Is it difficult to "depower" a cable slide?

[BrianT]

Something I've been thinking about...

 

Is it difficult to "depower" a cable slide? I don't want to disable it, I want to make it run much slower and less powerfully.

 

Thing of it is, if I bring in any of the other slides, you hear the little motor whirring and if you watch carefully, you can see the slide move ever so slowly and over the course of sometimes 20 or 30 or 40 seconds, comes gently to rest in it's new retracted position.

 

On the cable slide, however, when I bring that slide in, it's a jerk, 4 or 5 seconds of a fast moving slide and a thump as it slams into it's new position. Honest, I'm not in THAT big of a hurry. I don't need warp drive. I've got the time for it to move slowly.

 

Anyway, I wondered whether there would be a way to get the thing to move at a slower pace but still work. Would there be an inline resistor of some kind that could go inline with the hot wire to the motor? Or some other way to just suck some power away from it while it's doing it's thing?

 

I don't want to kill it. But it kinda reminds me of the super-duper water pump that I once installed in the RV... that ended up giving me 80psi. More power is not necessarily a good thing.

 

Anyway, thought maybe some of you might have a thought or suggestion.

 

Thanks

[Kirk W]

If it uses a 12V-dc motor you could cause it to run slower by lowering the voltage to it, but I think that I'd hesitate to do that. Have you talked to a dealer tech to see if what you have is normal? It sounds pretty strange to me.

[BrianT]

I haven't talked to anyone about it yet, other than the above post. My solution to date is basically to pulse the switch rather than just hold it. Not difficult for me. But I'd like to have something a little simpler for other people who just let 'er slam.

 

Yes, it's a 12 volt motor and original equipment from what I can see.

[skp51443]

If it is a belt or chain drive you could swap pulleys or sprockets to lower the speed, that would increase the force though.

 

Pulsing the switch is probably hard on both the motor brushes and windings, not sure I'd do that myself.

[oldjohnt]

FWIW I agree with Stanley and Kirk that adding any sort of a series voltage dropping current reducing "ballast resistor" to reduce motor speed would NOT be my first recommendation and short cycling a switch is indeed hard on the motor and switch contacts. The correct ohms resistance and more importantly the wattage rating would necessitate a decent sized Power Resistor. The better engineering alternative would be one of those universal brush motor speed control boxes like they used in years past before variable speed drills became common, but no idea where to buy one for that motor??? (Google 12 VDC Motor Speed Controller???) Ohms law defines the current through a pure resistive load, but an inductive motor which uses energy to create a magnetic field doesn't behave like a light bulb, and when you start changing the current and voltage heat and torque and resultant power (maybe enough maybe not) comes into play.

 

I do agree with your goal, Id prefer a nice slowwwwwwwww action.

 

John T

[BrianT]

Stan, it's a chain drive setup. The motor has a chain sproket that drives a piece of chain that connects to cables on each end.

 

I agree that pulsing the switch is probably hard on the electrical end of things. But not pulsing the switch has also ripped one of the cable pulleys out of the wall twice. Now do you have an idea of why I pulse the switch? FWIW, I have readjusted the cables since and it has not ripped the pulley out of the wall since but I also have not allowed the thing to open/close with full force, either. Hopefully, yoiu understand my reluctance.

 

I'll do some googling on the "12 VDC Motor Speed Controller". That might be worth the exploration. I do have an old history around electronics so did have an idea that any resistor in the circuit would be substantial. But I've also seen a few things working in tv service such as running a light bulb in the circuit and other seemingly unusual things done to lower voltage enough for a particular desired effect that I figured maybe I'd just throw out the subject and see whether there might just be a little trick that would easily knock this thing back to a more reasonable operation.

 

Thanks for the input!

[Randyretired]

I would consider changing sprockets to slow it down if the shutoff is a switch at the end of travel. Some use a current sensor and the increased torque would play havoc with that. As long as you kept an eye on the slide I think the down side of additional torque could be managed.

[BrianT]

Randy, I think it is a current sensor rather than a mechanical switch that cuts the power at the end of the movement. From all I can tell, that is working correctly. It's still a heck of a thump at the end of that movement, though. I would kinda worry that if one wasn't paying attention (um... my dear wife, for instance) and kept holding that button after the slide had come to the end of it's travel, the added torque provided by that smaller sprocket seems like it could do just as much damage or maybe even more than what it can do now. Not sure on that one.

[Randyretired]

Brian The current sensor is going to be a problem. Some have adjustments but I don't know how much. The way you describe the slam at the end of travel would concern me also. I don't know which is worse the hammering or the increased torque. Some electric motors turn at a slower rpm but changing anything may cause problems with the current sensor. Maybe others have some ideas.

[BrianT]

Thanks, guys.

[Ronbo]

The pulley pulled out of the wall when the two cable ends moving in opposite directions hang up on each other. This is possible when the cables are loose. I had to bolt all the way through the wall with an aluminum plate on the outside to repair mine