(FW)Nibbler- Horizontal Spinner

[Cameron_S]

As said before huge thanks for all the info it's a big help.

I think you're right Glen about the bar size, I was being a bit optimistic with the length. Reducing it should also help the spin up time, power needed and weight. With the only downside being the reduced energy which, as you said, might not be a bad thing. The dimension Alex talked about also seem a good alteration too (reducing the thickness to 12mm and increasing width to 60mm). This thickness appears to be easier to find and the increase in width should make it stronger (hopefully not having the same fate as Massacre's bar- nice to know that was 8mm and a weak metal ). Out of interest what sort of RPM does the bar spin at on Decimator and how much does the bar weigh (sorry if these are answered elsewhere)? I ask this because it has a great balance between delivering good hits and not pinging itself out the arena.

You all are unanimous in thinking the tz85a is a worth while upgraded and Aluminium not being up to the task, so these have been changed. Probably go for the 25x25x2mm steel arms as talked about by Glen.

With a few more of yous opinions on the motor choice, I think I'll stick with the NTM50-60. If it sufficient for the disk on Valkiri, it should be okay for me even if the spin up is a little slow. The reduced bar size should also help with this. I'll also try to design it so it can be upgraded in the future. After checking out the SK3 range they definitely look like a good upgrade for the future.

Might spec down the battery capacity a bit too (thanks again Glen). Also thanks for the reminder about increasing the discharge rate Gary. Something like this
http://www.hobbyking.com/hobbyking/s..._5S1P_40C.html I think would do with the increase to 50c and decrease to 2200Mah (drive battery). [Edit: ignore the following bit(miss read the post)- like the idea of having one battery, but don't think it's easily possible due to the different voltage between drive and weapon motor and the huge peak current that would be drawn from it].- Thanks for the information Gary about increasing the voltage, but I'll like to keep it 7s or lower. This is solely down to the limit of cheap brushless ESCs seems to be 7s.

As for the bearings vs bushings debate, I think I'll stick to bearing as I vaguely remember reading somewhere they don't have to line up as well (could be wrong about this).

Also out of interest why do larger wheels break gearboxes? Is it because of the increase in stresses from faster acceleration? Finally is they any way of reducing the likenesses of them breaking e.g metal gears?

The information so far as been brilliant and gives me a much better chance of making it an arena with a working robot. So once again thanks