couch design review

[Mark W. Ingalls]

All--

I'm just finishing up the dimensioning of parts so I can try out a couch remodel. Here are a couple screen shots from AutoCAD that I hope show the action of the unfolding mechanism.

Please criticize mercilessly, so the design can improve...

Folded position:

The green objects are struts that swing to the left when the couch is opened to a bed. We are looking from the end of the TC toward the front of the truck.

The bottom cushion is attached to several 17 inch long hardwood 1x3 'sleepers'. In the closed position the sleepers nest into a bulkhead. The bulkheads are sized to allow storage bins to be slid beneath the couch and retained with bungees or a yet-to-be-designed keeper mechanism.

Open position:

In the open position the right strut is oriented vertically and the 3 inch sleepers rest on top of 16-1/2 inch legs that are glued to the bulkheads. The resulting bed height allows the backrest cushion to be placed on the 10 inch shelf next to the right wall.

This orientation allows about 16 inches of free floor space between the kitchen and the bed, and also makes the climb to the top bunk easier.

The backrest is propped in the couch position with trapezoidal pieces of plywood, keyed to a 1x3 stiffener. In the bed position, the trapezoidal props are interference fit between the left cushion and the right strut, stopping the right cushion from falling through to the floor.

As time permits, I'll post the dimensioned components and a BoM...

 

[jimjxsn]

Mark,
A Really well thought-out design. Reminds me of the bed mechanism from my old ~70s VW camper in that it was taller in the bed position than in the seat position.

 

[chnlisle]

Ill say it again the level of talent around here is amazing.....CAD Wow!

 

[davinski]

Wow, this is cool. i like how you use the normal ledge of the camper as support of one part of the bed. Makes it high, as stated, and leaves more room in the camper for either more walking/storage space or for a bigger bed!

I'd watch that mechanism for space under the seat as space is such a big concern for all of us. Also, any play in it should it hit other things in the storage area.

Maybe under the seat would be a good place to store some extra cushioning for the bed??? Maybe behind the seat when in seat mode? I dunno, just thinking that more padding is good for my aching bones.

Also, what would you make the storage box out of, same material as it is now or reinforced?

Good work. Love it.

Dave

 

[EdoHart]

Think about the back cushion in the bed position

Nice design. Here are a few things I thought about.

It looks like you've provided for a horizontal support between bottom and back cushions while in the bed position, but that support will interfere with the bottom cushion while it is in the couch position. Or maybe your hiding it inside the right side of the camper while in the couch position. Also, if the cushions are the entire length of the couch, that horizontal support should be pretty substantial as it looks like it will carry a large portion of the load while in the bed position.

You will also need to leave slots in the upper, left support (as seen in your drawing) that runs from front to rear of the camper to allow clearance for the short green strut when it is in the bed position.

 

[DLN]

Mark,

Very interesting design. I don't see anything that hasn't been covered by others. I would do a mock-up on the mechanical geometry before building it, but maybe you've already considered doing so. Your layout on Autocad looks well done and thought out.

 

[winter200]

Very well thought out. I am not sure I am following on how the right cushion is supported on the left side when it is in the bed mode. I would look at maybe having a ledge on the right side of the left cushion that the left side right cushion would rest on. I would also look at maybe making a pivot point on the left side of the left cushion so that the left cushion could rotate up and allow access to the storage down below through the top. I have a test camper sitting in my driveway waiting for a new floor pack and front wall move. I have spent the last few days trying to figure out how to make the beds work like you have shown to use the space above by the window.

 

[benburnett]

couch

Nice plan. Let me know how it works out when you have a working model. Might be interested in using it ourselves.

 

[Mark W. Ingalls]

The back cushion is definitely not well executed yet. As of now, the couch backrests will serve double duty as the ledgers for the right bed cushion. I am expecting that once the prototyping process is begun a better solution will suggest itself if it appears necessary. (That is why marine architect Howard Chappell said the most important design tool is a comfortable chair!)


AutoCAD LT is not really 'CAD', it's merely of a 2D drawing package. At least it is possible to make fairly accurate prints. Even though we have 'real' cad at work, we often find it is more convenient to prototype a project on the fly in the machine shop and then take it back apart and draw the pieces after we get it working.

I am no longer a cabinetmaker by trade, just an engineer. I have my own shop at home to help stay 'real'.

 

[EdoHart]

Slide out struts for support

Provided the bottom (or back) of the cushions are a hard surface like mine, then to support the left side of the back cushion while it is in the bed position, you could use support struts that would slide out of what I think you are calling the sleepers. Move the bottom cushion into the bed position, slide out the struts, then lower the back. As you tilt the bottom while moving it into the bed position, gravity may extend the struts for you.

 

[Sam]

Great idea! I can't really tell but it looks like the back cushion is loose, or just wedged in place when in the couch position (like it is from the factory) I don't know about the others, but I have trouble with the back cushion falling over when off road on steep hills or anything rough. For me one of the reasons I like the new FWC couch is that the couch back is secured.

Keep it up can't wait to see the finished product.

 

[jimjxsn]

Sam,
I actually prefer the couch back being loose so I can lay it flat. I like being able to see out the right side window and can't do that with the couch backrest up. Just personal preferences

 

[Sam]

Jim,

That's a good idea, it would be nice for visibility. I usualy cary a dog or two in the camper so i can't put the couch back flat.

 

[Mark W. Ingalls]

In our (admittedly) limited experience we have placed the back cushion atop the seat cushion with the plywood side up when traveling. I can see why one would want to keep it in couch position for pets, however.

Meanwhile, I'm trying to keep the number of catches and tiny parts to an absolute minimum.

 

[Mark W. Ingalls]

Rev 0 - Initial Release

As it happens, the concerns over mounting the couch back took care of themselves, once the seat cushion was repositioned and the 'sleepers' lengthened somewhat. (This is why the design review is so important to the process.)

Herewith are some photos of the first prototype during our latest weekend trip to the beach at S. Padre Island.

Couch, showing how the back cushion wedges between seat and camper base...

Couch, showing arms in folded position and access to equipment stowed underneath...

Bed, showing right cushion extending to within one inch of the side window...

Bed, showing available floor space...

The prototype was fabricated from plywood off-cuts and $27 in hardware. I originally made four of the bulkheads but only used three.

I neglected to allow for the hidden 'step' inside the original couch base, so I had to rip some material off two bulkheads and notch their long arms to enable the couch to be closed. In the next version the arms will be relocated to eliminate the need for the notch.

I plan to re-make the arms and sleepers out of hardwood, but I'm not in any great rush... why fix it 'til it breaks?

Thanks for the valuable feedback, all.

 

[Mark W. Ingalls]

Rev 0 - Detail

Detail of sleeper, showing how it extends beyond the seat cushion approximately 3 inches...

Note the piece of 1/4 inch plywood glued to the top of the sleeper to provide a convenient surface for screwing the sleepers to the seat cushion (I don't like using angle brackets.)

Note also there is access to the small space above the first step.

Miscellaneous comments:

Folding the seat cushion out is a one hand operation.

It is very convenient to access stowed equipment without having to move the cushions. One can even access stowed equipment from outside.

We have not added the bungies yet, but nothing seems to have slid out from underneath on the maiden voyage.

It is now very convenient to sweep under the couch.

The bulkheads can be positioned to allow for different stowing configurations.

The couch||bed is now cantilevered at the door end, making entrance and exit somewhat easier with an extra toe-hold.

There is less head room with the top down, so that one cannot sit without slouching. However, this disadvantage does not seem to outweigh the advantages.

 

[jimjxsn]

Very nice! Keep us updated on any mods and your final design. Did you find that it was comfortable in the sitting position? The backrest looks a little upright. Is the backrest still loose?

When you finalize the plans would you be willing to post them?

Great work!
Thanks,

 

[DLN]

Mark,

Your prototype came out very nice. Quality work on the fabrication. I do agree that there's no hurry to fix what isn't broken. I'm going to live with the prototypes of the tailgate/back porch and inside table I've got on the camper now and see how they hold up and function in the long run.

One quick question if you don't mind. The couch back appears to be at 90 degrees to the seat cushion. Is that the final configuration and is it comfy enough?

 

[Mark W. Ingalls]

The backrest is now captured, angled at 90 degrees. It has to be placed before completely folding the seat, which clamps the back to the riser of the upper step.

Sitting position is comfortable as is, due to the 'give' of the foam allowing it to conform to ones back.

 

[Mark W. Ingalls]

Is that the final configuration?

I have been thinking about recycling the old legs as stops screwed to the wall on either side of the window. I would then connect them with a 1" square piece of varnished hardwood. The legs would fold down, creating a safety bar across the open window when sleeping with the window open. In the up position it would bear against the stops I recycled from the original seat. I'll definitely be mocking this up to see how it works.

I was also thinking about fabricating some 'L'-shaped knife hinges, to allow the back to be hinged to the seat permanently. But, I'm not real big on this, because it complicates the operation.