Penhook Posted April 29, 2014 Posted April 29, 2014 I hope I am posting this in the right place. I am trying to build a ball mill for making black powder. I have a motor out of a washing machine that turns about 1750 rpm . It is open with coils exposed and I don't like this about this motor. Can this motor be used or should I look for a wiper motor out of a car ? I have a 12 volt converter that I could use on the wiper motor if that is the best way to go. I would think that the rpm would be easier to manage with the wiper motor. I have never made a ball mill before and am lost on what would be the best way to go. I shoot in black powder matches and would like to make larger amounts , maybe a half pound of powder or more at a time because I usually use that much powder ever time I go to a match. Thanks for any advice you guys may give me.
BurritoBandito Posted April 29, 2014 Posted April 29, 2014 I would try and find a different motor. I'm not sure what the specs are on wiper motors, but you definitely want a TEFC (totally enclosed fan cooled) motor. Either that or find a way to isolate the motor from the rest of the mill, so that there is absolutely no way that powder or sparks can be exchanged between the jar and the motor.
MrB Posted April 29, 2014 Posted April 29, 2014 Ideally you'd get a sealed motor made for continual use. Low service models are usually brushless. My main problem has always been figuring out the SIZE you need. Rotational speed isn't really an issue, the power of the thing is. Window wiper engines are great for star-rollers and similar stuff that isn't going to be rotating for days on end, but eventually you will wear them out. You can just get a new one.I prefer to at least try and get something that uses DC current, and has variable speed, but thats not always an option. For ballmills it shouldn't really be needed. Get it right once, and leave it there.B!
Sparx88 Posted April 29, 2014 Posted April 29, 2014 Just a thought http://www.ebay.com/itm/Sanyo-Denki-103M89332-2540-Brushless-Synchronous-3-Phase-AC-Motor-Nema-42-/170933632721?pt=LH_DefaultDomain_0&hash=item27cc703ed1
Jakenbake Posted April 30, 2014 Posted April 30, 2014 The washer motor will work. The only concern would be how warm it gets. Since its an a/c induction motor there is no brushes to cause sparks.
Bobosan Posted April 30, 2014 Posted April 30, 2014 RPM reduction with correctly sized pulleys and belts generally allows use of a smaller horsepower motor. Factors such as jar size, number of jars and weight of milling media come into play.Isolate your washing machine motor from the mill area via a long belt and shield the motor.
nater Posted April 30, 2014 Posted April 30, 2014 (edited) I used this motor: http://www.grizzly.com/products/Motor-1-2-HP-Single-Phase-1725-RPM-TEFC-110V-220V/G2528 As I said in your other thread, get Lloyd's book. It is the bible of BP milling and mill construction for the amateur. Edited April 30, 2014 by nater
DeLormar Posted April 30, 2014 Posted April 30, 2014 Sparks and air float material is not a good idea.Better to find a enclosed motor, wiper motor will work fine for smaller mills up to 1,5 liter jar. I tried my one with a 4 liter jar and heats up within minutes. So better go to 110v/220v enclosed motors of about 1/2 hp
Penhook Posted May 1, 2014 Author Posted May 1, 2014 I have two motors I though would work but it seems I would be better off not trying to save money in this case. I will look for a better motor for making a ball mill than the two motors I have now. I have learned a lot from what you guys have said . I want to do things the right way and have something safe and working properly when I finish . Thanks to everone that replied to my post.
bob Posted May 1, 2014 Posted May 1, 2014 http://www.ebay.ca/itm/Baldor-Electric-Motor-M3542-TEFC-230-460-V-3-1-5-A-3-4-HP-1725-RPM-/251502497522?pt=LH_DefaultDomain_0&hash=item3a8eb78ef2&_uhb=1 Here is a cheap TEFC motor, might be worth checking out.bob
Jakenbake Posted May 1, 2014 Posted May 1, 2014 Thats a nice deal if you have a 220v outlet nearby to run it on.
Mumbles Posted May 1, 2014 Posted May 1, 2014 A 3 phase 220V outlet actually. Typically you'll want to look for 110V/115V/120V motors that operate 50/60Hz 1ph outlets. This is a standard outlet. Unfortunately, they are looking kind of expensive. Below is the cheapest one I found on ebay. You might be able to find something cheaper locally. http://www.ebay.com/itm/Dayton-50-Hz-Motor-1-2-HP-1-PH-1425-RPM-110-220V-56C-TEFC-/281319574750?pt=LH_DefaultDomain_0&hash=item417ff40cde
bob Posted May 1, 2014 Posted May 1, 2014 (edited) That's not a bad price. Kijiji often has some good deals, it would be with checking out.bob Edited May 1, 2014 by bob
hindsight Posted May 1, 2014 Posted May 1, 2014 The ebay motor ad that Mumbles linked says 60hz in the specs listing, but says 50Hz on the motor plate. I believe you have 60Hz AC in the US, while we have 50Hz AC. Usually that makes a difference for electrically powered appliances. What are the implications for using a motor like this on one frequency or the other?
BurritoBandito Posted May 3, 2014 Posted May 3, 2014 @Hindsight: I believe with AC motors the frequency determines the RPM.
Bobosan Posted May 4, 2014 Posted May 4, 2014 It may also run a slight bit warmer due to higher 60hz frequency but difference will be minor.
hindsight Posted May 4, 2014 Posted May 4, 2014 (edited) BurritoBandito & Bobosan-- Thanks. So in all probability, the motor should run fine on 50hz or 60hz AC. . Edited May 4, 2014 by hindsight
Bobosan Posted May 4, 2014 Posted May 4, 2014 You should be fine, Hindsight. Further reading located here and this discussion thread.
hindsight Posted May 4, 2014 Posted May 4, 2014 Bobosan, I appreciate the references. Didn't occur to me that this would have been discussed previously on APC. If the motor is designed for 50Hz and is run at 60hz, the voltage should ideally then be increased by 20% to maintain the same power. If designed for 60hz and is run at 50Hz, conversely, the voltage should ideally be reduced. BurritoBandito was correct in stating that the RPM would change with frequency.
Bobosan Posted May 5, 2014 Posted May 5, 2014 Yes, RPM would change but not significantly. The discussion thread reference.is from the LMPhotonics Motor Control website and called IPS Community. Happens to use the same forum software as APC so looks the same.
markx Posted May 5, 2014 Posted May 5, 2014 If one conefines itself to a certain mill jar (of specific dimensions) and there is no need to use other receptacles on the mill, then a combinations of a well tuned transmission ratio and an asynchronous ac motor with fixed rpm will work exceptionally well. But if the mill needs to work with jars of different shape and size, then the rpm control is a rather unavoidable neccessity. With that in mind I would venture the DC route, as on dc motors the rpm control is most easily applicapble over a wide portion of rpm-s. Applying the rpm control to ac motors is complicated and expensive when done correctly, whereas with dc motors the concept just merges into variable voltage control. Very simple and straightforward...I would choose a 12V set as this rating tends to have the cheapest price for components needed (power supply, pwm control board). Another very beneficial property of dc motors is the high torque they can supply over a very wide rpm range. With ac (especially the asynchorous type motors) the output torque is very dependant on rpm (interfetrence between supply frequency and motor rpm when pictured on a simplified stage)
Mumbles Posted May 5, 2014 Posted May 5, 2014 Sometimes things conveniently work out. The type of mill described in Lloyd Sponenburgh's booklet, and manufactured by Hobby Fireworks coincidentally turns a 6" jar and a 4" jar at near optimal RPM's. I somehow doubt separate parts are used for the 8" model, so that probably works too. A perfectly optimal mill is less useful than one that produces consistent product. A variable speed motor would seem more useful for a star roller to me.
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