Adding 2DOF motion to my 80/20 GS-4 Rig

There are a number of factors at play, the RPM, the available torque, CTC of the lever on the motor shaft and design leverage. It is the linear speed and effective torque that matter, see here for more info: http://www.xsimulator.net/community/faq/calculating-basic-linear-speed-and-forces.89/

Using a different example as @Pit explains winches are very slow RPM but have a lot of available torque, so you can dramatically lengthen the CTC of the lever on the motor shaft for high linear speed response.

I don't find the motor supplier file that helpful, as it assumes 24V. Basically what you could look for in the PDF is the equivalent of 200-320W, 3200-3600 RPM, 50 or 60:1 ratio box with metal gears, which depending on the combination would have 30-60NM torque.

Again I disagree as I am using 60:1 on 3600RPM motors and don't think that is too slow, as long as you use a suitable CTC, it is a question of torque and linear speed, not shaft RPM. Yes a compact design and weight come into play as to how much leverage you can and can't use.

To be honest I suspect you could use the 3600RPM/25:1 with the design he has at around 40-50mm CTC. I know @bsft has people up to 100kg on his desk racers, which have a shorter length to the pivot and use 40mm CTC with 3600RPM/25:1.

This is to give some comparable context.

A SCN6 runs 200mm/sec max. speed, which is a linear velocity of 0.2 m/s: http://miraiintertech.com/home/scn6.php

A SCN 5 runs 400mm/sec max. speed, which is a linear velocity of 0.4 m/s: http://miraiintertech.com/home/scn5.php

A 3600rpm/25:1 with 40mm CTC at 144 rpm gives a linear velocity of 0.6031872 m/s with 500 Newtons: http://www.endmemo.com/physics/rpmlinear.php

A 3600rpm/25:1 with 25mm CTC, which is as small as it is practical to go, at 144 rpm gives a linear velocity of 0.376992 m/s with 800 Newtons.

A 3600rpm/50:1 with 40mm CTC at 72 rpm gives a linear velocity of 0.3015936 m/s with 1000 Newtons.

A 3600rpm/60:1 with 40mm CTC at 60 rpm gives a linear velocity of 0.251328 m/s with 1200 Newtons.

@Avenga76's 75mm CTC at 100 rpm gives a linear velocity of 0.7854 m/s.

If @SilentChill is running 130mm CTC (not sure if that is the CTC or lever length) at 100 RPM then the linear velocity is 1.36136 m/s.

Design wise you can then take the known Newton for a given CTC, the distance from the motor to the pivot point and the angle used. Run that through the calculator gives you the magnitude of the torque that is possible per motor. Again the angle affects the outcome.

If 25 Newtons is applied 600mm from the pivot at a 90 degree angle then the magnitude of the torque is 150

If 25 Newtons is applied 600mm from the pivot at a 30 degree angle then the magnitude of the torque is 74.99999999999998

The calculators are useful for a basic comparative understanding of torque, CTC and linear speed, disregarding design, acceleration and deceleration effects, but there is nothing to say that the rated specs of a motor are.

For example the levers @SilentChill runs on his rig suggests the stated specs on his motors are far below what they are actually running at.

If you can't use the full torque and speed of a given motor then results will suffer.

Design will also be a factor as to how efficiently the speed and torque of a given motor is being used. For example a shoulder mount on a seat shaker takes advantage of the long axis of the seat as a leaver, but loses some efficiency with respect to torque, as that is applied at an angle. But as it has a long lever you can take advantage of the speed and larger CTC lever on cheaper DC worm gear motors. If you place engines in a compact design it takes more torque to drive it because of the shorter lever distance to the pivot, but you can apply the torque it has more efficiently, as it can be at 90 degrees.

There are many decisions and compromises in any given design.