ZENE High Performance RC Brushless Modification QA

[ZENE]

I have sorted out some questions about the previously released alloy differentials and RC modifications of brushless motors. I have tried my best to explain the attributes and parameters of the accessories.

I also hope to gain everyone's suggestions and try my best to achieve continuous improvement. Update, thanks again in advance for your time here.

What motivated us to redesign the LEGO differential? Why is the differential so important to high-performance LEGO sports performance? Here we need to start with some of the problems we encountered.

• Accuracy issues: LEGO differentials are limited in accuracy due to part manufacturing limitations, which may not be ideal in some applications that require high precision.
• High-speed toothing problem: Lego materials lack the strength and precision to rotate with high accuracy at high speeds, which results in gear toothing.
• Load Capacity: LEGO differentials are generally designed for lightweight models, so they may not be suitable for some heavy-duty applications.
• Friction and Durability: Friction can reduce efficiency, and parts can wear out over time, affecting differential life.
• Specific Use Restrictions: LEGO differentials are generally of a general purpose design and may not necessarily be suitable for all specific engineering or mechanical applications.

 

Some common questions - Differential part

Is the product a complete set or a separate accessory?

Answer: Currently we provide two types of products

1. Complete modification package for LEGO Technic 42143, 42156, 42096
2. Accessories part,
3. a) Independent differential, available in square, H-shaped, single-input, double-input types. Please refer to the figure below for dimensions (compatible with LEGO unit proportions)

 

figure 1

figure 2

figure 3

figure 4

b) Drive axle, alloy 1:10, 23801 & 11950

c) Drive axle, nylon 1:8 23801

d) Small set of differential + motor + planetary reducer + ES + drive axle + metal shaft + universal joint. The motor is a 2445 brushless motor and supports 2S (7.4v), 3S (11.1V) model aircraft batteries.

Compatible with "LEGO"/RC output

Answer: Yes, there are two ways of output, cross-shaped or square metal output shaft, with U-shaped universal joints with holes on both ends, fully compatible with your Lego. (Many thanks to @FriedlS for the HD shot)

figure 5

figure 6

This metal differential gear ratio:

Answer: 1.65:1

Does the U-joint have a LEGO shaft hole on one end? What is the difference when used without a U-joint? Or do they accept metal (hexagonal) shafts?

Answer: Yes, this universal joint has a lego shaft hole on both sides, just like CaDa's metal universal joints.

How deep is the U-joint at the differential input? How far away will the turning point be?

Answer: The bending point of the U-shaped universal joint is located outside the differential output, and the shafts can be connected in a consistent manner. The size of the differential can be considered to be the overall size and will not affect other designs of the structure.

Why do differentials come in black and white, are they the same?

Answer: The material is the same, the only difference is the color. Colors are generally sent randomly. If you have a request, please let me know.

 

 

Motor and planetary reducer part

Does the motor have a housing to attach it to the LEGO part?

Answer: Yes, the motor is currently connected to a planetary reducer. The reducer housing has enough holes for fixing to the chassis structure. Refer to the red arrow mark in Figure 7 for fixing to the differential and match the points in Figure 8. The blue latch, the blue arrow in Figure 7 connects to the metal shaft with the middle arrow in Figure 8 for power output.

figure 7

figure 8

Not sure what "bearing drive shaft" means, any ideas? Is that the hub?

Answer: The general Lego drive axle is a combination of 11950+92909 parts. The bearing drive axle is a combination of 11950+stainless steel specially customized 92909 parts. It has built-in ball bearings, which has better part strength and smaller friction. The service life is increased hundreds of times. (1:10 bearing transaxle cannot be linked with Lego wheels)

What is the reduction ratio of the planetary reduction gearbox?

Answer: The reduction ratio of the planetary reduction gearbox (i) is 1:4. Since the maximum speed of the matched 2445 motor can reach 50,000 rpm, the maximum speed after deceleration is 12,500 rpm.

What are the parameters of the 2445 brushless motor used?

Answer: 2445 brushless motor, 3600kv, maximum speed 50000, maximum voltage 13.2v, please refer to Figure 9 below

figure 9

Other questions

Transaxle rotation resistance problem

Answer: There will be some resistance to initial rotation, and after running for a period of time the resistance will reduce to normal ball bearing levels. The parts are all glued/screwed together nicely so the wheels won't come off unless something breaks.

 

What is the remote control and is it sold separately?

Answer: The commonly used 2.4G radio remote control RC gun handle and receiver with light control support one-handed operation (controlling direction, acceleration and deceleration). The remote control distance is stable within 400 meters. In addition, the receiver has a built-in gyroscope. , you can manually turn on the gyro mode to assist drift control.

If you need to purchase this part separately, please contact us.

What model is the battery and is it sold separately?

Answer: For general model aircraft lithium batteries, it is recommended to use 2S, which has sufficient power. 3S is a bit violent. There is no sales at the moment, please contact us individually if necessary.

About the lights of 42143, 42156, 42096

Answer: This kit comes with special lights that are compatible with the remote control. Some of the lights can be directly controlled manually using the same remote control handle, while other parts are automatically controlled. For example, the taillights will automatically dim and brighten according to the amount of the accelerator.

 

[Krxlion]

I really like that you elaborated your product. I am sure that someone (me included) that is interested in third party solutions for powering their MOC might choose your product. I don't know if this is not a problem that you made this topic to kinda just promote your product and answer questions (I am not bothered about that cause I find it interesting ). Anyway, nice presentation and I am looking forward for some MOCs from your side that are powered by your system!

[aFrInaTi0n]

Thanks for your informative post, Its excellent! 👍

Also I am one of Zene's already happy customers with one order of two units of the 1st version differential.

They are a high quality product and I would give my personal recommendation also for the very good service from ZENE - my pre-order questions were answered fastly and the sipping was also in the to-be-expected shippingtimes from CN Mainland to Germany.

All the best for the future of ZANA and their products which are a great addition and filling a yet-unfilled gap to the Brickhobby - at least for me.

1 minute ago, Krxlion said:

I really like that you elaborated your product. I am sure that someone (me included) that is interested in third party solutions for powering their MOC might choose your product. I don't know if this is not a problem that you made this topic to kinda just promote your product and answer questions (I am not bothered about that cause I find it interesting ). Anyway, nice presentation and I am looking forward for some MOCs from your side that are powered by your system!

I also hope the admins will understand the topic for informative reasons here for the interested people. For argumentations "isn't it somehow advertisment" I would answer - "I see it as an offer from the vendor to get as close to their community of customers as they can to make them happy and create good products".

Another question I have: As a 3D Model STL may already exist - is it planned to release a digital model of the differential (creates potential for allowing easy-copying for other parties, so I could understand that may be a reason the answer being "no")?

[FriedlS]

Great overview to this product!
I am also an happy customer of two differtials, motorsand hubs! 
 

[NoEXIST]

So there's a sort of generic rc differentials inside this frame? Must be really sturdy for Lego!

[Ryokeen]

@ZENE Does each differential comes with both output options ? The cross-shaped an square metal output shaft type and if not, how can one choose as it's not a selectable option in your shop

One thing i might add about the bearing hubs(the bearing drive shaft parts). The 1:8 scale ones are pretty sturdy, but at least in my case(it's long been resolved) are prone to manufacturing errors.
Another important bit about them is, they are problematic, if not unusable, in a driven high suspension travel use case. The pivot point of the hub no longer matches the pivot of an attached u-joint. It's around 1 stud offset. Sadly that prevents one from using those hubs in a fwd or awd vehicle.

Edited January 11 by Ryokeen

[glowytheglowbug]

I'm interested in buying the motors indivually with an esc, do you happen to sell the motors with the mount and adapter? 

[Lixander]

Nice and practical product.

i am interested at least in the differentials, but I want to use other brushless motors with them in off-road builds.

So the gear reduction frame, differentials and the wheel hubs (probably  the ones for 1/8 because I dont want to move to full RC wheels yet) work with a brushless Surpass Hobby F550 3800KV with a 90A ESC (on a 2S Li-Po battery)?

https://www.aliexpress.com/item/1005005016153941.html?spm=a2g0o.cart.0.0.53bc38daKb1S9H&mp=1

Edited January 11 by Lixander

[ZENE]

@Krxlion Thank you very much for your liking, bro. Currently, our MOCs used these accessories for LEGO 42096, 42156, and 42143 sets. The previous goal was also to design and modify LEGO cars. For the time being, the focus is still on the LEGO sets RC modification, after all, their design is very good. We have some sports demonstrations of these cars on YouTube. https://www.youtube.com/channel/UCoj1BNklidkrlze8oTlcg4Q

@aFrInaTi0n

18 hours ago, aFrInaTi0n said:

Thanks for your informative post, Its excellent! 👍

Also I am one of Zene's already happy customers with one order of two units of the 1st version differential.

They are a high quality product and I would give my personal recommendation also for the very good service from ZENE - my pre-order questions were answered fastly and the sipping was also in the to-be-expected shippingtimes from CN Mainland to Germany.

All the best for the future of ZANA and their products which are a great addition and filling a yet-unfilled gap to the Brickhobby - at least for me.

I also hope the admins will understand the topic for informative reasons here for the interested people. For argumentations "isn't it somehow advertisment" I would answer - "I see it as an offer from the vendor to get as close to their community of customers as they can to make them happy and create good products".

Another question I have: As a 3D Model STL may already exist - is it planned to release a digital model of the differential (creates potential for allowing easy-copying for other parties, so I could understand that may be a reason the answer being "no")?

You are definitely a brave and adventurous creator, haha. Thank you for your support and I really appreciate your work.
Regarding the design drawings, we have no plans to fully disclose them yet, as we are worried about others using them for commercial purposes.

@FriedlS You are very discerning, haha

 

@NoEXIST

17 hours ago, NoEXIST said:

So there's a sort of generic rc differentials inside this frame? Must be really sturdy for Lego!

It is almost indestructible. The previous version encountered very violent operations, causing the nylon material of the connector to melt. However, I later upgraded it to metal, and so far I have not encountered any damage.

 

 

9 hours ago, Ryokeen said:

@ZENE Does each differential comes with both output options ? The cross-shaped an square metal output shaft type and if not, how can one choose as it's not a selectable option in your shop

One thing i might add about the bearing hubs(the bearing drive shaft parts). The 1:8 scale ones are pretty sturdy, but at least in my case(it's long been resolved) are prone to manufacturing errors.
Another important bit about them is, they are problematic, if not unusable, in a driven high suspension travel use case. The pivot point of the hub no longer matches the pivot of an attached u-joint. It's around 1 stud offset. Sadly that prevents one from using those hubs in a fwd or awd vehicle.

@Ryokeen

Yes, our products now come with 2 output connectors for the user to choose. However, considering the possible waste and cost issues, we will consider letting the customer choose the connector in the future.

After seeing the problem you raised, I discussed it with the designer and he told me that he had encountered a similar situation before and that cutting the length of the U-shaped universal joint could completely solve the problem. But I may need more description from you, please send me an email and we can discuss more, if you still need to solve it.

 

 

5 hours ago, glowytheglowbug said:

I'm interested in buying the motors indivually with an esc, do you happen to sell the motors with the mount and adapter? 

@glowytheglowbug We mainly fix the connection of the brushless motor through the holes on the modified planetary reducer. You can refer to my description above. At present, we are connected to the differential, and the differential is connected to the chassis.

If you only need the motor and planetary reducer parts, you can consider similar connection and fixing method. If necessary, you can email me your detailed needs, support@zen-estore.com.

[ZENE]

1 hour ago, Lixander said:

Nice and practical product.

i am interested at least in the differentials, but I want to use other brushless motors with them in off-road builds.

 So the gear reduction frame, differentials and the wheel hubs (probably  the ones for 1/8 because I dont want to move to full RC wheels yet) work with a brushless Surpass Hobby F550 3800KV with a 90A ESC (on a 2S Li-Po battery)?

 https://www.aliexpress.com/item/1005005016153941.html?spm=a2g0o.cart.0.0.53bc38daKb1S9H&mp=1

@Lixander I checked the size parameters of your generator's motor, and they don't match our planetary reducer, but the differential and transaxle are not involved in this compatibility issue.

[gyenesvi]

@ZENE thanks a lot for the detailed answers! Your products seem promising, I hope we can evolve them in directions that make them useful for many use cases.

Here are my notes and further questions.

Differential

I like that it has two kinds of outputs, both U-joints and axles, this makes them usable both for independent suspension (with the U-joint) and for live axles (with the regular axle output). So I think it would be good to keep both options, so that a buyer could use it in both kinds of builds.

If I understand correctly, the input end behaves the same way, so that I can put a U-joint there, and the pivot point of the U-joint will fall right next to the frame. That would be great.

The differential is open, right? Would it be possible to make a locked version as well for off-roaders?

Another thing I have been thinking is that if the middle of the O-frame is filled with a differential in a housing, then we might not actually need the complete frame as a structural element (in case of a single output). I'd be really happy to have a variant where the end of the O-frame where there is no output would be simply cut off. It would be useful in live axles, where that part of the frame is just in the way of the steering linkage. Have you considered such a design? Could it be solid enough? Let me know if it's clear what I am trying to explain.

Wheel hubs

Thanks for the clarification about the bearings, I get it now. However, the issue about the pivot point of the U-joint that @Ryokeen mentions is really important. I am interested in AWD vehicles with significant suspension (and I guess many more people as well), so it is really important that the pivot point of the drive axle (U-joint) is in the same line as the steering/suspension pivot point. So the U-joint has to go 1 stud deeper in the wheel hub as far as I understand.

Motor

The motor / planetary reductor combo is really nice. If I understand correctly the motor's diameter is about 3 studs, so it fits into a 3x3 space, which is really useful. In fact it is critical for AWD vehicles, because that way it is possible to run a drive axle right under it, after minimal amount of gearing. Is this correct?

What I could not find out is the length of the motor / reductor combo. How many studs are the two together?

As for the mounting points. So those are pinholes in the front, right? It seems to me that more connection points could be added to the corners, making the front of it like in case of the PF L motor, so that it would be possible to mount it from the side as well.

Do you think such connection points could be added? That would make it quite a bit more versatile in mounting.

Another thing is the speed of the motor. For fast sports cars that's great, but another interesting use case of brushless motors is in crawlers. With modern ESCs, brushless motors can be run at very low speeds very precisely, while still being capable of quite good top speeds (for an off-roader). So for that use case, a 1000kv motor would be more than enough. With a 2s LiPo, that would mean about 7400 native RPM, which after 1:4 planetary reduction would result in about 1850 RPM output. That's like the fast output of a buggy motor, but hopefully more powerful (more torque). Something like that would be immensely useful for lego offroader builds, especially when combined with metal parts. Do you think that a variant like that could also be produced?

Thanks in advance!

Edited January 11 by gyenesvi

[Krzychups]

I have got the differential, brushless motor with planetary reduction and esc from ZENE. Both are very good!   

16 hours ago, Ryokeen said:

Another important bit about them is, they are problematic, if not unusable, in a driven high suspension travel use case. The pivot point of the hub no longer matches the pivot of an attached u-joint. It's around 1 stud offset. Sadly that prevents one from using those hubs in a fwd or awd vehicle.

I have got almost the same problem with 1/10 scale wheel hubs (look at the photo). In ZENE set there are metal shafts - I want to use them but I need cut them. 

20240111_183942 by Krzysztof Czech, on Flickr

6 hours ago, ZENE said:

After seeing the problem you raised, I discussed it with the designer and he told me that he had encountered a similar situation before and that cutting the length of the U-shaped universal joint could completely solve the problem. But I may need more description from you, please send me an email and we can discuss more, if you still need to solve it.

To solve the problem I need to cut the metal universal joints, right? I'm afraid this may not be enough because the metal part on the wheel hub (where the joint connects to the wheel hub) may snag on the centre of the metal joint.

20240111_184303 by Krzysztof Czech, on Flickr

[Ryokeen]

So this is how the 1:8 Hubs look with metal u-joints. The offset makes it very hard to make a stable driven and steered suspension as the upper and lower suspension arms can't be properly connected or will block the drive axle.

Cutting the u-joint isn't really an option as that would leave almost nothing of the side that needs to connect to the hub, so the torque applied to the wheel will act on very little material, around 1mm at most.

I think to solve that, a custom u-joint and maybe a different hub casing might be needed.

If one side of the u-joint would be an axle instead of an axle connector (where you can stick an axle in) that fits through the ball bearings it would be better.

Like this, that would solve the problem and also would unify the 1:8 and 1:10 hubs as a normal hex adapter could be used for RC tires and another adapter like the breakdisc with pinholes would work for lego compatible wheels.

 

[Krzychups]

20 minutes ago, Ryokeen said:

I think to solve that, a custom u-joint and maybe a different hub casing might be needed.

If one side of the u-joint would be an axle instead of an axle connector (where you can stick an axle in) that fits through the ball bearings it would be better.
 

 

I agree with you. I think the easiest way to solve the problem is to design and print a custom hub case. It is not a problem to design and print it for me (I have a 3d printer), but I would automatically lose my warranty on it.... 

[Lixander]

9 hours ago, ZENE said:

@Lixander I checked the size parameters of your generator's motor, and they don't match our planetary reducer, but the differential and transaxle are not involved in this compatibility issue.

I see. Thanks for the answer!

Also, if I cant fit the gear reductor on bigger motors........can I take the original setup to off-roading, maybe even some crawling? (I mean if the motor and ESC that are in the original setup will withstand the conditions of such usage, especially the ESC)

Edited January 11 by Lixander

[Ryokeen]

@gyenesvi

6 hours ago, gyenesvi said:

Another thing is the speed of the motor. For fast sports cars that's great, but another interesting use case of brushless motors is in crawlers. With modern ESCs, brushless motors can be run at very low speeds very precisely, while still being capable of quite good top speeds (for an off-roader).

Only partly true. Brushless come in 2 variants, sensorless and with sensors. Sensored motors have an additional pair of cables that tell the esc the position of the motor. Those are very sensitive to throttle and can be run at low rpms quite precisely.
The other type is sensorless, which i use and zene uses. Those "determine" the motor position by some sort of feedback loop over the 3 wires. Those motors have trouble at low rpm because the way of detecting the motor position works better at higher rpm.

So for a crawler you either use massive downgearing so the brushless motor can run at higher rpm without moving the vehicle much, or you use sensored brushless motors.

[gyenesvi]

6 minutes ago, Ryokeen said:

@gyenesvi

Only partly true. Brushless come in 2 variants, sensorless and with sensors. Sensored motors have an additional pair of cables that tell the esc the position of the motor. Those are very sensitive to throttle and can be run at low rpms quite precisely.
The other type is sensorless, which i use and zene uses. Those "determine" the motor position by some sort of feedback loop over the 3 wires. Those motors have trouble at low rpm because the way of detecting the motor position works better at higher rpm.

So for a crawler you either use massive downgearing so the brushless motor can run at higher rpm without moving the vehicle much, or you use sensored brushless motors.

I don't think this is the case anymore :) Some of the latest high-end ESCs can also control sensorless brushless motors really well (via that back EMF feedback loop), and that opens up new possibilities. It's just a matter of very well written firmware.

Here's an example (Furitek Lizard / Python):

https://furitek.com/products/furitek-python-40a-70a-brushed-brushless-esc-for-1-18-1-24-rc-crawlers

The same ESC can even control brushed motors! And it can be configured from a phone app (via Bluetooth connection) with all kinds of detailed settings. How cool is that!

Here's a review video of it, and I have seen quite a few more, all of them being blown by its performance.

 

Here's another promising one (Holmes Hobbies Crawlmaster):

https://holmeshobbies.com/speed-controllers/crawlmaster-mini-v3-rock-crawler-esc.html

[Ryokeen]

@gyenesvi
Yeah but the price is a bit higher for such esc. I mean 90bucks for a 40amps esc isn't cheap. The brushless i use would already get them to their limits.
But yes there are better esc ofc, it's just a matter of money you want to spend.

[gyenesvi]

40 minutes ago, Ryokeen said:

@gyenesvi
Yeah but the price is a bit higher for such esc. I mean 90bucks for a 40amps esc isn't cheap. The brushless i use would already get them to their limits.
But yes there are better esc ofc, it's just a matter of money you want to spend.

Sorry, I think I linked an older one, the latest one (the one in the video, Furitek Python X) is actually 80 amps continuous, same price:

https://furitek.com/products/furitek-python-x-80a-120a-brushed-brushless-esc-for-1-10-rc-crawlers-with-bluetooth

[gyenesvi]

4 hours ago, Ryokeen said:

The offset makes it very hard to make a stable driven and steered suspension as the upper and lower suspension arms can't be properly connected or will block the drive axle.

I think the problem with the drive axle into the steered hub is even more complicated. Even if it is redesigned in some way that allows a U-joint to be pushed all the way into the hub so that the pivot point falls in the same line as the steering/suspension pivot, there will be another problem: the U-joint, as it articulates up/down with suspension, will rub the pinhole above/below it, and will eventually be blocked. The only way to solve it is to allow more space there for the U-joint, but that excludes the use of a pinhole (the pin itself would collide with the U-joint). This is exactly the reason why lego hubs are made with CV joints instead of U-joints, and why the latest variants with the new heavy duty large CV-joints don't have a pinhole there, but instead have an integrated towball, because that way there can be space left for the joint. And there's no better solution than that. So unfortunately, this seems to be a half baked product, because the driven case is the one that's really interesting in case of RC and metal parts.

This problem of misaligned joints is even present in case of RWD sports cars, if I understand correctly (based on the image of @Krzychups)? I guess it only works because the suspension is minimal in those? What I don't get is how the axle lengths work out in that case? Seems like a bit more than half a stud offset to me, that would require axle of some half studs.. Maybe a 1 stud shorter axle works there?

Edited January 12 by gyenesvi

[Ryokeen]

@Gyenesvi ah that new one looks nice. I'm just curious how hot those will get as they seem to have almost no cooling.

And you're right any u-joint would rub there. So a bug with integrated towballs for more space and a proper cv joint would be neccessary. That leaves us with a new needed hub, a RC car like cv-joint and an adapter part for the male cv to axle form.

About the RWD sports cars, from my experiments, a suspension travel of 2 studs, one up, one down, so 2 in total, is possible.
I actually have 1 stud of fixed travel in my trophy truck rear axle. It's a live axle but the drivetrain goes down 1 stud and that works fine.
It worked okayish with a 5L axle between the u-joints, but had about 2mm of play.

[everybrickasculpture]

I will write more about my experiences with using Zene's brushless kits later, but I will say that I'm pretty happy with the parts so far.  The integrated planetary reduction motor is really quite nice.  I would recommend picking up a kit from them if you're curious.  Here are the three cars that I've finished so far.

 

 

Edited January 12 by everybrickasculpture
image format

[Krzychups]

6 hours ago, gyenesvi said:

I guess it only works because the suspension is minimal in those? 

Suspension doesn't have to be minimal but not too much either

 

6 hours ago, gyenesvi said:

 What I don't get is how the axle lengths work out in that case? Seems like a bit more than half a stud offset to me, that would require axle of some half studs.. Maybe a 1 stud shorter axle works there?

It's 0.5 offset. The 6.5 studs axle fits perfectly on this suspension. I want to use the metal axle 7L, and I need to cut it down by 0.5 studs. I have tried using 6 studs axles in the suspension - they fit, but how well this will work on offroad/onroad I don't know. Look at the photo.

20240112_070231 by Krzysztof Czech, on Flickr

20240112_070305 by Krzysztof Czech, on Flickr

[Krxlion]

11 hours ago, gyenesvi said:

I don't think this is the case anymore :) Some of the latest high-end ESCs can also control sensorless brushless motors really well (via that back EMF feedback loop), and that opens up new possibilities. It's just a matter of very well written firmware.

Here's an example (Furitek Lizard / Python):

https://furitek.com/products/furitek-python-40a-70a-brushed-brushless-esc-for-1-18-1-24-rc-crawlers

The same ESC can even control brushed motors! And it can be configured from a phone app (via Bluetooth connection) with all kinds of detailed settings. How cool is that!

Here's a review video of it, and I have seen quite a few more, all of them being blown by its performance.

 

Here's another promising one (Holmes Hobbies Crawlmaster):

https://holmeshobbies.com/speed-controllers/crawlmaster-mini-v3-rock-crawler-esc.html

That is some good research @gyenesvi. I would really like to test it out with brushless motors I own. I am just wondering if transmitter that I have is capable of handling all this functionality or does I need to change the whole setup (I am using DumboRC X6FG).

[gyenesvi]

6 hours ago, Krxlion said:

That is some good research @gyenesvi. I would really like to test it out with brushless motors I own. I am just wondering if transmitter that I have is capable of handling all this functionality or does I need to change the whole setup (I am using DumboRC X6FG).

I think it can run with any transmitter, that's independent. You can even set the BEC voltage (from phone config) that the receiver gets, but default 5V should be good for most cases.

14 hours ago, Ryokeen said:

@Gyenesvi ah that new one looks nice. I'm just curious how hot those will get as they seem to have almost no cooling.

As far as I have heard from RC guys using these, it does not really heat up :) And it does not consume much power, I guess because it's well optimized. People are using really small 450mAh batteries to run 2kg crawler rigs (with powerful motors and servos) for 45 mins.

9 hours ago, Krzychups said:

It's 0.5 offset. The 6.5 studs axle fits perfectly on this suspension. I want to use the metal axle 7L, and I need to cut it down by 0.5 studs. I have tried using 6 studs axles in the suspension - they fit, but how well this will work on offroad/onroad I don't know. Look at the photo.

Well that's the problem, if you need to start cutting metal axles to use it then it's not really well though out. I think this really needs to be revised, because even if it works more or less, in scenarios where the suspension angle is not high, it won't work for off-road case, the geometry will be really off compared to the suspension.