I electrified my push scooter with a power drill | Hacker News Reader

I electrified my push scooter with a power drill

eddieabbondanz.io

196 pointsspeckx66 comments

Oh man, this makes me wish I had photos from the electric skateboard I made when I was probably ~13 years old. It didn't use a drill but a motor I harvested from an actual electric scooter. (that scooter's charging circuit was defective and nearly burned down our house) All I did was mount it to an existing skateboard as a friction drive on one of the rear wheels, with a primitive switch on a wire as the control. It was not really practical, but I was kind of surprised just how well it worked for what it was. If I remember correctly, I had to adjust my center of gravity to keep it straight, but not by as much as one might expect. I later reused that motor to build a pretty badass Van Der Graaf generator.

I really admire the wiring job on this scooter! Goes way beyond what I did for the skateboard. And I imagine the scooter would have to navigate via only left turns. :D That is unless maybe a small third wheel were added to the end of it?

My first thought after reading this title: Oh cool, they've taken part in a drill and used the motor. I don't really know what that looks like inside a power drill. This will be an interesting post.

Immediately opened it and laughed out loud. Perfect execution, no notes.

This is exactly what I wanted even though it was not at all what I expected.

You’d love how I’m starting my generator. Same drill. Hodgepodge of springs and string to manage the choke. ESP32 committing obscenities in the middle of all of it.

This absolutely deserves to be documented

What is that one-way bearing TFA mentions. I understand its purpose, but where does one acquire such a bearing?

Had the same question. The article has an Amazon link to the bearings.

If I understand the question correctly then you're asking about a sprag clutch.

When used in-line on a shaft like this, a sprag clutch permits torque to be transmitted out of the drill motor but not into the drill motor.

Any operation as a support bearing for the spinny-bits is kind of a secondary function at very best (and may be ill-advised; a sprag clutch assembly may be shaped kind of like a roller bearing assembly, but that doesn't mean that it will live long in that kind of role). :)

Thank you.

Would it need a standard bearing on only one side of the sprag clutch, or should I double them up on both sides?

That's a very good question. If I were a mechanical engineer then maybe I'd be able to provide a very good answer, but I'm not. So the best I can do is spitball:

I'd like to think that the sprag clutch would be happiest if it didn't see significant deviation or loading in any dimension other than axial rotation, which suggests that at least one bearing on each side is good. Maybe even two. The constraint needs to be sufficient.

But I also understand that shafts can be overconstrained, and that this can cause non-obvious problems because shafts are seldom ever perfectly straight or perfectly aligned, and the support structure for the shaft is seldom perfectly rigid.

Empirically, this is how we wind up with things like slip yokes, flex discs, and also U joints on the drive shaft for a front-engined RWD car -- even when the differential is bolted in place to subframe members. Those are all things that seek to soften constraint of the shaft. (Some of that stuff tends to remain necessary even on front-engine Corvettes, where the transmission and the differential are also connected with an ideally-rigid torque tube that surrounds the rotating drive shaft.)

It's also how people in the Cartesian 3D printing hackspace often find a reduction in print quality when they see the Z axis lead screws flop around a bit on travel and then endeavor to "fix" that by adding more support bearings, replace flexible motor couplings with rigid, and otherwise stiffen up the spinny-bits.

The combination of the imperfect leadscrews becoming overconstrained imparts stronger forces on the gantry in the X and Y axes than the previous state (doing ~nothing at all) did.

If they can get past the "WTF! More rigid parts must be better!" stage, take these extra parts out, and learn to embrace the slop, then print quality tends to go get better again. The Z screws go back to (mostly!) being just Z screws again instead of also being unintended movers-and-shakers for X and Y.

It's a really interesting topic, but it is also one that I've never taken the time to get my head all the way around so I can't explain it simply. Hopefully I've given you enough words and ideas to let you conduct some useful homework.

Thank you! That was a delve into a topic I wasn't expecting.

TFA has a link to the amazon page for the bearing used. It's a bearing plus freewheel clutch. Most commonly (and in this specific case) it means sprag clutch[1], but it may be e.g. a ratchet/pawl[2] (like most bikes have) or a roller freewheel[3].

1: https://en.wikipedia.org/wiki/Sprag_clutch

2: https://en.wikipedia.org/wiki/Ratchet_(device)

3: Couldn't find a wikipedia page for this, so https://www.youtube.com/watch?v=AU4OguQmyMM

Thank you

Yup, I also have a sprag between the drill and the nut in the centre of the starter.

Honestly the hard bit was rigging something up to hold the drill in place - in the end, went with carpentry. Automating the choke just uses a strong spring, a Lego motor from the 90s, and, uh, Lego. And string. Latches with a solenoid when fully closed, and when coil power goes it releases it.

Like I said, obscenities, but it saves me a walk, in the rain, and allows me to keep the power on when I’m not here for months in winter and the sun is insufficient.

The first month was spent laughing at whatever had broken now, but it’s been two years now, and the only snag I had this year was that the string broke.

Engineered for… at least one 9 of reliability.

Same thought here. Did not expect this level of jank but I loved every photo and word.

The contrast between the 3D scanning and bolting a power drill to the side was fun.

Not enough gaffer/duct tape! But the inability to bank to the right side is perfect. Just do a 270 to the left.

  > inability to bank to the right side is perfect.

That disadvantage is balanced by the advantage of not having to open the kickstand at every frequent stop.

It's the Zoolander feature.

Its got the blue steel paint job

That's all nice and well -- but Matthias Wandel built a wooden scaffolding on wheels 12 years ago that was drill powered. That's _really_ crazy...

https://www.youtube.com/watch?v=rBmnQN78aZU

Hey all, author here. I had no idea this hit hackernews until my website traffic spiked. Happy to answer any questions. The scooter is still holding strong.

do you have alerts set up for your personal site's traffic?

No, just goatcounter and it showed a spike from HN.

How do you turn right?

I lean towards the right but lean the scooter towards the left a bit. As long as your body weight is rightward the scooter stays stable and you can turn.

Does the scooter try to stop abruptly when you completely stop the throttle? Most drills today have this behavior, that I don't know the terminology for, where they eliminate their inertia immediately upon the trigger no longer being depressed.

No the front wheel can freespin with the drill off because it has one way bearings.The drill does stop immediately but it doesn't impact the wheel.

OK, but here's a Lada in Russia powered by fifty cordless power drills.

https://www.youtube.com/watch?v=sv8Q4bDl6lo

A good friend of mine told me he would frequently come across a guy who had modified his bicycle with an electric drill.

He would see him leaning over and pulling the trigger get an electric assist on the uphill section of the commute.

Wonder how this would work with an impact? Also, since it already uses one-way bearings, could another drill/impact be fitted to the other side so that there are two “gears” available?

Squel the tires every few meters? Like an AC Cobra.

Wonder how this would work with an impact?

Not very well. It will work as long as the power demand is below the point it starts hitting, and then just stall with the tires absorbing all the impact hits once it reaches that point.

Pssssh that seems boring.

The real deal would be putting another drill on the back wheel, so that you have All-Wheel-Drive!

Feels good to see some one is enjoying and having fun with the tech

We are in the days of building the things we dreamed about as kids. Looks great for right turns!

I do wonder how long the electronics, motor and little (plastic) gears in the drill would last with this. Especially since I'd suspect that it's designed for intermittent use, where it has time to cool down between each screw / hole drilling that you'd do normally. If you drive 2 miles in one go, that'll be a lot of heat that doesn't have time go anywhere.

Somehow I'd suspect that it won't last all that long...

Drills are used sporadically. If a drill was used intermittently it would be on most of the time and occasionally off.

> If a drill was used intermittently it would be on most of the time and occasionally off.

But when the wipers in my car are set to intermittent, they are off most of time and ocassionally off.

I’m fairly sure ‘sporadic’ indicates random/unpredictable timing while ‘intermittent’ has a predictable pattern.

I get sporadic phone calls about intermittent issues with some system or other that I take care of out there in the world.

(I wish there were a pattern to any of it, since it's often very difficult to fix things that are usually working fine.)

No. Sporatic means the occasional presence of something. Intermittent means the occasional absence of something.

I suspect there's very little power needed once you're up to speed and cruising, but constant stop-and-go and long uphill runs will certainly cause it to overheat.

It's brushless so brush wear isn't a problem, but these motors are air-cooled and will actually be cooler at high speed, low-demand. Lugging it up a hill would be a worst case.

I used a lower price electric drill to polish some stainless steel, and after a single hour of continuous operation it was never the same again.

Don’t worry, that baby is air cooled when you’re at cruise speed

Fives of minutes!

Years ago, some guy was selling a kit for some imported mini bikes that used a cordless drill and a right angle gearbox. Something about not being able to sell the gas engines that came with them, or something:

https://www.youtube.com/watch?v=y8abvlYHK3Q

That one used a cable to pull on the drill's original trigger, so no rewiring needed.

Missed the opportunity to add vacuums and blowers and go upside down plus lateral and rotational movement, with fancy dark themed site and buzz words all over :)

Reminds me of the red green show sans duct tape

When all else fails, play dead

https://www.youtube.com/@RedGreenTV

It's only temporary, unless it works.

I remember watching this show as a teen while thinking I had to be the only person watching it.

Where have I seen something like this before. Right HAWK Hildesheim organized (locally) famous "Akkuschrauberrennen" https://m.youtube.com/results?sp=mAEA&search_query=akkuschra...

What is that 3D printed wheel made of that it can support over half of your weight while bumping along a road?

ASA, per the post

https://en.wikipedia.org/wiki/Acrylonitrile_styrene_acrylate

Yes, but you could have made it out of PETG just the same. I have some PETG parts here that we have tried to break but couldn't, that stuff is ridiculously strong for its weight if you use the right infill and you take the layer direction into account when designing the part.

and as a bonus, now you know how it feels to ride a BMW boxer motorbike in a turn ;-)

Love it. This is almost exactly how I electrified my crank-driven standing desk

Direct drive, yes, also direct drill.

Watch out for the gear change, may end up in hammer action.

You know you could have used a 90 degree chuck buddy. Or better yet, an angle grinder to make it a friction drive from above.

It's got 2 miles of range, adding those complications would likely eat up a lot of the range.

angle grinders run really fast, and even those with speed control just lower total power, not increase torque.

it would have made more sense to just mount the motor and the planetary, but I think the planetary is important here.

Turning right seems hard.

Is that why all politicians are suddenly turning to the left?

If that's what you're seeing then my guess is that, like this scooter, they'll be turning left three times so they end up going right.

I'm not sure where you are if you're seeing politicians turning left though.

video or it didnt happen!

add another wheel on the other side of the drill for a kind of sidecar-like stability? (tricycle style?)

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