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Unread 23-02-2015, 09:39
philso philso is offline
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Re: Elevator Design Help

Quote:
Originally Posted by shewejff View Post
We made our gearbox out of a 2" X 3" X 1/8" rectangular aluminum tube. That works really well for the size of our gears, but the holes really need to be drilled perfectly. With our rudimentary workshop tools, it took us a couple tries to get it perfect.
Your first tournament is later this week and another the week after. You need to evaluate your risk and determine what you can do in the time available. There is no "playing defense because you can't score" this year. Can you make a new worm gear box accurately enough? Can you get an AndyMark RAW box in time? Can you do something that emulates what oRyon Labs did? The last two options may be your best.


Quote:
Originally Posted by grem110 View Post
I assume that keeping the worm gear for its anti-backdrive ability is a must? I ran some numbers and discovered that using an RS-775-18 with a 35:1
oRyon Labs and others (including our team) have found that anti-back drive is not really necessary. Even if you choose gearing such that the winch backdrives slowly, your drivers can probably learn to live with it. The alternative is to not be able to do anything significant on the field.

The RS-775 and RS-550 motors rely on the integral fan for cooling. The can overheat and fail if you are going to run them at low speeds (including stall condition = 0 rpm). The CIM, Mini-CIM and BAG motors rely on the thermal mass and heat dissipation through the motor casing, without air being forced over them, for cooling and will be much more durable in this kind of application.