Feather weight spinner questions

[webby]

Right ok, good to know.

so which one from the 2 i posted would you recommend?

Im leaning towards the turnigy one as i feel it would be more reliable.

Thanks for your help

[typhoon_driver]

To be honest, you will struggle to get useful recommendations as there are so many to choose from and relatively few have been used by roboteers.

I've solely used the scorpion motors with great success but advice that I would pass on would be, support both sides of the motor pulley shaft. The shafts and casings are not meant for the forces they will see in a combat robot and i have snapped shafts and bent casings on motors.

For such a light disc you will get away easily with either an outrunner or inrunner. Outrunner generally has greater torque, inrunner greater speed. Depends what is needed in your design. I'd recommend increasing your disc size and weight but that's up to you.

Which ever motor you go for, run it at it's highest possible voltage. The difference in current draw of my big scopion when running on 10s vs 6s is dramatic (9A vs over 100A) based on black box recordings I have from the esc I used. This makes a huge difference to the stress put on your esc, wiring and batteries and will allow the machine to run for longer comfortably.

[maddox10]

If you can't "ruggedize" the motors, the best bet is to use one you can replace most easy.

Otherwise, it's budget and creativity.

As written by others, each to his own.
I prefer the NTM range of motors. Affordable and easy to adapt/rebuild.

[webby]

Right thanks for all your help guys.
I am purchasing a Turnigy XK3665-2400KV motor.
2400KV
80A
1185W
But unfortunately haven't ordered it as Hobby king has broke!

Any ideas on the ratio for the pulleys for the 1kg 100mm disc?

Thanks!

[maddox10]

It seems the motor is ment for 4S, and that gives a motor RPM of 35520.

I would go for a 4 to 1 ratio.

[Eventorizon]

Hobby King has been broken for several days on the UK server end. I've been trying to order some receivers but I can't 'add to basket'.

Given how light it is, I would say go for a 3:1 ratio and just live with a slightly longer spin up time. Your weapon won't have much punch otherwise given how light it is.

[webby]

OK thanks for your help, that was my theory with a lighter disk = faster speeds and quicker spin up time.
so what size timing pulley would i be looking at on the motor and disk?

Thanks

[maddox10]

What I would try.

http://www.beltingonline.com/10-toot...ey-al27t5-4916
http://www.beltingonline.com/36-toot...ey-al27t5-4932 *
http://www.beltingonline.com/36-toot...ey-al27t5-4932

*But I prefer a smooth pulley on the disk. Call it a quirk.

[Eventorizon]

*But I prefer a smooth pulley on the disk. Call it a quirk.

This interesting. I know most people run a smooth pulley on the weapon. Conker and Binky seem to be in the minority. Conker has toothed pulleys on both, which is why it can reach insane speeds despite the wind resistance, and Binky had a one way bearing, its still good after 2.5 years of combat and testing.

[grant_ploughbot]

This interesting. I know most people run a smooth pulley on the weapon. Conker and Binky seem to be in the minority. Conker has toothed pulleys on both, which is why it can reach insane speeds despite the wind resistance, and Binky had a one way bearing, its still good after 2.5 years of combat and testing.

Having a smooth pulley is purely to take alot of the shock out of the motors when you impact something andd unless you have it really loose wont make any difference to the speeds your disc can get up to. 720 has the highest top rpm spinner at the moment and that's on a smooth pulley, and Rango has about the fastest spin up time again on a smooth pulley. Its all personal preference but its there to help the rest of the system from shock by adding abit of slip.