Are these motors sufficient for my 6DOF project

[Marc1911]

Hi there,

I'm doing my research on choosing the right AC motors for my 6DOF project.
I would like build a configuration like Thanos has build -> link
and found the following worm gear motors:
1) JS-CMRV 050-713-0,55kW-28Upm Euro 203.83 each -> link: 3x230/400V, 0,55kW, n²=28, i=50, M²=119Nm, fs=0,5, mounting position B3, hollow shaft 25mm, 10,1kg.
2) JS- EV 050-801-0,55kW-36Upm, Euro 260,05 each -> link: 3x230/400V, 0,55kW, n²=36, i=38, M²=95Nm, fs=0,7, mounting position B3, hollow shaft 25mm, 13,1kg.

Can someone confirm if this worm gear motors are a good alternative. I thought better go for a motor with the gearbox attached. Not sure if the worm gear concept is the one to go for. Not even sure if you can call it gear box?? What about the rest of the specs?

[tronicgr]

Hi Marc,

I was going to write you on your emails today but since you posted here...

This motor you choose is good,
1) JS-CMRV 050-713-0,55kW-28Upm Euro 203.83 each -> link: 3x230/400V, 0,55kW, n²=28, i=50, M²=119Nm, fs=0,5, mounting position B3, hollow shaft 25mm, 10,1kg.

For 6DOF platform with load about 200kg.

But if you can afford it, I would suggest this, so you can handle the load very easily (not stressing or overheating the motor) as you will have to also consider that the load is not static but dynamic and its mass is shifting during Surge-Sway motion.
2)http://www.js-technik.de/produkte/getriebemotoren/schneckengetriebemotoren/3213/sev-ev-063-90s-0-75kw-24upm?c=176

You WILL NEED Worm gearbox! Trust me... Its not fun trying to stabilize a bevel gearbox...


For inverter, use a 0.75kW (1HP) inverter for the 1st motor like the TECO EASY DRIVE E2-201-H1F, 79060204

And a 1kW (1.25 or 1.5HP) inverter for the 2nd motor.

Thanks
Thanos

[Marc1911]

Hi Thanos, thanks a lot for reviewing this. I was going over this formula to determine maximum kgf/cm for these motors using rods of 60 cm and my calculations show max lifts in kg for options 1) 32 kg and 2) which is more expensive even 25 kg.
The motor you found has 750 watt and 24rpm which would lift 50kg. So if I'm right in 6DOF the motors operate in pairs and lift then 100kg and thus 6 motors will lift in total 300 kg.

Formulas used:
Torque = Power (Watt) / RPM * 0.105
Kgf/cm = Torque / 0.09806649
Lift capacity per arm = kgf/cm / arm length

Questions I have:
1) If I decrease the rod/arm length I'm able to lift more. What's the rule of thumb for a rod length to have still adequate motion like on your and Fabio's platform?
2) What's the effect of the crank length on max lift weight? Any rule of thumb there?

[tronicgr]

Hi Marc,

There is no rule of thumb. You might have to try some different arm lengths to see if you get satisfactory motion while staying in the load limits of the motor. A good way to try is to make a model like this and try different dimensions or distances, until you get a motion range that is good enough for you.

For the crank arm, the bigger it is the more speed and motion range you will get, but in combination with long rods too. If you have long arm but short rods you will face issues. A good way it to have selectable length arm with multiple holes, something like this:

crank arm.jpg (4.05 KiB) Viewed 2774 times

Thanks
Thanos