Or a bench grinder or skill saw or washing machine or sump pump or attic fan.
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I did think of that, using the two different systems, and it’d be so much easier to do, but I’d also like to do this method just to see if it’s possible. I was also thinking of separating the systems in the same holding mechanism, so that it pivoted about a foot out from the pole, rather than around the pole itself, but I still think around the pole would be cooler to watch.
I’ll keep that in mind, because doing 2 separate systems would be so much easier to actually accomplish.
I was thinking of something like that but I wasn’t sure if it’d work. It’s basically hooking a battery charger to a battery and then taking power from the battery as it charges, right?
You said you would be using a ball right? What happens when this ball slips? Feel like replacing the tv? Or will you have a safety system just in case?
I was inspired by this video:
http://dvice.com/archives/2010/04/ball-balancing.php
So maybe something ball shaped but flexible so it can grip to the pole.
What do you recommend as a safety system?
i want one of these
http://www.youtube.com/watch?v=_i3zfL1VUGo
I’m not exactly sure… Some sort of friction system that activates after the tv stops moving? I’m not exactly sure… I would be using a completely different system… haha
Spring loaded rubber grips that lock on the pole? I could probably use a less powerful motor to hold those open and then when the motors stop moving, those could close.
use He to make the TV neutrally buoyant, then you could use almost any motor to use it. Or, use liquid He and levitate the TV on superconducting magnets.
Ryutso,
If you get this system installed in your bedroom, I have GOT to see some pictures :ahh:
Toby,
What you are asking leaves me wondering about safety. This is a point where we have to really point you to a mentor that can discuss this with you and watch over what you do. Household current is not something to fool around with as it can kill and set fires if mishandled.
As you can see from the above answers, four CIMs are an overkill for this project as you don’t need to raise the TV that quickly. We typically are raising devices on a TV set at much less than one foot per sec and typically the height of the TV (30-40 inches) in about 15 seconds. Any faster and the support hardware and structure take too much of a beating when you stop. The garage door opener motor in the link that Sanddrag has given above looks like a pretty good start. Remember that the motor is designed to lift a balanced garage door so it is likely producing the required lift for you project. It might even have all the needed end limit switches that you should use in your project.
Al has some great advice here.
I’ve spent a lot of time crawling surplus sites (usually for 540 sized motors), there are a lot of cheap, slow, torquey motors out there. What’s nice about that is you really don’t have to do much, or possibly no, gear reduction, and depending on what you buy, they could have a nice low efficiency worm gear to hold it in place.
We all know that a fuse reacts faster than a circuit breaker, right? (If not, consider yourself informed). Now look here (1.8 MB PDF file). According to the graph on Page 4, how long can a 40A fuse hold a 100 A current?
Give me any motor and I can get it to lift 25 pounds. What changes is speed.
OK, so I think everyone understands that a CIM is probably a poor choice for this application. 120 VAC will smoke it immediately, a 12V power supply big enough to manage it will be expensive, and 120 VAC geared motors are plentiful and cheap.
Al spoke about electrical safety: heed his words if you enjoy living. Even an accidental brush against 120 VAC can be fatal. That would ruin your day right quick. Setting the house on fire is just a side benefit.
Also consider mechanical safety: The whole system needs to support at least 3 or 4 times the heaviest weight it;ll ever see, and if it were mine I’d go for a factor of not less than 10. If it were to break, the damaged TV would be the least of the problem, since the pole embedded in my cousin’s chest will really cheese off Aunt Sally…
If I was looking to do this project on the cheap, I would look for things that already do the motion that you require.
For example a drill press table travels up a pole (using a rack and pinion), and also can swing around the pole.
So you could buy something like this http://www.harborfreight.com/16-speed-floor-drill-press-43378.html
Stick a low rpm high torque motor on the lifting crank, and then drive a firction wheel on the horizontal surface of the column to rotate.
If you wanted to separate the 2 mechanisms i would move away from a pole and use drawer slides on a vertical frame, and then pivot the frame at the bottom like a turret using a lazy Susan bearing.
Without knowing the specs of your tv/system it is hard to recommend a motor. On the cheap side of things I will echo finding something at http://www.surpluscenter.com/electric.asp on the expensive side you can find something exactly speced for your project at http://www.grainger.com