Ryokeen

@Lixander that sounds better and yes depending on the motor the shaft shouldn't move at all. If it did move it could rub against some parts, but well that depends on how the motor is build. Normally the shafts should be very ridig and no where near easy to move.

@Lixander You should investigate that rattling sound. If it comes from the gears, you might sand them down a bit to make them a bit less than 1 stud wide as they might rub a bit on the portal axle part. If it's not from the gears and your motor does that sound, then that one has an issue and that would also explain why it isn't as fast as it should be. Apart from a slight high pitch noise on low rpms(you can hear that at the beginning of my vid) brushless motors are very silent. If they make some rattling noise, it means something inside the motor is rubbing(or a bearing is damaged)

@Lixander Ok well i have a similiar motor, 3250kv on 2S LiPo with a total reduction of 7.6:1 and that's how full throttle looks like with 82mm tires. Edit: just rewatched your video a page bag, that rattling noise from the motor gears sounds rly bad. Even unlubed without bearing it should not sound like that.

@Lixander The video you posted a page back with the throttle by knob and lever, was that full throttle on gas with a i think, 2.77:1 reduction ? Cause for full speed that already looked a bit slow. also i would suggest that you don't go less than the 5:1 reduction you got know as models with such a motor normally have a reduction of 7:1 to 10:1(i use 7.6:1 and get up to around 40km/h). Also check that the transmitter is calibrated and the endpoint is properly set.

Nice work so far. Sadly Lego tires are so hard and stiff you can't properly get the balloon effect :D

Quality is what i expected. A solid gear. I see one said that he shredded 2 of them in a short time, i doubt that or he messed up the spacing between the gears. Or he used a special hardened spur gear(the one the pinion/motor gear meshes into) without any lube and a too tight meshing, i don't know. But to grind the teeth down on 2 of those gears sounds a bit fishy, cause first a tooth would break and not just grind down. You get that from improper meshing.

I have to say the bodywork of your projects is always amazing

Nope works well, i'm not sure if they were just a bit lazy and rounded 3.175mm to 3.2mm. I did not notice any slack or play and you secure the gear with a screw anyways

@Lixander German conrad that's the one i have :D

@Lixander The conrad online store has some 12t mod1 pinion gears for 3.175mm shafts, at least that's where i got mine from. If you can't or don't want to order from there and can only find pinion gears with a 5mm shaft hole, there are cheap adapters from 3.175mm to 5mm. The mod(ule) 1 is the important thing as that defines the spacing of the teeths and thus the radius of the gear related to the number of teeths.

Yes currently i use it with a 36t plastic gear, or well 2 gears a bit sanded down and glued together with resin so have more contact area. Together with either dry fluid or a few drops of silicon oil works qute well. After 4h of driving with very sudden acceleration and breaking i couldn't find any wear. You should try to either use dry fluid or any lube that is suited for outdoor use like chain lube if you can't enclose the gears. Silicon Oil+dust and dirt will turn into grinding paste :D

@Lixander What shaft diameter does that motor got ? You might look into mod(ule) 1.0 pinion gears. They are available at least for 3.2/3.175mm and 5mm and could solve your problem with having to use an axle adapter, as it's kinda hard to center the connection properly. If the motor is properly secured and as i see you can 3D print parts so that should be easy to do, that could work aswell. I do that on my cars with a mod 1.0 12t gear which is exactly the same size as an lego 12t gear and never had skipping gears.

Brakes on an esc means that a motor won't change rotation direction in an instant. With breaks an esc will first use the motor to slow down/break and only if you stand still and then push the throttle into reverse again, the motor will spin in reverse. Boats or tracked vehicles(tanks) mostly don't have breaks as they either drive slow or don't have much force applied if directions are changed. About your speed, check the battery voltages(each cell) and internal resistance(check online about lipo health). Any decent charger(not usb) can do such checks. Just to make sure the LiPo is still good as yeah they age and don't like to be stored full or empty. Else the motor could have gone to hot wich can damage the coils or magnets, degradin performance. Had a testdrive with a 3652 motor and a total reduction of 8:1 and a car of about 1.5-2kg. And it got quite warm. So my main concern about the 2445 or smaller motors is that they could get quite hot if used in any vehicle in the 1kg+ range. After all that scale is mostly used in 1:16 or smaller rc cars.

Lego should do something like that, would be a top seller. Small and looks like a lot of fun to drive indoors aswell. As a kid(or even now) i would have saved up several years of birthsdays to have something like that. Nice work dude :)

Can only agree with what @gyenesvi said. Also some more technical data on the individual parts would be helpfull. Like the gear ratio of the differentials(it's about 2.65:1, counted the teeths) or the BEC(power supply from the ESC to the receiver and servos) specs, like voltage, continous amps, the type of battery connector of the ESC(T-deans, XT90,XT60), are only 2s or 3s LiPo's supported. Has the ESC a break function ? If so can that be turned off as it would make 2 motors actually usefull for tracked vehicles. All that might not be needed for the 3 full conversion kits, but for the individual parts, that would be good to know. The ESC data mainly as that determines what kind of Lipo one needs and if more than 1 geekservo can be used without overstressing the ESC BEC.

Worm gears have siginificant friction under load but more important here is, you loose all ability to free roll. Means as soon as you let go of the throttle the wheels stop. From my experience(unless it's very small 12t gears) gears get damaged because the axle holes on the supporting lifarms wear out. That increases the play and missalignes the gears disturbing the meshing. Besides 3300kv even on 2s is a lot of rpm. Considering that and similiar setup as the 20tooth and 12tooth gear with only 2 buggy motors already had axles melting for me, the 24000 rpm(2s LiPo) will always cause problems.

Cada got new parts in their shop, like the 5x7 half-frames,split T-frame and the leaf spring parts.

@killerfrostIf the inner Diameter is 6mm it might fit. Send you a pm

@killerfrost I'm afraid that it won't work that way. The part i designed is the male part of a "cv" joint that is supposed to fit into 1:10 and 1:8 scale RC axles with the matching female part. And the female rc axle parts are 10mm in diameter with 6mm diameter space in it where the ballhead of my part fits in. That won't fit in the Zene parts as they have max 8mm of space

Yeah but that's mostly on offroad(buggy) cars but i would add as much cast as needed for stable driving as caster for an onroad car is more about self centering and keeping the line than smoother suspension. I have an older nitro RC that is pretty fast and that thing got 2 degrees of caster angle(negative) and that is more than enough. I mean 30 degrees is a lot, never seen that on any onroad car. From my experience, if you go faster yes it is worth but you don't need super good ones. Main point is, just springs tend to bounce up and down a bit after they got compressed. That will lower your traction and at higher speeds that's bad for steering and breaking(breaking puts more tracton at the front where a 2wd can't break). Even cheap non oil springs have most of the time at least a friction dampening build in to reduce the bouncyness.

No particular reason, other than i knew how to mount 540er brushed motors and 3650 motors have almost the same mounting points. This is what i use for mounting, just some short m3 screws through the part 32814 holes and half liftarms to fill to a gap of 5 studs. The pinion gear then rests at pinhole level so everything that can mesh to a mod1 pinion gear(12 tooth or 16 tooth works best) can be used. I wouldn't recommend doing the steering like i did or how real rc cars do it as frictionless pins have way to much slack. I get away with it cause i use some metal pin replacements that sit very tightly and reduce slack a lot. So using a gear and rack might be better if you don't have such metal parts. At first i thought about adding caster angle but it would make the suspension way to complicated, because either one have to tilt the whole axle along with the steering mechanism or(and that should be possible) i would have to use RC Hubs with a build in cast angle. But from my experience on-road RCs hardly have caster angle, or if only a few degrees. 30 degrees sound way to much and makes steering way to hard. Honestly i don't know where i could make it more simple, but i misunderstand what you mean with that. The cassis itself is quite simple, it just might look a bit messy with all those cables. Thats's the brick build chassis without the rc components and stub wheelhubs and motor, around 470parts Well depends on the bodywork thats build ontop :) So far with tires it's 28 studs in width. And if you mean that the wheels might stick out during steering, the pivot/rotation point is actually only half a stud further towards the tire edge as when using the defender wheels.

A bit background about the last few months of tinkering: Some might have seen that a few users, including me, experimented with small non lego/bricks brushless motors and rc parts to build either smaller cars or trophy trucks. I had my own shot on a trophy truck but sadly at that scale some problems couldn't be solved properly. One of those problems was the wheel mounting, i did use hubs with ball bearings from Zenebricks, but with just pins holding them, they would still come of at higher corner speeds. But i didn't want to give up on fusing RC components and bricks, as i love rc cars and i love building stuff. So i thought maybe even with reinforcements a live axle/multilink suspension at RC speeds and offroad just won't work as i want. That's when i thought ok, then maybe some proper on-road or rally car, best with awd or at least 4wd to get more traction and stability. At that point i only had the Zene wheelhubs with bearings and some might have read the conversation about them, they are not suited for a driven and steered axle. I tried to solve that problem but it boiled down to the fact that i needed at least one custom part, either a shortened/custom u-joint or something else. And as i knew that m3 screws fit well into pins i figured that RC parts that are mounted with m3 screws might fit the lego system aswell, so i ordered some cheap tamiya parts as those are widly available and it did fit well. That set the direction for my experiments, fusing RC wheelhups with Lego/Bricks. But wait..they can't connect to Lego axles, so i needed an adapter. I found someone who helped me with a proper cad design and specs, as some of you might have seen in the brushless post, and i ordered some parts. I got them 2 weeks ago and it all worked so well and i build a small prototype. The advantages for me were/are huge, for one, except for the custom parts every other RC part is cheap to replace, all 4 wheelhups cost less than 10€ together. I can replace worn out ballbearings in the hub(and i can clean them) for very little money and there is almost no slack at all in the stearing. Apart from that, by using toe-in/out can be adjusted, left and right wheel steering can be adjusted and the big problem was solved..RC car tires are secured with a proper nut and won't just come of that easy. Fast forward, after all that text, here are some screens: More screens here -> Bricksafe gallery That is my current prototype chassis, currently with on-road touring tires with 82mm diameter. The whole layout is roughtly oriented on most on-road RC cars, except that i choose to center the motor to move it further back and get some weight on the rear axle. Also i choose to not use geekservos even thou it complicated the steering setup but with all that traction i was worried that the geekservo wasn't strong enough. Also i need them for another project, so i put in a cheaper 15kg servo. Features: AWD Adjustable ride height Adjustable steering Adjustable toe-in/out RC shock absorbers Aluminium axles Zene metal differentials Uses common 12mm (1:10 scale) hex mounts for wheels Internal gear ratio is 7.95:1 (spur and diffs) 3250kv brushless motor on 2s (3s possible) 82mm tires And now for the magic custom part: That small part provides the connection between how RC wheels are driven and the lego system and are currently made out of aluminium. It offers a 1 stud long axle part so any axle connector can be attached, be it an common axle connector or a u-joint. The movement range is a bit more than the old lego cv's, i would say about 40 degrees, but that also depends a bit on the RC axle part. A 2mm driveshaft pin needs to be pressed through the hole at the ball end, i designed it that way cause it's easier to manufacture and the pins tend to wear out after some time, so this way i could replace them. There you can see how it's used an the mentioned driveshaft pin that needs to be pressed in. They do need some space to move that's why there is an o ring in the RC axle and a small spring that pushes the driveshaft in a bit. That was only neccessary for the front axle as there is more movement. A first testdrive showed that all the work was worth it. The prototype is fast, stable and fun to drive until a screw(metal 2l pin substitude from a uk shop) got loose cause it was the only screw where i forgot to use locktide :D Next would be more testing and deciding what kind of bodywork i want to do. From the dimensions it's based on a Subaru Impreza WRC but a Skyline should fit aswell. Think it all depends on whether i can find good 80mm rally tires or not. Feel free to ask questions and discuss and thanks for all the fish. Edit: Had finally the opportunity to make a shot vid. Sadly a 2L axle at the front left drivetrain broke, rendering the whole thing into rwd. Think that was an old brittle part and broke on a 360spin, but then again i added those weakspots on purpose to have cheap and easy to replace points of failure. So that testrun was on 2S LiPo and abour 50-60% throttle. https://www.youtube.com/shorts/Cuvu2y7sEfA

So finally the last parts for a proper prototype arrive and so far it all fits nicely(except that i couldn't find 35mm m3 screws :D) So apart from the custom made adapter parts everything now can be replaced for little money. Ball bearings can be changed if worn out(Zene glues them), wheels are secured with a proper nut and almost 0 play in steering. Toe in/out and chamber(i think) can be easily adjusted but for me the biggest advantage is more wheels are and more narrow wheels. Everything with 12 hex fits. Also the pivot piont is better(not perfect) and is just on the edge of the wheel. So far, front driven and steered(lacks servo attachement yet) axle: How the tamiya parts are attached to lego parts. The spring adds some tension as the driveshaft needs some play. The adapter part can be seen in the wheel hub and attached to the axle connector. The axle connector is there so that different suspension arms lenghts can be used also together with the 2 3/4 axle it serves as a weak cheap link in case of an accident that can break.

The barcode garbage scanner truck in studless ? nice, a set i ever wanted and never had

As said, it was just a quick test build to see if the parts fit propery. Ofc the driveshaft is to long(but will always be about 1 stud longer) but even with the setup as in the picture there is a solid 3 stud suspension travel. Unlike lego cv-joints dogbones don't click or stay in position so they can move freely in and out of the axle in the wheelhub, together with an small o-ring that gives enough play. Once i get the needed pins and some other parts i can say more on how it performs, but for street cars or ralley ones it should work quite well and most parts are easy to replace if they break