Bit of advice on my drumbot please

[calumco]

Re: Bit of advice on my drumbot please

LOL jamie haha

gary i could kiss you..... but i wont, but still thats a brilliant idea! means i can make the bulkheads higher meaning the drum can run freely upside down aswell as it wouldn't have been able to before and the robot can be alot shorter as all the internals can fit in vertically above the motors got a pair of 100mm wheels with bearings inside already..... propper job!

nylon came today aswell, so hopefully start making tomorrow/friday

[RogueTwoRobots]

Re: Bit of advice on my drumbot please

Ah yeah, that's something I forgot to add yesterday. Smaller wheels seem to be more reliable with drum spinners (from my experience anyway). Drumroll had 75mm wheels, Drumroll II has 125mm wheels; the greatly-increased speed of Drumroll II is handy for darting about the arena, but there is much more force being placed not only on the drill shaft, but also the nuts melted into the wheels, especially when the shocks from impacts are going through your robot. I'm currently on my third set of wheels with Drumroll II and am planning on making a new set soon. The nuts began to pull out of the first set (home-made), with the second set one became partially loose then got jammed on (the pair I used at the champs) and the current set, while holding up fine in that respect, don't quite have a level of grip or robustness I'm happy with. By comparison, the old Drumroll ran the same set of wheels for four years without any problems.

[calumco]

Re: Bit of advice on my drumbot please

surprisingly after just 5 and a half hours today i've got something which resembles a robot......

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Going for lipos for the drive and drum as i wana save as much weight as possible for hardox wheel guards and lower back armour. i may even cut the top down so it slopes down towards the back to save on nylon weight as its heavy and to get it even more compact but ill see how i go on space inside. suprised aswell because nothings gone wrong so far or been mounted wrong lol i must be learning after 3 years finally

next job one day next week is to get the speedos mounted, make my own ali bracket for the drum motor and wire most of it up and hopefully give the drum a slow spin up and drive about

[Mouldy]

Re: Bit of advice on my drumbot please

Make sure you chop those teeth of before you spin it up lol

[calumco]

Re: Bit of advice on my drumbot please

Did some yesterday, cut the bulheads down on the top so that they are sloping down towards the back and its looking pretty cool now sorted out the motor mounting, and cut the teeth off the drum but the drums now totally screwed still badly off balance without any teeth on now im guessing from the welding and weld replacing stainless on the drum and so forth so its once again off balance. thinking about sending it to someone to get teeth made but i don't think it'd be easy balancing it so i may get tom or kenny or someone to make me a beater style weapon instead of the same dia. but pics to follow soon.....

[calumco]

Re: Bit of advice on my drumbot please

Pics

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Last picture showing the weight, need to make a new motor bracket atm so the motor won't be looking wonkey much longer, was going to go for lipos but for the space i had avaliable nimhs were easier to work with. may go for a slightly lighter weapon as the drums 3.7 kg atm aswell wana hopefully aim for a 3kg weapon

[typhoon_driver]

Re: Bit of advice on my drumbot please

Sell the nimh and get lipo. Find space to fit them in. You would notice a huge difference if you were to do a direct comparison in spin up time.

[RogueTwoRobots]

Re: Bit of advice on my drumbot please

It's a drum, it's ridiculously compact and it's blue - what's not to like?

[PJ-27]

Re: Bit of advice on my drumbot please

Your not Scottish as well are you Calum?!

[RogueTwoRobots]

Re: Bit of advice on my drumbot please

Being Scottish is awesome, so it's no wonder everyone wants a piece of the action

[calumco]

Re: Bit of advice on my drumbot please

I would gary but the cost of buying more batteries and chargers etc isnt something i can afford atm so if anything i'd upgrade that later on. decided i wanted to put what money i have into a new weapon for the time being.

and yeah lol i couldnt decide what colour to go for and i thought i'll go blue to match the other drumbots lol

[death robotics]

Re: Bit of advice on my drumbot please

[quote=calumco]LOL jamie haha

gary i could kiss you..... quote]

Proof that FRA members know each other a little too well

[widow_twanky]

Re: Bit of advice on my drumbot please

Can i just ask why people use belts for the drive on the drum?

I get the gear reduction and shock absorbtion issue. I'm asking because i have some sprockets and chain which would probably suit and just wanted to know the pros and cons of each

Andy

[RogueTwoRobots]

Re: Bit of advice on my drumbot please

Both are perfectly usable forms of transmission for drums. I think I chose belts over chains initially because I wanted a bit of slip (although not sure how much a timing belt actually slips during a hit) and if you have flanges on the pulleys, the belt is less likely to come off, whereas a chain could be prone to jumping off or snapping during a large impact. Having said that, I've never worked with chains and sprockets on spinning weapons, but I'm sure I've seen DragonStrike's chain on the arena floor more often than on the motor/disc (and it usually seems to make its way there after a large impact)

And for the obvious; pulleys are lighter than sprockets and easier to machine, which is handy if your facilities are limited. You can get larger reductions in gearing for a certain diameter than you can with sprockets although they usually are the more expensive option, albeit only by a few quid.

They're the main reasons that come to mind and why I chose belts, but if you've got - and want to use - chains, it shouldn't be too much of an issue.

[PJ-27]

Re: Bit of advice on my drumbot please

NST snapped a chain at the last UK Champs and I think that was the only bot to use chain driven weaponary.

Chains are a nice option because they're readily available and you can make them to the size you want, plus everything Jamie said....