3D Printed Stackable BRUSHLESS Motor Gearbox 

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The problem with your torque measurement now, is that because of the high velocity you are coupling a significant amount of intertia. The motor inertia might seem very small, but because of the gearbox it is amplifier by n^2. None of the cheap brushless motors actually quote rotor inertia, but generally its somewhere around 30 gcm^2. That means that with your 64x reduction gearbox, you are dealing with an inertia at the output of about 0.0123 kgm^2 (note the change in units). Guesstimating the speed of the output shaft, its probably around 0.3 rotations per second, 1.9 rad/s. This results in an angular kinetic energy of approximately 0.0217 J. Thats quite a lot of energy stored, especially if you want to try to slow it down in a very short period of time. Point being is that you are generally measuring much more than just gearbox output torque. Torque testing should indeed be done at zero speed. Also, are you aware that there are specially wound BLDC motors meant for slow speed operation? These quadcopter motors are optimized to work in a constant high velocity, but the ones optimized for slow speed are much more well suited for most robotic and servo tasks. You can easily find relatively cheap ones if you search for 'gimball BLDC' and similar search terms.

Really cool design, thanks for sharing! If it is accurate, that amount of torque out of a 3D printed gearbox is wild. +1 for adding an encoder for better low-speed control.

Great design. You are measuring 9500N of force by the load cell however, your load cell has a max capacity of 200N!

This gearbox is one of the better ones i've seen on YT! Good job. Btw since you can't do a static torque test, it would be nice to see what weight it could lift at a given radius. For example, build a simple drum with 50mm radius with a string attatched to some weights. Then you could try different weights and speeds. Also, this would enable dynamic endurance testing which would be really interesting to see. And, maybe even try different filaments. Maybe nylon or petg as gears?

As you have concluded, measuring torque while using an ESC won't really tell you much. There are some very nice alternatives to ODrive now that would work well with the size of motor you have. In particular: the Tinymovr (R5) and Moteus controllers. They are much smaller than an ODrive, come with the encoder built in, and mount directly behind the motor.

You could try testing how much weight the gear box will lift at given ratios. Knowing that would help determine what kinds of applications you might be able to build this into. Long Term speed test for heat and wear would be good too.

Why do people who use 3d prints often dont use any oil or lube for gears? I see it so often that they push bone dry gears together. But respect for the build!

Do a weight test with the motor, like put a pulley on the end of the motor and a string/wire and keep adding weight until something fails.

Wow, thanks. One or two weeks ago I designed planetary gearbox for 5010 myself but I didn't get to assembly. It's nice to come across same idea, u saved me couple of hours of tweaking. Thumbs up!

Absolutely mind blowing. One of the simplest gear boxes I've ever seen. Thanks for sharing :)

What I find most impressive about this quadcopter is the potential it has for DIY enthusiasts and makers. With the ability to design and print your own quadcopter without having to purchase expensive parts, it opens up a whole new world of possibilities for those interested in robotics, engineering, and design.

These would be perfect for hub motors in a build. I could definitely see this being extremely beneficial.

That 3d printer is amazing. I've never seen print quality/ such a small bead from the nozzle in a hobbyist's printer.

This is really cool design. Prints pretty easy too. Fantastic work.

Amazing project, you tested, you printed, and posted the step files. Is a proof that you really know what are you doing. I enjoy your engineering projects. I will use this gearbox as a sailwinch for my rc-sailboat. Let's close loop this marvel.

Great design, I am in the process of automating my pool, and these gearboxes will be great for automating the valves, e.g. I can automate the flow to bypass the solar heater if the pool temp is too high, or remotely control flow distribution from pool to spa, etc. I'll probably be using steppers and arduino IOT. Thanks for your community spirit.

A truly masterful design

Thats a really cool design, the rotating planet core that is just one free spinning stack of gears is quite fascinating. -1 for the torque test, because the peak is highly influenced by the inertia

great and simple one, easy to mount....thank you! Ill try using it for a powered cart for hauling stuff around the garden

Cool design, excellent explaining!

The major blunder in the test comes from the fact that when the shaft is stopped in the load cell, the motor stops, thus we don't det the stall torque but instead the torque necessary to annihilate the angular momentum of the motor's hub, shft, planets holders, planetary geers, ... everything that spins gets some angular momentum to annihilate with a counter torque if you want it to stop

TY, This is exactly what i was looking for

Says it feels very smooth as the GB siezes up

This looks amazing.

Nice design. with a few slight modification in particular of the end piece you could make them stackable and destackable without requiring reassembly of the individual modules.

Extremely interesting content, stellar editing and format. Subscribed.

Great video, as always!

Very cool man. I really like how that came out, and the modular setup. It'd be interesting to see how big of a fish it could reel in.

Nice grinding gears sound!

This guy needs more subs! Awesome content

Nice job designing and printing ! To really measure the torque, you could use a pulley as an end shaft, and try to wind a cord around the pulley while refraining the wire with one of those luggage weighting hooked, until you stop the motor. So you can get rid of the starting couple & the inertia 😉

That's really awesome

It would be neat to see it taken to the extreme where the final output has such an incredibly high reduction that it can be embedded in something unmovable and still function. I remember seeing a similar setup where the output was embedded in concrete but it will functioned because the extreme reduction summed up to basically no movement on the out put. Wonder how many reduction gears you'd need to achieve something similar.

This is just a wonderful piece of engineering. Thank you for sharing this. Have you considered expanding the systems with levels of other ratios? So have a level of x3 or x2 or x5. Then you can stack them to get to any final ratio you want.

Nice work!

Very good project ! Great

A quick way to electronically reduce the speed and increase your motor's torque is to desolder the connectioms to the three phases ( at the stator) and rewire them in a wye configuration if they are currently wired as delta. This will cause current to enter one phase and be forced to energize an additional coil on its way back out of the motor. The scope of this mod is to reconfigure the phase connections from parallel to series. The motor will have more energized coils at any given moment, thus increasing its torque. I've used this trick before with good success and my motors live longer and run cooler. Keep in mind that you will decrease the maximum speed. That is the tradeoff.

That's really cool! The only problem i can imagine is for every stage added you get more friction, but i guess you could just beef up the motor used if so.

Waw, really amazing ! No go and build a robot arm with this !

Planetary gearsets are 3-way adapters for gears. This design uses 1 of them as housing, and the other 2 change ratios like a car transmission. An old-fashioned manual transmission could do this more simply, or an Allison transmission is more elegant. Or add another motor (it can generate too, right?) and just 1 planetary gearset and you have a hybrid transmission. All 3 of those are modular designed to change while the vehicle is in motion, without having to stop and bolt in other parts. But this is a good learning exhibition - a launchpad to talk about transmission designs. Thank you for making the video.

Amazing dude! SUBSCRIBED

I'd be really interested to see a similar thing but with different combinations of gearbox modules with different reduction ratios. With this, you could design a clutch mechanism that disengages the gearbox modules so you can get a variable gearbox out of it.

This has a great application for a trolling or outboard motor for boat. At least that's what I'm investigating

The Jim Lahey clip earned my subscription Sir. 👍

that is brilliant! those would work well with stepper motors

+1 for integrating a sensor and odrive in a future video. I'd love to see what kind of torque is possible to get out of these low-end BLDC's with 3d printed gearboxes. This is a great video. Keep up the excellent work!

I think you can reduce a lot of the sound problem if you build conic gears instead of plain ones, they are more efficient in high speeds too.

Used your amazon affiliate to the materials for this build. Thank you for this amazing build.

Cool project! I’m a hobby machinist, so I’m super curious about what the measurable differences are between machined tool steel gears and box which are hardened, and the printed version. Power, load, speed, noise, cost, and reliability come to mind. I have no opinion; it would just be interesting to have data that guides when, for example, plastics, steel, or hybrid designs are optimal choices.

Dude you’re so funny, the edits caught me off guard a couple times hahhaa 😂

Just mount the arm with the load cell to the gearbox case and mount a longer shaft to the output shaft, so you can grab it with a glove to apply a breaking force to the output shaft. Now you can do continuous torque measurements at different rpm's without the influence of inertia!

0:52 "+/-/Magic?" Love the humor! Subscribed! 😂😂

Newly found your channel while searching for an alternative to the ODrive since they're going closed source now... Wonderful channel you got here, and wonderful stackable gearbox! Have you done a split-ring planetary gear at all?

well now i finally understand what is torque, thanks

Another idea may be using different motors on this gearbox (Brushed DC, Stepper, etc), and perhaps making different mounting plates, but the core+output being a “universal gearbox”of sorts.

cool!! thank you!

I love this idea!

holy crap, you're using a TI n-Spire! That's cool!

Loving the How Ridiculous reference :)

The going brushless bit floored me🤣🤣🤣

use simplefoc to control the driver at low speeds, even without encoders. it works great, and can be upgraded to encoders. there is even somewhere a board which lets you do a control by amperage

Great design👍

Great design, I would be interested in the backlash of the gear box. If it is almost backlash free, I could use the design for a 4th axis in my CNC machine

Creative video, thanks for sharing :)

Love to see this ..converted to magnet gear box

Very neat

you got me with they go wrrr

"3 wires? That's kinda scray." instantly subscribed bro I love your humour

I think what's missing is the ability's to hot swap out the reduction. Maybe a inner shaft that engages only at selected ratios controlled by an outside sliding mechanism, or the rings could twist lock into place with a manual switch to unlock a retractable back stop where said rings bottom out on the previous one.

Pretty neat! Try a prony brake instead of a load cell.

i love your use off TPB! high5 brother got you a sub!

It would be very good to see a metal sheet laser cut version to be a fast and cheap option to produce. Great project.

You could build the best crawler/trail truck with this. ;) Great video!

coooool! good job 👍

Applications: Mechatronics, like robotic grabbers, RC crawlers... You could make some wild automated kitchenaid mixers, or dough machines, cutters/log splitters.

amazing!

Nice project! Would be great, if you could design a rotary encoder step on the output side for automatic backlash compensation

you could make a simple dynamometer by introducing a clutch between the output and the load cell so that way you would get it's dynamic torque.

Congratulations! you made another screwdriver)

that is fucking cool as hell. you earned a sub

Another idea could be using different gear profiles, but an otherwise identical format. Could maybe try and get a series going akin to that “Design a Fan Blade” series although I don’t know how to build that hype i guess! Herringbone Gears are the ultimate if I remember correctly, although there is probably some downsides i am forgetting.

You could make a shredder and use the gearbox for the shredder axis to see if the torque is sufficient to crush plastic parts (it could aldo be a cool thing to watch)

Thanks for your video. It made something click. 👍

im actually going to pick the files up and see if i can put them in any of our machines to see how well it holds up against actual mechanical force compared to raw movement will take a while but ill let ya know

depending on rotation speed, the 16:1 would most likely work as a very heavy duty Power Wheels Brushless motor conversion/gearbox kit!

Nice dude.

Mount it to a mountain bike brake disc and then add the load cell to the caliper. Will allow you to measure the torque while it's spinning

An involute profile on the teeth should help your noise issue. In addition, it didn't look like there was any backlash between the gears. For something that small, the backlash would be extremely small. .001 inch backlash would be more than enough, but hopefully not too much to cause some issues. I'd look into a liquid lubricant. Most planetary gearboxes take oil, not grease. Might give you a bit of a bump in efficiency!

I like this stackable option. I have been trying to make a 3d printed windmill, but I haven't found a gear box that works for it and I don't have the skill to make one myself.

You could try using a disk brake off of a motorcycle or even a bicycle to create a torque dyno to get more accurate torque readings at any speed.

Man I wanna make this on a industrial level, compact modular motor it could be revolutionary on repair and replacement in the field

this is AMAZING MEN !!!!!!!!!!!!!! 🤩🤩🤩🤩🤩🤩

I've been using very similar looking motors in my RC tank. Easily capable of ripping the 3D printed tracks apart...

Perfect for a jack or precision moves

Make a hand crank generator out of it! It would be interesting how many watts you can get out of it, and watthours before it breaks. Great Scott has some videos about this also.

You have too few subscribers, this is an engineering masterpiece.

really nice video !!!! i really want to see the video with the odrive

Clever!

4:09 I think you should put some engine oil or grease to lubricate those gears so it will not sound loud and will work smoothly ❤. Also gears will not wear out.