Power toool motors - worth scavenging?

It's been a while since I spent any serious time at LMR, or indeed building robots. A pressing need to totoally renovate a Victorian house has taken priority so that I can generate enough money top pay the mortgage interest when rates rise again !

However, a by-product of the rennovation is that I retired some of my old power tools. They worked, but having moved up from occasional DIY to extreme DIY I wanted tools with more grunt. So,sitting on my desk I have a hammer drill and a jig saw - both mains powered - and a cordless screwdriver. I have posted these on Gumtree but no takers, so I'm wondering if I could strip the motors out for future robot projects. I see two challenges here and am looking for ideas/assurance that it's worth the effort to keep these rather than bin them.

Challenge 1: a power source. The drill is a 240volt, 400watt device, and the saw 240volt, 350watt. How can I power these from batteries?

Challenge 2: speed. The drill operates at a fixed speed of 3,100 rpm. The saw has "electronic speed control" - whatever that is - but appears to be based on 3,200 rpm. Somehow I need to get this down to something that's more useable - I have this mental picture of a robot head whipping round at 3,000 rpm :). A gearbox or step-down of some sort will be needed. Does anyone have experience of finding and fitting gearboxes to old powertool motors?

The cordless screwdriver is a 3.6volt device delivering 180rpm under no load. This looks a lot more useful.

LMR seems to have had a makeover since I last visited - I think it was being hinted at in The Pulse. Haven't searched for new features, but have noticed a few changes to the logo. Looks good.

240 V motors and a makeover

To use a 240 V AC motor from a DC battery will be a challenge. Converters do exist, but those are mostly designed to operate heavy stuff (like your drill) from a car battery. I don’t think any small robot will benefit from that setup. Who needs a 400 W of power in a DIY robot?

Consider recycling those motors, rather than reusing. There is magnets and enameled copper wire inside them.

 

About the makeover: check out the new /about page from the main menu.

battery powered tools
It is worth. But don’t use AC drills and saw’s, its complicated. I have similar idea myself, but i plan to use NiCd battery powered drill engine. I buy a cheap drill and I get one 12V engine with gearbox, a 12V NiCd battery and a charger. Full set! Only H-Bridge is missing.

As the yokel said …

If I was going there, I wouldn’t start from here!

Question is, how can I use what I’ve got, not how can I get a cheap motor. :slight_smile:

In the robotics team, we
In the robotics team, we sometimes use Drill motors (with gearboxes) and modify them so we get exactly the performance we want. Make sure you get drills with voltages near 12VDC.