I’m a little worried about the cost coming from a machine shop in super low quantities hahaha. I’ll need to see what a place like jlcpcb would quote. Perhaps for 3d printing steel if it’s cheaper than machining
2 Likes
Oh, true, this is like a perfect application for that. Very curious what the quote looks like
2 Likes
I haven’t been reading closely but I did just come back from a CNC lathe. What do you need made?
1 Like
I want to experiment with bushing washers that are not flat, like these.
So far I’ve experimented with ones like the first picture here and I really liked what I felt. This can be used to tweak straight line stability separately from how supportive the bushing feels in turns, and potentially even tweak how the bushing feels at certain point in the turn.
I would like to get these shapes made in a few different variations to play with and compare how each of them feel.
Been running the first type on these pictures for the last two sessions on double chubbies and they made the board feel almost as stable in the middle as double chubbies did on flat washers which was exceptional stability, while turning nearly as well as chubby/barrel on flat washers, which was a very turny setup even by my standards.
@tuckjohn I’ve actually just quoted it on jlcpcb’s metal SLM 3d print service and it’s 8$ per piece printed from 316 which is a great price. Machined would be 25$ per piece. That would be fine if I know what I want exactly but for getting like 10-15 different pieces just to experiment with what works, that’s quite steep.
8 Likes
I assume the curved face of these washers goes against the bushing, right? Have you noticed bushings getting permanently deformed by the cone shape digging into them? Are you worried it would be possible to split a bushing by tightening the washer too hard and the cone stretching the bushing ID open?
Correct, the curved face goes against the bushing! Actually I’ve been running my setup like this for a long time, then I decided to “fix” it and swapped the bent washer to a new flat washer. After that the ride feel dramatically changed and I only just figured out why.
After a lot of use like this one my bushings has a permanent deformation as it sort of adapted to the washer, but much less severe than the angle of the washer. That doesn’t really seem to affect anything though. No signs of cracking on any of my WFB bushings. Different formulas may fair worse.
Omg yet another parameter to optimize…!!
Wild. the possibility space is so huge😰
Could even optimize it so toeside/heelside have different shapes, if there was a way to keep it from rotating… too much to think about haha.
How’re your 3D printed ones holding up?
3 Likes
It would be cool to see the diameter of the bushing washers be larger than the actual bushing diameter.
2 Likes
Agreed
Know anyone with experience making precise washer-like bushing interfacing parts?
1 Like
Would 6061 aluminum ones hold up or do they need to be steel?
3 Likes
As a completely uneducated person, I feel like aluminum would be more than sufficient.
As it’s just acting as spacer between the actual washer and the bushing it’s working so far. Only had two sessions on them yet though.
Now I have the boardside washer being the bent steel washer and the roadside washer has the 3D printed cone on it. I like the feel, but it’s definitely closer to a short track setup than just one of the washers being cone and the other flat. So we will see what I’ll end up running at esk8con. If the turny part is super tight it might stay as is, otherwise I may run the bent washer + a flat washer. Also depends on how much the straights would end up scaring me.
No clue. Would probably need to be thicker than it is now. I bent flat washers from steel from regular usage, the more complex geometry might give it enough strength that alu is fine though
2 Likes
I wonder if this is only working well because the Dualities put basically zero percent of your weight into the bushing stack (vs normal RKP trucks where you’re constantly standing on the bushing stack). I could see this not being a noticeable difference on RKP because it would just permanently deform the bushing to match the washer very quickly, requiring you to tighten your kingpin to take up the slack. Just a thought!
8 Likes
Very cool. I’m curious, have you needed to use shorter bushings to accommodate the spacers, and does that reduce to total lean available? Do you preload the bushings to squish into the spacers, or is there a gap around the outside when the trucks are neutral?
2 Likes
My guess is the washer would be slightly thicker than standard. Which would add more preload.
Or it could by much thicker and we could move to standard height bushings. 0.6.
My guess is slightly thicker for a touch more preload which will help with the stable center, but keep the turn nice and responsive.
2 Likes
I’m also wondering about these questions. Maybe these cone washer experiments deserve their own thread?
4 Likes
Welp the cone washer experiments might not be a good idea, or at least definitely not for both sides…
To get the feel right the bushings needed to be tightened until they were close to taking the shape of the washer to begin with, and this required a fair bit more preload then what would be considered usual, that said, I wouldn’t say it’s an extreme amount.
I snapped a kingpin today. I’m thinking running chubbies over the 25 degree lean (ie, removed lean stoppers) might have accumulated stress on the kingpin over time, as the sides of the bushings hit the sides of the bushing seat, which causes extra forces. I was running my chubbies to the same lean angle since last May…
But snapping a kingpin on the second session of having a cone washer over both bushings, I don’t think it’s coincidence that they snapped now and not before.
Alternatively this might be proof that dualities need lean stoppers to run chubbies safely for extensive periods of time, but I still think the timing is no coincidence.
10 Likes
Also I am pretty sure this is the one and only broken kingpin on dualities so far and I was definitely pushing it way beyond what’s intended. With the kingpins surviving so much of my extra abusive setup for so long, I wouldn’t worry about ever breaking it on a normal setup.
Removing lean stoppers from a truck that has chubbies in it is definitely a “do at your own risk” thing. And the cone washers also it turns out…
One thing that I haven’t tried yet on Dualities but in theory might feel similar to cone washers without the unnecessary risk and weird bushing deformation is running cup washers that are meant for cone bushings and flipping them over.
Like this
2 Likes
What was it like when it snapped?
4 Likes
7 Likes