First Time Bot Builder/Buyer

This is a rough price breakdown for my bot - its a 4WD invertible (I hope!) rammer so quite similar to what youre after:

Motors - 4 x 9.6V cordless drill motors - £40
Batteries - 4 x 7.2V Nicad packs - £20
Wheels - 4 x 75mm blue wheels - £22 (Although Id strongly recommend using 100mm blue wheels if you wanna be invertible - I managed it with the 75mm ones but vertical space is tight! Main bot chassis is only 50mm high!)
Speedos - 2 x Electronize 30A with external relays - £100 (15A microprocessor Electronizes are a cheaper option but only by about a tenner each)
Radio gear - 6ch Skysport - £120 (Technobots 4ch kit would be better though, and only £40)

Then theres the things you forget about at first:

Battery chargers for nicads - 2 x fastcharge units - £40
Miscellaneous nuts/bolts/screws etc - Could well possibly be up to £30 depending on how much you use.

So, going by the cheaper options Ive listed, youre looking at £255 give or take a bit, not including materials for chassis etc or any form of weapon. Thats the cheaper end of the scale anyway...... :)

EDIT: Forgot about things like a removeable link, power light, failsafes, mixer etc - approx £35-£40 on top of that

(Message edited by K_C_R on April 25, 2007)

Jamie, if you are going to spend £120 on radio gear. You may as well get a Spektrum for an extra £30, we have 2 they are brill. Unless its too late.

Spektrums werent around in 2003 unfortunately :)

£120 was one of the cheaper quotes I got for the full kit; receiver, tx and rx nicads, charger and servos etc (one greedy model shop were trying to flog it for £170 - no wonder they went out of business)
It was also before the 6EXA came out, back when the Skysport 6 was the main product, hence why it still cost a lot

ABS Roller from car boot £2 = 4 off 100mm dia wheels
3/8 UNF Deep Manifold Brass Nuts from your local motor factor another £2.

So for under a £5 you could get four wheels thatll fit on drill gearboxes.

As good quality wheels that arent likely to break? Questionable.

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

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?

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.

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:p

(Message edited by xtreme on April 26, 2007)

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