TwistedAndes - Ver Mensaje Individual

saggcl · 19-05-2012, 14:41:32

On the rear steer I also see no way to make the rear self center with a manual valve.
I do plenty of rear steer systems and the guys that have run them say it is one of those things that after having it you never knew how they did with out. I do feel this is more critical for bigger rigs because it may be harder to see everything.
The system can get a little expensice but it ends up around 600$ on top of what parts you need anyways. there is some corners that can be cut though as well to get it down more. If anyone is interested give me a call and I can discuss it, rather than sit and pimp here.

Originally Posted by AmundI've put some thoughts into this (but warning: they are just thoughts, no experience yet). I'm thinking some caster is good to keep the rear wheels from wobbling or making the rear-end drift/steer etc if you drive straigt at a little speed, as there will probably some give in bolts, cyl, hydro lines, fluid etc.

Over here it looks like all the comp rigs with rear steering use a small joystick valve for the rear, then a button for it to return to center. I don't think I'll like running that, so I thought up something better (but mainly cheaper). Will need a bit of rods and joints though:

Put in a drag link like you would if you were to run a steering box. Put your hydraulic two-way spring loaded valve on a Watt-link with the drag link on one side, lever on the other (fancy word for a bar with three holes: drag link on one end, valve in center, and connect lever to other end). I don't know if that explanation is understandable, but the point is that you'll get a lever with absolute position of the wheels (instead of relative with a normal set up). I.e. when you push the lever forward (for steering left) the valve will open in that direction, the cylinder (on the axle) turns the wheels, and the lever will follow. Let go and it stops. Make a little tick or something so you can feel center in the lever. I think that'll give me a much better feel and control over the rear wheels as I drive.
Hey now that you got your star how about a diagram!

Originally Posted by JRHey Sean, I need to talk to you about a rear ram when you have time.

Anything you want to tell us JR? You coming back to AZ this year?

Originally Posted by CJ LagosI use an orbital with the power beyond port and a hand valve between the seats. The setup is definately bad ass but on my next one I think I'll look harder at a 2nd pump to keep the two systems separate.

Mine definately does not self-center, and it really doesn't bother me. I just turn back and line the tires up by eye. I've gotten good enough with it that I can do this while moving now, at first it took a while. Rear steer is a lot harder than it looks! I very rarely have a problem with the rear tires moving on their own, they hydraulics hold them in place well. My hand valve is open center. If you drive on the road you can tell that the tires bleed off to one side and slowly turn themselves, but I have discovered I can very quickly tap the hand valve even at high speeds to re-adjust. On the trails, you are constantly turning the tires that is never an issue. I have a feeling this quirk stems from the single ended cylinder, my next one will have a double ended on both ends.

I didn't measure caster, I set the pinion angle. I don't think it matters as much because there can't be the return to center with the hand valve.

If I was racing, the self-centering would be more of an issue. I want to put a light on the dash to indicate when they are centered but it just isn't that important to me.

CJ

Ditto....I've been running the same type set-up for two years now and could never go back to front only steering. I fought reservoir volume issues initially and ended up with a double tank set-up that resolved the overflow probs. A fair amount of heat builds up in mine which seems to be controlled well enough by a LARGE tube type tranny cooler up front. You really get a feel for the rears position after a bit of use...you'll feel even a slight bit of crab when your running fast or slow and a quick tap on the joystick will bring you back straight with the world without looking. If you've run cutting brakes before (sandrails, comp rigs?) the quot;second naturequot; feel is similar.

i've only had my rear steer rig on the trail once since building it and by the end of the weekend, i could feel even a little bit of crab walk. just tap the joystick and i'd be driving straight again. a sensing ram is an option but considering the added $600-$700 cost, i can already tell that i just don't need it. it is very easy to tell where the rear wheels are without looking. and to me, it doesn't seem that critical. hell, i don't drive on the street and 40 mph is very uncommon.
besides, it would seem cumbersome to have to quot;holdquot; the joystick in place to keep it from self centering when i didn't want it too. na mean?

19-05-2012, 14:41:32	#9
saggcl Senior Member Top 1000 Fecha de Ingreso: Oct 2007 Ubicación: Santiago Edad: 46 Mensajes: 3.314	Re: Caster en Rear Steering ??? On the rear steer I also see no way to make the rear self center with a manual valve. I do plenty of rear steer systems and the guys that have run them say it is one of those things that after having it you never knew how they did with out. I do feel this is more critical for bigger rigs because it may be harder to see everything. The system can get a little expensice but it ends up around 600$ on top of what parts you need anyways. there is some corners that can be cut though as well to get it down more. If anyone is interested give me a call and I can discuss it, rather than sit and pimp here. Originally Posted by AmundI've put some thoughts into this (but warning: they are just thoughts, no experience yet). I'm thinking some caster is good to keep the rear wheels from wobbling or making the rear-end drift/steer etc if you drive straigt at a little speed, as there will probably some give in bolts, cyl, hydro lines, fluid etc. Over here it looks like all the comp rigs with rear steering use a small joystick valve for the rear, then a button for it to return to center. I don't think I'll like running that, so I thought up something better (but mainly cheaper). Will need a bit of rods and joints though: Put in a drag link like you would if you were to run a steering box. Put your hydraulic two-way spring loaded valve on a Watt-link with the drag link on one side, lever on the other (fancy word for a bar with three holes: drag link on one end, valve in center, and connect lever to other end). I don't know if that explanation is understandable, but the point is that you'll get a lever with absolute position of the wheels (instead of relative with a normal set up). I.e. when you push the lever forward (for steering left) the valve will open in that direction, the cylinder (on the axle) turns the wheels, and the lever will follow. Let go and it stops. Make a little tick or something so you can feel center in the lever. I think that'll give me a much better feel and control over the rear wheels as I drive. Hey now that you got your star how about a diagram! Originally Posted by JRHey Sean, I need to talk to you about a rear ram when you have time. Anything you want to tell us JR? You coming back to AZ this year? Originally Posted by CJ LagosI use an orbital with the power beyond port and a hand valve between the seats. The setup is definately bad ass but on my next one I think I'll look harder at a 2nd pump to keep the two systems separate. Mine definately does not self-center, and it really doesn't bother me. I just turn back and line the tires up by eye. I've gotten good enough with it that I can do this while moving now, at first it took a while. Rear steer is a lot harder than it looks! I very rarely have a problem with the rear tires moving on their own, they hydraulics hold them in place well. My hand valve is open center. If you drive on the road you can tell that the tires bleed off to one side and slowly turn themselves, but I have discovered I can very quickly tap the hand valve even at high speeds to re-adjust. On the trails, you are constantly turning the tires that is never an issue. I have a feeling this quirk stems from the single ended cylinder, my next one will have a double ended on both ends. I didn't measure caster, I set the pinion angle. I don't think it matters as much because there can't be the return to center with the hand valve. If I was racing, the self-centering would be more of an issue. I want to put a light on the dash to indicate when they are centered but it just isn't that important to me. CJ Ditto....I've been running the same type set-up for two years now and could never go back to front only steering. I fought reservoir volume issues initially and ended up with a double tank set-up that resolved the overflow probs. A fair amount of heat builds up in mine which seems to be controlled well enough by a LARGE tube type tranny cooler up front. You really get a feel for the rears position after a bit of use...you'll feel even a slight bit of crab when your running fast or slow and a quick tap on the joystick will bring you back straight with the world without looking. If you've run cutting brakes before (sandrails, comp rigs?) the quot;second naturequot; feel is similar. i've only had my rear steer rig on the trail once since building it and by the end of the weekend, i could feel even a little bit of crab walk. just tap the joystick and i'd be driving straight again. a sensing ram is an option but considering the added $600-$700 cost, i can already tell that i just don't need it. it is very easy to tell where the rear wheels are without looking. and to me, it doesn't seem that critical. hell, i don't drive on the street and 40 mph is very uncommon. besides, it would seem cumbersome to have to quot;holdquot; the joystick in place to keep it from self centering when i didn't want it too. na mean?