That’s a bit too complicated, you’re thinking of a recycling hydraulic system like on machines. Think of it more like a brake. 1 sealed plunger piston, 1 actuator (ring piston).
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how much force is this really going to generate without any sort of boost? Last I checked motorcycles dont use boosters.
WEre you thinking of rigging this up to a hand held mechanical pump? like literally a break lever?
No, it’s based on surface area of the pistons. The ring piston is going to have a high surface area (lets say for guessing, the outer diameter of the ring piston is 25mm and the inner hole is 15mm. That gives us 2100mm squared of surface area. Now lets say there is an 8mm master cylinder piston, at 200mm squared surface area. That gives us over 10x pressure ratio. So if we have a linear worm gear servo capable of pushing 100 lbs, then there is half a ton of pressure at the kingpin.
Drop the master piston size down to 5mm, and now you have over 25x the pressure ratio. The math here is finding a reasonable size actuator, then sizing a piston size to give us the desired pressure at the kingpin
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I see Ok,
let me sketch that system up
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Btw I just made up those numbers, I don’t know off the top of my head the diameter of a kingpin or bushings
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I made this post a while ago, I never got around to it but there’s some information you can look at on it that might be of some help
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are the magnitudes roughly on par?
Yes, hydraulics are cool that way, it works whether its as small as a bicycle brake or moving boulders with an excavator. Just simple leverage arm math.
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what about this as a master (its a slave here)
Generally speaking this cylinders work both ways, its just about making the area ratios work ?
It could work, but the exact diameter might not for this purpose. Since the ring piston is very specifically sized to truck kingpins, the master would ideally be sized appropriately for the actuator strength with a safety margin in mind. Whoever has a lathe to turn the ring piston would also be easily able to make the master piston too, as it would be the same thing: rod with o-ring or Q ring, hollow cylinder with a fitting on the end.
Im not so sure about this, Only the inner diameter is fixed to the diameter of the kingpin.
you could fatten the ring as long as the hollow diameter remains the same
exactly that. Perhaps not a stepper/rack because that requires power to hold position.
Like a smaller version of this will work. No power is required until a change in pressure is needed. Otherwise system draws 0 power to hold a clamp pressure.
Yes, outer diameter can be fattened, but only to an extent before it could collide or interfere with the hanger. so not infinitely adjustable.
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trouble with all this is is a complete system bring up.
theres nothing quite like it on the master side.
The hydraulic systems of this size I know of are almost always hand operated.
Basically we are talking mountain bike brake sizes
Modifying a brake lever from a mountain bike seems reasonable and a more assured way to a proof of concept
I’ve taken those apart too and it is a simple rod with an O ring on it with holes in the cylinder to grab oil from a small reservoir. I can make more detailed cad files for these parts and make them easy to machine on a lathe if someone actually wants to try to make it.
Something like this attached to a bike brake lever?
Changed Link, its still not a great option due to the low strength
alternatively and much cheaper
I personally don’t like the idea of tightening kingpin to increase stability… bushings can only go so loose or so tight before bad things happen on either end of the spectrum. Plus, ime tight trucks do not always equal stability… and I’d rather not sacrafice manuverability for the illusion of stability with tighter trucks… better to use lower rebound bushings to begin with. Either way I’d love to see things experimented with, and I’m sure I won’t disuade anyone from trying new things just getting my thoughts out.
Worm gear on an adjustable baseplate would be cool, but it would be tough finding the right duro bushings to work well across the range of angles since the higher stability lower angles will feel so much softer with the same bushings.
IMO, the best course of action is an adjustable steering damper, something that can be adjusted on the fly by speed from the vesc. On the rear truck- for me, any dampers on the front made for a horrrrible ride.
The steering damper on the rear of this setup worked wonders to eliminate speed wobble, something like this that would adjust with speed would be my perfect solution- set your angles, bushing setup, and just have a stable ride at speed and all the agility and carving at low speed. Only thing this was lacking was that if I was to go real fast I’d crank it a few turns first.
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I value your input, but thats not really whats trying to be achieved here.
You raise valid points, and most of them have been discussed and explained
bushings: we’re using bushings specificly designed to work across many compression factrs
Steering dampener: does not provide the same effect (works on rate of change of lean angle, rather than proportional)
Rear/Front: the ring pistol solution can be applied to one (most likely both)
I totally get what your saying, but Im hoping were past arguing the merits of this, and just sorta going for a proof of concept.
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