Brushless motors in the lego world - general topic

[gyenesvi]

1 hour ago, Krzychups said:

Regarding it, I meant that these planetary gearboxes are made for motors which have got about 2 mm shafts, for example the A2212 motor has got 3,17 mm shaft, so it wouldn't work. I hope you undestand it.

I understand, thanks!

[HorcikDesigns]

@Krzychups Well, great minds think alike, I guess. :D No, just kidding, I have aeen many similar designs and just wanted to make my own. The mounting points areto be made by the user, with help of connectors or 5x7 frame. I considered adding a layer of 8mm (1 stud) with loads mounting points in all directions, but it would affect printability, or it would be too bulky. 

[Krxlion]

Hi everyone!

Recently I tried my way of squeezing RC components into one place and below I present you my results - first working prototype. 

It is 3D-printed "holder" for all RC components except BL motor. It also features studded size - 9x9x4. Quite big (could be squeezed even more with smaller ESC and/or battery), but it holds:
- ESC (35A surpass hobby)
- Receiver (x6fg)
- Battery (3s, 900mah, 58x30x25mm)

3D-printed case features half stud pin holes to connect it further to lego model. Carved space around the battery is for ventilation purposes. ESC radiator also have space to give warmth away. We can open the case and get out small cable to recharge the battery if needed, no need to took apart all assembly. Below, I present it on my work-in-progress model. Also, here is a GALLERY for more pictures if someone is interested.

 

[NV Lego technic]

That looks incredible!btw, what's the battery voltage?

Edited July 7, 2024 by NV Lego technic

[Krxlion]

1 hour ago, NV Lego technic said:

That looks incredible!btw, what's the battery voltage?

It's 3s, 11.1V. I didn't properly test the battery yet in terms of how long it last, before recharge. I was just driving my work in progress model, tweak something and so on.

[2GodBDGlory]

Cool to see an all-in-one solution for brushless Technic cars!

[Krzychups]

Hey, cool to see you have started to design parts to your brushless vehicles (like this). By the way, which 3d printer have you bought?

Edited July 9, 2024 by Krzychups

[Krxlion]

2 hours ago, Krzychups said:

Hey, cool to see you have started to design parts to your brushless vehicles (like this). By the way, which 3d printer have you bought?

Thanks Krzychups, I just want to have clean build, without rubber band or anything similar to hold all the RC components. The 3D printer is Bambu Lab A1 mini. I am using almost default settings as they are really well-prepared for printing lego'ish things. By the way, if someone is interested I can share the 3d models of this case and a cover. I was using mostly https://marian42.de/partdesigner/ tool to get it done.

[LabManager]

On 7/7/2024 at 7:41 PM, Krxlion said:

3D-printed case features half stud pin holes to connect

What 3D printing technology do you use? Did you drill side holes or your printer can print such holes without extra support?

[Krxlion]

1 hour ago, LabManager said:

What 3D printing technology do you use? Did you drill side holes or your printer can print such holes without extra support?

It uses standard PLA filament to print, if that is what you asked. This case required some support, yes. Bambu Studio (3d printer app) offers easy to use support feature. I could probably print it with even better quality with smaller nozzle, but this one do the work and pins are holding pretty good.

[Krzychups]

Hello everyone!

On 10/30/2023 at 3:35 PM, Krzychups said:

@Daniel-99, can you show me your custom wheel hubs (the joints connections)? I want to make something like those. 

Yesterday I started designing the wheel hubs with bearings which @Daniel-99 has, I asked for photos and informations almost 1 year ago. Zene's wheel hubs have 1 stud offset or 0,5 stud offset, it is almost impossible to make a FWD vehicle. That's why I designed it. I need to add mounting points. At the moment it looks like this:

the wheel hub 1 by Krzysztof Czech, on Flickr

the wheel hub 2 by Krzysztof Czech, on Flickr

Parts:

• the metal shaft with a hole for kind of bolt or pin,
• the 3d printed wheel hub with a place for metal bearing,
• the 15x21x4 mm bearing
• the metal shaft,
• the metal universal joint.

@Daniel-99, I know you have different types of wheel hubs, can you take some photos of them? I want to make different mounting points.

Other photos are on my Flickr.

 

Edited August 6, 2024 by Krzychups
Typos

[Lixander]

Well, that went wrong smooth enough............with my new buggy, I managed to tear the small pins of the CV joints in the driving wheel hubs, the new planetary ones - part 46490c01

So I replaced the CV joints with metal U-joints and the wheel hubs with portal ones with an additional gearing of 3:1; so in total, the model has around 5.61:1. Still, the model can`t run......I think the new red 28t differential also has a surprise for me.

But anyway, I think that the wheel size contributed or caused this, as the model uses 120mm RC tires paired with the 56mm d. rims. Might be also the weight, at around 1.5 kg / 3.30 lbs / 53 oz.

In any case, I think I will scrap the buggy :/

P.S.: Pay attention to your CV joints, even the new ones, especially when put under stress/ run at high speed or/ and torque.

 

Edited August 12, 2024 by Lixander

[Krzychups]

Hey folks

I have got the first protopype of the wheel hubs.

20240827_181400 by Krzysztof Czech, on Flickr

20240827_181407 by Krzysztof Czech, on Flickr

The main problem of it is that it's very hard to drill 2 mm diameter hole in the M4 threaded shaft. Also, there's possibility that it may break near the hole - look at the photo. My shaft is crooked a bit and a wheel wobbles, it doesn't spin correctly. The bearing is not glued now. I've printed it using 0,2 mm nozzle, instead of 0,4 mm nozzle which are normally factory installed to get higher qualiity. Unfortunatelly the printing time is 4 times longer . 3D printed parts are printed from PCTG. 

20240827_193430 by Krzysztof Czech, on Flickr

Regarding my planetary gearboxes, I have 2 of them, I'm waiting for another motor. At the moment I'm using a plastic adapter to Lego Technic shafts, instead of metal ones. 

By the way how to hide images?

[2GodBDGlory]

2 hours ago, Krzychups said:

Hey folks

I have got the first protopype of the wheel hubs.

20240827_181400 by Krzysztof Czech, on Flickr

20240827_181407 by Krzysztof Czech, on Flickr

The main problem of it is that it's very hard to drill 2 mm diameter hole in the M4 threaded shaft. Also, there's possibility that it may break near the hole - look at the photo. My shaft is crooked a bit and a wheel wobbles, it doesn't spin correctly. The bearing is not glued now. I've printed it using 0,2 mm nozzle, instead of 0,4 mm nozzle which are normally factory installed to get higher qualiity. Unfortunatelly the printing time is 4 times longer . 3D printed parts are printed from PCTG. 

20240827_193430 by Krzysztof Czech, on Flickr

Regarding my planetary gearboxes, I have 2 of them, I'm waiting for another motor. At the moment I'm using a plastic adapter to Lego Technic shafts, instead of metal ones. 

By the way how to hide images?

Cool project!

I remember hearing that a larger layer height for 3D prints was stronger, because you have fewer joints to break. Do you think implies that using a smaller nozzle also makes a weaker print? I'm not sure, but if it does, I'd think a project like this would need strength over precision. Not that I really understand what you're doing, but it's a thought I had!

As for hiding photos, I assume you're talking about the spoiler feature? If so, it's activated by a little eye icon at the top of the text box. I'm not seeing it on mobile right now, but it's at least there on PC

[Krzychups]

23 hours ago, 2GodBDGlory said:

Cool project!

Thank you!

23 hours ago, 2GodBDGlory said:

I remember hearing that a larger layer height for 3D prints was stronger, because you have fewer joints to break. Do you think implies that using a smaller nozzle also makes a weaker print? I'm not sure, but if it does, I'd think a project like this would need strength over precision. Not that I really understand what you're doing, but it's a thought I had!

Not sure about it. Anyway, I need both of them, strenght and precision. Before I've started using the 0,2 mm nozzle I've printed one part with the 0,4 mm nozzle, it looks bad with such a level of details. It's another design I've designed in the past.

Spoiler

20240828_213924 by Krzysztof Czech, on Flickr

20240828_213902 by Krzysztof Czech, on Flickr

I want to make and design wheel hubs that anyone could make for themselves. I'm also thinking about making a tutorial how to make them in the future.

Edited August 28, 2024 by Krzychups

[2GodBDGlory]

18 hours ago, Krzychups said:

Not sure about it. Anyway, I need both of them, strenght and precision. Before I've started using the 0,2 mm nozzle I've printed one part with the 0,4 mm nozzle, it looks bad with such a level of details. It's another design I've designed in the past.

  Reveal hidden contents

20240828_213924 by Krzysztof Czech, on Flickr

20240828_213902 by Krzysztof Czech, on Flickr

 

Yeah, those don't look ideal, so if what you have is working, that should be good!

[Alcsan]

On 8/27/2024 at 8:20 PM, Krzychups said:

I have got the first protopype of the wheel hubs.

Could you share the CAD files please?

[Krzychups]

1 hour ago, Alcsan said:

Could you share the CAD files please?

Hey!

I've made some corrections, this version is a bit different compared to my current version. If you want the stl files, hmmm... - you need to wait until I will finish the project.  If you don't mind me asking, what do you need these files for?

Edited September 19, 2024 by Krzychups

[Alcsan]

On 9/19/2024 at 8:22 PM, Krzychups said:

If you don't mind me asking, what do you need these files for?

I was trying to design a custom wheel hub too, and I thought that CAD files of your designs would save me some time, but then I just decided to base it on the model of the standard Lego wheel hub that I exported from LDraw. Anyway, it didn't work out well yet, because my design relies on press-fitting bearings and plastic parts together, and PLA gets too loose for that. I also tried TPU, but it ends up to be too fragile and flexible due to significant under-extrusion since I don't have a proper setup and TPU absorbs water from the air. Maybe I will just end up glueing bearings to PLA. What filament do you use?

I'm gonna have a break from that and try Zene's wheel hubs instead. I'm aware of the issue with the offset, but I hope I can find a balance in cutting the joints much enough to make them steer and little enough to keep them hold tight.

Anyway, good luck with your project, it will be interesting to see its next iteration.

[HorcikDesigns]

Hello brushless friends, 

I would like to show you my second version of adaptor for BL motors to be attached to LEGO MOCs. In a form factor of L-motor! (more or less)
Inside the block is a custom built planetary reduction, you can choose whether you would like to use 0.5 or 0.6 module gears. 0.5 version is tested so far in oofroad 1.5kg vehicle and 2430 5800KV motor and works well.

You can download and print the files from my makerworld profile. As you can see, there is some assembly required.

https://makerworld.com/en/models/680795#profileId-609221

 

 

 

 

 

[Aurorasaurus]

1 hour ago, HorcikDesigns said:

I would like to show you my second version of adaptor for BL motors to be attached to LEGO MOCs. In a form factor of L-motor! (more or less)

Wow, your exploded view looks awesome. What a cool project!

[Variteck]

Thank you HorcikDesigns.

How much is the speed reduction ratio?

[Krxlion]

@HorcikDesigns you did a marvelous job with this one. The size being 3x3, with 8 (I believe) stud long, is a great fit to Lego contraptions. I would like you to share with us some details if you can:
- What is minimal and maximal RPM output on the motor. Do we get like a spectrum between 380-2812 RPM (I based those numbers on brief calculations)? Because in my case in-runner motor with planetary reduction (although it was two-stage planetary reduction) concluded with poor RPM range
- How did you make this explode image (some cad program like Autodesk Fusion)? I am currently testing brushless solution with A2212 1000kv motor, with 3s battery and results are promising. With a medium size model, like yours (around 1.5kg), there is no issue with running. But I modified a recent G500 Lego model to work with my motor, and it started to cog slightly. I think I am not having enough power, so I ordered two more different brushless motors, to test those.
- Does your test model is capable of crawling, slow RPM, or is it suited mostly for high-speed off-road?
- Is it possible to test your solution in heavier model?

Edited October 7, 2024 by Krxlion

[2GodBDGlory]

Cool stuff! I take it those plastic gears are commercially available? Not having enough resolution to print something like that was always my mental barrier to trying to design anything like this (Well, I guess more to print replacement parts for Lego planetary hubs)

Also, lots of other cool stuff on your Makerworld! I'll have to print some of it!

[Krxlion]

9 minutes ago, 2GodBDGlory said:

Cool stuff! I take it those plastic gears are commercially available? Not having enough resolution to print something like that was always my mental barrier to trying to design anything like this (Well, I guess more to print replacement parts for Lego planetary hubs)

Also, lots of other cool stuff on your Makerworld! I'll have to print some of it!

I think on chinese website you will find plenty of 0.5M(module) gears, so you might order more in advance, haha. :D I couldn't find those locally, but you may, if you live in Canada. ;)
Regarding printing, I find my Bambu Lab A1 mini with 0.2 nozzle so precise that you can really achieve great results with it (the printer is not so expensive either).