635 replies to this topic

[RegimentalPyro]

Those rollers are good - I have some in my ball mill. You'll want some 1621 bearings [halfinch InnerDiam] to go with them. The 1621-2RS [2 Rubber Seals] provides some measure of protection against the ingress of powders etc into the workings of the bearing.

However for those who are a bit financially challenged there is a much cheaper way, although you do have to have access to a woodlathe.

Nip down to wilkinson or similar and puchase a couple of wooden rolling pins from the cooks department. Use a woodlathe to form spindles of the desired size for your bearings and pulleys

Now take an old bicycle inner tube and cut it into segments the length of the rolling pins. Ease and push the rolling pins up the middle of the inner tube segments so that they are encased.

Hey presto cheap [?1.50ish] sturdy rollers for your ball mill.

Edited by RegimentalPyro, 16 December 2005 - 09:50 AM.

[richard2]

[quote Ritual33 Posted Today, 03:53 AM
i see 10 for ?16.91 :| ]

That does not include postage. The guy selling them is in the US and postage is only by airmail so is even more than the rollers cost. If I could find something similar in the UK then I would not bother however I can't.

Regards

Rich

[Draco_Americanus]

I hear about alot of people having the motor burn out after a day of heavy use, this might not be the case with everyone, but it happens alot.
But if you can make your own, by all means do so, custom made to your liking and you'll get much bigger loads.

I think people that have a rocktumble fail are overloading the poor thing. Now if you are useing a cheap harbor frieght one, then chances are you blew a belt and not a motor or the belt is too tight. I have both a loretone and a harborfreight rocktumbler and after useing a better belt on the harborfreight one it works quite well for what it is and have run it for weeks. (I used a fiber reinforced v-belt on the harborfreight one)

[EnigmaticBiker]

Tomorrow im going on a motor-hunt, I'll be going to washing machine repair places etc and to the recycling place and backstreets lol, I live in a crappy area so I'm sure I'll find one down a back ally somewhere, just wondering my dad seems to think a washing machine wont work because its designed to run both ways, is there any special motor I need to look out for? I can I just rip anyold one out? Does it need to be the main motor or the pump motor? Im confused :S

Drew

I just built a mill with a windscreen wiper motor I got from ebay for 50p!
Whole mill cost less than ?15!

PM me if you want details or I'll post if others are interested.

Simon

[karlfoxman]

I just built a mill with a windscreen wiper motor I got from ebay for 50p!
Whole mill cost less than ?15!

PM me if you want details or I'll post if others are interested.

Simon

Yeah post pictures please, i will post the pictures of mine and wazi's mill soon. We used a ac motor geared down to 80rpm by worm drives, huge torque.

[Ritual33]

I'm interested, i thought windscreen motors were not rated to be run all the time?

Anyways post post post!

Regards,
Drew

[EnigmaticBiker]

I'm interested, i thought windscreen motors were not rated to be run all the time?

Anyways post post post!

Regards,
Drew

Please bear in mind I've built this to be as cheap as possible (whilst still being fairly safe).

1 Land Rover front windscreen motor 0.50 the joy of ebay!
1 m 10mm steel studding 2.30
4 25mm OD 10mm ID sealed bearings 3.50
4 plumbing clamps 0.40
~600mm 7mm ID rubber brake hose offcut 2.00
2 80mm "jubilee" hose clips 2.30
2 15mm "jubilee" hose clips 1.00

had the wood/fastners/glue/rubber sheet/electric bits already.

Windscreen wiper motors seem to be reliable even when used for hours on end (I'm sure someone mentioned it earlier in this thread).

It is a well sealed motor that does not get hot after more than an hours use.

The worm drive mechanism and housing etc were ground off, leaving its' shaft exposed and it was mounted with a large screw on a few sheets of nice smooth rubber sheet to damp the vibrations.
Ok, I've been driinking.

I used a section of brake hose for a flexible direct drive to a roller and for the surface of the rollers.

Power supply (2amp) needs to be properly sorted as this is the limitation; getting rather warm and can cut out after a couple of hours.To get the speed correct it's running at about 6-9v, using an old rheostat controller from a heater to restrict input voltage to the transformer.

I'm now testing various free media I can find or make:- marbles, lead alloy filled pipe, might try granite or flint pebbles (not for dry compositions obviously).

Will post a pic soon,

Simon

[karlfoxman]

For a power supply your best off using PWM as this will keep the torque there. I used it many times and its pretty good, using MOSFETS you can get 10-30 amp easily.

[EnigmaticBiker]

For a power supply your best off using PWM as this will keep the torque there. I used it many times and its pretty good, using MOSFETS you can get 10-30 amp easily.

You're right, the makeshift power supply is only adequate for light loads, when I tried a jar with lead filled copper tube it doesn't have the torque. I got it working using an old bike battery, using the supply to charge it.

Not sure what PWM means, Power wave management?

I was thinking of a cheap 6v lead-acid battery charger.

Know very little about MOSFET components, is there a inexpensive standard item or circuit that can be simply wired up.

Simon

[karlfoxman]

You're right, the makeshift power supply is only adequate for light loads, when I tried a jar with lead filled copper tube it doesn't have the torque. I got it working using an old bike battery, using the supply to charge it.

Not sure what PWM means, Power wave management?

I was thinking of a cheap 6v lead-acid battery charger.

Know very little about MOSFET components, is there a inexpensive standard item or circuit that can be simply wired up.

Simon

PWM = PULSE WIDTH MODULATION, have a read of THIS if you are good with soldering then build it. It will handle more than 20 amps and will turn that no problem keeping the torque as it pulses the motor on and off. The faster it pulses the faster the motor goes. Radio control cars use them for the motors. I guess with simple mods a RC car speed control will do it, and it will be remote Ensure no one is on your frequency!

Edited by karlfoxman, 29 December 2005 - 01:51 PM.

[paul]

http://www.eleinmec.com/category.asp?1

This page shows techniques for PWM and so on in a way easily understandable to the beginner.

I think it is not that complex like the link above...

[EnigmaticBiker]

PWM = PULSE WIDTH MODULATION, have a read of THIS if you are good with soldering then build it. It will handle more than 20 amps and will turn that no problem keeping the torque as it pulses the motor on and off. The faster it pulses the faster the motor goes. Radio control cars use them for the motors. I guess with simple mods a RC car speed control will do it, and it will be remote Ensure no one is on your frequency!

Interesting stuff, a bit too involved for me, as I daren't start another hobby at the moment, however tempting.
Useful to understand the principles behind motor control and the MOSFET components are surprisingly cheap.

I think I'll probably find the ideal voltage/power required for optimum speed, then build a substantial variable power supply around it.

The RC controller with variable frequency (+amp, +radio antenna) has amusingly evil potential don't think the police helicopters round here would appreciate it tho, neither would the judge . Could give a whole new angle on radio controlled flying.

Thanks for you input.

Simon

[EnigmaticBiker]

http://www.eleinmec.com/category.asp?1

This page shows techniques for PWM and so on in a way easily understandable to the beginner.

I think it is not that complex like the link above...

I might have a go at using the "Simple Motor control from AC" circuit. Until I get around to making a variable power supply or MOSFET based controller.

Managed to get the windscreen motor going well enough to make a batch of BP using large marbles, which worked ok. They do chip though, so will have a limited life.

Tried to mill shellac with marbles but it is far too hard.

Then I tried lead alloy filled 22mmOD x 25mm copper pipe, an amazing difference in quality!


Cheers,

Simon

[littlejohny]

I have made a real basic ball mill it uses an old fan motor it's got no belts just directly onto the shaft. It spins reasonably well, but the problem is after just 20mins of running it is to hot to touch thats without the milling jar on it either. will this be allright

[RegimentalPyro]

Hmmm - Prob not really.

The load of a mill jar charged with lead media will very likely burn out your motor. Try looking for something a bit more powerful. A search for "single phase motor" on Ebay will bring up a plethora of suitable motors.