Variable Output Switches

[red bandit]

I have an automatic bullet casting machine and I want to be able to slow down the main drive motor (120v) when I run large bullets because the molds get too hot. I'm looking at Variable Output Switches and they are avalible in 1K, 5K & 10K ohms. Is that the amout that it would slow down the motor? I want to slow it to about 60-80% of full speed. Would I want the 10K? Any help is greatly appreciated. Thank you.

Switch "B" is what I was thinking about using.

http://www.mcmaster.com/#speed-pots/=llyqq1

[fredintoon]

I have an automatic bullet casting machine and I want to be able to slow down the main drive motor (120v) when I run large bullets because the molds get too hot. I'm looking at Variable Output Switches and they are avalible in 1K, 5K & 10K ohms. Is that the amout that it would slow down the motor? I want to slow it to about 60-80% of full speed. Would I want the 10K? Any help is greatly appreciated. Thank you.

Switch "B" is what I was thinking about using.

http://www.mcmaster.com/#speed-pots/=llyqq1

Hi Bandit,
potentiometers work by reducing voltage and it's not good for electric motors to run that way.
What you need is a VFD, a device that reduces the motor speed by changing the current frequency:-
http://www.wolfautomation.com/Produc...FZE-MgodoEEASw

[natemoen]

Fred is right. VFD is what you need to do it right.

What kind of setup so you have for casting? I would like to see that!

[CaptonZap]

[QUOTE=red bandit;402135]I have an automatic bullet casting machine and I want to be able to slow down the main drive motor (120v) when I run large bullets because the molds get too hot.[QUOTE]
The type of control is dependant on what type of motor the machine has.
Is it a brush type motor, or induction type?
A brush type can use a router speed control, and induction will need a variable speed drive.
CZ

[red bandit]

It's a Ballisticast commercial casting machine.
I don't know if the motor has brushes or induction. I will have to check.
The reason I asked the original question is the later machine has a potentiometer switch to adjust the speed. I'm not sure how slow it will go. That's why I was asking about the 1K, 5k or 10k. Maybe I only need to run 80% of full speed. I think 60% would be a little slow.
router speed control, variable speed drive. Is one a potentiometer?

[crazy steve]

You want to be careful about running the motor slower. If you do have a 'universal' (brushed) motor, an adjustabe pot will be best rather that a multiple-output unit (a VFD won't work with a universal type motor). A VFD will be required for a brushless motor. Two caveats about doing this; if it's a brushed motor, make sure the switch is rated for at least 200% of the full load motor current as shown on the nameplate. Two, with either type the motor will likely run hotter at lower speed, so think about some sort of thermal protection for it so you don't burn it up.

Electric motors really like to run at full/rated speed, running them slower with reduced voltage (particularly into a constant load) is hard on them. Generally, a gear ratio change to change speed is better.

[fredintoon]

It's a Ballisticast commercial casting machine.
I don't know if the motor has brushes or induction.

Hi Bandit,
I googled ballisticast and viewed a video of a Mk 11 in action.
I couldn't see what kind of drive motor it had but man, does that thing spit bullets.
Do you run yours once a year or do you make bullets for your entire shooting club?
What you could do at no cost and little effort is run a big fan on it, just like keeping the XS11 engine cool when you tune the carbs.
And, since you ask:-
guns, beer and bikes what more could you ask for.
Wine, women and song?

[DiverRay]

Looking at the site, it seems the company already uses a gear reduction. I could be wrong, but I've not seen many electric motors that run as slow as that one was. You should be able to buy a different gear reduction unit, with a different gearing, that will bolt up. Check Granger, or one of the big houses that handles bearings and motors.
Let me know if you are doing 45, as I will need to reload once I get the part from Colt to repair my gold cup.

[CaptonZap]

It's a Ballisticast commercial casting machine.
I don't know if the motor has brushes or induction. I will have to check.
The reason I asked the original question is the later machine has a potentiometer switch to adjust the speed. I'm not sure how slow it will go. That's why I was asking about the 1K, 5k or 10k. Maybe I only need to run 80% of full speed. I think 60% would be a little slow.
router speed control, variable speed drive. Is one a potentiometer?

If you were to call the company and ask to speak with an engineer, you could ask him if it is a Universal or induction type motor.
If it is a universal, as Steve pointed out, you will not need a VFD, as it changes the speed by varying the frequency of the input power.
My reason for suggesting a router speed control for a brush type motor is that all of the controls that I have played with are a pulse width modulation (PWM) type of supply, which means that the power supplied to the motor is composed of pulses of full voltage electricity, of longer or shorter duration, giving more or less total power, and which mitigates some of the drawbacks of voltage lowering arrangements typical with the rheostat (potentiometer) type controls.
Again, as Steve pointed out, whatever arrangement you come up with, monitor the motor temperature closely.

"Happiness is a warm gun" (Beatles, '68)

CZ

[Petersg_99]

I would bet that the motor is a simple 120V motor that pretty much plugs into 120V. If so you can use a variac variable transformer. You do need to be careful about not overloading the motor for the voltage you're pushing, but this might do the trick for you...

http://www.amazon.com/Variac-Variabl.../dp/B006NGI8VS

[Petersg_99]

Read their comment about variacs. make sure you size the variac for the current your motor needs...

I would bet that the motor is a simple 120V motor that pretty much plugs into 120V. If so you can use a variac variable transformer. You do need to be careful about not overloading the motor for the voltage you're pushing, but this might do the trick for you...

http://www.amazon.com/Variac-Variabl.../dp/B006NGI8VS

[CaptonZap]

It might be easier to find a tool speed control rather than a variac sized to his needs, since they, variacs, seem to have gone the way of discrete component electronics.
And there again, you are using reduced voltage as the control, rather than the reduced total power input of the PWM control.
Anyway, the first thing is to find out what type of motor it is, the rest of this is just us flapping our gums.

Makin' the best of a snow day,

CZ

[ViperRon]

If the manufacturer can not help or will not make a suggestion it might be helpfull to get the model and manufacturers info off the unit as well as the plate info off the motor. Then people here might get info off the web or be able to give a good solid suggestion. It may be an intirely different motor in the later model to allow speed change. A caution on trying to use a VFD or PWM with out knowing for sure what you have it could die even with a fan cooling it. Many modern motors have a thermal switch in the windings that will open to prevent fire. Some motors depend on a start circuit to get them to run speed quick and using a PWM could make them overheat. Some thermals reset and others are fused and most are hard to get to. If there is any way to change gearing in a transmission its a better solution that way you don't have to worry what type magic smoke is in the motor.

[red bandit]

Right now the only thing in overload is my brain. I appreciate all the info but you guys are way over my head. So I think I will call the manufacturer and see what they have to say so I don't burn something up. They have always been very helpful. I didn't see anything on the motor to indicate brushes or induction. However I did not see a place to change the brushes so that may be my answer. Yes it's a Mark ll. It comes with two fans on it and I've added another. Yes, it's a gear reduction and I don't want to buy another. A lot of work and money when I don't run many 405 gr bullets. I shoot competition and shoot at many clubs and sell to whoever wants them. Helps pay for my shooting expenses. Thanks again. You guys are great.

[Geezer]

I'll second Captain Zap, go look for a router speed controller. It'll do what you're asking for.

BTW, do you cast any .458" bullets? If so, I'd be willing to buy some for my .45-70...

Tony