Krzychups Posted March 16 Posted March 16 (edited) 50 minutes ago, Krxlion said: Regarding your chassis, the transmission attached to BL motor is kinda bulky, is there no way to shrink it down? Sorry, that was the previous version before I've bought planetarny hubs. I've build it just to play with it. I won't use it anymore in a new RC car. Instead I'll use my special gearbox to attach the motor (similar to HorcikDesigns' A2212 gearbox, I've modelled it on this design: https://cults3d.com/en/3d-model/game/brushless-motor-for-technic-jlt ). There's no point in paying over the odds. I'm not ready to publish it yet, but in the future I'll do so. 50 minutes ago, Krxlion said: ONE THING TO NOTE THOUGH: I would advise to solder thicker wires (f.e. 16AWG). I just bought another cheap ESC, and took battery and motor cables from it. Can I ask why? What's the purpose? 50 minutes ago, Krxlion said: Maybe I will try to create a post today on my model. Looking forward to it! Edited March 16 by Krzychups Added the link for the A2212 gearbox Quote
Krxlion Posted March 16 Author Posted March 16 21 minutes ago, Krzychups said: Can I ask why? What's the purpose? There are two reasons: 1. Thinner wire will get more hot quicker, thus there is a chance it will desolder itself from the plate. 2. Thicker wire will serve as a "heat backup", because it will get slower to higher temperatures. Of course, my suggestions are from my experience, so you may as well try without it. Crawlers are not pushing electronic as much as other cars, so it may work. I just replaced my as a precaution. Quote
Aurorasaurus Posted March 17 Posted March 17 16 hours ago, Krzychups said: Hello everyone! I'd like to share the results of my work with you. I've done reverse engineering. It looks almost like Zene's differential, maybe with some small changes. Instead of metal adapters, I'll print them from nylon (the black parts). I highly recommend printing from strong material. The final cost is about 4 times cheaper than buying the differential from Zene. This is super promising! Will you also make models for a version with 2 drive inputs for use with more wheels? 13 hours ago, Krzychups said: Well, it's a bit dirty. It a sturdy and simple chassis. Looks much better than before. It looks functional and strong, I like it. Are you using metal or CF axles? When I tried using my 1400kv motor with an XL motor planetary reduction thing, I snapped axles the moment I gave it full throttle. Or maybe you're running 2s and its not an issue? 15 hours ago, Krxlion said: I watch all @Aurorasaurus clips on YouTube, how do you get so much time to build all of these in such a short time, man! :D Great work! Well, I'm out of work, so I can spend a lot more time on lego at the moment while I search for a job. I'm glad you like seeing what I'm making, that makes me feel better about putting the time in to publish things. I took apart the brushless rally car after sending it 2 meters in the air at a skate park... As they say, its not the fall that kills you, its the sudden stop at the end... Worth it :D Also, I drove this model on asphalt a bit, and after a little while I noticed less and less launch speed. I was a bit confused until I saw the tires. The rear ones had lost a lot of tread! So I've ordered some more RC tires that are approximately the same size, because I'm not done with this idea yet. Quote
Krzychups Posted March 17 Posted March 17 (edited) 6 hours ago, Aurorasaurus said: This is super promising! Will you also make models for a version with 2 drive inputs for use with more wheels? Thank you. I can, but you will need a another gear. This gear comes with the differential, so it may be quite expensive. 6 hours ago, Aurorasaurus said: It looks functional and strong, I like it. Are you using metal or CF axles? When I tried using my 1400kv motor with an XL motor planetary reduction thing, I snapped axles the moment I gave it full throttle. Or maybe you're running 2s and its not an issue? For axles, I use Lego axles with connectors and metal u-joints. I use a 3s battery. I remember breaking one of the Lego 3L axle connectors and twisting one of the axles up with this mad torque. Edited March 17 by Krzychups Quote
Aurorasaurus Posted March 17 Posted March 17 1 hour ago, Krzychups said: Thank you. I can, but you will need a another gear. This gear comes with the differential, so it may be quite expensive. Whats the differential? I will try look for the other gear on aliexpress. Quote
Krzychups Posted March 17 Posted March 17 6 minutes ago, Aurorasaurus said: Whats the differential? I will try look for the other gear on aliexpress. Search this and look at the photos on Ali: On 2/28/2025 at 8:53 AM, Ryokeen said: could also find it on amazon labeled as an upgrade part for the following "SG 1603 SG1603 SG1604 UD1601 UD1602 1/16" Those are WlToys. Quote
janssnet Posted March 17 Posted March 17 (edited) On 3/16/2025 at 9:30 AM, Krxlion said: I see you have moved more and more into boat stuff @janssnet. Well ... not really. Wintertime, can't test drive. Therefore the boats. Will not bore you with the car developments, put them in a single picture. Current status, after all the LEGO prototyping, constructed a very competitive 1:10 on road race car, driven by 4x 1300kV in-wheel motors, controlled by an ESP32 and a 4in1 BLHeli-s ESC (not an AM32). Waiting for a test by world's #8 ranked RC-driver ;) If any interest happy to post about it. Regarding the AM32.... On 3/16/2025 at 11:35 AM, Krzychups said: The 40A ESC looks very small and it's also much cheaper. Please note, these (drone-) ESC's do not support coasting/freewheeling. At low speeds, no problem. At higher speeds car stops very abrupt. For this purpose, there is a 'car mode' option in the configurator, but not sure if this combines with the Sinusoidal Startup Mode for crawlers. Edited March 17 by janssnet Quote
Krxlion Posted March 17 Author Posted March 17 3 hours ago, janssnet said: Well ... not really. Wintertime, can't test drive. Therefore the boats. Will not bore you with the car developments, put them in a single picture. Current status, after all the LEGO prototyping, constructed a very competitive 1:10 on road race car, driven by 4x 1300kV in-wheel motors, controlled by an ESP32 and a 4in1 BLHeli-s ESC (not an AM32). Waiting for a test by world's #8 ranked RC-driver ;) If any interest happy to post about it. Regarding the AM32.... Please note, these (drone-) ESC's do not support coasting/freewheeling. At low speeds, no problem. At higher speeds car stops very abrupt. For this purpose, there is a 'car mode' option in the configurator, but not sure if this combines with the Sinusoidal Startup Mode for crawlers. That is a really promising project. Take your time and finish everything you need. And that part about getting a pro racing driver :O - this must mean something big is happening. :D Regarding 40A AM32 ESC, I need to agree with you. I was just tweaking settings in my model, and I was sure that one (Running Brake Level), will actually help to work like the car would have a flywheel (free coasting). On one example the motor feels like running for 3-4seconds after I release the throttle, but in reality when I do this on my model with all the driveline, gearbox, etc. It doesn't want to run faster than 20% of regular speed. This setting also messes up torque delivered on a start-up and slow speed control. In the end I put it back on 10, and just keep in mind to drive more reasonably (no sudden stops, and no full throttle in the beginning). All in all, even with normal size cars, you should avoid situations I mentioned in my sentence above. I will have to try if you can mix both sinusoidal start-up, and try to find a way to have some kind of flywheel system with software. One question though, what programming software do you use, or are you using official AM32 website? Quote
janssnet Posted March 17 Posted March 17 (edited) On 3/17/2025 at 3:57 PM, Krxlion said: I will have to try if you can mix both sinusoidal start-up If you select 'car mode' it will override all other user settings, including sinusoidal startup. Please find a screenshot of the old configurator here. Therefore it is either a. Slow Crawler Drive mode or b. Car mode with coasting/freewheeling. On 3/17/2025 at 3:57 PM, Krxlion said: One question though, what programming software do you use, or are you using official AM32 website? To program the AM32 yourself you will have to fork the (open source) code in GitHub. Not something I feel very comfortabel with. As said earlier, the builders are accessible through their Patreon site (Alka Motors) and they/he is very responsive. I'm using an ESP32 (Arduino/IDE, C++) to control the BLHeli-s ESC's to overcome the problem you describe (make a drone ESC act like a car ESC). Not sure if this is the right content for this forum. Happy to explain in more detail, in summary, it is a throttle delay (or throttle mix) which reacts as shown in the graph attached. And the ESP32 communicates in DShot with the ESC, digital protocol, works great. Short demo here: https://drive.google.com/file/d/1TKuYVhSsZs5md0r51-DHAHPn-WSxRe_9/view?usp=sharing Edited April 18 by janssnet Quote
Krxlion Posted March 17 Author Posted March 17 (edited) 21 minutes ago, janssnet said: If you select 'car mode' it will override all other user settings, including sinusoidal startup. Please find a screenshot of the old configurator here. Therefore it is either a. Slow Crawler Drive mode or b. Car mode with coasting/freewheeling. To program the AM32 yourself you will have to fork the (open source) code in GitHub. Not something I feel very comfortabel with. As said earlier, the builders are accessible through their Patreon site (Alka Motors) and they/he is very responsive. I'm using an ESP32 (Arduino/IDE, C++) to control the BLHeli-s ESC's to overcome the problem you describe (make a drone ESC act like a car ESC). Not sure if this is the right content for this forum. Happy to explain in more detail, in summary, it is a throttle delay (or throttle mix) which reacts as shown in the graph attached. And the ESP32 communicates in DShot with the ESC, digital protocol, works great. Short demo here: https://drive.google.com/file/d/1TKuYVhSsZs5md0r51-DHAHPn-WSxRe_9/view?usp=sharing The throttle delay demo: https://drive.google.com/file/d/1Yfl2rxSdD5c7wy40Aaa_jzyiRnPzHwF0/view?usp=sharing Oh my god, I am laughing so hard, because I just discovered what you described here. It works, but you cannot have a cake and eat a cake, so you have to choose between slow sinusoidal startup for crawling or Car/Basher checkmark for bashing around and free-coasting. I must say though that it is huge, because one ESC can actually do both things, and it only matters what you prefer more. EDIT: Thank you for your explanation, I really start to understand now how things work. I have asked AM32 community about it, maybe it will lead me somewhere. Edited March 17 by Krxlion Quote
killerfrost Posted April 3 Posted April 3 (edited) On 2/5/2024 at 9:49 AM, Ryokeen said: @Krzychups if you go for the complete rear assembly, with the suspension arms and differential housing, you are very limited as you will have trouble changing the width of a vehicle or sometimes even the ride height. And at that point you might as well just use a full rc car chassis and just slab a brick body on it. That's why i went for the hubs only so everything else can be done how i need it. The adapter i need looks a bit like this : 10mm pins can be exchanged as they are prone to wear. These hubs are designed to use the newer cv joint as well as have a 10x5x4 mm bearing and a metal cv axle with a max diameter of 11 mm. There's 3 different hubs, the small and large hubs plus a universal caster hub. The caster hub is made with a 14 degree negative caster which fits on a 1 stud offset between the upper and lower ball joint. The spacer is to in-between the metal cv axle and the bearing since theres a small gap (>1mm) from the lip the spindles snap into. Hopefully the link works The part you made should work with these parts. https://bricksafe.com/pages/Killerfrost/truck/new-project I will upload the studio files to bricksafe as well to share as well as pictures of the 3d printed parts. Edited April 3 by killerfrost adding more text Quote
Knott Posted April 8 Posted April 8 (edited) Hey guys, sine my topic got deleted few weeks ago I managed to solve all remote control issues I had and I'm 15% done with assembly schematics. I finally got it moving, then after 15 min of careful driving I smashed full throttle and twisted two chinesium axles, two u-joints and 1 plastic CV joint knuckle, zero additional friction damage. Any worthy replacement ideas? Edited April 9 by Knott Quote
Aurorasaurus Posted April 9 Posted April 9 4 hours ago, Knott said: I finally got it moving, then after 15 min of careful driving I smashed full throttle and twisted two chinesium axles, two u-joints and 1 plastic CV joint knuckle, zero additional friction damage. Any worthy replacement ideas? https://m.traxxas.com/products/models/electric/x-maxx-ultimate On a more serious note, I'm aware of carbon fibre axles, have you tried those? I doubt that anything thats the roughly 5mm thick thats required for lego compatibility will be able to take the load you're putting on it. Quote
Lixander Posted April 9 Posted April 9 (edited) While the carbon-fiber axles are more durable, there are also more rigid.............that means that they might snap kind of more easily. Going for smaller metal axles with some metal linkages will be the safest option in my opinion. Buuut, considering the price of the metal parts, some small carbon-fiber axles with some metal U-joints would do the trick most likely. Also, I did not manage to test the reliability of the metal U-joints at high speeds, as these might shake a bit, and under the torque and RPMs of the brushless set-ups that might mean problems. Edited April 9 by Lixander Quote
gyenesvi Posted April 9 Posted April 9 15 hours ago, Knott said: I finally got it moving, then after 15 min of careful driving I smashed full throttle and twisted two chinesium axles, two u-joints and 1 plastic CV joint knuckle, zero additional friction damage. That motor setup seems waaaay overpowered for lego components :) But I guess having that drive axle supported in multiple places, and putting it together from smaller pieces and connectors could help. On the other hand, what is that motor setup you are using? I know that Surpass Hobby motor, I have been interested in it, but is that a planetary reduction on it? What kind and how did you fit them together? Seems like an interesting combination. Even one of those motors would be great for many builds. Do you have more info about it? Quote
Aurorasaurus Posted April 9 Posted April 9 2 minutes ago, gyenesvi said: That motor setup seems waaaay overpowered for lego components :) But I guess having that drive axle supported in multiple places, and putting it together from smaller pieces and connectors could help. On the other hand, what is that motor setup you are using? I know that Surpass Hobby motor, I have been interested in it, but is that a planetary reduction on it? What kind and how did you fit them together? Seems like an interesting combination. Even one of those motors would be great for many builds. Do you have more info about it? https://www.zenebricks.com/products/high-performance-rc-brushless-esc-accessories-for-motorized-lego It seems like it comes from zene. Quote
gyenesvi Posted April 9 Posted April 9 8 minutes ago, Aurorasaurus said: https://www.zenebricks.com/products/high-performance-rc-brushless-esc-accessories-for-motorized-lego It seems like it comes from zene. Oh, I thought it's a different one.. Quote
Knott Posted April 9 Posted April 9 (edited) 3 hours ago, gyenesvi said: Oh, I thought it's a different one.. It is, I just asked ZENE for 1/16 reduction for more torque instead of speed, results above... I'm using two surpass hobby 2445, paired with their 35A ESC and Zee 5200 mAh 50C for each motor I was about to buy MTP axle, but they also use alu, I'm now thinking about this one: https://a.aliexpress.com/_EwLfi1A However I would have to file down axles, or drill u-joints to fit the axle, maybe both of those solutions @gyenesvi Here is everything you asked for :) Red bushings represent R156ZZ bearings, grey bars were modified (I sacrificed one bearing, heated it over a gas burner and then pulled with long alu rod into the liftarm, so it fits flush and creates perfect bedding for new bearing, removed any excess material that would collide with nearby bricks) to hold bearings, 6L alu axle is supported by the motor and two bearings. Black 3x3 piece represents motor front plate with attachments Edited April 9 by Knott Quote
Ryokeen Posted April 9 Posted April 9 14 hours ago, Aurorasaurus said: On a more serious note, I'm aware of carbon fibre axles, have you tried those? From my experience, if you twist aluminium axles, the carbon ones will just splitter away. They have great bending strenght, but torsional they are way weaker than aluminium axles. @Knott Try to avoid long (unsupported) axles, or try to reinforce them with some stoppers or other parts(i have some weird 2l connectors that don't have a stop in the middel inside) Also keep in mind, bigger RC cars have big chunky driveshafts. Got one car here that is "only" 7-8kg but used 5mm thick hardened steel driveshafs(an each part is shorter than a 16L axle) Along with that, they use either cush gears(some rubber "gears") or slipper clutches to lessen sudden forces from either impacts(landing) or sudden accelerations. But it is kinda strange that the aluminum axles twisted like plastic ones and the metal u-joints are totally fine(and they have way thinner pins) 3 hours ago, Knott said: I'm now thinking about this one I tried that aswell, works semi good as the weak part is the shaft to brick axle connection. Either use short aluminium axles and file them down or mutilate a 4L axle with center stop and get rid of the 1L part and file down the stop part to be D shaped. 8 hours ago, Lixander said: Also, I did not manage to test the reliability of the metal U-joints at high speeds, as these might shake a bit, and under the torque and RPMs of the brushless set-ups that might mean problems. Yep they do, but if you brace them properly(best with bearings) it's fine. Quote
Knott Posted April 9 Posted April 9 30 minutes ago, Ryokeen said: @Knott Try to avoid long (unsupported) axles it is kinda strange that the aluminum axles twisted like plastic ones and the metal u-joints are totally fine Yep they do, but if you brace them properly(best with bearings) it's fine. Whole point was to have wide travel distances, I hope that adding one softer spot and reinforcing others will save me further expenses, it's easier to replace one carbon 2L than whole shaft One u-joint got shredded, another bent so hard it doesn't spin freely Quote
killerfrost Posted April 9 Posted April 9 I'm working on making a transfer case that the surpass motor snaps into and using 10x5x4mm bearings to support the axles and can use the lego diff's. 3:1 or 2:1 reduction from the motor will keep the axles from twisting with 1 motor and provide plenty of power to move the vehicle with ease. I'm trying to keep it contained in a 5x7 rectangle liftarm. Without the motor it will be 5x7x8. With motor it will be 5x7x11 studs. Quote
gyenesvi Posted April 10 Posted April 10 10 hours ago, Knott said: Here is everything you asked for :) I don't know if the rendered images are for me, but I was interested in the motor itself with the planetary gears, not how it is built in. But you provided most of that info too already, except the kv rating of the motor..? With about a 3000 kv motor, the resulting speed would be about 2200 RPM at 12V, which could be really nice! 10 hours ago, Knott said: It is, I just asked ZENE for 1/16 reduction for more torque instead of speed, results above... So that's interesting, I think that can result in something of an ideal speed and torque balance! Did you only get the planetary from them or is it put together with the motors by them? If they made that motor with the planetary gearing as a product, I'd buy that! Does it fit into a 9L space, or does it need 10 studs of space length-wise? Quote
killerfrost Posted April 10 Posted April 10 Here's the 3 versions of the wheel hubs, the black hub has a caster angle of 14 degrees which allows for a 1 stud offset from upper and lower ball joints, the small hub, this is the only way I can think of to make it useable in the same fashion as the caster and regular hub. The regular hub has the small spindle snapped in and the cv fits in very nicely. these are printed on my cheap elegoo printer with pla. If you want the stl's, my bricksafe url will be below. https://bricksafe.com/pages/Killerfrost/truck/new-project Quote
Knott Posted April 10 Posted April 10 5 hours ago, gyenesvi said: I was interested in the motor itself with the planetary gears, the kv rating of the motor Did you only get the planetary from them or is it put together with the motors by them? If they made that motor with the planetary gearing as a product, I'd buy that! Does it fit into a 9L space, or does it need 10 studs of space length-wise? It came with planetary reduction attached and also glued in bolts to stop me from removing it :) Regular motor from ZENE comes with 1/4 planetary reduction and 25a ESC that can support only 2s lipo, I however purchased 35a ESC to run 3s packs and requested 1/16 planetary reduction They don't sell just the reductions, its only sold mounted on a motor, however I negotiated down the price for 3 differentials, 2 motors and 1/16 reduction without esc, so far very satisfied with my purchase, but now I need to order good drive shaft that survives it Motor is 3600 kv, it's size is 3x3x9,2, slightly longer than 9 studs and require 10 studs open space but I have a plan to use 2 2x3 flat top bricks attached to a liftarm at the back of the motor to push / lock them in, although it did not seem necessary yet as it's very hard to pull them out Quote
gyenesvi Posted April 10 Posted April 10 7 hours ago, Knott said: Regular motor from ZENE comes with 1/4 planetary reduction and 25a ESC that can support only 2s lipo, I however purchased 35a ESC to run 3s packs and requested 1/16 planetary reduction Motor is 3600 kv, it's size is 3x3x9,2, slightly longer than 9 studs and require 10 studs open space but I have a plan to use 2 2x3 flat top bricks attached to a liftarm at the back of the motor to push / lock them in, although it did not seem necessary yet as it's very hard to pull them out Thanks for the info, that sounds interesting, I'll ask them if they'd sell the a motor with the same reduction for me too. Is it possible to order with all different sized motors as well? I'm thinking about the 3300kv 2435 instead of 2445, which should come out 10mm shorter if I am right, and would just fit into 8 studs length.. Quote
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