Building annealing machine-need electronics help!!

[cheese1566]

Building a case annealing machine like the Brass-O-Matic and jmorris's. I need help from any electronics experts out there!!

I have a 12 volt DC-1 amp gear motor that spins at about 42 RPM at 12 volts. I need to variably reduce it to a range of about 10-24 rpm. I just purchased a 25 Ohm/3watt rheostat from Radio Shack. It is not reducing it enough. If I connect it to 5.5 volts, I get the rpm range with good torque, but without much room for error in the range of variance. I would like to use my 12 volt power supply instead of my converted computer ATX power suppy for power.

What should be my next try?

The next one they had was a 5K ohm potentiometer.

[7of7]

You can also increase the size of the pulley used to rotate the case holder. If it is indirect drive.

[Calamity Jake]

NO flames, just a ? What is so important about 10-24 RPM?

The RPM of the brass does not effect the anneling process at all, as long as the case is turning and heat is applied for the proper amount of time and in the right area every thing will be good.

[cheese1566]

Take a look at the brass-o-matic website and the unit built by jmorris on the top sticky...the cog wheel needs to turn at a variable slow rpm to turn the case baseplate wheel, this determines how long the brass sits in the flame...making it automatic.

[jmorris]

The diameter only effects how far the “blade” moves in this application. The machine indexes “X” amount every revolution of the indexing wheel regardless to diameter.


http://en.wikipedia.org/wiki/Maltese_Cross_mechanism has a little more information on the Geneva drive principal.


I think Jake may not know exactly what kind of machine you’re talking about here so I’ll include a photo of mine on its first run. The cases don’t turn they are just slid into the flames for the amount of time the gear motor takes to complete a revolution. So RPM directly affects the amount of annealing done.

http://i121.photobucket.com/albums/o213/jmorrismetal/still.jpg



When tinkering with mine, my power supply wouldn’t adjust low enough for 50 bmg brass so I just added a light bulb in line with the negative (positive will work the same) to act as a resistor and it worked fine and that’s something you probably already have.

[cheese1566]

I may try the light bulb or maybe adding a resistor. That makes sense.
I did find a PWM (pulse width modulator) controller for DC motors on the internet for $20. I am reading this will allow 0-100% variation with no loss in torque. I was hoping the rheostat would be a cheap imitation.
It is an ongoing project, I will do some more tinkering and keep building the rest. :)

[Storydude]

For ~20 dollars, you can pick up a 20-40RPM Gearmotor from Surpluscenter.com

http://surpluscenter.com/item.asp?UID=2009031812305363&item=5-1660&catname=electric

[montana_charlie]

I’ll include a photo of mine on its first run.
Your photo is interesting, and I was examining your control panel (in the background) when I began to wonder what happens when you select "Permanent Press"...?

CM

[cheese1566]

I picked up my gear motors from the surplus center. I went with the 42rpm 12 volt motor. Good torque and solid, just need to reduce it down. I am now aiming at buying the PWM DC motor speed controller. I am consdering buying two since I am accumulating two of everything now to make two units,, or have spare parts. I cannot see only buying one part and paying S&H.

[Shiloh]

Your photo is interesting, and I was examining your control panel (in the background) when I began to wonder what happens when you select "Permanent Press"...?

CM

LOL !!

Everyone is a comedian!!

Shiloh

[Shiloh]

For ~20 dollars, you can pick up a 20-40RPM Gearmotor from Surpluscenter.com

http://surpluscenter.com/item.asp?UID=2009031812305363&item=5-1660&catname=electric

Thanks for the Link!

I need a motor to rotate the cases in a container of water. A lot less sophisticated than what you guys are making but it will work. This motor fits the bill.
Here is my Hi-Tech annealing system and the results. I want to make one that rotates for more even heating. I flip the torch back and forth to try and keep things even. The cases from the first batch done the same way, loaded and fired fine. Twice and going on a third time. No problems and NO Splits !!

Shiloh

[jmorris]

Shiloh, it looks like your cases might be a little "well done" this link is a good read

http://www.6mmbr.com/annealing.html

FWIW if the flame turns orange it's over done any more and you are doing much more harm than good.

It's hard to tell from a photo so don't take offence if I'm wrong, just trying to help.

jm

[Shiloh]

No offense taken.

Some may be a little, but just a little. There is still a little spring in the necks but they aren't "stiff" like before. I got a 650 TempilStik from these guys
http://markingpendepot.com/index.asp?PageAction=VIEWCATS&Category=172
and practiced on some Turkish 8mm brass. When the mark melted I stopped.

The whole reason for making a device is for more consistancy.
Thanks for your input!!

Shiloh

[jmorris]

Sounds like you've got it figured out. One place to get gear reduced motors (if your not picky about speed) is from power windows. I have a buddy that works in a paint and body shop that gives me boxes of acuators and motors every month or two. Might be worth a trip to talk to someone at a local shop. Then you just need to make a plate to sit your can on and you'd be good to go.

[Shiloh]

Sounds like you've got it figured out. One place to get gear reduced motors (if your not picky about speed) is from power windows. I have a buddy that works in a paint and body shop that gives me boxes of acuators and motors every month or two. Might be worth a trip to talk to someone at a local shop. Then you just need to make a plate to sit your can on and you'd be good to go.

Sounds like something I'm looking for.

I had a motor from the fan of an old CPU. It was the brushless variety. I put in a rheostat dimmer switch, turned it on, and....nothing. Same speed no matter which way you tuned the dimmer. My buddy said that resistance switches won't work on that kind of motor. Has to do with cycles or Hertz.

Something that is 20-30 RPM's is fine. Cheap or free is preferable. You've seen my set-up. This is to be NOTHING extravagant. Simple is superior. Just something to rotate a basin of water with a cartridge brass on it. Heat and knock it over with the side of the torch tip. Don't get me wrong though, if I had machine or more power tools, I'd be using them!!

I appreciate your input. Nice tip about the color of the flame. I'll go experiment.
I kept it so there were no burns on the brass. Heat till it almost glows and the brass changes color, then back off. Thanks!!

Shiloh

[jmorris]

Something that is 20-30 RPM's is fine. Cheap or free is preferable. You've seen my set-up. This is to be NOTHING extravagant. Simple is superior. Just something to rotate a basin of water with a cartridge brass on it.

I don't mean this to sound silly but you don't have an old record player sitting around do you?

[montana_charlie]

rotisserie motor too slow?

[herb101]

most model train set controler are 12 to 16v and will ajust the amps .

[Shiloh]

I don't mean this to sound silly but you don't have an old record player sitting around do you?

I thought of that. A garage sale phonograph would be just the ticket. Thanks.

Shiloh

[Dean D.]

I was reading this thread earlier and was doing some thinking. I had an old Emerson microwave that burned up the Microtron tube so I thought I would tear it apart and salvage what was left, fan, etc... I just finished stripping it and found the turntable motor to be a 120v synchronous motor rated at 2.5-3 RPM. :mrgreen: :drinks:

I would think given the proper diameter of turntable that this should work well for a drive motor for an auto annealer. What do you all think?

[jmorris]

You have to be able to adjust the speed, some AC motors will not allow this. For the auto annealing rig above your looking for 3-9 seconds per revolution or 20-6 rpm. The reason for this is that a .223 case is done quicker than a 50 BMG case.

If you are doing it like Shiloh's set up rpm would be far less critical and I think the faster it's spinning the more consistant the heating.

[montana_charlie]

120v synchronous motor rated at 2.5-3 RPM.

I would think given the proper diameter of turntable that this should work well for a drive motor for an auto annealer. What do you all think?
An auto annealer (like the one in this thread) doesn't have a drive motor attached to a turntable.

The 'saw blade' (turntable) is simply a carrier that moves each case into the flame. It has no motor.

The carrier is turned incrementally by a small actuator motor which has a disk with a finger on it. Every time the finger comes around, it advances the 'sawblade' one position.

If your actuator motor turns at 3 rpm, that is one turn in 20 seconds. Your case would stay in the flame for 20 seconds...which would probably melt the neck right off of the body.

CM

[runfiverun]

if the motor turned the blade directly and not like a gear
that would be one turn in 20 seconds true, but his case would only be in the flame part of the turn by moving it away from the center.
his case would only be in the flame for like 90* of movement,depending on how big his wheel is.
so for 90* it would be cut down to 5 seconds.
since i don't know the math, i would have to do it though trial and error.
not a big deal as a 223 case would require less time them a larger case would.
and once you figured out one. the other families of cases should be pretty easy as you could adjust the flame or use two torches.

[Dean D.]

I guess I did not understand how this annealer worked. Just looking at the pics I deduced that the sawblade turned via a drive motor.

Oh well, I just posted the info in case someone was looking for a low speed motor for a simular project.

[jmorris]

you can go here to see more about the machine I built (the first two are video links you have to click on to play) http://s121.photobucket.com/albums/o213/jmorrismetal/annealer/

The thread sort of got side tracked by another idea for a simple way to turn a single case while heating it by hand.

[cheese1566]

herb101 had the idea of using a model train controller.

What are the voltage outputs on these?:confused:

Do they control train speeds by reducing voltage or by limiting power to the locomotive?

My motor is if for 12 volts, reducing the voltage will make it slower- but I lose power (turque) when doing so...

[n4yut]

Don't forget you can use a Winshield wiper motor from a salvage lot , it has a gear reduction so if you do have to use a lower voltage the loss of torque won't be so noticeable.
The model train controller lowers the voltage to reduce speed.

[briang]

Most train controllers run at 16 volts and reduce the voltage. I have one I use for various things. I wired it to an old rheostat I found and now I can set the volts with the the train controller and adjust the amps with the rheostat. I do not remember the range of amps I can get, sorry.

[Shiloh]

Don't forget you can use a Winshield wiper motor from a salvage lot , it has a gear reduction so if you do have to use a lower voltage the loss of torque won't be so noticeable.
The model train controller lowers the voltage to reduce speed.

I've never seen a windshield wiper motor. I'm assuming from the post that it turns only one direction and some sort of cam makes the wipers go back and forth??

Let me know will ya!!

Shiloh

[jmorris]

I've never seen a windshield wiper motor. I'm assuming from the post that it turns only one direction and some sort of cam makes the wipers go back and forth??


Most windshield wipers use some type of eccentric drive so they just go round and round. They also have multiple speed settings as well. DC motors are easy to reverse just reverse the polarity.


http://en.wikipedia.org/wiki/Geneva_drive
http://en.wikipedia.org/wiki/Eccentric_(mechanism)