Placing of Motors & actuators

[Battlestar]

Hi folks,

This is a general enquiry. How critical is the siting of the motors and actuators in relation to the pivot point in a 2 motor set-up? Does anyone have a way of working out the optimum distance from the pivot point?

Thanks in anticipation,
Mike

[motiondave]

this depends on motors used and the frame type. Generally, motors at the rear and about 15 deg angle and mount the motors to connect at shoulder height is best by far. Motors under the frame also work, given allowance for weight.
Do you have a frame in mind? I have built 7 sims all with different motor positions.
Cheers, David.

[Battlestar]

Thanks for your post David. I am in the process of building my rig, based on a wooden platform supporting a GTOmega frame and chair on top of a universal joint. I have seen pictures where you placed the motors at the front. Does this make it easier on the motors? I will be using 2 x 12v motors running at approx. 200 rpm and I intend to have the pedals and monitor also moving on the rig. So I'm really wondering how crucial the placement of the motors and actuators is.
Cheers, Mike

[motiondave]

Hello, placement of motors is fairly crucial, but I have tried several various spots and they all work.
What motors, 12v at 200rpm, yes but what torque. For example, mine are 20nm torque, but the stall torque is higher. I have found some motor suppliers quote stall torque, which really is a false figure.
Now, having the motors, either as far away from the pivot point and under the centre of gravity, like I did, has a wheel barrow effect - leverage.
My foot motor sim uses that idea, I can have 120kg of 6'3" bloke on it no problems, and it moves flawlessly, because of leverage. Mind you, I am only 80kg at 6'.
If you are looking for a compact design, from, what it sounds like, that will work, having the motors near your feet or about 700mm away from the pivot. Closer will also work, but you need to allow for weight of driver.
Hope that helps and ask questions as you need to .
Cheers, Dave.