Ball Milling FAQ

[moondogman]

The ebay seller link below has a very good selection of pulleys @ good prices.

 

http://shop.ebay.com...1.c0.m270.l1313

 

 

EDIT TO ADD:

Would it be any benifit to have both rollers under power?

Rather than one under power & the other free wheeling.

 

Old guy

 

Thats who I got it from. Way fast shipping got it yesterday. The prob with driving both shafts in my situation would be that pulleys would prevent me from putting the shafts close enough together unless i got a double pulley for the drive pulley. I have everything now to start assembly except the jar.

 

Steve

[oldguy]

LOL,

 

I bought my 1 inch solid steel shafts today from a local steel yard.

Pillow block bearings arrived in the mail yesterday.

Pulleys are in the mail.

It's coming togather slow but sure.

[Bilbobaker]

Can we define properties and chemical reasons for choosing different woods to char. conv.?

Seems to me basa and cotton wood are light enough as both balsa and willow but wouldn't some cedars do well also?

[Mumbles]

It's primarily trial and error, but there do tend to be trends. Relatively lightweight low resin woods tend to be the best. Woods that are very dense tend to be slower. Woods with a lot of sap tend to be the best for sparks. It gives guesses for how well certain things will work, but you never know until you try. There are many examples that do not necessarily fit into those trends.

[oldguy]

Slowly coming togather.

 

[oldguy]

1 INCH (116M) PILLOW BLOCK BEARINGS

 

 

[marks265]

OOOOH nice bearings old guy. Looks like you'll have something pretty nice when you're done.

 

Mark

[dagabu]

I hate to be a bother but what will each of the jars weigh when full? The shaft may need a center support due to sag. You will see the jars wearing quickly at the point of contact so a guide or hold off may be needed.

[oldguy]

It’s a work in progress. I decided to drive both shafts that turn the jar, or jars. Waiting for another 6 inch pulley now & hope it arrives today. Rather that a 1/3^rd HP, I upgraded to a brand new TEFC ½ HP. Once all the parts are here, I will do a final mock-up. To insure everything fits well. Then, sand, prime & paint the platform before the final bolt it all together. Last but not least, I have to finish the jars. Then we will see what this little puppy will do. I would guess its about 80 lb capacity, running both big jars.

 

 

[oldguy]

I hate to be a bother but what will each of the jars weigh when full? The shaft may need a center support due to sag. You will see the jars wearing quickly at the point of contact so a guide or hold off may be needed.

 

Thanks for the heads up.

The 12X12 jars will run about 40 possibly 45 lbs apiece including media.

Both shafts are 1 inch solid cold roll steel, both under power.

If need be, I will add a center pillow block bearing to both shafts.

Just have to wait & see how they roll.

Adding 2 more pillow block bearings and guide's where needed would be easy.

 

LOL, I'm glad I enjoy building this, as it adds up a little at a time.

Just bought 8 ft of 1 inch ID automotive heater hose to slide over the roller rods @ $20.

Also bought brush on paint for the platform @ $22.

Edited April 9, 2011 by oldguy

[oldguy]

2nd 6 inch pulley & 3 end caps arrrived today.

Pressing bearings on shafts now.

Glad I have a press, otherwise that would be a SOB.

[pyrogeorge]

oldguy

I suggest you to put two pulleys at the back of axes to avoid slipping..

you can se my mill..

[oldguy]

I don't think anything will slip with my design.

I have the pulleys already & there will be an swing arm idler pulley on the driver belt to adjust belt tension.

 

 

This is the platforn on a rolling work bench.

It will be double platform & have 2 inch square tube steel legs when finished.

Motor will be on the lower platform.

 

Cocktail hour is at hand, more tomarrow.

[Bonny]

Pressing bearings on shafts now.

Glad I have a press, otherwise that would be a SOB.

 

Are you talking about the pillow block bearings? They should never need to be pressed. They should slide freely on a cold rolled shaft. Even on a tighter tolerance shaft like 'superior turned and ground' the bearings should not need pressing.

 

I don't think anything will slip with my design.

I have the pulleys already & there will be an swing arm idler pulley on the driver belt to adjust belt tension.

 

This is the platforn on a rolling work bench.

It will be double platform & have 2 inch square tube steel legs when finished.

Motor will be on the lower platform.

 

Cocktail hour is at hand, more tomarrow.

 

That's a great looking set up. That should last forever and pound out the BP. Great idea on the idler for tension, especially with a rig that size.

Something to try, on the pillow blocks, tighten the lock collar and set screw on one end of each shaft only. The bearings should last longer as they won't be stressed from bending/expansion/contraction of the shaft.

[dagabu]

Are you talking about the pillow block bearings? They should never need to be pressed. They should slide freely on a cold rolled shaft. Even on a tighter tolerance shaft like 'superior turned and ground' the bearings should not need pressing.

 

 

 

That's a great looking set up. That should last forever and pound out the BP. Great idea on the idler for tension, especially with a rig that size.

Something to try, on the pillow blocks, tighten the lock collar and set screw on one end of each shaft only. The bearings should last longer as they won't be stressed from bending/expansion/contraction of the shaft.

 

Bonny, are you an HVAC guy? I use that same trick on some on my problematic blowers and get much better life from DODGE L-50 pillowblocks.

[oldguy]

Are you talking about the pillow block bearings? They should never need to be pressed. They should slide freely on a cold rolled shaft. Even on a tighter tolerance shaft like 'superior turned and ground' the bearings should not need pressing.

 

That's a great looking set up. That should last forever and pound out the BP. Great idea on the idler for tension, especially with a rig that size.

Something to try, on the pillow blocks, tighten the lock collar and set screw on one end of each shaft only. The bearings should last longer as they won't be stressed from bending/expansion/contraction of the shaft.

 

Thanks for the heads up on the lock collar & set screws tightened on one end only.

I thought the bearings would slide right on, along with a few nudges from a rubber mallet.

I agree they should not need to be pressed on. Oddly, they did.

So I slid a 1 & 1/8th inch ID steel tube over the end of the rod - against the bearing & used the press to jack them into place.

For some odd reason, the tolerance was VERY tight. Maybe Chinese steel, who knows.

Hell if I know why, but they are on now.

[Bonny]

Bonny, are you an HVAC guy? I use that same trick on some on my problematic blowers and get much better life from DODGE L-50 pillowblocks.

 

No,but I spent almost 6 years working in a machine shop.

 

Thanks for the heads up on the lock collar & set screws tightened on one end only.

I thought the bearings would slide right on, along with a few nudges from a rubber mallet.

I agree they should not need to be pressed on. Oddly, they did.

So I slid a 1 & 1/8th inch ID steel tube over the end of the rod - against the bearing & used the press to jack them into place.

For some odd reason, the tolerance was VERY tight. Maybe Chinese steel, who knows.

Hell if I know why, but they are on now.

 

Was the steel rusty or dented up ap at all? It doesn't take much to make bearings a bitch to get on. Also, do the lock collars have 2 set screws each? If so, tighten them both first. Then 1 screw at a time, crack it loose and re-tighten. The screw bites a bit deeper that way.

[dagabu]

The shaft may have needed dressing first like Bonny says. This is important because you will never get the bearings off the shaft if you dont have 1-2 thousandths play between the shaft and collar. Even good American ground shafts need to be dressed from time to time. Also, a chamfer at the end of the shaft will save you lots of headaches since a shaft end will dent easily and cause a locked on bearing easily.

[oldguy]

Hung over today, way to much free booze, black jack & casino fun last night. But alls well that ends well, as we left considerably ahead. They had a killer lounge band that did great Vietnam war era Motown type soul music, so this old guy & wife was out showing the youngsters even old folks can still shake a booty without looking like stupid fools.

 

Shafts were a little rusty. I hand sanded them. Looking back I should have used a wire stripper wheel on a grinder hub to take them down to shiny bright steel. My bad, the only way these bearings will come off is with a hydraulic gear puller (which I have). Beforehand, I did put a slight camphor on the shaft end edges & have the protruding ends covered with crutch tip to protect them.

 

Once it’s all together I may fabricate a sheet metal guard to cover the pulleys & belts,. LOL, have not touched a sheet metal brake in 25 years, but have access to one. So, I may do that as a safety factor

 

Just out of curiosity what is the average life span of a bearing like this (Browning VPS 116M). I would guess they will outlast me. But, if not, they would be easy to change out, as everything is right on top & easy to get at.

 

 

[Bonny]

Hung over today, way to much free booze, black jack & casino fun last night. But alls well that ends well, as we left considerably ahead. They had a killer lounge band that did great Vietnam war era Motown type soul music, so this old guy & wife was out showing the youngsters even old folks can still shake a booty without looking like stupid fools.

 

Shafts were a little rusty. I hand sanded them. Looking back I should have used a wire stripper wheel on a grinder hub to take them down to shiny bright steel. My bad, the only way these bearings will come off is with a hydraulic gear puller (which I have). Beforehand, I did put a slight camphor on the shaft end edges & have the protruding ends covered with crutch tip to protect them.

 

Once it’s all together I may fabricate a sheet metal guard to cover the pulleys & belts,. LOL, have not touched a sheet metal brake in 25 years, but have access to one. So, I may do that as a safety factor

 

Just out of curiosity what is the average life span of a bearing like this (Browning VPS 116M). I would guess they will outlast me. But, if not, they would be easy to change out, as everything is right on top & easy to get at.

 

Glad you had a great time last night...hangovers suck at any age though! Unless you have kids or idiots wandering around, I wouldn't bother with the guards. Put it this way, NO ONE should be close while it's operating.

As for the bearings, they should last quite awhile. You can't really estimate a "lifetime" as it depends on usage.

[oldguy]

Milling bland single chem's, I will do that in the shop. But, behind a framed in sound proofed plywood blast shield. For more reactive mixes, BP & the like, that I will do in a small bunker built of sand filled cinder block mortared together, reinforced with plywood, covered with sand and tin roof. You are right, no children, grandchildren or stumbling idiots will be around when milling goes on. So, belt guards would not be a necessity. For the most part, the mill is being built in the hope I can mill - 8 mesh mg/al down to - 50 to 100 mesh. LOL, I would hate to see the mill go up in flames. But, nothing ventured, nothing gained. I have about 50 some pounds of small mg/al ingots I made ready & waiting for crushing & screening, to be milled down.. Edited April 11, 2011 by oldguy

[oldguy]

1/2 HP TEFC motor is bigger tham my little 3 lb harbor freight rig.

[moondogman]

Updup's math and answer are correct despite using a couple extra steps. (and using pi as a verb )

 

Ratios of the diameters are sufficient.

 

7" OD jar / 1.5" OD roller = 4.67 turns of roller per turn of jar (280 rpm)

 

280rpm * X diameter pully = 1725rpm * 2" diameter pully

 

12.32" pulley.

 

 

Now, the optimal speed in these jars is actually closer to 75rpm, so that more closely corresponds to a 10" pulley. You may have more luck finding them if you refer to them as sheaves instead of pulleys.They're also not cheap. I found the correct size for about $40 at the cheapest.

 

Nailed it. I finished putting the mill together yesterday. 76 rpm im gonna mill some Kno3 today and give it a try.

[oldguy]

 

All thats left on the mill is to bolt the motor down, add the idler arm tension pulley, a belt & this little 90 lb capacity mill is spinning.

[WSM]

Milling bland single chem's, I will do that in the shop. But, behind a framed in sound proofed plywood blast shield. For more reactive mixes, BP & the like, that I will do in a small bunker built of sand filled cinder block mortared together, reinforced with plywood, covered with sand and tin roof. You are right, no children, grandchildren or stumbling idiots will be around when milling goes on. So, belt guards would not be a necessity. For the most part, the mill is being built in the hope I can mill - 8 mesh mg/al down to - 50 to 100 mesh. LOL, I would hate to see the mill go up in flames. But, nothing ventured, nothing gained. I have about 50 some pounds of small mg/al ingots I made ready & waiting for crushing & screening, to be milled down..

 

Hi oldguy,

 

If you leave the MgAl ingots alone and only mill what you will need in the immediate future, it will always be "fresh". I've considered that ingots would be the best way to store it...

 

My two cents worth...

 

WSM

 

Nice mill, by the way!

Edited January 1, 2012 by WSM