Need Help Understanding Mill Motor Specs

[reVoxAHB]

Hi Fellas, looking for direction here. The boss at work handed me down an old motor used in our auger. It's Italian with the following specs:

It looks like:
M: 80/ACS HP: 1 N:0394
kW: 0,75 min-1: 1700
V: 240 A: n/a Hz 60
V: 450l n/a uF: n/a Ser: S1
IP 55 COS: 0,99 CL: F

Does this min -1@ 1700 indicate the motor runs at 1700 rpm?

He's motorised my MashMaster MillMaster using a 3 1/2" drive pulley and 9" pulley on the mill:


Where I reckon it's driving way too fast. From other threads, I've come to understand that slower speed and higher torque is the go. And I've noticed many are using 1" and 12" pulleys on the MillMaster

 

[reVoxAHB]

Whoops! Didn't mean to post so quickly.. meant to preview post :blink: doh!

Had a few more questions:

1.) Do you reckon a 1" pulley on the motor, with 9" (as is) on the mill will gear it lower to where it's adequate for use with this motor? Or is it worth grabbing the 1" and 12" respectively?

2.) I bent the shaft installing the hand crank some years ago. There was a batch where the tooth needed to be slightly filed out to fit the key (I did not know this at the time and forced the handle on). The rollers spin 100% fine, and it's not even noticeable at hand-crank, obviously I get a touch of wobble in the pulley at motorisation. but the point is, this has always shit me. It's like buying a new car only to smash the front end on the drive home. And while the vehicle is operational, the flaw is there.

So, I'm considering selling the MillMaster off, with hopper, hand-crank and custom fabricated stainless gear guard (AHB BB, can find the thread later) to purchase the new MashMaster MiniMill.

As the MiniMill roller diameter is changed (38mm (1 1/2") diameter rollers) and rollers geared, will this change the pulley size requirement in relation to this motor? Or 1" and 12" also presumably fine? Can I get away with 1" and 9" on the MiniMill?

Thanks for any help.

reVox

 

[FNQ Bunyip]

from a quick search it looks like its running about 660rpm ...

I think the general is between 150 to 300 rpm ...

can't help on the motor , but i'd say you need to slow it down...

cheers

 

[FNQ Bunyip]

linky

this converter gives 1x9 = 188 rpm , if your motor is doing the 1700 you mentioned ... its not the calculator I used when I did mine (can't seem to find it ) but it seems right ...
cheers

 

[glaab]

u sure thats 1"?, looks like about 3"

 

[reVoxAHB]

u sure thats 1"?, looks like about 3"

The pulley that's currently on the motor now is 3 1/2" inch. I intend to buy a 1"

 

[matho]

that 1700 rpm is for 60hz it would be a 1400 rpm at 50hz

cheers matho

 

[reVoxAHB]

linky

this converter gives 1x9 = 188 rpm , if your motor is doing the 1700 you mentioned ... its not the calculator I used when I did mine (can't seem to find it ) but it seems right ...
cheers

Hey, that's really useful Bunyip B) . Thank you. So next need to find the ideal target rpms for the minimill, assuming I go in that direction.. sell off the millmaster for minimill.

From the Monster Mill faq's
"What RPMs should I run my mill at?

The best speed to run all of the drill driven mills at is around 150-250 rpms. Does it have to be exactly 200 rpms? NO WAY. A range of 100-300 is fine, and if you are willing to have a little more flour, then you can run it a little faster. I generally tell folks to run it as slowly as your drill will run it without stalling plus a little more. It usually takes a little more torque to get the mill going than to keep it going, so you will have to give it some more power to start the mill, and then slow it down once you are milling. You should experiment with faster/slower speeds and see what it does to your grain."

But that's drill driven. What about motor/pulley driven? Bunyip you say the general is 150-300 rpms.. anything in that range fine or?

Cheers

 

[FNQ Bunyip]

Well spotted Matho ,, yep Hz will drop the speed back ... so with the revised input speed it would be around 545rpm the way it is and if you change the 3.5 to a 1 it will be around 155rpm ...

the 150 to 300 range was what I found when looking into it a few years back and just went with it when setting mine up , AFAIK mines around 175 rpm from memory ..

I'm no engineer and just used an old motor I had laying around and got pullys to do want I want..
cheers

 

[Wolfy]

QLDKev has a 'mill speed calculation' on his website: http://home.exetel.com.au/qldkev/
If you click on 'mill' then 'motor' it will tell you the following:

Often it is discussed, 'what speed should I run my mill at' without any reference to what mill they are running. The RPM of the mill should be what you have calculated for your size rollers. You need to calculate it based on the surface speed of your rollers, which is proportion to the circumference of your rollers.

To calculate your roller surface speed in mm per second the formula is
speed = 2 x pi x R x RPM / 60
pi = 22/7
R = Radius of roller
RPM = planned revs
60 = convert minutes to seconds.
A range of 250mm per second up to 500 mm per second is OK. Larger rollers may be able to run faster than this without too much flour.

I don't know where the formula came from, but it still should be helpful for you.

 

[reVoxAHB]

Where are you guys seeing 50Hz? Or am I not understanding the spec. card in relation to the other data?

edit: the photo does kind of look like 50! just verified on the mill itself, clearly a 60.

 

[QldKev]

Where are you guys seeing 50Hz? Or am I not understanding the spec. card in relation to the other data?

edit: the photo does kind of look like 50! just verified on the mill itself, clearly a 60.

The motor says 60, Australia is 240v 50Hz

QldKev

 

[QldKev]

QLDKev has a 'mill speed calculation' on his website: http://home.exetel.com.au/qldkev/
If you click on 'mill' then 'motor' it will tell you the following:

I don't know where the formula came from, but it still should be helpful for you.

2 pi R is the circumference of a circle. ie the roller.
So 1 rotation = the surface distance travelled

time that by the RPM

The divide into seconds to get a easy number to read.

QldKev

ps. hope you find the site useful.

 

[Wolfy]

ps. hope you find the site useful.

I did, and I got how to use the formula, I was just not sure where the basis for the suggested speed was from, if it was from some book/theory/place that should also be referenced for the OP in this thread.

 

[reVoxAHB]

Thank you so much for the direction, fellas.

Using your calcs I went with a 12" and 2" pulley@ 1400RPM or 233.3 Large Diameter RPM. Frank from MashMaster also chimed in, "Between 100 and 300 you can mill, after that exact speed and gap setting will result in a particular crush." and that was his response specific to the MiniMill.

Youtube clip of motorisation:
Final with custom hopper (chute not attached):

Thanks again all,
reVox

 

[reVoxAHB]

Pics from other side, housing eg gear guard protection. I wanted easy access to the roller wheels for adjustment, so included a swinging door with magnetic latching:

And open:

reVox

 

[peaky]

Great looking set-up! How many kilos of grain fit into the hopper?

 

[reVoxAHB]

Great looking set-up! How many kilos of grain fit into the hopper?

I reckon around 10kg. I'll know for certain, the next time I knock out a 50L batch of something big