Ryokeen

That's one of the reasons why no hobby grade RC car uses glued in bearings. It just won't hold. What is done there is that there is a small notch between the bearings so that the outer one can't slide in and the inner one can't slide out. The outer bearing get's pressed in by the hex adapter and the wheel, the inner bearing get's pulled outwards by the thicker part of the axle(in the metal U-Joint atempt the small splint thought the joint and axle). Sometimes along with the notch, different outer diameters for inner and outer bearings are differend aswell. The inner bearing got the bigger outer diameter to prevent movement. But anyways almost always 2 bearings are used with a notch(small inside "ring" in the wheelhub) to limit movement of the bearings. But fitting that in the space of a lego wheelhub means very thin bearings.

So far i've had good results with some lithium grease. Used that for some gears and small turn tables and so far, after a year, nothing bad happened. Edit: Silicon Oils(low viscosity) for RC shocks work aswell. They are also unlikly to have any effect on plastics or rubber as they else would cause problems with the seals an other parts.

@Krzychups Nice done there, looking forward to it. Side note. I have those HSP parts here, they do fit, but are a bit higher than Lego pins, means the ballcup won't be exactly one stud above like with lego towball pins And they do hold, but not as much as lego parts, so you need to connec the lower and upper arms, which can be a problem as they might be 1/4 stud more apart than they should be

@aFrInaTi0n Nope think just the 8t gear. The 12t half bevel ones might be a different aluminium alloy but on their site it's just aluminium, where as the 8t is declared as stainless steel.

@vergogneless Nice order, have fun :) 2 advices..some locktite for the 2L 3L metal pin replacements can be usefull if you don't want the screw to get loose without having it screw in to much. 2nd..the 8t gears are from stainless steel, which is harder than the aluminium (12t, 24t and so on) so it might erode the aluminium gears(especially without lube). That actually happend when i used an 8t/24t downgearing. Fine aluminum dust everywhere.

Slight correction, discardged is mostly around 3.2-3.4V depending on how low you want to got(should not go below 3.2V). 3.7V is commonly used as a storage voltage as it's neither full nor empty.

@aFrInaTi0n Had that with one 5L liftarm from them aswell and in the process it got slighly bend. So i looked and the bearings they use are most likly "Miniatur Kugellager Zoll / Inch R156 ZZ / 2Z 4.762 x 7.938 x 3.175 mm". A good sorted store for bearings(kugellager-express) should have them. Just in case you need spare ones or want to pack some in printed/modifiered brick parts.

@gyenesvi The u-joints from them are shorter than regular ones. By about 3/4 stud in total. So the hub works well with their u-joint others will have an offset.

Thought the same, i have some RC cars(and lego hybrids) that can drive 50km/h+ and they are waaay faster than shown here. But yea a crashtest is pretty pointless unless one is still designing an RC car and wants to know the weak spots. I doubt that. I had a crash at 20km/h , not even frontal. A lot of pins broke/bent, same for Liftarms and axles. Panels are quite stable though

You do know that Lego themselfs use strings and used to have customers cut pneumatic hoses ? Anyways, great idea on such a small space :)

@NoEXIST so you have 2-3 Motors per PF Output. Keep in mind that Motors draw more current while starting and that with such an amount of motors the voltage could drop quite a lot in the frist few moments. I don't think smaller ESC have that much capacitor storage to compensate for that.

I just meaned that milling a lets say 2mm in diameter and 8mm in depth shape(4 times the corners of the axlehole adapter) can get problematic :) that's all

Most motor shafts are D shaped so 2 maggot screws won't do much, might even make it worse. Think of it that way, the side that got the hole for the screw is also lighter as it got the hole. The tiny imbalance of the weight of the screw vs the material that would be there in the adapter is neglectable. That's why you screw on the motor and why the motos have longer shafts. Also the + shape in the adapter is nice and Zene does it like that, but when i talked to some cnc operators they told me that it's actually not easy to make with the depth of 8mm(1 stud). They suggested either use electrode erosion(expensive) or use another shape. That's why my metal wheelhub adapters have an axle part. The lego axle to axle adapters are actually quite strong, i use them in my main driveshaft to connect metal axles and not one broke so far. All in all nice work so far :)

That's a 3mm fibre optic cable for diy projects. A bit more milky because it's one that has a certain amount of light going out along the cable. Not the tightest fit with lego pins(as they have 3.12 something mm diameter) but worked well in my Delorean. And i assume it's a lot cheaper than anything from lego (around 8€ per meter)

Good thing is, the fibre optics cables look like they can be easily replaced by 3rd party parts. In case one needs other lenghts, or they get damaged.