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[RipSlider]

I have at home a rather cheap drill purchased from B+Q - it is one of their own brand 14.8 volt fella's - I believe I paid about £30 for it.

I am more than a little impressed by the performance of said drill. Not only does it seem to get a lot out of the battery, but the level of torque is produces is brilliant. It has no real issues driving 8mm holes into engineering bricks, which my mains Ryobi drills struggles with.


I've not taken the drill apart, but I was wondering if anyone know what sort of motor would be powering this? And can I buy something similar for my boats?

I was also wondering if it would cheaper to buy a drill and take it apart rather than buy motors from the model shop. my local wants >£40 for a 700 BB. I'm guessing the drill has something approximating a 700 Torque, and if so, it would be cheaper to buy the drill.

Or is the performance more likely to come from a weedy motor and a cunning gearbox set up?


Thanks

Steve

[Guy Bagley]

strangely enough i was at a trade fair yesterday where both ryobi, hitachi and dewalt had all their tools on display.....

 have you considered contacting ryobi cusatomer service centre and asking if a replacement motor can be purchased....

 we did this recently for a company makita product, the motor was cheap and delivery was swift.... i guess ryobi would offer  a simialr service, its got to be worth the cost of a phone call or email to find out....

[catengineman]

Boot fair drills are great for the boat builder the motors I have removed are in the same league as a Graupner 900 turbo and the planet gearbox comes in handy for winch drives.


even some of the battery cells can be used and I never pay more than £2.50 per drill.

R,

[portside II]

These drill motors are very thirsty for amps ,or it maybe just the ones i have found ,these mostly have the name Johnson on the side .
But on the other side relating to the drill conversions has any one tried to use the trigger controller as a speed controller for a boat , these things are capable of handling various drill bits and materials without a glitch so spinning a prop should not be a problem
What do you think ?
daz

[catengineman]

Looked at this as a sort of mechanical operated speed controller even tried to reduce the spring strength to get the two servos to work.
Yes I tried two servo = 1 for the trigger
                              = 2 for the direction
 
I FAILED but as you said they can handle some stress! which is why I thought of using one but became beyond economical viability in both channels and operational requirements.

R,

[Sandy Calder]

Drills tend to use low torque ,high free-running rpm motors with a high ratio gearbox.
The high free running rpm is an asset in drills as a fan cooler can be fitted

.....but..............
If you put any load on them they slow to a crawl.They are not suitable for direct drive.

These or dust-buster motors are described as "bad 540 motors" in the technical section of modelboatmayhem.
Sandy Calder

[sheerline]

I had one of those cheap drills with knackered batteries so dismantled it and fitted the 'no name' motor into a speedboat hull, direct drive onto a 40mm three blade prop. With twelve cells producing 14.4V the motor screamed round and the boat went like the clappers. The drill was a two speed 14.V with a high low/ ratio gearbox. I figured the motor was very high torque because when I opreated the trigger, the machine was not only fast but the drill would twist in the hand as it shot up to full revs.
I think this would be a good indication of whether the motor was a high or low torque unit before you even try taking the drill apart. Some machines are simply powered screwdrivers and have a single low ratio box fitted, I believe these have the low torque high rpm motors which are generally no use for most models as a primary power unit.
As to another feature, my motor was fitted with a fan which is obviosly meant to cool the motor so perhaps another indication of a high power unit here. I can't give you any current readings under load on this one as I have forgotten but I think we were up in the low teens if memory serves me correctly, needless to say I only got five or ten minutes out of a 3,300mA pack but the boat, although heavy does go like stink!

[Sandy Calder]

Hi Steve,
I reviewed your original post.

The mains motor in the Ryobi drill may be of the electromagnet type,wound such that the power input drops at high loading.
If so, a comparison and any conclusion about the power and torque 14.8 volt drill would be misleading.

The fact of life about about the permanent magnet motor is that you get low torque and high free-running rpm or high torque and low rpm.You can't get both.

If you are going for a direct drive motor I think you should forget geared drill motors however wide you cast your net.
Sandy Calder