635 replies to this topic

[alany]

My baby mill uses a 40 W fan motor. It gets bloody hot, even with the small *cardboard* fan I made for it, but it works and handles a 3" jar OK. Unfortunately it got soaked a few days ago when a downpipe burst and flooded the pyro shack. It has gone all moldy and horrible and may need to be rebuilt from scratch.

[Amleth]

As i am aware, all washing machine motors are brush motors, so which motor inside a washing machine am i looking for?
i'm hunting tomorrow you see.

Drew

Actually, an awful lot of washing machine motors are induction motors. I've recovered five of them from various abandoned machines and have yet to find a brush motor. And not all washing machine motors are bi-directional, either. Some may even have two seperate coils for different speeds, requiring you to pick a particular one to wire up and gear for in your design. What sort you find all depends on the manufacturer, as different ones take different design approaches to separating the operation of the agitator and the spin cycle...

My own mill runs from a single-direction, single-speed, 400w induction motor from a washing machine.

You may find dryers a better bet. They're all one-way, one-speed motors, so a lot easier to wire up, and they don't need to be as powerful as a washing machine motor as they don't have to shift as much mass, so they're often (but not always) smaller. However, if you're scavenging freebies and not exactly spoiled for choice, any of the above will work just fine if configured correctly.

Edit: Typos.

Edited by Amleth, 27 January 2006 - 07:11 AM.

[Plays with Fire]

Heya, so far I've been using a ball mill made from an old Lego Robotics set, including the motor (which was easily modified to accept my 6VDC input ), and glass marbles (yeah, I know...get over it!). It's fine for milling about 100g of bp at a time, but i want to make a better ball mill that can handle a larger load. I've successfully removed the motor from my father's treadmill , and plan to use it for the mill.

Anyone else ever use a treadmill motor for their mill? I'd be quite intrested in hearing about it...

Also, this thread mentions several times cutting brass rods into cylinders as media, but can any brass rod from the hobby shop be used, or must it specificly say "non-sparking"? The rods i have conduct electric current and im not sure if that is a sign of whether or not it could spark due to the fact i've never taken a physics class (thats what i get for going to an alternative school , eh?)?

If they can be used, i assume i should remove the polish first (but mommy, i like shiny !!!)? I've tried and a brilo-pad removes it easily.

Sociopathicly yours,
Plays with Fire

[Frozentech]

Heya, so far I've been using a ball mill made from an old Lego Robotics set, including the motor (which was easily modified to accept my 6VDC input ), and glass marbles (yeah, I know...get over it!). It's fine for milling about 100g of bp at a time, but i want to make a better ball mill that can handle a larger load. I've successfully removed the motor from my father's treadmill , and plan to use it for the mill.

Anyone else ever use a treadmill motor for their mill? I'd be quite intrested in hearing about it...

Also, this thread mentions several times cutting brass rods into cylinders as media, but can any brass rod from the hobby shop be used, or must it specificly say "non-sparking"? The rods i have conduct electric current and im not sure if that is a sign of whether or not it could spark due to the fact i've never taken a physics class (thats what i get for going to an alternative school , eh?)?

If they can be used, i assume i should remove the polish first (but mommy, i like shiny !!!)? I've tried and a brilo-pad removes it easily.

Sociopathicly yours,
Plays with Fire

On the APC forum there was a person who used a treadmill as a ball mill, with only minor modifications. He had his milling jar rolling on the belt. Considering how heavy a load treadmills are called on to carry, his jar size was potentially huge. I figure you could use a 15 gallon jar without even starting to load it down.

I use brass rod for most milling now. You never mention the jar size you will be using, but for a 3 lb jar, you would want to use cut up 1/2" or about 12 mm diameter rod, cut into length the same as the diameter or 50% longer perhaps. I recommend getting a metal cutting blade for a small jigsaw to speed cutting up enough rod to fill your jars half full.

Run the mill empty with just the brass media for a few hours, and it will remove the burrs and any polish as well. Brass is non sparking, meaning it does not shed tiny incandescent particles when struck a hard blow. The fact it conducts electricity has no effect on it's use as milling media.

Glad to hear that you are getting away from the Lego and glass marble stage of making BP. Time to get real. If you can, I recommend you get ahold of Lloyd Sponenburgh's book "Ball Milling Theory and Practice for the Amateur Pyrotechnician". All answers will be revealed

[fishy1]

Heya, so far I've been using a ball mill made from an old Lego Robotics set, including the motor (which was easily modified to accept my 6VDC input ), and glass marbles (yeah, I know...get over it!). It's fine for milling about 100g of bp at a time, but i want to make a better ball mill that can handle a larger load. I've successfully removed the motor from my father's treadmill , and plan to use it for the mill.

Anyone else ever use a treadmill motor for their mill? I'd be quite intrested in hearing about it...

Also, this thread mentions several times cutting brass rods into cylinders as media, but can any brass rod from the hobby shop be used, or must it specificly say "non-sparking"? The rods i have conduct electric current and im not sure if that is a sign of whether or not it could spark due to the fact i've never taken a physics class (thats what i get for going to an alternative school , eh?)?

If they can be used, i assume i should remove the polish first (but mommy, i like shiny !!!)? I've tried and a brilo-pad removes it easily.

Sociopathicly yours,
Plays with Fire

all metals will conduct electricity,

[Plays with Fire]

all metals will conduct electricity,

Well, duh! I kinda feel stupid for forgeting that , although some metals are much less conductive (higher resistance) than others, such as our favorite in this hobby, nichrome. And just to prove I'm not a, how do you say it over there, a ninny, metals conduct electricity because the electrons (often refered to as a 'sea of electrons') in a metal can slide past each other and go fom atom to atom as if they weren't attached; the more difficult it is for them to slide means that metal has a higher resitance, and means that there is more friction present, therefore the higher resistance a wire has, the hotter it gets for the same current , which explains our good friend Mr. Nichrome.

Thank you for the replies and can I cut the brass rod with a standard Miter (Circular) Saw?

[Frozentech]

Well, duh! I kinda feel stupid for forgeting that , although some metals are much less conductive (higher resistance) than others, such as our favorite in this hobby, nichrome. And just to prove I'm not a, how do you say it over there, a ninny, metals conduct electricity because the electrons (often refered to as a 'sea of electrons') in a metal can slide past each other and go fom atom to atom as if they weren't attached; the more difficult it is for them to slide means that metal has a higher resitance, and means that there is more friction present, therefore the higher resistance a wire has, the hotter it gets for the same current , which explains our good friend Mr. Nichrome.

Thank you for the replies and can I cut the brass rod with a standard Miter (Circular) Saw?

I don't see why not, if you install a metal cutting blade. Clear the cut pieces off as they are separated, might be iffy if a cut off piece bumped that blade.

[Plays with Fire]

Okay, I'm having a bit of trouble figuring out how to wire my permanent magnet DC motor so it can plug into the wall; it has 4 wires coming from it, two on each side of the back. On one side there are two blue, and the other side has a red and a black (I assume positive and ground, respectively?). It's a DC motor, but I know how to make a simple bridge rectifier with 4 high-current diodes from Radio Shack (an electronics supplier in the US), and that part shouldn't be a problem.

I have no clue what-so-ever as to what the blue wires are for, and being as the motor is mostly enclosed, I can't just find out by looking. I've searched the internet, without luck, using the specific model, part number, manufactuer, etc. I think thats because they really don't want you to open the treadmill or tamper with the components for liability reasons (you know how much us Americans love to sue over nothing and make millions doing so ), but I need to know what they are for. Also, on the motor there is a label with simple information about the motor such as part number, description, voltage, HP (2.5 ), speed, rotation, etc. After reading more about motors, I realized that I don't know if it needs a capacitor to funtion (there are several big ones on the circut board) and if it does, how should I go about attaching it (in series?), or does it need some complex circut?

Sincerely,
Plays with Fire

P.S. I would just get a simpler motor from a junkyard/dump/"amnesty site", but I have no such place anywhere near me (I guess that's life in the US suburbs!).

[littlejohny]

P.S. I would just get a simpler motor from a junkyard/dump/"amnesty site", but I have no such place anywhere near me (I guess that's life in the US suburbs!).

Shame that, I've been looking around for a little while for a washing machine motor, get this, my friends mother had an old washing machine and an old dryer sitting on their varandha for the last 2 years and got ridd of them on thursday

Actually, an awful lot of washing machine motors are induction motors. I've recovered five of them from various abandoned machines and have yet to find a brush motor. And not all washing machine motors are bi-directional, either. Some may even have two seperate coils for different speeds, requiring you to pick a particular one to wire up and gear for in your design. What sort you find all depends on the manufacturer, as different ones take different design approaches to separating the operation of the agitator and the spin cycle...

My own mill runs from a single-direction, single-speed, 400w induction motor from a washing machine.

You may find dryers a better bet. They're all one-way, one-speed motors, so a lot easier to wire up, and they don't need to be as powerful as a washing machine motor as they don't have to shift as much mass, so they're often (but not always) smaller. However, if you're scavenging freebies and not exactly spoiled for choice, any of the above will work just fine if configured correctly.

Edit: Typos. Actually, an awful lot of washing machine motors are induction motors. I've recovered five of them from various abandoned machines and have yet to find a brush motor. And not all washing machine motors are bi-directional, either. Some may even have two seperate coils for different speeds, requiring you to pick a particular one to wire up and gear for in your design. What sort you find all depends on the manufacturer, as different ones take different design approaches to separating the operation of the agitator and the spin cycle...

My own mill runs from a single-direction, single-speed, 400w induction motor from a washing machine.

You may find dryers a better bet. They're all one-way, one-speed motors, so a lot easier to wire up, and they don't need to be as powerful as a washing machine motor as they don't have to shift as much mass, so they're often (but not always) smaller. However, if you're scavenging freebies and not exactly spoiled for choice, any of the above will work just fine if configured correctly.

Edit: Typos.

Well isn't this strange I have now opened up 2 washing machines and 3 dryers just to have a look at them and they all had exactly the same motor, and yet they were all different brands

[pkhow]

Can any one help with what to add to lead to make it hard.
I got hold of and have added 4% then increased it to 10% antimony but it had little effect. I read that you should also add some Tin which also does not seem to have made it any harder.

[EnigmaticBiker]

Can any one help with what to add to lead to make it hard.
I got hold of and have added 4% then increased it to 10% antimony but it had little effect. I read that you should also add some Tin which also does not seem to have made it any harder.

I'm looking at a technical manual that describes lead alloys, it mentions ranges of additives:-

arsenic 0.1 - 0.3%

antimony 6 - 14% (for chemical use)

Tin is mentioned at 8 - 10% in Regulus metal. Not sure about this in terms of hardness, tin is fairly soft and a proportion of soft solders.

The hardest lead I have encountered is "Type metal" which is a lead/antimony mixture.

[karlfoxman]

You could just use brass rod media that stuff is very hard wearing! I still use lead media that we made but will be using brass soon for the other mill jars we have.

[Pretty green flames]

You could just use brass rod media that stuff is very hard wearing! I still use lead media that we made but will be using brass soon for the other mill jars we have.

I agree. Hexagonal brass rood will turn everything into dust in half time than it would take with lead media, I still don't use it for BP though.

[Frozentech]

I agree. Hexagonal brass rood will turn everything into dust in half time than it would take with lead media, I still don't use it for BP though.

Why don't you use it for BP, Jaka ? Since I started using .75 inch hex bar chunks as media, I cut the time to make good quality lift powder to 2 hours from 4. If not for the cost, I would use brass exclusively.

[edit] One place to order brass hex bar online is onlinemetals.com Online Metals - Brass Hex Bar

Edited by Frozentech, 19 February 2006 - 09:09 PM.

[Damp Squib]

If any of you have an ebay account get in touch with thorneykev he has just actioned a htopoint tumbler motor starting bid ?6.00 the auction has ended no takers,see if you can sort something out or ask if he'll put it up for auction again with a buy now option

Edited by Damp Squib, 19 February 2006 - 10:10 PM.