First Time Bot Builder/Buyer

[woody]

First Time Bot Builder/Buyer

Questionable.
Yes ...Ive not yet tested mine ...but to me they look O.K. .

http://shop.bodybuildingforyou.com/Images/ASOT/ab-slider.jpghttp://shop.bodybuildingforyou.com/I.../ab-slider.jpg

[xtreme]

First Time Bot Builder/Buyer

so would that gimson kit do me with 4 wheels instead of 2 and 4 motors instead of 2 then? would that speed controller in the kit handle the 4 motors?

then i would need radio gear, batteries, chassis, fixing (bolts,screws etc),then armor.

what else?

[ewan]

First Time Bot Builder/Buyer

I would suggest that to handle four drills the Sabertooth controller should be mounted securely to an aluminum block or extrusion or similar for additional heat sinking and a fan directed upon the board (you could run a small fan from your main battery or receiver power). Also avoid stalls. But up to 14.4v that should be fine even for four drills.

I have used one un-heatsunk unit with two 9.6v drills at 18v (100mm wheels) for around five minutes without any problems beyond a hot controller. Its just a case of taking all the precautions you can.

[xtreme]

First Time Bot Builder/Buyer

how many 7.2V NICAD (2300mAh) batteries would i need to power the 4 motors or should i go with drill batteries instead of the rc car packs? drill batteries are like half the price too

(Message edited by xtreme on April 26, 2007)

[ewan]

First Time Bot Builder/Buyer

This looks like an excellent option http://cgi.ebay.co.uk/Radio-Control-Battery-Pack-12V-3700mAh-SC-NiMH-Compact_W0QQitemZ300103587339QQihZ020QQcategoryZ34 063QQssPageNameZWDVWQQrdZ1QQcmdZViewItemhttp://cgi.ebay.co.uk/Radio-Control-...MH-Compact_W0Q QitemZ300103587339QQihZ020QQcategoryZ34063QQssPage NameZWDVWQQrdZ1QQcmdZViewItem

And remember youll need a charger suitable for whatever pack(s) you choose

[xtreme]

First Time Bot Builder/Buyer

ill get a cpu fan and heatsink that should work right? if i got it cooled how long will i be able to run it for?

[xtreme]

First Time Bot Builder/Buyer

would that one battery power 4 motors?

[xtreme]

First Time Bot Builder/Buyer

Hehe look i dont wanna be this simple. ohh i asked him, he knows nothing about the radio gear or weights. there using upsidedown wheel barrows as bodies. http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ih=020&sspagename=STRK%3AME WA%3AIT&viewitem=&item=300104293276&rd=1&rd=1http://cgi.ebay.co.uk/ws/eBayISAPI.d...STRK%3AMEWA%3A IT&viewitem=&item=300104293276&rd=1&rd=1

[ewan]

First Time Bot Builder/Buyer

A substantial aluminum would be a good bet, and also any general cooling fan should do. Places like maplin should have suitable stocks, for example http://www.maplin.co.uk/Module.aspx?ModuleNo=32006&criteria=fan&doy=26m4http://www.maplin.co.uk/Module.aspx?...a=fan&doy=26m4 which is nice and compact for a potentially small machine also technobots have a cheap offering if youre going to be buying things from there http://www.technobots.co.uk/index.html?lang=en-uk&target=d538.htmlhttp://www.technobots.co.uk/index.ht...rget=d538.html

[ewan]

First Time Bot Builder/Buyer

Yup, that battery would be fine, though you could do with a spare so you can charge one while the others in the robot. Those wheelbarrows look like ancient relics hehe. The windscreen wipers and batteries probably arent worth the £50

[xtreme]

First Time Bot Builder/Buyer

better get to bed up at 6 james baker is emailing me about some second hand stuff so ill drop you a message see what ill need for my build gimson and ebay should have it all. thanks for the helpful info tonight ill be back bugging you again Cheers

(Message edited by xtreme on April 26, 2007)

[ewan]

First Time Bot Builder/Buyer

No problem, I best be off too, oh the joys of early mornings hehe

[typhoon_driver]

First Time Bot Builder/Buyer

I dont want to pee on anyones chips but I would be wary of relying on both a large heatsink and fan combination to keep a speed controller cool.

What you have to remember is that in a battle the motors could be be slammed from full forward to reverse and everywhere in between. A drill motor can draw relatively large currents and these will happily blow up a speed controller with a low current handling capability.

I dont want to get into a debate with anyone and this is not meant to be offensive to anyone. Just stating a few facts.

I am sure that it could quite happily be implemented but it will require a fair bit of thought to make sure you get the required air flow and keep it cool.

[grant_ploughbot]

First Time Bot Builder/Buyer

I think these speedos have prety good current limiting, not too sure on how well but ewans done a few tests and they seem to work well lie that.

[jamesb]

First Time Bot Builder/Buyer

you should ask mark lumb about his opinion of the sabretooth.
in my opinion, heatsinking it in the way described is pointless, as you are heatsinking the plastic case, which is never effecient anyway. secondly, the current limiter is a safety feature, and cannot be relied upon once it is hit once, to be reliable the next time.

On 2 9.6v motors at 9.6v or lower, maybe the sabretooth is ok, if you resin it to stop all the heatsinks falling off, but for 2 pairs in parallel??? No, I dont think it will be enough.

go with the 2 electronize from technobots or the 1 scorpion (scorpions are £85 from me) for this application I think, or 2 sabretooth in resin.