route. IMHO the gearbox is way cheaper than any hospital trip (and associated guilt). Safer for tipsy or otherwise distracted brewers too.

Over a span of a couple weeks i found a 1/2 HP 1725 RPM motor for $60 delivered on ebay. You can get better prices on lower HP motors, as well as motors that need mounting work. I found a $10 1/2hp sump motor but then punted it off to someone else when i didn't feel like making a mount.

tip- replace some of the key screws/bolts on the mm3 to make them finger workable. When you get a jam in the middle of brew day you don't want to have to go looking for tools.

Which gearbox did you go with?

 

[SankePankey]

Thanks for the info its helped a ton. Picked up an Emerson 1/3 HP 1725 HP Single phase, single speed motor for $40 so I am on my way.

No prob. That's the exact spec motor and price I paid. Mine is GE. Good first step!

 

[ToastedPenguin]

No prob. That's the exact spec motor and price I paid. Mine is GE. Good first step!

How do you figure out the torque on the output of a gearbox based on the motor being used? I have found quite a few 10:1 gear reducers under $100, but I can't figure out exactly what I need besides the 10:1 ratio and based on what I have seen not all 10:1 gearboxes provide the same output.

 

[outside92129]

Most folks go with a 1/3 or 1/2 HP motor and use the gearbox to lower the RPM to "acceptable" levels. My motor is 1/2hp at 1725rpm and i use a 10:1 on the mm3, joined with lovejoy spider/jaw couplers.

 

[SankePankey]

How do you figure out the torque on the output of a gearbox based on the motor being used? I have found quite a few 10:1 gear reducers under $100, but I can't figure out exactly what I need besides the 10:1 ratio and based on what I have seen not all 10:1 gearboxes provide the same output.

I found a Grosschop link that told me what it was. The link doesn't work anymore that I have. But it said that a 1/3 hp at 10:1 yields 100 in-lb. I believe that they all work the same way in multiplying torque when reducing revolutions per minute. I don't know if at 10:1, it is 1:10 or what the variable is but just remember the info from Grosschop.