Using brushless drill motors

[Henry Nourse]

So we're new to robot building and are thinking of using brushless drill motors since we have access to decent ones for free but does anyone have any experience taking them apart for use in a robot as a drive system? I've seen videos for brushed motors but the brushless drill we took apart looked very different on the inside. I understand the basics of brushless but the rest is a mystery to me!

[R9000]

I've never seen a brushless drill personally, and I'd think they'd be fairly rare given the motors usually have low startup torque, which is not what you need when drilling. I mean I suppose if you can take the motor out of the drill, pretty much all brushless work on the same principle, just connect three leads to your speed controller. But I have no idea how good they'd be. It's only the brushed ones that have been proven for use in Featherweights. Was there any specific problem you were having, and could we get a picture of the drill's insides to get a better idea?

[overkill]

Brushless motors are more common in high-end drills - most brands have one or two models in their range. The motors have WAY more torque than their equivalent brushed versions; both of mine will shear off screw heads and damage your wrist before they stall. I had a look at replacement motors on a spare parts site and the main issue was that the motors had casings that integrated with the drill body and gearbox, so using it outside of the drill would be complicated. Other brands might be different, but the ones I saw are nothing like a convenient 550 or DeWalt brushed motor. If you can get the motors for free its worth experimenting, but work on a plan B as well.

[Ekushiru3]

I have the same idea when I first participate in this sport, and I got few 'Worx' brushless. Those worx motors were never be used because I didn't find properly sensored esc to drive them.

Brushless drill motors are sensored with 5 pin 'Hall' wires(the wire a sensored brushless has to connect to esc for detecting the rotor position), so they won't be powerless when startup if used in drills. However, all the model use sensored escs have 6 pin wires, so if you use the model esc, the sensored function is disabled. I found electrobikes have 5 pin sensored escs, but those esc are too large to fit in a featherweight.

If you can find proper escs, the motor would be really powerful.

[Eventorizon]

Passing on what I have heard - Most brushless drills are built in such a way that all the parts are integrated the housing of the drill, rather than being a drop in unit like the brushed ones. End result is, you take it out and it won't work unless you make a custom housing to hold everything in exactly the right place.

If you can find one that isn't like that then I'd reckon a hacked TZ85A with SimonK firmware would handily control one of the 22.2V Brushless drills.

[overkill]

That is what I have seen too, Alex. The motors have odd mounting tabs that fit into the drill body and some have separate bearings that are housed in the drill case - when the motors are taken out, they hardly look like anything we would recognize. Its starting to sound more & more like a false economy to use brushless drills.

[Ellis]

The gearboxes will be funky but probably very nice, and worth harvesting/investigating in case you can mount a more traditional motor.

[daveimi]

You could go old school and keep the top of the drill and cut the plastic handle off. I've recently moved to brushless drill drivers for work from Makita and DeWalt and they're a lot lighter for more power. Batt is also a lipo so lasts longer and doesn't weigh anything. Makes a difference over a day's work.

[Ellis]

The problem with that is the brushless tools will have what is essentially an ESC inside the handle.

[Runsler]

couldn't this "esc" be used? putting the " " here because it is different to the ones we're used to, but doing the same job... only the input signal is different. But maybe there is a workaround for that?
Maybe flash new software on them, or adding a small extern chip to convert that signal (would think that could be as small as the transceivers are).
Software and electronics is really not my strong side, so just throwing in some ideas and hope you guys could pick one out that could work, but possibly nobody else did think of before

[R9000]

I mean I suppose you could hack it to receive PPM signals from the receiver if you know what you're doing, but I'd guess that the characteristics of drill ESCs aren't really what you want for a fighting robot. The same way we don't use brushed drill ESCs for robots, they're adequate for controlling the drill, but not much else.

[Henry Nourse]

Having read this lot we've figured out a way that we're going to try and put it all together. We know that our Brushless ESC's with the motors alright so what we'll try to do is take the motors out and set up some kind of system for holding them using the upper body of the drill in the faint hope that it works!

[MattLampitt]

Hi fellas, sorry to drag up an old thread but the last year or so brushless drills power to weight and size ratio has gotten seriously too good to ignore lol. The gearboxes on some of these new high end drills are incredible. Wondered if anyone has managed it yet?
I’ve brought one to tinker with. Was going to hook it up to a brushless bb80 with simonK on and see If it would work without the sensor.

[robotic_ants]

While RC hobby technology has advanced and access to Asian manufactures has improved since 2017, the price of brushless motors in commercial products has so far commanded a premium price.

Its my opinion the cost of a brushless drill set up by time you've made modifications does not outweigh the simplicity in terms of maintenance and repair or the robustness of a simple gear drive or off the shelf planetary gearbox with a hobby motor.

With brushless drills your also paying for a battery technology usually Li-Ion which is not widely used in the hobby and heavier than LiPo's. Then onto the electronics again not something that can be used in a robot, usually these are fully potted and not as easy to interface with RC gear like an inexpensive and infinitely more programable VESC.

I feel we have advanced on from drill motors like we have moved on from windscreen wiper motors. A standard BRUSHED drill set-up is still a good way to get started and learn from for a really low cost but people that use them do generally move onto more tried and tested brushless setups using parts designed for robot combat.