Thats crazy, mine loosed up within 30 mins or so. Its almost like Im riding a push board.
2 Likes
One of mine feels like this too but the other is still dragging. Maybe Iāll take a short videoā¦ 
They are very fun to ride though, the torque is the most I had till now. The diyeboard hubs with replaceable sleeves, also 75KV, were not far away but became really hot doing my usual testing route. The torque while on flat is really funny, canāt wait to get them a bit faster with 12s but even at 10s @ 40kph they are a lot of fun 
At the moment power consumption is a bit high but thats because of the coasting issue and will hopefully soon be gone The wheels ride very smooth, similar to my MBS Landwheel crossover but those were a bit better dealing with debris on the road.
3 Likes
Guys I find the Paris 195 and stock rear truck not wide enough for Hummie deck mounted drop through. It rubs a little bit and never bit but I would prefer a bit better turning. I am planning to make a few custom axle bolt out of 7075 Alu for SR. I was looking for somewhere to CNC them but itās seems to be too expensive. So the plan of action is try to do it myself at a makerspace. This is the first time I will be using a Lathe. Wish me GL. Also who is interested in a pair if this goes well? Itās a 4 steps diameter axle bolt 
But in aluminum? Wonāt u need steel?
1 Like
For axles steel should definitely be used. Aluminium is fine for prototyping, but I would never ride them on a daily basis.
I ran a FEA and the few material I found usable are 7075 Alu and 4043 steel. Iāll go with the 7075 first and see if itās gonna hold up. FEA was ran with a 150kg load on 1 bolt so Iām definitely not that heavy. Iāll let you guys know how it goes.
Maybe the load will be much more than ur weight in use if u hit a big bump. Iād u get it in even mild steel be safer n just bend
7075 is stronger than 1018. From I have read. Iāll run FEA again.
1 Like
What is the ā¦forget the term but the point at which fatigue occurs? Aluminum will be much lower while steel can be repeatedly stressed like a spring with no deterioration
2 Likes
yield strength.
I mean the point at which no deformation occurs but microscopic stress n weakening. So no yielding happening and w the micro fracture leading to a true snap n not even a deformation
Titanium makes more sense?
Titanium is expensive, hard to machine, weaker than steel.
about x10 as expensive as aluminium
Titanium(Grade 5+) is stronger than some steels, but kingpin material is hardened, what is the grade again?
Fatigue limit
This value is the maximum stress which can be applied over an infinite number of cycles. The fatigue limit for steel is typically 35 to 60% of the tensile strength of the material. Fatigue strength is a term applied for nonferrous metals and alloys (Al, Cu, Mg) which do not have a fatigue limit .
Despite this wiki quote ti does have a fatigue limit too. But not aluminum I believe. So every stress of aluminum is further towards a snap while ti and steel, if under their limit can take the stress infinitely. And then rather have a yield than a break and the softer steels seem safest in a way as theyād just bend. And much easier to machine n cheap.
3 Likes
@Winfly I was going to say exactly what Hummie said
Your aluminum axle would definitely hold the load, for a short while
Aluminum have a finite lifespan under cyclic loading, and opposite than steel, it does not have a minimum stress level that guarantee infinite fatigue life
Titanium appears to be better than aluminum, but Iāve never looked deep into it
Bottom line, donāt go aluminum unless you want an unexpected faceplant
An important observations, in most cases the best material is not the best for the application most aplications, thatās why you see lot of counter intuitive (at first glance ) material choices
2 Likes
Iām looking at some 4340 chromoly or 1144 Steal atm. McMaster has 1140 in stock and advertised as high strength and easily machined so I guess Iāll try those first.
1 Like
Strangely yesterday evening the loose one totally locked up, had to turn it with full force, now its back to the same state as the other, so both are not so free spinning now 
I ordered the toolset needed to have a look inside so maybe that will enlighten me 
1 Like
Only thing I can think of something mustāve gotten in a hole.