Alternative hydraulic hand pump.

[GENX]

I was considering utilizing the suspension compression hydraulic circuit to make my truck kneel ( install a second set on the rear) so that I could hook up stilts to the habitat and drive out from under it.. hook up to a flatbed and then raise truck (unkneel).. but I think I may be too ambitious on this considering I could probably buy a trailer and get in effect a "flatbed" for my purposes.
But let's say I incorporate into the design a habitat that could be equipped with side attachment points for stilts... does anyone know the PSI on the kneeling circuit?

 

[GENX]

Saw this video of RVGlobeTrekker navigating some deep holes and was observing the tire mounted on top.
Also was inspecting torsion on the sub frame, the compactness of the habitat. Gotta say I was quite impressed. Now this is not to say that the tire on top isn't a ticking timebomb, but thought it worthy to throw it out into the discussion here on the hydraulic portion of cab tilt / Tire loading on vehicle rack..... it didn't seem to introduce as much instability due to the weight as I thought when he was navigating some of the terrain. Of course going slow is pretty key and when the velocities get up the force will be multiplied.

 

[coachgeo]

I was considering utilizing the suspension compression hydraulic circuit to make my truck kneel

was thinking a kneeling system too..... honestly though might be less expensive, easier to install say a 2.5k small UTV or boat? winch on all 4 corners; winch on chassis and cable attached to the axle, for squatting the truck. If you dont want to stop and crawl under for squating... put a pulley on the cable-- spring attached to pulley on one side and truck on other...... to pull some slack in cable, back out of the way..... enough cable slack to allow for full droop of each axle end without loosing the spring...... yet enough to keep pulling when in full stuff too.. maybe two springs??? not worked that part out yet.

each corner controllable in cab could have advantages too (side hilling for example)

 

[GENX]

Might be easier to engineer beefy jack stands.
But I thought this way a guy could pour sonotube to the height he needed to create a resting pad in between habitat flat bed swaps.
Could make a nice guest suite too in between excursions.

 

[Ronmar]

Typical ag/light industrial hydraulics run under 2500PSI. The cylinders are sized to deliver the required force within the max system pressures allowed. I think those are about 2.5” cylinders, with a 1“ rod? With 2500PSI, they would push with 12,300# and pull with around 10,300# of force respectively.

I did cycle my cab hydraulic system before I removed it but did not measure the pressure required to compress the suspension. It is very easy to measure that system hydraulic pressure for anyone who still has the kneeling system installed, as both pump outputs share the same line into the hydraulic manifold. You simply remove the output line off of the hand pump and install a JIC-4 to 1/4NPT adapter and attach a hydraulic gauge like in this video.

 

[Third From Texas]

Saw this video of RVGlobeTrekker navigating some deep holes and was observing the tire mounted on top.

Oh, people have done it. People do a lot of things with these trucks. Like reduce the departure angle and then go try to tear the hab off using terrain for grins.

But it will fit up top. It will also fit bolted to either side, bolted to the front, slung underneath the transfer case. or mounted on top of the habitat. But there are reasons you might not want to use those methods.



I'm just saying that I certainly wouldn't add another million pounds of force above the CoG.

ymmv

 

[Ronmar]

Was re-visiting the spare location as it is getting close to time to make those final design decisions. If I am willing to lower the rear exit angle to 30deg, I can get the spare tucked up under the rear end, with all its weight suspended from the main truck frame structure. In a captive spring design, the weight of the habitat is a prime factor in how much torsion it will have to withstand when the main frame twists out from under it when passing over rough terrain. The spare tire and a 50 gal water tank are the two largest single masses I am dealing with. The water tank I placed over the point of solid attachment to the frame, but the spare wound up being at the worst possible location at the opposite end of the habitat…

This solves that problem, but creates a design compromise or two, such as covering the rear shackle recovery points, and I don’t compromise very well… Even a 30deg exit angle would have passed the “Pit of despair” test though… Decisions decisions…

 

[Third From Texas]

Was re-visiting the spare location as it is getting close to time to make those final design decisions. If I am willing to lower the rear exit angle to 30deg, I can get the spare tucked up under the rear end, with all its weight suspended from the main truck frame structure. In a captive spring design, the weight of the habitat is a prime factor in how much torsion it will have to withstand when the main frame twists out from under it when passing over rough terrain. The spare tire and a 50 gal water tank are the two largest single masses I am dealing with. The water tank I placed over the point of solid attachment to the frame, but the spare wound up being at the worst possible location at the opposite end of the habitat…

This solves that problem, but creates a design compromise or two, such as covering the rear shackle recovery points, and I don’t compromise very well… Even a 30deg exit angle would have passed the “Pit of despair” test though… Decisions decisions…

Mine are the 50 gal water tank and the battery bank. I have space allocated under the bed for the water tank but for reasons that you mention, I find it less than ideal. My batteries are either going aft above one of the fixed mounting point s (or they could still end up in a box external to the hab).

But yeah, the water tank bugs me. It's not only above one of the captured springs but it's outboard of it as well. I really don't have much choice unless I leave the water external and add a heat solution. For now, it's going under the bed. I know the water tank isn't going above the cab, though...

 

[Ronmar]

Yea I am putting that tank under the bed or couch/bench and elevator bed platform to gain a little more useable living space. I am going to keep the batteries down on the chassis, so the concept of getting the tire down onto the chassis REALLY appeals to me, even at the cost of 10deg of exit angle. I can make up a bridle to maintain a rescue point at the rear.

 

[coachgeo]

Mine are the 50 gal water tank and the battery bank. I have space allocated under the bed for the water tank but for reasons that you mention, I find it less than ideal. My batteries are either going aft above one of the fixed mounting point s (or they could still end up in a box external to the hab).

But yeah, the water tank bugs me. It's not only above one of the captured springs but it's outboard of it as well. I really don't have much choice unless I leave the water external and add a heat solution. For now, it's going under the bed. I know the water tank isn't going above the cab, though...

mount the tanks with capture spring-ish too. Mogs have been done that way. This way you can mount where weight is low and your not as stuck on having it in a spot less liable to flex.

 

[Third From Texas]

mount the tanks with capture spring-ish too. Mogs have been done that way. This way you can mount where weight is low and your not as stuck on having it in a spot less liable to flex.

I'm not concerned about the tank flexing and breaking. I'm concerned that adding the extra 500lbs to one side of the hab (which sits on capture springs). The capture springs are calculated for a specific cargo weight and I'm somewhat over what would be in the standard M1079 shopvan. It's something that could be calculated and adjusted by changing the spring size, but I won't know until I complete the finhal build.

 

[GENX]

Yea I am putting that tank under the bed or couch/bench and elevator bed platform to gain a little more useable living space. I am going to keep the batteries down on the chassis, so the concept of getting the tire down onto the chassis REALLY appeals to me, even at the cost of 10deg of exit angle. I can make up a bridle to maintain a rescue point at the rear.

Sacrificing 10 Deg of departure angle really is not going to be a problem I don't think... There is a video of Endless Adventure romping his truck on an impossible to climb hill without winch.... I am not sure I am going on much trails like this where the truck can't get up it in low gear.. Occasionally winching is fine, but making a day of it.. I don't think I need to be on that trail with my camper.... of course the pot holes and pits of doom are what will get you....

 

[GENX]

Mine are the 50 gal water tank and the battery bank. I have space allocated under the bed for the water tank but for reasons that you mention, I find it less than ideal. My batteries are either going aft above one of the fixed mounting point s (or they could still end up in a box external to the hab).

But yeah, the water tank bugs me. It's not only above one of the captured springs but it's outboard of it as well. I really don't have much choice unless I leave the water external and add a heat solution. For now, it's going under the bed. I know the water tank isn't going above the cab, though...

I'd put the batteries inside was it me. LiPo's are susceptible to cold and even Lead Acid's to some degree but Lithium's more so.

 

[GENX]

Was re-visiting the spare location as it is getting close to time to make those final design decisions. If I am willing to lower the rear exit angle to 30deg, I can get the spare tucked up under the rear end, with all its weight suspended from the main truck frame structure. In a captive spring design, the weight of the habitat is a prime factor in how much torsion it will have to withstand when the main frame twists out from under it when passing over rough terrain. The spare tire and a 50 gal water tank are the two largest single masses I am dealing with. The water tank I placed over the point of solid attachment to the frame, but the spare wound up being at the worst possible location at the opposite end of the habitat…

This solves that problem, but creates a design compromise or two, such as covering the rear shackle recovery points, and I don’t compromise very well… Even a 30deg exit angle would have passed the “Pit of despair” test though… Decisions decisions…

Swing arm?

 

[GENX]

Swing arm?

Swing out and pin someway Or Even Swing up with Hydraulic assist and pin out of the way for recovery without removing. There are always compromises. Eh?

 

[GENX]

Better angles of the pit of doom in this video.

 

[Ronmar]

No lithium. Circulating heat down to the batteries is not all that difficult…

 

[Third From Texas]

I'd put the batteries inside was it me. LiPo's are susceptible to cold and even Lead Acid's to some degree but Lithium's more so.

Yeah, it froze down here. Once.

But I spend the vast majority of my time in places that don't ever freeze. And if it's going to freeze in some place, I need to be driving to another place.

I do actually still snow ski and was planning to take the truck up to CO for a few winters, but a lot of that depends on how quickly we can get oil production ramped back up in the good old USA (which should be about five minutes into 2024 I suspect).

Anything external to the hab (water, batteries, etc) can be designed to be heated if the need were to ever arise. That said, the truck batteries are already external and I'm only using half the allowed space (never more than duals to run the truck). Building another"all encompassing battery box" is another thing I've considered. While I would like to keep the batteries in house, I'm not opposed to moving some or externally. Right now, my second pair of 6TL's are are house batteries.

My plan is to keep the house batteries in the hab, but plans change. LiPos aren't ever going to do anything but increase in price and by the time I get ready to power the hab they may be well beyond my budget (honestly, they already are).

 

[coachgeo]

No lithium. Circulating heat down to the batteries is not all that difficult…

that only works if your engine is running. Camping in winter for a week boondocked would be issue.... unless of course you have a propane or diesel fired coolant heater as part of your habitat heating system. (or a APU with an engine that uses coolant)

 

[Third From Texas]

that only works if your engine is running. Camping in winter for a week boondocked would be issue.... unless of course you have a propane or diesel fired coolant heater as part of your habitat heating system. (or a APU with an engine that uses coolant)

My onboard gas water heater and electric heating elements disagree...