DIY Telescoping Lift for RTT on Trailer

dagtwo

New member
Hopefully this illustrates the idea a little bit better. The first picture is in the low/stowed position. The second picture shows one of the sides being lifted up. This should allow someone to lift a side a few perforated holes at a time. The RTT mount (green) would be able to move along the two front and rear arcs of the pivot arms (orange), allowing the telescoping posts (blue) to stay vertical with minimal binding. I'm sure there are ways to make this more sturdy and robust. This is just a proof of concept. I would love to have an fully actuated lift with linear-actuators on all corners, but with my experience with actuators, I wouldn't trust them after going over some moderate off-roading. I believe this concept could take some abuse. All it needs is some minor welding skills and some locking pins. Maybe some simple gas struts to help. Feel free to tear this design apart. I like criticism.

RTT Telescoping design (1).pngRTT Telescoping design (2).png
 

high-and-dry

Active member
That design while at first I was great idea, after looking at it, it will still cause binding. Equal lengths arms at different angles are going to cause end to pull and the other end to push on the vertical tubes and it will bind.

But I will say it wont bind as much as a fixed anchor point. ( or even pivoting )

Actuators are easy, but you would still want, in my opinion, a pin to lock it in the down position so the actuator is not taking the shock loads of bumps.

edit upon further review Its going to bind up tight. when you lift, your going to be imparting a side load equal to or greater than the lift load, as the pivoting arms are going to be levers pulling the vertical tube sideways instead of trying to lift them.
 
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dagtwo

New member
That design while at first I was great idea, after looking at it, it will still cause binding. Equal lengths arms at different angles are going to cause end to pull and the other end to push on the vertical tubes and it will bind.

But I will say it wont bind as much as a fixed anchor point. ( or even pivoting )

Actuators are easy, but you would still want, in my opinion, a pin to lock it in the down position so the actuator is not taking the shock loads of bumps.

edit upon further review Its going to bind up tight. when you lift, your going to be imparting a side load equal to or greater than the lift load, as the pivoting arms are going to be levers pulling the vertical tube sideways instead of trying to lift them.
I agree. The pull direction is wrong. But I wonder if it could be compensated by a simple elastic band stretched in a triangle pattern with the bottom point on telescoping post? Keeping the pull direction in line with the vertical axis. Just spitballing. Also, I agree with the locking down. Figured a locking pin on the telescoping post and you can see there's a tab coming down from the RTT platform for locking pin to the horizontal piece of the telescoping tube.

Thanks for the input. I'm about a year out from building something, so the more I can brainstorm this stuff the better.
 

high-and-dry

Active member
Just use actuators. Just figure out how high you want to lift em. Then buy ones that lift that much. The ones I bought cost 65 bucks and are rated outdoors.
 

blueman9

New member
You might want to try something similar to what this guy did.

He's moved on to linear actuators eventually, however he started with just gas struts. I'm doing a modified version of this right now, and I taught myself basic welding with a Harbor Freight Titanium Mig Weldder. But, basically I used 11 gauge (1/8) tubing, 2" outer and 1.5" inner. Ideally if you can find it, 1.75" outer will work perfectly, but it will have to have the weld seam removed, doable but pricey or really hard. I opted to get 6" 14 gauge 1.75 insert that necked it down to an appropriate size so it wasn't so loose that it bound.

I bought my gas struts off McMaster-Carr and got 4 x 100lb lift capacity struts (My tent weighs 275 and my rack 105), and with the insert and UHMW strips it goes up and down really smoothly.

It's definitely a thinker problem, but nowhere near impossible.

I'm away for Christmas, but when I get back after the new year I will try to take pictures and give a proper description.
 

Mark2457

Member
You might want to try something similar to what this guy did.

He's moved on to linear actuators eventually, however he started with just gas struts. I'm doing a modified version of this right now, and I taught myself basic welding with a Harbor Freight Titanium Mig Weldder. But, basically I used 11 gauge (1/8) tubing, 2" outer and 1.5" inner. Ideally if you can find it, 1.75" outer will work perfectly, but it will have to have the weld seam removed, doable but pricey or really hard. I opted to get 6" 14 gauge 1.75 insert that necked it down to an appropriate size so it wasn't so loose that it bound.

I bought my gas struts off McMaster-Carr and got 4 x 100lb lift capacity struts (My tent weighs 275 and my rack 105), and with the insert and UHMW strips it goes up and down really smoothly.

It's definitely a thinker problem, but nowhere near impossible.

I'm away for Christmas, but when I get back after the new year I will try to take pictures and give a proper description.
Would love to see more details
 

Mark2457

Member
So I had some further thoughts on this

My big issue is that when i want to use the annex, I need the tent to be about 18 inches about the trailer. The rest of the time it can be level(ish) with the top of the trailer

I've built a rig in the garage with an electric winch on a slide, so I can lift the tent and slide between trailer and truck. This made it necessary to find the exact center of mass of the RTT so I could winch it and keep it level.

Just bought an RSI SmartCap and was looking at which load bars to buy and came across the Thule Xsporter Pro (https://www.thule.com/en-us/roof-rack/truck-and-van-racks/thule-xsporter-pro-_-500xt). This has 16 adjustable heights. So it got me thinking, If I build a strong cross brace in the trailer I could just used a bottle jack with a 20-inch stroke under the center of the RTT, I could use that to raise the tent on setting up camp. Here's an option: https://www.harborfreight.com/autom...ong-ram-hydraulic-flat-bottom-jack-36468.html

Is this a crazy idea?

Ultimately, I want something automated, but right now, i want something quick and easy that I can use to test out the plan.
Mark
 

NatersXJ6

Explorer
So I had some further thoughts on this

My big issue is that when i want to use the annex, I need the tent to be about 18 inches about the trailer. The rest of the time it can be level(ish) with the top of the trailer

I've built a rig in the garage with an electric winch on a slide, so I can lift the tent and slide between trailer and truck. This made it necessary to find the exact center of mass of the RTT so I could winch it and keep it level.

Just bought an RSI SmartCap and was looking at which load bars to buy and came across the Thule Xsporter Pro (https://www.thule.com/en-us/roof-rack/truck-and-van-racks/thule-xsporter-pro-_-500xt). This has 16 adjustable heights. So it got me thinking, If I build a strong cross brace in the trailer I could just used a bottle jack with a 20-inch stroke under the center of the RTT, I could use that to raise the tent on setting up camp. Here's an option: https://www.harborfreight.com/autom...ong-ram-hydraulic-flat-bottom-jack-36468.html

Is this a crazy idea?

Ultimately, I want something automated, but right now, i want something quick and easy that I can use to test out the plan.
Mark
Maybe sketch out how that would work? Do you have a lid on the trailer? In order to lift 20”, that has to start at least 20”, or more, below the bottom of the lift. Are you willing to give up the center point of the trailer to serve that purpose? Is the tent floor and trailer floor sufficiently reinforced to lift the tent on a point load, or will you need some sort of subframe? Will you be able to reach the center to pump the jack? Can you contain the oil that will eventually leak?

Have you considered the simplest solution? Leave the tent up 18” all the time? Or, shorten your annex? You still have the advantage of covered “standing” room and storage underneath for your gear or sitting in chairs if the weather goes foul.
 

ducktapeguy

Adventurer
One of the problems with telescoping tube is the balancing the clearances needed to lift it without binding while maintaining a tight enough tolerance so it's not wobbling all over the place when you're sleeping in it.

You could use a 4 bar linkage similar to this mechanism


This requires more length for the tent to pivot down, but it can be locked into position with a diagonal crossmember to maintain rigidity. I would probably look into a 3-link mechanism that would allow you to pivot one side of the tent up, then lock in in place with a short support leg, then lift the other side and do the same.
 

Mark2457

Member
Maybe sketch out how that would work? Do you have a lid on the trailer? In order to lift 20”, that has to start at least 20”, or more, below the bottom of the lift. Are you willing to give up the center point of the trailer to serve that purpose? Is the tent floor and trailer floor sufficiently reinforced to lift the tent on a point load, or will you need some sort of subframe? Will you be able to reach the center to pump the jack? Can you contain the oil that will eventually leak?

Have you considered the simplest solution? Leave the tent up 18” all the time? Or, shorten your annex? You still have the advantage of covered “standing” room and storage underneath for your gear or sitting in chairs if the weather goes foul.
Thanks for reply

Don't have a lid on the trailer. the trailer is about 18 inches tall and the tent will be at least 4 inches about that, so 20 inches is just about perfect

Most of the trailer storage will be on slides (2 at back and one at front side), so center point will be least used area

I figure I will need some kind of sub frame. Initial thought is to attach some cross members (probably a cross-shape) to the existing rails

Hadn't thought about reaching the jack (I presume I could extend the handle out to the back which would obviously shorten the stroke distance) or oil leaks (nothing will be touching the trailer bed)

Right now, the plan is leave it up at 18", just trying to minimize about instability, wind resistance and improve fuel economy. Shortening the annex isn't really an option; otherwise, it would be a pain to get in and out and the usable space would be grossly reduces as it sloes down over 3 feet

Some food for thought
 

NatersXJ6

Explorer
Thanks for reply

Don't have a lid on the trailer. the trailer is about 18 inches tall and the tent will be at least 4 inches about that, so 20 inches is just about perfect

Most of the trailer storage will be on slides (2 at back and one at front side), so center point will be least used area

I figure I will need some kind of sub frame. Initial thought is to attach some cross members (probably a cross-shape) to the existing rails

Hadn't thought about reaching the jack (I presume I could extend the handle out to the back which would obviously shorten the stroke distance) or oil leaks (nothing will be touching the trailer bed)

Right now, the plan is leave it up at 18", just trying to minimize about instability, wind resistance and improve fuel economy. Shortening the annex isn't really an option; otherwise, it would be a pain to get in and out and the usable space would be grossly reduces as it sloes down over 3 feet

Some food for thought
It has a decent chance of working, but long term reliability is questionable. If you get a good jack from HF, they seem to be good forever, and a bad one usually shows it’s truth early, but you are going to use it in heat and cold, rattling down roads, and base much of your camping happiness on its reliability? I would look for a scissor-style car jack to perform the same function and gain the advantage of mechanical reliability with a crank (easier to reach at a distance) instead of a pump lever. Note the scissor jack will also not collapse under load, making it somewhat more safe, but still have some telescopic locking members.
 

dstock

Explorer
This was my setup with linear actuators, 16" of travel, worked out very well for several years. I used threaded tube adapters in the tops of the telescopic posts after a welded nut setup failed (mostly due to a poor weld on my part). Trailer went all over in this configuration, Death Valley, Mojave Road....miles and miles of washboard road with zero issues. I had lock out pins to when it was it was down and up but frankly didn't need to use them. Build thread in my sig.

This is a pic when I was testing out the wiring



Final product
 

Mark2457

Member
It has a decent chance of working, but long term reliability is questionable. If you get a good jack from HF, they seem to be good forever, and a bad one usually shows it’s truth early, but you are going to use it in heat and cold, rattling down roads, and base much of your camping happiness on its reliability? I would look for a scissor-style car jack to perform the same function and gain the advantage of mechanical reliability with a crank (easier to reach at a distance) instead of a pump lever. Note the scissor jack will also not collapse under load, making it somewhat more safe, but still have some telescopic locking members.
Thanks for suggestion.

Was looking at scissor jacks and came across this, which look intriguing



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