Help Opening drills.

I bought 2 Challange drills to use in my first robot,but cannot get the screws out from behind the chuck. Yes, I do know its a reverse screw :P
The screw just wont budge.

Are they the 9.6v drills? If so, i use them in Mr happy, probably just a very tight screw- try harder to un-do it.

Just watch out you dont chew the head of the screw though before you get it out - I did that with my first drill (it was also really tight) and I ended up having to hacksaw the shaft in half to get the chuck off because the head was completely chewed and wouldnt turn. Ive learned my lesson now though :)

A hack saw eh?
Think Ive found a solution :P

or drill it out, then you still have the shaft to mount wheels on.

how do I drill them out? You mean with a screwdriver bit?

Try smacking the chuck with a hammer for a while then try unscrewing again - it works sometimes hehe

This is why you should buy them pre-stripped :wink:

A hammer eh? Il Give it a try :S

Lol, nice subtle advertisement there Ewan :)

Yeh :P
If I drill this screw out,then how can I attatch a wheel?

i got these same 9.6v drills today, i used an impact screwdriver to undo mine, just clamp it in a vice, one good hit and it came loose.

i have a couple of questions

1.do you remove the torque and chuck bit and just have the motor and plastic gearbox bit left? then mount wheels straight on the shaft (its a bit short) or do you do something else?

2. what voltage/batteries should i use to run 2 of these motors in my machine(im a bit worried that these motors look a bit weedy for a 12kg machine.

3. last thing is what sort of speed controller is recommended for my setup.

Whats an Impact screwdriver?

1.Dunno
2. I was told to use the batteries that came with the drils and over Volt the motors to 12V
3.Buy some of Leos 6~12V 100a Speedos.

drilling out is simple, put a drill bit into a second drill, insert it into the end of the drill you are taking apart, and drill the reverse thread screw until its head comes off. you should now be able to unscrew the chuck. The wheels should be made with a 3/8ths UNF thread in them. screw wheels onto the drill shaft. lock in place either with a grub screw in the wheel or shaft, split pin, or a nut tightened up to the wheel.

I recommend the electronize speed controller if you plan to overvolt these motors, ( which both technobots and I sell). another option are mtroniks controllers, the marine 25s I sell being good.

remember you need to lock the torque rings too. i suggest m5 grub screws.

finally, 2x 9.6v drills on 12v should happily run a featherweight, as long as you have them balanced right, ie, do not have the motors at the back and all the robots weight on its wedge at the front. it will have trouble. 4 of these drills would be a really good drive system, but be aware that the harder you push them, the shorter the life of the plastic gears.

I didnt personaly find the left handed screw to be tight at all, Try an impact driver, if not - as James said- drill them out.

An impact driver is like a screw driver but you hit the top of the handle with a hammer and the force turns the screw driver bit.

I use 30amp electronize with exsternal relays. I run my motors on 21v so if you use urse on 12v you wont have any problems.

If leos speedos can handle the current you will be fine.

Wheels can be bought from Ewans shop to fit the drills, I suggest the 75mm blue wheels, with 3/8th UNF nut inserts- Its what i use and havnt had a problem.

If you plan not to run any higher then 12V then my speed controllers can take currents that are way higher than normal drills can dish out. They have held a Graupner Speed 720 in stall. But if you plan to one day switch to 24V for instance, my speed controllers will not do that.

James,If I drill the head off the screw,then the rest of the screw will still be in the shaft. So how would I screw a wheel into it?

Drill the head off the screw .....unscrew the chuck ......grasp remains of L.H. retaining screw with pliers and undo it.

You may find that the small L.H. screw comes out as you drill it ......the drilling action is in the correct direction to do this.

A bit of brute force maybe required to unscrew the R.H. threaded chuck .......try sticking the short end of a large L shaped Allen key in the chuck then whacking the long end of the L with a hammer.

Heres an American site showing the dismantling process.
http://www.wa4dsy.net/robot/drillmaster/index.htmlhttp://www.wa4dsy.net/robot/drillmaster/index.html

Thanks Woody,il take a look ;)

Of course another approach is to take the chuck off and leave the torque limiter in place. Turn it to its highest setting (usually marked with a drill symbol) and carry on. Doing it this way means that it will slip under very high loads but it also means that your motor will not be burned out by these same loads. Works for my bots.