Drills

Does anybody know where I can get cheep 7.2v drills (must be 7.2v) for my next project.

at almost all cheap drill- gerarboxes you can add any standard RC -car Stock Motor. Just remove the pinion gear from the old motor and mount it on the new one. I have done this successfully with 2 LRP GT2 11 winders (41000 rpm at 7,2 V), 15 quid each. Works fine, the plastic planetary gearwheels of the 1´st stage don´t melt :) until now (after 10 minutes under full RPM).
Helmut

question for helmut; how do you remove the pinion gear from the drill motor and mount it on the car motor? In the past I tried, once, and couldnt, since it seems to be welded on and doesnt seem to have a grub screw holding it in place.
Any help would be very much appreciated.

Hi
It´s possible to remove the pinion carefully with 2 screwdrivers, but some people have bad experience with this kind of working. Better: a pinion puller, you can buy this tool for a ridiculous price. example
http://www.slotracer.ca/miva/merchant.mv?Screen=PROD&Store_Code=SR100502&Produc t_Code=H107000http://www.slotracer.ca/miva/merchan...100502&Product _Code=H107000

I made the tool by myself from a scrap piece of 15*15*1.5 box section, just slice one side ca 5 mm with a saw and cut a m 3 thread on the opposite side. Works sufficient.
Helmut

i use a butane torch (a mini one) to heat up the gear than just use a flat head screwdriver to lever the gear off, works fine :)

glen
i used the same method before, (well proven since more than 20 years :) )but another german builder told me, he had not removed the pinion by this way, but the rotor shaft :sad: .... IMHO its better using the tool, takes just a few minutes of preparation.
Greetings from Austria (the no kangaroos country)

thanks for the advice guys, i think ill get a pinion puller, seems the best bet; not got much in the way of workshop accessories for preparing metal etc. Next silly question then, whats the best way to keep it on the model cars shaft....

http://robotwars.00server.comhttp://robotwars.00server.com

thats simple. you can press the pinion on the shaft easily by using a vise. the shaft normally comes out a little on the rear side. all shafts of this 540 or 550 series have a diameter of 3,17 mm (must be some odd inch unit) and the same fixing holes. For more security you can add a drop of loctite (if you want to remove the pinon after glueing, you have to warm up the pinon with a lighter or so).

regards
Helmut

have many people had problems in the UK with the pinions in the gearboxes shearing and the gears shredding?? ive had really bad experiences with drills honestly.

also helmut, could you provide some more info on how you made that gear puller?

Thanks Helmut, just lookin for the right type of drills and Ill be sorted.

Thanks for you advice and have a merry xmas.

You could always buy just the drill type motor and make a gearbox.

thats what I did.

Glen, sounds like your gears werent correctly meshed. They tear up real quick if even 1mm out.

If anyone gets sick and tired of drills, let me know on info@jamesbaker.f9.co.uk and Ill tell you how much my custom made gearboxes cost. They are not as cheap as drills can be, but they are supplied with motors and ready to bolt in. Choice of ratios and module. I can even do a double trouble gearbox which uses 2 motors to turn 1 output shaft. Quite neat.