[Serviceguyuk]

Originally Posted by CAMODADDY

Thanks Mike that information is a big help. I have a motor an lift already I was just trying to use a better motor, so I ordered a new one from Robotmarketplace. The quality and prices look great though on the RCBRmin site.
Bryan

Hi again Bryan,

I'm just trying to help

Below is a spec sheet for the standard Tamiya RS-540 motor manufactured by Mabuchi.



It's all a bit complicated unless you know about it but I'm guessing you want more torque for your lift application.

The term 540 (the standard Tamiya RC motor) usually refers to a frame size (physical dimensions) where within that frame size there are a number of winding and turn options that are able to be accommodated giving different characteristics i.e. higher or lower speed and torque. The graphs indicate two variations to help visualise it The trick to selecting any motor AC or DC is selection of speed, torque and efficiency and the best point to start if where the lines cross on the graph! ! ! !

There's usually a whole load of stuff and nonsense written about turns and speed but here's a good guide

Number of turns refers to how many times the wire is wound around each pole of the armature. The higher the number of turns the greater the torque delivered. However that also means a lower RPM.

More turns e.g. 27T gives higher torque, less RPM & longer battery life.

Less turns e.g. 19T gives less torque, more RPM but a shorter battery life.

The number of winds or windings is the number of wires wound around the armature. Sometimes the wind is increased in order to compensate for the torque lost with less turns.

A single wind gives most power/torque at lower RPM

Two, three or four windings give less low speed power where the most power (torque actually) is delivered at higher RPM.

It all becomes very complex very quickly but with a bit of fairly simple maths and experimentation you could figure out what you need.

Also consider that with a screw jack assembly the load is not constant as the screw thread is constant as is the geometry of the levers but the load at various points of the length of the screw is not. When lowered and starting to raise the initial load is very low as the slack in the screw thread is taken up but this quickly rises to it's highest level as the full weight of the dump is taken on with little lift for many turns of the screw. At about 45 degrees from horizontal where the load starts to dump and tilt rate increases due to the lift geometry and load decreases.

All in all you may have to suffer a little with a slower speed to gain the required lifting torque or a much higher speed that slows almost to a stall condition depending on what motor you choose.

I know your initial question was simple and I've probably massively over-complicated it but it may help inform you a little when choosing one of the hundreds of little DC motors that's available

Or maybe not . . . . . . .

By the way all this pseudo-technical stuff doesn't make me the go-to guy, it's just some things I've picked up and others I used to work with a few years ago

Best of luck

Mike