Using a dryer motor for a ball mill

[froggyb99]

I took apart an old dryer to get the motor so I could make a ball mill. I do not know very much about electronics or wiring, but is it possible to get this motor to run on a normal 120 volt outlet? If so, how do I do this?

 

Preview attachment IMG_20160528_105417507_HDR.jpgIMG_20160528_105417507_HDR.jpg3.8 MB

Preview attachment IMG_20160528_105445824_HDR.jpgIMG_20160528_105445824_HDR.jpg3.8 MB

[MadMat]

I can't seem to view your pic.s, but to answer your question, yes, you should be able to get it running with a simple appliance cord. It may be as simple as hooking each wire from the cord to a connector on the motor. Since I can't see your pic.s I don't know for certain, but most of those type of motors have male "spade" type connectors on them. By attaching female spade connectors to the ends of the cord wire (crimp connectors, no soldering needed) the motor can be simply "plugged" onto the cord. (All I get from your pictures links is a site that asks if I want to start a gmail account)

Edited May 28, 2016 by MadMat

[memo]

dryer motors are normally a open motor, lots of sparks, should use enclosed motor that is fan cooled

 

memo

[froggyb99]

I tried to put the pictures on in a different way, hopefully this works

Motor 1.html

[OldMarine]

Perfect motor for a ball mill exploder.

Don't use it!

[MadMat]

Are there windings on the armature of the motor? (the center part of the motor that actually spins) If it is simply a solid "drum" of metal, this motor is an induction motor and would be safe for using on a ball mill. What memo and marine were worried about is if the motor has brushes. That would be apparent if the armature has wire windings and is not a solid drum of metal. Brushes would be a bad thing because they create small electric arcs when the motor is running. I can't quite tell from the picture which. Look inside the motor and give it a spin by hand, if you see coils of wire on the part that is spinning, don't use it, period. If it is an induction motor, you can power it up by connecting your wires to the two larger spade connectors with the holes in them. they are on opposite sides of the plastic block.

Edited May 28, 2016 by MadMat

[lloyd]

"Unfortunately for you, this motor has brushes; it's going to cause small electric arcs and if there's any bp dust around it, Boom!. Sorry. Not all is lost though, this would be a good motor for a star roller. Since your comp.s are wet around the rolling machine, it shouldn't be a problem."

=-=

I agree with your wiring callout, but you're going to have to explain how you "know" this motor has brushes.

 

It sure looks like a conventional induction motor with start winding to me!

 

Yeah... such motors DO create one really FAT spark when they switch from the start winding to the run winding. However, that contact where the spark occurs appears to be enclosed the the switch housing on this one.

In any case, unless the motor you chose were a TENV or TEFC type, and specifically one specified for explosive dusts (Class II) and NOT for explosive vapors (Class I), then you're going to have to deal with making it safe yourself.

There are several ways to do that. The simplest is to build the mill so that the motor is enclosed by the mill's housing in a way that prevents ANY air from the milling area from entering the motor enclosure. That is, after all, what Totally Enclosed (so-called 'explosion proof') motors do, but within their own geometry.

Lloyd

Edited May 28, 2016 by lloyd

[MadMat]

Lloyd, I kind of spoke before thinking about it. I did edit my post, and it makes more sense. You must have caught it right when I was doing the edit.

Edited May 28, 2016 by MadMat

[lloyd]

Sorry, I swapped the Classes above. I have edited it for correctness.

L

[lloyd]

Heh! We all do it... Yep. I see that edit.

[MadMat]

As far as the centrifugal switch goes, it does look like it's enclosed because of the large plastic block. Either way, the design of the ball mill SHOULD separate and enclose the motor.

 

Even discounting the explosion hazard, I wouldn't want BP dust to get into the bearing of the motor.

Edited May 28, 2016 by MadMat

[lloyd]

OH... I also meant to add that the motor shown is ALREADY designed for 120V/60Hz, so given that there are only two lugs available for spade connectors, I'd say those are the two where power should be applied.

 

Ground would never be connected with a quick-disconnect lug. It would have been a screw lug connection. So, I'd look for evidence somewhere on the frame of where the ground wire was connected (likely with a GREEN-headed screw), and be SURE to ground the motor frame in any installation.

 

I'd say it doesn't matter MUCH, since both sides of the motor have some sort of switch, but it looks like the left-most lug should be the 'hot' (black) lead, and the right-most one the white (neutral). That, because the left lug is likely the one connected to the overload disconnect (that thing with the blue wire).

If you have a meter, you can determine which lug goes to the blue wire, and make that the HOT side.

 

LLoyd

[lloyd]

Y'know... I should have said WHY I suspect that start switch is fully enclosed, and just forgot to say it... Dryers are notoriously linty, dusty, fire-prone appliances. The likelihood of flammable lint collecting on the motor is high. Washer motors often have open start switches, but dryers seldom do (any more... they used to!).

 

LLoyd

[froggyb99]

Thank you all for the replys. I have gotten the motor to start working by using an old computer cable. I was unaware of the sparks that this motor could create. Like MadMat said, would it be safe to use this for a ball mill if I built a separate box for the motor? A design like this is what I would go for. If it is still unsafe to mill black powder, would it be safe to just mill charcoal?

http://www.skylighter.com/images/newsletter/91/Neds-Ball-Mill.jpg

[lloyd]

You're going to have to provide SOME means to cool that motor. Totally open motors like that are usually designed a bit more 'casually' as far as heating, because they're never going to have to work in a tight enclosure.

 

So... some baffles, maybe METAL intake AND exhaust filters, and maybe a cooling fan to bring fresh air will probably be necessary. ALL that will still be a lot cheaper than buying a good Class II TENV or TEFC motor.

Lloyd

[MadMat]

Dam Lloyd,

you keep beating me to the punch

I was going to post something about dryers having dust/lint problems and you already posted it. Then I was going to mention that type of motor would need some air circulation for cooling, but you already had posted it. Ho wam I going to get my daily typing practice? hahaha

[lloyd]

Well, Paul,

I was carefully reading your mind... and I'm just a faster typist! <G>

LLoyd

[MadMat]

Well,

if the sparks, enclosure and air circulation are too much for you, it would still make a nice motor for a star rolling machine.

If the motor is, as guessed, an induction motor, chances are real good it runs at 1750rpm. All you need do is put a much larger pulley on the drum end to tone down the rpm and you could make a pretty good rolling machine for large batches of stars.

Edited May 28, 2016 by MadMat

[lloyd]

I just don't get that!

Star rolling can be just as messy, dusty, and dangerous as milling. You might wet the stars IN the rolling drum, but unless you're using exclusively the Toro process, you'll be sprinkling (can we say "dusting") dry comp onto the wet stars.

 

Typically, the star rolling area of a commercial shop is dirtier than any other place except the mixing room. (Neither should STAY dirty, but be cleaned thoroughly and often)

 

No sir... if you build a star roller, it needs to be to the SAME level of electrical safety as a ball mill.

 

Lloyd

[Arthur]

The Chinese can be very good at putting motors the other side of a wall and feeding a shaft through a small hole. It would work but the motor you chose is far from MY idea of a suitable motor. -too many possibilities to get ingredients and mixed powders inside the motor and close to the start winding contact sparks.

 

IMO a TEFC (totally enclosed fan cooled) motor would serve you better. though specifically an explosive dusts and atmospheres rated motor would be best.

 

If you cannot get a good big motor then get a good smaller motor and moderate the load rather than risk kilos of powder spilling into an open motor.

 

IME ceramic media saves a lot of load weight and makes the turning load a lot less and may facilitate using a smaller motor.

 

Added;

If you really have to use that motor consider having it outside the work space and transmitting the power by either shaft or hydraulics, AGREE as above it's not a good motor for a mill or a roller.

 

Small hydraulics can be found in some street cleaning vehicles.

Edited May 28, 2016 by Arthur

[Arthur]

https://www.google.co.uk/search?q=TEFC+motor+image&espv=2&biw=1440&bih=760&tbm=isch&imgil=PhgKidsvOR_XoM%253A%253BCYWI29AzJbl11M%253Bhttp%25253A%25252F%25252Fxiaolaoda.en.made-in-china.com%25252Fproduct%25252FvoeEqwzPQZVj%25252FChina-IP54-NEMA-Series-Three-Phase-Asynchronous-Electric-Motor-TEFC-Motor.html&source=iu&pf=m&fir=PhgKidsvOR_XoM%253A%252CCYWI29AzJbl11M%252C_&usg=__e1NFBxRn12g1bmAuqmJRifORpXk%3D

 

 

TEFC motor the fan in the end cap blows air over the finned body to cool it. There is NO way in for dust. Lots of sizes exist.

[MadMat]

Actually I was thinking of the toro method when I said that. Opps, I never thought about the possibility of dusting dry comp on the growing stars. But then again, I have never rolled stars (yet). Hmm... I once saw a video of someone that used an electric drill to power his star roller. You know the kind of drill that has vents right over where the brushes are.... I guess it's just another reminder NOT to pay to much attention to You tube videos.

Edited May 28, 2016 by MadMat

[Arthur]

It's you that will get burned in a fire, it's you who must think how to minimise the risk and degree of burns. Youtube is for entertainment not for learning -unless you know and trust the author.

[lloyd]

Arthur,

Being in the business of making automated machinery to build explosive devices, I've had to spend a bit of time around hazardous location motors.

 

I know you didn't intend to muddy the issue, but I need to make clear to others here with less experience that JUST being a TEFC or TENV motor does not, in and of itself, ensure that it's designed for a hazardous location.

 

Often, such motors are built specifically to protect themselves against abrasion hazards, but without specific thought being given to ignition, containment, and combustion gasses cooling.

 

For a motor to be "properly safe" in an explosive environment, it must be a Class II (dusts) or Class I (gasses) or combined Class I & II hazardous location motor.

 

Class II motors exclude dusts using seals on their shafts. Class I motors contain and cool combustion gasses before allowing the cooled products to exit around the shafts.

 

Most pyrotechnic applications (except where flammable solvents are used) will require a Class II motor at a minimum, although a combined-Class I/II is better protection, and will allow the use of flammable solvents, also. Class III motors are NOT suitable for use in explosive environments.

 

Most amateurs opt NOT to pay the rather steep premium for class-approved hazardous location motors, unless they're lucky enough to find used ones inexpensively. That's why we like to dwell on the other ways they can be kept safer.

 

Here's a decent SHORT writeup on the classes and divisions for haz-loc motors: http://ecmweb.com/content/how-select-motors-hazardous-locations

 

LLoyd

Edited May 28, 2016 by lloyd

[memo]

i have a tefc coming for this