Motion Dynamics mill motor - how much power do you feed yours?

[karlosus]

Hi folks,

I've got a vanilla (non-sensing) Motion Dynamics Home Brewer Special driving a geared MillMaster 2 roller but I find that it stalls out with very little provocation so I'm wondering how much power you feed yours?

Mine is hooked up to a cheap eBay 12V supply rated at 250W. The motor is rated to 20A which at 12V is 240 Watts so I thought this unit would give enough juice.

Alternatively I might be asking too much of the motor trying for a 0.75mm crush. I find this gives good efficiency and acceptable sparge time with my Grainfather but to get there I need several passes and I'd like to do it in one.

Cheers.

 

[GibboQLD]

a cheap eBay 12V supply rated at 250W

Any chance you could share a few pictures of the power supply?

Picture of the unit and the ratings panel would be a good start.

 

[mckenry]

Sounds like the same setup I have, except for the sensing unit.
Have you tested the voltage output? Not sure if we have the same one. If its the one recommended by motion dynamics in the monster thread about motorising, then it has a variable output screw. Mine was very low. Outputting something like 12V. I cranked it all the way up. Cant remember what it is now, but it was a significant change.
When I mill grain (@1.3mm) I need to have the speed at about half. Then when its going I slowly crank it all the way up to full bicky. Rips through it.
So, my first look would be at your voltage output. Crush shouldn't matter to that motor. Its a beast.

 

[Weizguy]

http://aussiehomebrewer.com/topic/44766-mill-motors/?p=1028874z

No, a 12V @ 30A is great, any lower though and the mill will probably struggle (especially on the bigger mills). Its a current hungry motor and the more you give it, the more torque it has.
If you ran it with a 35 or 40A you'd get even more torque,

 

[karlosus]

Thanks for the replies folks.

Any chance you could share a few pictures of the power supply?

Picture of the unit and the ratings panel would be a good start.

Here are some pictures of the power supply and the controller.

Sounds like the same setup I have, except for the sensing unit.
Have you tested the voltage output? Not sure if we have the same one. If its the one recommended by motion dynamics in the monster thread about motorising, then it has a variable output screw. Mine was very low. Outputting something like 12V. I cranked it all the way up. Cant remember what it is now, but it was a significant change.
When I mill grain (@1.3mm) I need to have the speed at about half. Then when its going I slowly crank it all the way up to full bicky. Rips through it.
So, my first look would be at your voltage output. Crush shouldn't matter to that motor. Its a beast.

I don't recall changing the voltage output on the power supply but it seems to be giving 15V turning an empty mill, I haven't tested it under load/stall though.

http://aussiehomebrewer.com/topic/44766-mill-motors/?p=1028874z

Thanks Les. Man, I wish I'd seen this post before buying the 20A supply recommended on the product page. I thought I would get smoke rather than more torque at 30A.

 

[DJ_L3ThAL]

Hey guys, I've got a non-sensing version on an original monster mill (I believe) which seized the other night resulting in my having to unplug everything and push my feeler gauge up through to release the grain blockage. Upon getting it started again the speed control no longer works and the motor appears to be running at almost full speed only. Nothing looks fried or blown on the circuit but it's quite odd behavior straight after the motor seizing. Thoughts on how to troubleshoot?

 

[Maheel]

Hey Karlosus

the case on the PS looks all bent up? did it come like that or did you get angry and whack it ?

it looks close to shorting out in the thing just inside it...

i would out a cover over it as i have had a few of those ebay power controllers etc go BZZZZZITTTTTT and let out blue smoke in the past
i am always worried about the quality of their insulating methods etc..

 

[karlosus]

Did it come like that or did you get angry and whack it ?

I have been known to give some frustrating gadgets a whack. I call it "durability testing", but in this case I believe the dent happened in transit.

 

[Weizguy]

Thanks Les. Man, I wish I'd seen this post before buying the 20A supply recommended on the product page. I thought I would get smoke rather than more torque at 30A.

Sounds like it pays to research before purchasing, although you'd also think that you couldn't go wrong by buying the PS recommended on the seller's own web page.

It could be that the PS is mislabelled and a lower powered unit, like other eBay sellers were passing off a while back.
You could check that with an ammeter, or talk to the vendor before spending more money on another PS. See if they have other similar issues with their recommended PS.
MD recommended paying on eBay with PayPal, so you could get your money back if there is a dispute with the good not being the power level you paid for.

Maybe you could negotiate a refund, or part therof, by sending a photo of the bent case to the original vendor

 

[Judanero]

Hey guys, I've got a non-sensing version on an original monster mill (I believe) which seized the other night resulting in my having to unplug everything and push my feeler gauge up through to release the grain blockage. Upon getting it started again the speed control no longer works and the motor appears to be running at almost full speed only. Nothing looks fried or blown on the circuit but it's quite odd behavior straight after the motor seizing. Thoughts on how to troubleshoot?

I had a similar problem, my speed controller function stopped working right before a cap popped on the board- Motion dynamics guys were really helpful, basically bypassed something and sent the board back to me... They identified a likely dodgy PSU being my particular problem so may not be an indicator in your situation.

Also maybe check the jumper on the pins (near the toggle switch connections from memory) I remember a poor connection there also caused a weird problem.

 

[DJ_L3ThAL]

I had a similar problem, my speed controller function stopped working right before a cap popped on the board- Motion dynamics guys were really helpful, basically bypassed something and sent the board back to me... They identified a likely dodgy PSU being my particular problem so may not be an indicator in your situation.

Also maybe check the jumper on the pins (near the toggle switch connections from memory) I remember a poor connection there also caused a weird problem.

Thanks mate, will checkout those two items! I did play with the ON/OFF toggle switch which doesn't seem to be turning the mill on or off either. Will report back!

 

[Zorco]

All these numbers for the ratings are not aligning and I would imagine it confuses.

Looking at the motor in the image above, it states its rating is 200W. That is meant to be continuous rating. 24 hours a day, seven days a week, 45 something degrees centigrade, horrid smell in the air... Continuous.

Then selecting a 250W power supply is ok. Might need to protect the motor with a fuse or breaker but a bit over is fine.
But surely nothing more than that into the motor as we would exceed motor rating and burn it out.

I think those imported power supplies, however, are not 250W continuous. Perhaps they are like these pallet rack shelves that say 250kg per shelf but the moment you put 150kg in the middle of the shelf span, it buckles. So the load is actually 250kg spread perfectly across the span....technically not lying, but not good.

250W is probably going to be some rating for 3 seconds withstand and then it may need to run at lower load to recover from the 250W excursion.

I'm sure it depends wildly on supplier and that some people haul 250W continuous from theirs day and night.

If I could try and be helpful, I'd point one and all to a solid PC power supply. They are just about free and are great.... And in the majority of cases their ratings are continuous.. But even then, 500W units are the common ones!

Then you just need to protect the motor. 200/12=16.67r A

Automotive blade fuse and you're set. Light blue for 15A and yellow for 20A

I'd spend the contingency in the motor design and go for the 20.

A mongrel thing those ratings.

Remember those stereo systems? 6000W PMPO? Peak music power output....ahh the smell of marketing wank!

And I wonder about the comment from the supplier in the link above. More torque at 30A, more torque at 40A?
While Amps and torque relationship is fine, at 40A into 12V, that's 480W!

To be fair, I'm not sure it was the same model motor as the 200W I referred to so maybe that motor could handle 480W continuous.

The real world may tell me it all works great at 40A, but coming back to my point about the ratings..... Can get confusing.