Low bucks motorized grain mill

[IslandLizard]

I was in Harbor Freight last week and saw this little variable speed bench grinder and wondered if it might work, it's 1.3 amps which I'd guess would be about .2 horse so it probably stalls out pretty easy.
I've looked at small bench grinder motors before but this the only cheap variable speed model I've seen so far. It'd be about $42 after the usual 20% off coupon.

Great innovative idea, but...
That grinder spins way too fast: 10000 rpm at full power. That full power is not a lot to start with, and you lose more in the snake, if it doesn't burn up at even 10% of that speed.

 

[BeardedIdiot]

I placed my order based on this thread as well. So far I'm into the project:



Cereal Killer - $99.00

Motor - $22.65

Lovejoys - $14.07

Overkill ATX PSU - $0.00

Wires and Bolts - $0.00 (hopefully)



I'm debating the dedicated stand right now... I'm running short on floor space and it might be better if I just kept everything confined to a bucket-top approach.

I'm planning a dedicated stand, so that I have everything collected together in one place. Right now I weigh in one spot, collect weighed grain in another, Mill somewhere else, and store my mill, bucket, and drill in 3 separate spots. With a cart, it's all contained together and I never have to look for anything.

 

[J_Hanna]

Great innovative idea, but...
That grinder spins way too fast: 10000 rpm at full power. That full power is not a lot to start with, and you lose more in the snake, if it doesn't burn up at even 10% of that speed.

I just assumed that since it has a 0 to 10000 rpm variable speed motor you could run it around the 300 rpm sweet spot, it would be tricky to actually tell what rpm it was turning at but a little trial and error should get you in the ballpark.
I don't think anybody would seriously consider connecting it via the flex shaft. Most people would remove the flex shaft and both grinding wheels and connect a lovejoy to the one of the 2 output shafts.
As far as power goes the original Molon AC motor I used worked okay and it was only .33 amps, the grinder is 1.3 amps so it might work fine, or it might not. I'm pretty happy with the DC motor so I won't be buying one to find out.

 

[IslandLizard]

I just assumed that since it has a 0 to 10000 rpm variable speed motor you could run it around the 300 rpm sweet spot, it would be tricky to actually tell what rpm it was turning at but a little trial and error should get you in the ballpark.
I don't think anybody would seriously consider connecting it via the flex shaft. Most people would remove the flex shaft and both grinding wheels and connect a lovejoy to the one of the 2 output shafts.
As far as power goes the original Molon AC motor I used worked okay and it was only .33 amps, the grinder is 1.3 amps so it might work fine, or it might not. I'm pretty happy with the DC motor so I won't be buying one to find out.

I looked at your blog, you've got some interesting projects!

Reading a bit closer I now understand better what you're after.

My HF 1/2" heavy duty low speed drill I use on my Monster Mill (MM, 1.5" rollers) has a 7.5A motor (110V). I run it at about 1/3 to half the speed and certainly starts to groan and pull amps when milling. The speed is probably controlled through a simple Triac so it won't supply the full 800W, but possibly 250-400W at those speeds and at maximum torque. That's around 2.3-3.6A.

It would be hard to believe that 1.3A bench grinder motor could pull a roller mill especially at highly reduced speeds. My old 200W drill couldn't, would stall and just hum.

 

[J_Hanna]

I'm sure you're right. After thinking about it for a few minutes I believe the Molox only worked because it had a gearbox, the free spinning small bench grinder would probably bog down very easily at 300 rpm.

That little bench grinder looks interesting though, I'd really like to find a use for it other than chewing up pocket knives.

 

[govner1]

I just assumed that since it has a 0 to 10000 rpm variable speed motor you could run it around the 300 rpm sweet spot, it would be tricky to actually tell what rpm it was turning at but a little trial and error should get you in the ballpark.

I don't think anybody would seriously consider connecting it via the flex shaft. Most people would remove the flex shaft and both grinding wheels and connect a lovejoy to the one of the 2 output shafts.

As far as power goes the original Molon AC motor I used worked okay and it was only .33 amps, the grinder is 1.3 amps so it might work fine, or it might not. I'm pretty happy with the DC motor so I won't be buying one to find out.

Even 300 RPM is too fast. You need to mill at about 175-180 RPM.

 

[J_Hanna]

Sorry to offend, 300 rpm was the speed I was trying to set my drill press to for an unrelated project; it just got stuck in my mind. The last time I thought about the mill project was about a year ago and my memory isn't what it used to be...

 

[govner1]

Sorry to offend, 300 rpm was the speed I was trying to set my drill press to for an unrelated project; it just got stuck in my mind. The last time I thought about the mill project was about a year ago and my memory isn't what it used to be...

It's the first thing to go!
I know from experience. Just ask SWMBO!!

 

[BeardedIdiot]

Just ordered the worm drive, Lovejoy couplers, switch, and spider fitting (how is the spider fitting 4x the cost of the couplers?!).

I've got a cereal killer grain mill I got for Christmas. Hopefully this power supply will work with it.

Well. The Lovejoy couplings and spider showed up today. Neither of the couplings are the right size, and Amazon sent the wrong spider size.



I'm going to stop by Grainger tomorrow to see if they have the right sizes in stock. Hopefully I can get all 3 pieces tomorrow. If not, it will just have to wait until next week.

Sigh.

 

[govner1]

I ordered my Lovejoys from one of their local distributors. The spiders were the least costly item.

 

[BeardedIdiot]

I ordered my Lovejoys from one of their local distributors. The spiders were the least costly item.

The reason this spider was so expensive is because they sent me the wrong one. The Lovejoy couplers are size L050. The spider they sent was L099. It was at least double the size it should have been.

I'm returning the spider and at least one of the couplers. I've got a couple more on order from Grainger to try. I'm probably going to have to grind down the motor shaft. the 7/16" coupler is too small, and the 1/2" coupler is too big.

 

[govner1]

Have you looked at metric sizes?

 

[Spellman]

I'm using a 11mm coupler on the cereal killer, and a 12mm on the seat motor shaft.

I forget if I posted anything about this or not, but I broke my car seat motor about a year ago. I had some red wheat that it had an awful time with and was stalling my 16a atx supply. I didn't have a reverse wired in and I got the bright idea that if I manually turn the motor in reverse a little it would dislodge the stuck grain and I would be able to continue milling. Well it dislodged it, but I also stripped the internal gears on the motor and ruined it. User error, my fault. I then hooked up the molon motor and have been using that since. Every time I brew I think, oh I should get another seat motor and try again, but never get around to it. This new cheap power supply has renewed my interest and I just might get around to doing it now!

 

[BeardedIdiot]

Have you looked at metric sizes?

I'm checking metric sizes on Monday. Hopefully those will fit without any adjustments.

 

[govner1]

I'm checking metric sizes on Monday. Hopefully those will fit without any adjustments.

One of mine required a keyed metric (motor) & std non keyed (MM 3 roller mill). Lovejoy had both.

 

[BeardedBrews]

I placed my order

Well, I also received the wrong spider, but it was 100% my fault. A quick trip to Grainger and $3 fixed that problem.

I have all the parts now, just need to find time to work on piecing it together, hopefully I will have time before this weekend. There's 80# of grain burning a hole in my pocket!

 

[BeardedIdiot]

FYI, anyone using the car seat motor, you can buy the correct electrical adapter on Amazon:

http://www.amazon.com/dp/B00RW3BZWA/?tag=skimlinks_replacement-20

It's $14.78 right now. Not as cheap as a couple of spade bits, but its got nice long leads, and a locking clasp, and you don't have to alter the motor in any way.

 

[BeardedBrews]

Victory is mine!

http://youtu.be/CP7_ZC6w304

 

[Huaco]

Ok @BeardedBrews @BeardedIdiot. I know you one of you had a mix-up on your Love Joy's. What sizes did you end up using? What are you using for your power supply?

 

[BeardedBrews]

Ok @BeardedBrews @BeardedIdiot. I know you one of you had a mix-up on your Love Joy's. What sizes did you end up using? What are you using for your power supply?

I'm using these

11mm no keyway for the cereal killer

12mm with keyway (because I can't read) for the seat motor

Basically, you want 11mm and 12mm, or get pretty close with the cheapest available standard size.

I did L050 couplings which seem about right, and like an idiot, I initially ordered the L075 spider (too big). Grainger hooked me up for $3.00 on a correct L050 spider, and it turns out I could have just gotten the couplings from them too.

 

[BeardedBrews]

What are you using for your power supply?

Forgot part of your question.

I'm using an 850W ATX power supply (massive overkill at 70+ amps but since it was sitting in my basement, it was free). It is a "single rail" with two modular PCI connections. I took a single 12v wire and a single ground wire from one of the PCI pigtails to drive the motor, and I'm using the power supply switch to turn it on and off.

I suspect that the 16 gauge wire that's the PCI pigtail isn't going to love a constant 20 amp draw, but I'll have to crush more than a pound to know that for sure.

I tried to capture the turn rate on the shaft during the crush, I'd say it would be a very rigorous rate if you were turning the hand crank that fast, but slow for a drill. When I run my next batch I will try to count the RPMs.

 

[Huaco]

I'm using an 850W ATX power supply (massive overkill at 70+ amps but since it was sitting in my basement, it was free). It is a "single rail" with two modular PCI connections. I took a single 12v wire and a single ground wire from one of the PCI pigtails to drive the motor, and I'm using the power supply switch to turn it on and off.

So, I picked up a ~280W single rail power supply yesterday from my IT guy in the office. Whey you say your 850W is overkill, how much overkill do you have? You think my 280W ps will work? If not, I can just pivot my plan with that ps and use it as a benchtop power supply for other projects.

 

[govner1]

Well, I also received the wrong spider, but it was 100% my fault. A quick trip to Grainger and $3 fixed that problem.



I have all the parts now, just need to find time to work on piecing it together, hopefully I will have time before this weekend. There's 80# of grain burning a hole in my pocket!

I wouldn't mill more than you need immediately. Shelf life on properly stored in milled grain is longer than milled.

 

[BeardedBrews]

So, I picked up a ~280W single rail power supply yesterday from my IT guy in the office. Whey you say your 850W is overkill, how much overkill do you have? You think my 280W ps will work? If not, I can just pivot my plan with that ps and use it as a benchtop power supply for other projects.

The motor specs claim to stall at 25 amps, which is like 320w at 12v DC.

I would bet you will be fine. Mine didn't seem to get close to stalling, I'd say it has plenty of spare power.

 

[BeardedIdiot]

Ok @BeardedBrews @BeardedIdiot. I know you one of you had a mix-up on your Love Joy's. What sizes did you end up using? What are you using for your power supply?

I'm using these

11mm no keyway for the cereal killer

12mm with keyway (because I can't read) for the seat motor

Basically, you want 11mm and 12mm, or get pretty close with the cheapest available standard size.

I did L050 couplings which seem about right, and like an idiot, I initially ordered the L075 spider (too big). Grainger hooked me up for $3.00 on a correct L050 spider, and it turns out I could have just gotten the couplings from them too.

I'm using L050 couplings from Grainger. 10mm for the Cereal Killer and 12mm for the motor. 11mm was too big for the mill for me. The 10mm slides on smooth but has no wobble whatsoever. Same for the 12mm on the motor shaft. Slides on smooth with no wobble.

I also got an L050 spider from Grainger. I'm returning the spider and couplings I got from Amazon, since none of them are the right size for anything .

Edit: I am only returning the spider. It costs as much to ship the couplings back as I paid for them, so I'll keep them and try to find some other project to use them for.

I'm going to try to get my ATX power supply wiring fixed up, and get everything connected together to see how it runs this weekend. I don't have a brew day planned at the moment, so I'm not sure if I'll be able to run any grain through or not. I might have some really old grain I don't want to use that I can try it with.

I'll post pictures of any progress I make.

 

[BeardedIdiot]

Wire 1 black up to the green, with a switch between if you want it to have an on/off switch. That fakes the supply into thinking there is a motherboard attached and turns on the supply. I soldered all the black (neutral) together with a lead running to the motor as well.

Hey Spellman, when you say wire "1 black up to the green, with a switch between", do you mean you soldered all the black together with a lead to the motor, except for 1 black wire which you connected to 1 side of the switch, with the green connected to the other side? Is this because with the switch between the green and a black, cutting it off cuts of power to the green and it turns the power off?

Just want to make sure before I start soldering wires together this weekend.

 

[BeardedIdiot]

Well I clipped all the wires but black, yellow, and green. I haven't soldered them, but I do have then all wrapped together (blacks, yellows, and 1 black to the green). I'm wondering if my psu is different, because I'm not getting any voltage delivered through the wires. After an hour of screwing with it, I think I'm just going to buy a switching power supply off amazon like this one:

http://www.amazon.com/gp/product/B004MS4Z70/?tag=skimlinks_replacement-20

 

[BeardedBrews]

http://www.sidewindercomputers.com/atxpoonco.html

An atx power supply doesn't turn on until the mother board tells it to. There are two pins that you have to connect before you can get power.

I had a jumper thing like I linked. Many people just jam a paperclip in there, which works fine as well.

Search ATX Jumper for pictures and instructions on Google.

You will want to look at the data sheet for your power supply to see which of the wires actually have all 300 watts of 12v.

 

[BeardedBrews]

Well I clipped all the wires but black, yellow, and green. I haven't soldered them, but I do have then all wrapped together (blacks, yellows, and 1 black to the green). I'm wondering if my psu is different, because I'm not getting any voltage delivered through the wires. After an hour of screwing with it, I think I'm just going to buy a switching power supply off amazon like this one:

http://www.amazon.com/gp/product/B004MS4Z70/?tag=skimlinks_replacement-20

I was too slow typing

 

[Firewalker11]

I got my Lovejoys from Surplus Center, the drive motor too. I opted for a 60 RPM motor, less tearing, more crushing.