double ended hydraulic cylinder

[bigdogrod]

not sure what to call it, but does anybody make a cylinder that both ends extend from the center? or the ram slides through the center. have a hairbrained idea that i could use it on my monster trucks like the real ones have.

https://custom4x4parts.com/product/full-hydro-steering-cylinder/

[ddmckee54]

Not that hairbrained of an idea, you'd just have to custom build the dual ended cylinder. To get proportional steering you'd have to build a feedback system so that the controls would know the position of the ram in the cylinder.

It'd be slower than a servo controlled steering setup. But you wouldn't have to worry about shock load from hitting an obstacle at speed ripping the gears out of the steering servo. You might blow a hose, but stripped servo gears would be a thing of the past.

Don

[frizzen]

They exist, but it's probably going to be a scratch build, or special order from someone that makes cylinders?

'Double ended' or 'double acting' seem to be your keywords.

Are you going to run it with a hydro pump and valve block, or make a bracket with a pair of cylinders mounted opposite each other with a servo directly giving fluid & space?

[bigdogrod]

frizzen, that's not a bad idea, i was thinking of a cylinder with 2 ends that move and the center stays still, but 2 single cylinders mounted to a central pin might work as well, although more complicated


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[Jared]

I think Frizzen was suggesting instead of using a pump driven system, you could use a servo pushing on a separate cylinder to drive the steering cylinder/s, sort of a master and slave setup. They would have to be equal displacement, or close to it. It would in effect be a remote mounted steering servo. Bleeding the air might be an issue, though.

Using two steering cylinders is certainly possible, though. I built a hydrostatic steering system on a 1:1 Farmall tractor with two cylinders that I'm very happy with.

[bigdogrod]

not a bad idea either, but takes up a lot of room. i saw one guy did cable steering that looks pretty realistic

[frizzen]

Yeah, i had just ment a remote steering servo moving a hydro push/push system tucked up in chassis, with lines down to the steering cyl. (Plus probably a reservor, bleeders.) Instead of the full pump and block setup like the excavators

I almost suggested Axle mounting 2 cylinders fixed to like a link mounting plate or something would work great too and easier to get parts. I didn't know if you could get small enough cyl/big enough axle to actually work ok

[Hemi1966]

This is how I did it in my grader


https://i.postimg.cc/2ywvPpKw/IMG_0762.jpg (https://postimg.cc/fSVJ9PZt)

[bigdogrod]

that looks awesome, but very few people have your skills... lol i've seen your builds.

[mbudz10]

I built one earlier this week but need to finish designing a low profile pump/valve/reservoir combo to fit into a crawler I am building. So far though it is very strong with other pumps and valves I have for my excavators. I will post pics and details as soon as I am done building the pump and such. Below are some of the ways to make a hydro and cable steering setup from youtube.


Hydro static https://www.youtube.com/watch?v=VbCCDVEKP2k

Cable https://www.youtube.com/watch?v=QEgDi36XkvA&t=1s