Motorised Monster Mill

[Maheel]

$5 from the shop

works well as a hopper

 

[QldKev]

$5 from the shop

works well as a hopper

Good hopper,
Great water for a brew
Awesome to use if the wife has a white top on :icon_chickcheers:

 

[manticle]

Depends on the wife.

 

[marzross]

Has anyone used those ebay motors on the mash master mini mill. I was thinking of getting one for my mill.
Cheers mario

 

[crozdog]

This is the same as I have
http://www.ebay.com.au/itm/24V-250W-Electr...=item2a144e1fe9

same seller

are you running this on 24v or 12v? how do they go on 12v? I ask as I have high current 12v PSU's but not 24v.

Thanks

 

[QldKev]

are you running this on 24v or 12v? how do they go on 12v? I ask as I have high current 12v PSU's but not 24v.

Thanks

Have a look on my website. I've got some info about the conversion. 12v is perfect as it give you 160rpm.

QldKev

 

[kjparker]

Have a look on my website. I've got some info about the conversion. 12v is perfect as it give you 160rpm.

QldKev

Yep, 12v. 24volts would be way too fast. I got the idea to use this motor from reading that very website!

 

[crozdog]

Have a look on my website. I've got some info about the conversion. 12v is perfect as it give you 160rpm.

QldKev

Thank for the info. Looks like I was right in thinking that halving the voltage (24v - 12v) will halve the speed. I also think that the current would be doubled. That's not an issue for me as I have server PSU's that output 30+A B)

Looking at this to power my JSP Malt mill which has 10" rollers :super: The malt mill web site says it can run at up to 400rpm, but under 200 will be fine.

Beers
Crozdog

 

[QldKev]

Thank for the info. Looks like I was right in thinking that halving the voltage (24v - 12v) will halve the speed. I also think that the current would be doubled. That's not an issue for me as I have server PSU's that output 30+A B)

Looking at this to power my JSP Malt mill which has 10" rollers :super: The malt mill web site says it can run at up to 400rpm, but under 200 will be fine.

Beers
Crozdog

Talking DC, not AC as they are totally different.

At half the voltage your current draw is still the same, but you half the speed.
So usable power
250w / 24 = 10.4amp
10.4 * 12v = 125w usable; which happens to be enough torque for mm2 mills, and the correct RPM

If your mill is happy at 400rpm, does your power supply have a decent -12v capacity.
+12v and -12v = 24v

More torque and faster crush.

I would not run my mill that fast.


QldKev

 

[crozdog]

Talking DC, not AC as they are totally different.

At half the voltage your current draw is still the same, but you half the speed.
So usable power
250w / 24 = 10.4amp
10.4 * 12v = 125w usable; which happens to be enough torque for mm2 mills, and the correct RPM

If your mill is happy at 400rpm, does your power supply have a decent -12v capacity.
+12v and -12v = 24v

More torque and faster crush.

I would not run my mill that fast.


QldKev

i thought that 250W @ 12v = 20.8A i.e. same power with less voltage will need more current.

I have seen how guys have modded 2 PSU's I have to make 24v supplies.

I have several PSU's even 1 that can supply 147A @12v

FYI, checkout this site for info on using many high current server supplies http://www.rcgroups.com/forums/showthread.php?t=1292514

 

[QldKev]

i thought that 250W @ 12v = 20.8A i.e. same power with less voltage will need more current.

I have seen how guys have modded 2 PSU's I have to make 24v supplies.

I have several PSU's even 1 that can supply 147A @12v

FYI, checkout this site for info on using many high current server supplies http://www.rcgroups.com/forums/showthread.php?t=1292514

If you wanted to have the same torque at a lower voltage you would need to reduce the resistance...

Ohms law states

I = E / R

I: current
E: voltage
R: resistance

so for a 250w motor at 24v we have E and I, we need to cal R

R = E / I
R = 24v / 250w
R = 0.096

so thus

I = E / R
I = 12v / 0.096
I = 125w

125w @ 12v = 10.4amp

resistance is a constant at any (I) voltage.

 

[crozdog]

If you wanted to have the same torque at a lower voltage you would need to reduce the resistance...

Ohms law states

I = E / R

I: current
E: voltage
R: resistance

so for a 250w motor at 24v we have E and I, we need to cal R

R = E / I
R = 24v / 250w
R = 0.096

so thus

I = E / R
I = 12v / 0.096
I = 125w

125w @ 12v = 10.4amp

resistance is a constant at any (I) voltage.

Yes I agree with ohms law, but I was thinking along the lines of power (P) = VI

I was assuming that if P stays the same & V halves, I must double. However i now realise that if V halves, I stays the same & P also halves.

What is the impact to torque? does it stay the same or halve? I think it halves...is that right?

 

[QldKev]

Yes I agree with ohms law, but I was thinking along the lines of power (P) = VI

I was assuming that if P stays the same & V halves, I must double. However i now realise that if V halves, I stays the same & P also halves.

What is the impact to torque? does it stay the same or halve? I think it halves...is that right?

power is relative to torque and rpm

so to reduce the power you must reduce the torque at the given revs


So if you wanted too
Run this motor at 24v, and use gearing to drop it back to 160rpm and you will have shit-loads of power. But then you miss the simplicity of the motor setup.

 

[motiondynamics]

Those motors are the cheaper versions of these motors:

http://www.motiondynamics.com.au/dc-motors...-rpm-clone.html
http://www.motiondynamics.com.au/dc-motors...or-400-rpm.html

Though I can get those if you guys want?

 

[QldKev]

Those motors are the cheaper versions of these motors:

http://www.motiondynamics.com.au/dc-motors...-rpm-clone.html
http://www.motiondynamics.com.au/dc-motors...or-400-rpm.html

Though I can get those if you guys want?

The first one looks pretty decent, hooked up with your controller kit I think there would be no stopping it


QldKev

 

[Spork]

For those 24v motors you blokes are running off 12v to get the right RPM - how would one of these work to power it?

 

[cdbrown]

Why use them when the 12v rail of an old pc power supply does the job?

 

[kjparker]

Those motors are the cheaper versions of these motors:

http://www.motiondynamics.com.au/dc-motors...-rpm-clone.html
http://www.motiondynamics.com.au/dc-motors...or-400-rpm.html

Though I can get those if you guys want?

Yep, they certainly are!

I looked at your motors originally, way before I even found the one I ultimately used. The main reason I used the one I did was the mounting method. These ones made more sense for the way I wanted to run it, and I knew of others running the same motor.

 

[Spork]

Why use them when the 12v rail of an old pc power supply does the job?

Because I have 2 of these at home (long story, don't ask) and only 1 old PSU - which has had rain on/in it and I don't know if moisture / rust / 240v is a goo0d combo...
If the jump starters are not suitable I guess I could source a cheapPSU though.

 

[cdbrown]

Check freecycle as there's always pc's given away. Unfortunately I don't know about the jumpers so can't really comment on that sorry. I just know that a psu hooked up to a 24v motor does a great job in driving the mill. It has heaps of torque so make sure both the motor and mill are secured to a solid bench/shelf and the shaft is aligned.