Hydraulic Alternative?

[SolarT]

I recently picked up and am restoring a 1970 twenty footer.
I have some issues to resolve with the hydraulic system and got to wondering.
Has anyone switched to a system of four linear actuators?
Working with them in the past, I believe they could be another way to go.
Comments please.
TIA
Jeff

 

[marininn]

The roof will not support hanging from the tips of the actuators, but just make it tie into the lower part of the frame (for the top half). Some framework that starts where the cables attach, goes up to the ceiling and attaches to the tip top of the actuator.

I would do the actuators if you have this ability, would be superior to the cables.
If one cable breaks then your whole camper is broke.

 

[JackandJanet]

How do you regulate the four separate actuators so they raise and lower the top at the same time and rate?

The cable system is really quite robust and reliable, if it is properly maintained.

- Jack

 

[marininn]

You use a HappiJack controller.

 

[SolarT]

The roof will not support hanging from the tips of the actuators, but just make it tie into the lower part of the frame (for the top half). Some framework that starts where the cables attach, goes up to the ceiling and attaches to the tip top of the actuator.

I would do the actuators if you have this ability, would be superior to the cables.
If one cable breaks then your whole camper is broke.

I can't quite picture what you're describing. If you'd like, please elaborate. Thanks

 

[SolarT]

How do you regulate the four separate actuators so they raise and lower the top at the same time and rate?

The cable system is really quite robust and reliable, if it is properly maintained.

- Jack

The ones I've used are very steady and accurate in their movements. I think that with proper limit switches it could work. A good guide rail system is a must.

 

[JackandJanet]

The Happijac looks a bit "fiddly" and seems a pretty expensive replacement kludge for what is a perfectly straightforward lifting system. If installed, you cannot just press and hold one button to raise or lower the top. You have to monitor the whole operation to make sure the top is not "tiliting". It is NOT a device that automatically regulates the rate of movement. It just gives you a remote control way to activate all screw jacks.

- Jack

 

[marininn]

Yes, hippiJAck way too expensive for what you are doing, but for the guy that cannot imagine being able to manually control 4 motors, that run at about the same speed anyway, Hippijack is his alternative. I try please everyone.

To use actuators you are going to push the roof up. Alaskan campers use them and push from floor to roof. Alaskan campers are made for this so the roof structure supports being pushed up and the entire roof being held up at 4 points on the roof corners.
HiLo are meant to be held up by the lower frame of the upper section.

You need to resolve this so you can push the roof up.
Put your elbow on the table, bend wrist 90 degrees. The table is the bottom of the top section of Hilo bolted to your elbow, your arm is something you fabricate up and install to transfer the load up to the roof (but not to the roof), and your hand is where the actuator pushes. By pushing up on your hand your arm pulls the table up.

 

[Lwwilltravel]

I have often thought why they did not have like a hydrolic jack at the same position where the cables are on the otside somehow, but I think be just like what you are talking about that they somehow all need to work exactly the same speed etc.

 

[SolarT]

If you use actuators with Hall Effect sensors included, Firgelli makes a controller for up to four actuators. It synchronizes them, for $200.

 

[SolarT]

Yes, hippiJAck way too expensive for what you are doing, but for the guy that cannot imagine being able to manually control 4 motors, that run at about the same speed anyway, Hippijack is his alternative. I try please everyone.

To use actuators you are going to push the roof up. Alaskan campers use them and push from floor to roof. Alaskan campers are made for this so the roof structure supports being pushed up and the entire roof being held up at 4 points on the roof corners.
HiLo are meant to be held up by the lower frame of the upper section.

You need to resolve this so you can push the roof up.
Put your elbow on the table, bend wrist 90 degrees. The table is the bottom of the top section of Hilo bolted to your elbow, your arm is something you fabricate up and install to transfer the load up to the roof (but not to the roof), and your hand is where the actuator pushes. By pushing up on your hand your arm pulls the table up.

I'm thinking of attaching the actuators to telescoping square steel tubes. Welded to each half. I found a synchronizer to balance them.

 

[marininn]

I have often thought why they did not have like a hydrolic jack at the same position where the cables are on the otside somehow, but I think be just like what you are talking about that they somehow all need to work exactly the same speed etc.

Truck campers also need their jacks to work at the same speed for exactly the same reason. Thousands of truck campers have motorized actuators/legs that do not sync at all, is up to the user to manually do that, they somehow work. TC owners are not necessarily more able to do this than a HiLo owner.

The cable system is pretty effective, but the weakness is that the cables have been known to break, and that is a catastrophic failure! If only one cable fails then the whole top could be ruined and the camper cannot be used. It will also ruin the vacation.
Six cables, having a pair of cable mid-ship, would solve all these issues, but would add a few extra bucks to the price.

There are worse roof lift systems out there, particularly the HECO lift, what a disaster!!! So, it could be worse if you were unfortunate to own a camper with a HECO lift.