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The only potential issue with V-Belt is that when you put a shock through the system the V can dig into the pulley and actually transmit a lot of force - if you can found a round belt it will be a lot safer, though as people above have said - many are using V-belts without any issue.
We never had a problem with a chain on Vortex, but there are plenty of people who have so Im assuming that we just got lucky !
Ed
http://www.teamstorm.comhttp://www.teamstorm.com
John,
I have tried virtualy every opion for spinner drive and after much experimentation I have come down to usig 6mm pitch HD Stainless Steel roller chain for the fetherweight and dual SPA V belts for the heavyweight
I have another F/W spinner under costruction that uses a 5mm pitch 9mm wide HTD timming belt. This was chosen because of the velocity of the drive train and complex belt route. HTD belts are good up to 80M/S! were 8-10M/S is about the fastest I would comfortly like to run a chain.
As for ratios, I use 3.1:1 reduction in the featherweight, 1:1 on the heavyweight and 4:1 on the new Featherweight.
LOL, Ed, on Vortex all the shock was in your opponent faces and in their featherweights, I cant recall anything stalling Vortexs disk.
BlacknBlue used twin HTD timing belts, 5mm pitch 9mm, on either side of the disk. They also worked reliably. I guess any method described above will work well as long as the engineering is sound.
The only problem with chain is if you do not get the engineering right the chain can come off. But DS and Scorpion seem to have got it right now. But that caused another prob the chain did not come off the shaft on the EV snapped which would not have happened with belt drive. Glad to know your robots up and running Rob rematch.
Thanks for the advice folks, much appreciated.
John, Our first spinner used the same pancake motors. It had a 2:1 ratio on a 600mm dia disc with the disc weighting only 500 gramms. These motors are very slow compared to an EV or Astro so a big gear ratio would make it run slower, It used a large O-ring for the belt from a car asseccory shop on 2 very deep pullies. We did have one problem with the motor as the shaft is only pressed into the disc armature and it started spinning after only a few test hits. A couple of grub screws fixed this easy enough. On testing we were actually using 240W of power once the disc got to full speed and even more spinning up, so after a fight it was red hot but we never burnt it out.
Thanks Mark- very useful to know about the need to secure the shaft before we use it! Handy to know that its normal for it to get really hot too. I hope to start making the featherweight in the next couple of weeks, although presently the main focus is getting the Roboteq and the NiCads into Ka-Pow! for Birmingham. thanks again everyone.
Im not too sure what range of cars you have in the UK, but over here in Oz, I found a 12v 75watt pancake motor which seems to handle 24v quite nicely. It came out of a Ford Telstar. It weights 750g, 110mm diameter and 40mm tall including shaft(shaft is 8mm double D shaped).
If your looking for a non-pancake style motor to suit your design better, a Mini EV is a cheap and effective weapon motor. We have one in our featherweight, Vertical Limits, which has a 3.4kg 300mm diameter flywheel which rotates at around 4000rpm. The Mini EV survives a full battle just running of two crappy 2.3amp SLAs in parallel.
You can buy Mini Evs here: http://www.robotmarketplace.com/marketplace_motorsmisc.htmlhttp://www.robotmarketplace.com/mark...otorsmisc.html
On that link, check out the HTI motors with 5mm shafts, they might be a half decent motor, but I havent personally used any.
Will let you know about the HTI motors as we are trying them out on one of our new spinners we are useing 2 to power the 2kg disc.
I believe the HTI motors will do quite nice if you run them on 12-14.4v and possibly 18v if you gear the weapon enough and share the load between two motors. Ive seen a few of them smoke at 24v, mainly in Hellbringer X (Aussie Rambot with 4 x HTI motors with SS2 gearboxes on 24v powered by 3600mAh Battlepack)