Harbor Freight 3lb "Rock Tumbler"....Is this worth the money?

[BlastFromThePast]

Well I returned the second POS tumbler. Again it ran for 5 minutes then stopped. I retensioned the belt, lubricated the rollers, and no improvement. I think I'm going to just make one myself. It's crazy how so many people here have them and they work fine. Maybe I put a curse on them because I said "is it worth the money" . It was a sad sad day. Had to drive to harbor freight 4 times in the last 2 days.

[Shadowcat1969]

I use the 6 pound mill with one jar on it and it works well. I usually have to let it spin up and then put the jar on, when I would much rather remote start, but it works. I keep the roller surfaces and the outside of the jar well cleaned and buffed with fine sandpaper.

 

I got my 6 pounder for $35 a couple years ago during one of Harbor Freights sidewalk sale, so you might get lucky in the next couple months, I'm sure they have one coming as soon as the weather breaks for good.

[dynomike1]

Just as well. Your going to build one anyway. The motor is going to be the hardest thing to find.

[nater]

I built a larger mill using a 5 quart thumlers model b jar, and the motor was the easiest part to find. The replacement jars for the tumbler were all backordered for a while.

[dynomike1]

I'm using 6x8" PVC scrapped everything but motor.

[psyco_1322]

You might take the mill out of the box and test it there at the store before leaving with it. That way you know it works and don't waste any unneeded trips.

 

I think oiling the mills is definitely what keeps them going. Not only oil the points where the rollers are, but also oil the motor, if it has a place for it. My Thumlers has two slots on the ends of the motor to oil the bearings inside, and boy does it like it!

[Arthur]

Given Mumbles good reports for this mill yet you have two failures, I'd have a good look at everything soon! Were they possibly 230v mills? Old stock with dried grease in bearings.

Some tumblers have motors as low as 20watts so getting stuck is easy! Ball mills tend to have bigger motors and the guy who once used a 50gal plastic drum for a mill used three phase and a ramp up controller! He did make 35Kilos of powder in three hours though.

[Bobosan]

Everyone has experience with the 6lb tumblers. The OP, BlastfromthePast, is getting the single drum 3lb tumbler. There may be a difference in motor capacity.

[psyco_1322]

Here in the US, most everything is run on 120V. The only stuff that's 240V is large appliances, such as washer/dryer, AC units, and heavy equipment like welders. The 240V cords are quite larger and unmistakable when it comes to the outlet, since they are completely different shapes.

 

While the single drum ones might have a different motor, he did say it wouldn't even run without the drum on it.

[Bobosan]

yup, he did mention that. Sounds like the HF store got a shipment of returns from other HF stores.

[Mumbles]

The HF mill that I had was a single jar model. I never had any issues starting or running batches. I did let the motor and stuff get up to speed, then add the jar, or give it a little kick start. It didn't have the torque to get going, but once it did it was usually fine. I also had to run it with the jar in a certain orientation. The rubber jar would rub against the body of the mill otherwise and sometimes generate enough friction to stop everything.

 

Maybe I just got lucky with mine. I was once told that both models have the exact same motor, but things may have changed since I got mine circa 2001/2.

 

If you do go the route of making your own, we can certainly help. It's not all that difficult, and actually not all that expensive if you're patient with ebay or have some good sources for certain materials.

[BlastFromThePast]

I appreciate it. I'm gonna pick up a washing machine motor that I have at my parents house tomorrow and I'll make a wooden frame for it. I just have source a place to get some pillow block bearings and a belt.

 

Also, what's an optimal RPM for a ball mill?

Edited March 27, 2013 by BlastFromThePast

[Mumbles]

The optimal RPM of a jar is dependent upon the size of jar and media you're using. For most conventional sized mills, somewhere between 65 and 80rpm is usually around the sweet spot.

 

The critical speed is calculated by taking 265.95/sqrt(Jar ID - media diameter). The critical speed is the speed at which the media will be stuck to the side of the jar by centipetal force. 65% of the critical speed is considered to be about optimal. Some other factors can allegedly play a role, such as jar geometry and adjusting for slip.

[Dean411]

I haven't read everything thats been typed up but are you overloading the jar it cant handle a jar weighing 15lbs.

I have a 3 and 6 lb HF model and haven't had any problems if there not overloaded with weight.

 

Dean

[Mumbles]

A fully and properly loaded 4" jar with lead weighs around 6lbs.

[BlastFromThePast]

"I haven't read everything thats been typed up but are you overloading the jar it cant handle a jar weighing 15lbs.

I have a 3 and 6 lb HF model and haven't had any problems if there not overloaded with weight.

 

Dean"

 

 

Okay, the issue had absolutely nothing to do with an overloaded jar. As I stated before, the mill would start up (with no jar even on it), run at top speed for maybe 1 minute, and then would stop due to an excessive amount of friction somewhere in the system. I tried to troubleshoot every possible area where the friction could occur, and it did not help. When I tried to spin it manually, again with no jar on it, it would squeak and not rotate on its own... Let's move past this as I have returned it to HF.

Edited March 27, 2013 by BlastFromThePast

[Shadowcat1969]

I actually found that I had an issue with mine when I had the belt tension TOO tight, believe it or not. Once I found the sweet spot, it's been working great!

[layedbackkustomz]

How about save yourself the head ache and just buy a lortone rock tumbler from ebay or amazon. there built to last and run great plus you can pick them up for 40-50 bucks. now if you go the route of making a proper mill then sit down and prepare your self for the cost involved. now you can get lucky and build one for 50 bucks like you see so many people have on the net. but by experiance it doesnt work that way and can cost up to 250-300 for the mill then wiring can be a hassle because if its done wrong the motor can burn up.now lets talk cost for the jars. a 1 gallon jar uses 6" pvc pipe and end fittings the fittings can be as much as 10-20 a piece depending on your local market then you need primer and glue and a rubber test cap. now here is the kicker to fill the drum with a proper load of media can cost about 100 for lead and much more for ceramic. as far as alumina i have a big bag of it but its too light so dont waste your money on it. now with all that said i really like the lortone rock tumbler and have never had a issue with it. and its not much of a investment to get started and to see if its something your going to keep doing.and if it is then think about making a mill of bigger size. what im saying is it will cost more to make a small mill of the same size as a lortone tumbler. now to let you know the best thing i ever did was to make a proper mill and 2.2 lbs in 3 hours of some awesome powder is worth every penny i put into the mill.

[BlastFromThePast]

Is there a way to remove the rollers from the HF mill. I want to clean the portion that passes through the plastic bearings and apply some performance oil to it. The last two I had I think were really gummed up with something which is why it wouldn't even rotate. I want to avoid another trip back to the store

[Bobosan]

Check the Skylighter thread below. It has information on modifications and pics of roller removal.

 

http://www.skylighter.com/fireworks/how-to/ball-mill.asp

[BlastFromThePast]

Can someone tell me what kind of oil they use to lubricate the roller bearings? I found some "fellowes performance oil" here and the msds says that it's pure canola oil, which seemed to work pretty well for the first run yesterday. The only thing is that when the batch finished and I took a look at the point where the roller enters the bearing, the oil had taken on a black color. I thought maybe there was some kind of plastic solvent in the oil I had used which is why I looked up the msds but as far as I know, plastic doesn't dissolve in canola oil..So I'm just making sure it's normal to see this.

[Bobosan]

That Skylighter article shows 3 in 1 oil being used. I used to use light sewing machine oil but now use Marvel Mystery oil. Regardless of what you use, the bearings are going to wear and in the process, produce the black dirty oil you see. Clean off and add drop of oil to each one before every mill run.

[BlastFromThePast]

Will do. When you say wear, though, I mean, people here have the same mill and have been using it for at least a year or so if not longer, right?

[Bobosan]

Right.....and if cleaned and oiled before each use, should last a long time.

 

Mine is over 3 years old and even with cleaning and oiling the plastic bearings, they wore so much that the rollers had a lot of slop inside the plastic bearings.. I replaced them with bronze oilite ones. I think newer 6 lb tumblers have a black plastic bearing of some type material. The older one I have used a white plastic material.

 

A loaded drum is going to exert a lot of downward and lateral force on the rollers and bearings so cleaning and oiling will help keep it running longer.

[Mumbles]

Yes. They will not last forever, but properly taken care of you should be able to get several years out of it, at least based on personal experience and reports from others. About the only thing I needed to replace on mine was the belt every so often, along with periodic cleaning and oiling. There was often a black dust around my milling area, especially after heavy use. I was never quite sure if it was from the oil, the coating on the rollers, the rubber jar rubbing, or the belt. It was probably some combination, plus some charcoal or blackpowder.