Jack knife conversion

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Fawn
Posts: 46
Joined: August 28th, 2021, 9:33 pm

Jack knife conversion

Post by Fawn »

Hello to you savvy Chinook folks.
I am often traveling solo in my 1998 Chinook Concourse. Opening and closing the jack knife sofa (I like keeping the aisle and dinette free) is becoming a bit much for me. I'd like to convert it to a platform bed.
Does anyone have plans they can share - measurements, materials, removal procedure, etc.
At the end of it all I can sell the bed to anyone who is in need.
I saw a couple of posts here but couldn't quite put it all together and I'd like to share something with a friend who will help with the conversion.
Cheers,
Fawn
JabberBox

Re: Jack knife conversion

Post by JabberBox »

I simply removed the jacknife cushions, left the jacknife frame in place attached to the floor. I then took measurements and built a twin bed frame that i attached to the jackknife frame. Dont ask me for pictures because i lost them all when my new walmart hard drive failed during a backup.
Kirah
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Re: Jack knife conversion

Post by Kirah »

That's essentially what I did as well: removed the cushions, removed the back. Then I laid a couple pieces of plywood over the top of it, and a piece of that non-skid stuff you put under carpets, to keep the mattress from sliding around.

The result is a non-standard size, so I had a mattress custom made by a foam shop (https://foamforyou.com/), which is cheaper than it sounds. It's big enough for one short person and - if it's cold enough - a dog, but just barely :lol:
1999 Premier, now minus all passenger side cabinets and appliances :twisted:
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Blue~Go
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Re: Jack knife conversion

Post by Blue~Go »

You brought me out of the woodwork with this one :)

Here is what I did and I've been quite happy with it. To start, my previous campervan had a different system of couch/bed. You can actually still buy the framework, but anyway, the concept was that the seat cushion (30" wide) stayed in place, and then the backrest (14" tall) somersaulted over and ended up on the outside for a possible 45" bed (see RB components sofa/sleeper hinge).

That was fine, but the problem was that as a couch it was too narrow to sleep on. And then as a bed it was sooooo wide (even wider feeling in a narrow van). Same with the Chinook couch, plus added humpy uncomfortableness (at least the campervan one was flat).

So I modified it (the campervan one, before I had my Chinook). I made the seat cushion (which was 30" wide, but normally about 6" of it was under the backrest so unusable) slide out. So in other words, the backrest just stayed where it was, but I could pull the seat part (now the bed) straight out to just where I wanted it. No backrest to have to store somewhere.

That worked great, so I wanted to re-create it in the Chinook. I also just hated the stock couch anyway because the "three hump" design seemed so unnecessarily uncomfortable and unflat. One big criteria I had was that if possible, I did not want legs touching the floor (because they always seem to scratch or dent the floor).

If you like this idea, you probably won't re-create it exactly - because you would not have the exact same parts and pieces to work with. But maybe it will give you an idea.

At the time, I did not know I could just buy that whole mechanism that my campervan had (but you can, at RB Components) so I worked with what I had. I started by removing the entire backrest mechanism from the Chinook couch. Then I took away the seat cushion. So I just had the bottom frame left. That made a good foundation to build on.

Now, how to telescope the bed support with no floor legs? (And no million dollars.)

What I did was got two sizes of steel square tubing that slide inside each other. The outer set has holes in it, the inner set is solid. I had a seat cushion from another campervan that was more of just a box shape (no humps) so I used that. I cut the outer tubes to 30" and mounted them on the ledge at the outer wall side of the Chinook couch (we'll call that the "back"). Where they cross over the front of the couch framing they sit between two starboard (plastic) blocks I drilled and tapped into the frame of the couch there (can't screw through them as they need to be hollow for the slider tubes). They overhang by about 3" for a similar cantilever to the original couch. The inner tubes slide into the outer ones, and can pull out. The inner tubes have a hole drilled in the top just at the front edge, and I drilled and tapped a bit of threaded rod into the bottom metal frame of the seat cushion.

Hence, I can just pull on the lower cushion and it slides out as far as I want it to, carrying the inner tubes with it (or you can drop it into the main tube holes to lock it in place if you want to). I typically slide it out to about 30" beyond the backrest, which makes a good solo bed IMO. At that point the inner tubes are pulled out around 6". Seems quite sturdy. Probably wouldn't do jumping jacks on the outer edge of the bed while pulled out but no problems in typical use since 2014. It slides right back in in the morning.

One note here is that I would make some prop legs for the outer edge of the inner tubes if I were going to lay the backrest down and sleep two (I had done that in my previous campervan as well). But probably instead of scraping them across the floor, I would just make some removable props with felt on the bottom. No need when solo.

Side bonus: If you're like me you rue the day that Chinook decided to put the bed on the driver's side, so that every time you visit a friend and park on the street you roll out of bed. (And doesn't it seem like more campsites slope to the right? Doesn't it?). Well, I fixed that. I started out with some blocks I could insert under the larger tubes right where they cross the front of the frame when I wanted some counteracting tilt. At the same time I put the rear edge of the outer tubes on little "axles" (bolts) instead of just a straight attachment. Now I could raise the bed up on the outer edge at will.

Eventually I decided I just wanted it raised up permanently. More comfortable as a couch, I can park on the street and never fall out of bed, and if I'm sloping the other way no problem, it rolls me into bed. (I prefer not to use the leveling blocks if I don't have to every time.) I find that a little tilt is not too bothersome during the day; but having a 30+" bed on a tilt is not that great.

I can see two ways to do this without the assortment of other campervan parts I had.

1) Use an RB Components somersault type folding sleeper hinge (or even an entire couch they sell).
2) Make your own or have one made to your specs. The mattress/bottom section is probably best made out of steel tubing (or maybe 8020 these days?) on the inside which is how my stock RB type bed was on my other campervan. At least my design relies on that bottom cushion section it being somewhat self supporting and the forward bottom edge being strong. Mine has a steel tube framing inside the fabric and cushion. But I'm sure there are other ways. The main thing is just the "leave the back where it is at the wall and just slide the cushion out" concept.
3) Combination of above.

I realize this leaves a bit to the imagination. But maybe it will spark an idea. I have really liked it. No trying to sleep or nap on a rail-thin bed. No trying to walk around a mammoth bed (that you had to convert). It really makes the "Gee I wish I had a huge RV with a permanent bed" feeling pretty much disappear. Obviously to each their own, but that's been my experience.
1999 Concourse
Fawn
Posts: 46
Joined: August 28th, 2021, 9:33 pm

Re: Jack knife conversion

Post by Fawn »

Wow!! Thanks so much for all of this incredible information. It looks like I now have plenty of options. I can't say enough how much I appreciate this forum and people's generosity in sharing information. I just today unbolted the sofa and will proceed with plans to add the platform. Next stop foam and back cushions. Safe travels everyone.
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Blue~Go
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Location: 1999 Concourse

Re: Jack knife conversion

Post by Blue~Go »

That's great.

I just re-read Kirah's post above. That is a really good and simple way to make a ~39" bed.

I found that I liked having the backrest. Mainly because it's like a 72" long coffee table* on the window side :lol: (my backrest is a rectangle shape not a humped shape like the original Chinook one). But also for an elbow rest or in case I (gasp) sit the regular way on the couch (it happens once a decade or so). Also I slightly liked the idea of being able to still make the 45" wide bed; and 30" is enough for me when solo.

Anyway, just wanted to come back and add to this, because Kirah's way is super simple (secure plywood platform to existing bottom frame, add mattress) and does give you a wider bed.

BG

*So as mentioned above, the basic backrest for my couch is rectangular, so the top surface is already a pretty rigid rectangle of about 5" wide and 72" long that runs along just beneath the window. To improve that for coffee table use, I grabbed a "hobby board" from Home Depot (6" wide and only about 3/8" thick by about 2' long but could be any length), varnished it, and now I just set it on the backrest top for an even better coffee table type surface.
1999 Concourse
Fawn
Posts: 46
Joined: August 28th, 2021, 9:33 pm

Re: Jack knife conversion

Post by Fawn »

Thanks. This is perfect for a future improvement.
Flame
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Re: Jack knife conversion

Post by Flame »

I want to do this!!! How do you remove just the jackknife cushions? And leave the factory frame. Some details please. Thanks!
1998 Concourse V-10 Triton....AKA...Land Shark
chin_k
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Re: Jack knife conversion

Post by chin_k »

If I remember correctly, they are just bolted down with some screws and bolts, and if you look around the bottom of the frame, you should be able to see all of them.

Edit: there are four bolts that hold the metal frame onto the rest. If you take out these shoulder bolts, you should be able to lift out the cushion. If you want to DIY the top, then you will need to remove the staples, screws, etc., that wrap around the top horizontal frame. You can either replace the cushion yourself, or you maybe to bring it to a upholstery shop and have it re-upholsterized the way you wanted. Just need to make sure the mechanism will continue to work, or you may even replace the mechanism to fixed one, etc.
2000 Concourse dinette, on 1999 6.8L Ford E350 Triton V-10 Chassis
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