Starting Point

Yeah I'd highly recommend getting a charger that can charge at an amp or two. It will become invaluable during events.

Just the problem that i'd need 4/6 chargers depending how many battery packs i need >< which im guessing would be £100 atleast

What do you think to these http://cgi.ebay.co.uk/Intelligent-1-...item1c0b5a5722

Managed to do a bit of building today, had a few problems... made a test rig for the axe and it just destroyed itself without the full axe even attached, wood ripped of the base... might have to learn to work with metal sooner then i was planning lol

Second problem I'm running a victor 883 as the speed controller for the axe it works fine off 21.6V (3x7.2V) but if i try to run it off 28.8V (4x7.2V) it doesnt come on. The victor is rated up to 30V so I thought 28.8V would be ok but prehaps not?

Try checking the current drawn when the axe fires

For the voltage problem, 28.8V is the nominal voltage of having four 7.2V packs connected up (1.2V per individual cell). When a battery cell is freshly charged though, it can be up to 1.5V so multiplying that by 24 (total number of cells in four 7.2V packs) gives 36V. Even if they only charge to 1.4V each, that's still 33.6V so the chance is that it is too much for the controller.
I assume it goes back to working again if you revert to 21.6V after trying the 28.8V setup? If so, then the controller's probably got an excessive voltage cut-out circuit in it to protect the unit.

Cheers for the tips, I think you are right as the batteries were fully charged. I dont think it was anything to do with current draw as it just didnt come on atall. Think I might just run it off three packs anyway seeing as thats powerfull enough to destroy the rig I made. Would HDPE or Nylon 6 be stronger then wood when the axe tries to rip the screws out as the wood just splits along the grain line, or am i going have to go straight to metal?

Nylon would be able to take it if thick enough but to be honest I much prefer metal and aluminium really isn't that hard to work with. Some basic tools and you're away! I also gotta say if you're gonna have that axe swinging around I think you really should go for metal!

Yeah oki think it might have to be metal then, btw before my rig destroyed it self it swang the full length axe at some fair power, made large hole in some chipboard. What thickness alliminum would you recomend and where am i looking to buy it from?

Anyone any idea how to limit the return speed of return using a DX6 and victor 883 to say 20%?