Some Bed Platform Support Ideas/Options

[220629]

Thanks all for the replies. My mind can't grasp ano'd alu bonding to plywood, which is why I keep asking. Silicone I can see, but it is a flexible adhesive, which is better than nothing.
I'm wanting a secure bond because i'm using quickframe and need the plywood skin to help stiffen the span. I'm sandwiching 5/8" ply in the center of the quickframe and want to also adhere that to the QF tongue. I may silicone and screw/rivet this and stop thinking about it.

Not that you asked...

Assuming sheet material combined with the structural shape, bonding may not be as critical to the stiffening as is just the material being together in the mix. Some reasonable number of spaced pop rivets or fasteners using Nutserts will likely provide what you need. The sheet goods provide distribution of the loads. Sheet goods will not particularly add stiffness until you get to 3/4" thickness and it doesn't sound like that is your plan.

Silicone with some fasteners should be fine.

vic

 

[Rensho]

Not that you asked...

Assuming sheet material combined with the structural shape, bonding may not be as critical to the stiffening as is just the material being together in the mix. Some reasonable number of spaced pop rivets or fasteners using Nutserts will likely provide what you need. The sheet goods provide distribution of the loads. Sheet goods will not particularly add stiffness until you get to 3/4" thickness and it doesn't sound like that is your plan.

Silicone with some fasteners should be fine.

vic

I'm hoping the sheet will act as a skin and prevent surface elongation, therefore resist bending. This only works if the skin to frame is a rigid contact. Positive location/contact with skin and frame using a mechanical fastener will work, as long as the holes in the skin don't yield/tear.
I could also go with an alu skin vs plywood, just 3-4x the cost.

 

[220629]

... Positive location/contact with skin and frame using a mechanical fastener will work, as long as the holes in the skin don't yield/tear.
...

In my opinion, it would take quite a bit of flex before any fasteners combined with washers would pull through. By the time that is a problem you likely have bigger issues. Larger style flat washers combined with pop rivets can provide distribution without protruding much above the surface.

That said, I don't recall and haven't personally seen what you plan to use. vic

 

[Rensho]

In my opinion, it would take quite a bit of flex before any fasteners combined with washers would pull through. By the time that is a problem you likely have bigger issues. Larger style flat washers combined with pop rivets can provide distribution without protruding much above the surface.

That said, I don't recall and haven't personally seen what you plan to use. vic

I'm not explaining things very well. The screws and rivets will for sure hold and not yield. The thin plywood holes will yield/elongate.

 

[JP4]

I'm not explaining things very well. The screws and rivets will for sure hold and not yield. The thin plywood holes will yield/elongate.

Could you perhaps glue some wood stringers to the inner side of your extrusions? I tried my setup without the 2x2's and it was a little flexy with just the ramps. With the addition of the glued 2x2's there's almost no discernable flex and it added very little weight. The wood, plywood laminate is very strong and will probably minimize any flex that might pull on the other fasteners.
JP

 

[bstory]

Hi all,

I know guys like things strong and the posts in this thread show that. But sometimes the lightest solutions can work great.

We have Ikea bed slats in their own frame - double bed size - sitting on two side lockers over the wheel wells. My husband put an small upright rail at the right distance on each side locker, so the whole bed slat unit wouldn't slide around, but other than that we just use gravity. The bed can't slide forward because we have a vertical bulkhead/bathroom wall across about 2 feet of the end of the bed. It can't slide back because of the back doors.

However, when necessary two of us in our late 60s can easily lift out the slats by sliding them out the back doors and put them in storage if we need the van for moving sculpture or anything else.

If there is nothing to hold the bed from sliding forward it would be easy to put a stop of some sort on that end.

We are two fairly solid 170-180 lb people and a 35 lb dog. We used to have a 60 lb dog on the bed with us sometimes. No creaking or sagging, no issues whatsoever. We have used this bed for 4 years - 3 cross-country trips and one from New England to Florida. Most comfortable bed we have ever had. We use an Ikea foam 4" foam mattress on it.

The slats cost us quite a lot less than aluminum ramps but probably a bit more than 2 x 4 stock and plywood - about $80.

I don't think Ikea is selling the exact unit we got in 2010, but they have similar items.

 

[PaulDavis]

Ikea no longer makes that bed base, at least not in that width. I used your setup as an inspiration for ours, but the deal now is that a double/full base comes as two halves bolted together with 4 not-very-robust bolts along the length. It absolutely will NOT span a space like the one you show above. A very small child sitting on it will break it. That's why we added the I-beam, as shown over here: https://sprinter-source.com/forums/showpost.php?p=328002&postcount=148

 

[bstory]

Well, Paul, that looks like a good solution.

But what a shame that such a good product is no longer available in this country. I did notice that Ikea still sells the one we got in Sweden, so maybe there is hope for those who want one in the future. It was and is perfect for our application, as we do take it in and out from time to time.

Maybe the market will address this gap?

 

[Pennsyltucky Chris]

I used aluminum angle with threaded rivets to hold some 3/4" glued into a mitered 2x4....also used some aluminum u-channel to keep it from flexing

The panels are three sections that can be removed


Sent from my iPhone using Tapatalk

 

[220629]

Hi all,

I know guys like things strong and the posts in this thread show that. But sometimes the lightest solutions can work great.

...

Very nice looking bed setup by the way.

... but other than that we just use gravity. ...

It appears that your van OEM cabin area is isolated from the bed area. My van is open.

Something to consider for those with a more open van.

Gravity works when every thing is normal. I use 1/4-20 wing nuts and short pieces of line to secure the bed deck and supports into place. That is to help hold things in place in the event of a crash or even just a panic stop. Chunks of bed platform hurling forward will add to the troubles. Especially in the unlikely probability, but very dangerous tip over accident. If that should ever happen I'll have enough stuff tumbling around in my van that I really don't want the bed platform added to the mix.

My securing method isn't crash tested, but it's better than nothin'.

vic

 

[JP4]

Very nice looking bed setup by the way.


It appears that your van OEM cabin area is isolated from the bed area. My van is open.

Something to consider for those with a more open van.

Gravity works when every thing is normal. I use 1/4-20 wing nuts and short pieces of line to secure the bed deck and supports into place. That is to help hold things in place in the event of a crash or even just a panic stop. Chunks of bed platform hurling forward will add to the troubles. Especially in the unlikely probability, but very dangerous tip over accident. If that should ever happen I'll have enough stuff tumbling around in my van that I really don't want the bed platform added to the mix.

My securing method isn't crash tested, but it's better than nothin'.

vic

Good point. I think many of us overlook the potential for chaos in a violent accident with everything being torn loose and flying forward. Ditto the roll over scenario. Even the commercial conversions don't always seem like they're well engineered for accidents.

I put ratchet straps over my panel bed and secure it to tie down rings on the floor. Hope to never have it tested.

JP

 

[JP4]

Nice bed JP. Do you have any pictures of the 8020 and the installed bed?

Just finished carpeting the first panel. A little 3M 90 spray adhesive and staples. Each finished panel weighs 19.1 lbs. Bounced up and down on a single panel and no real flex.
JP

 

[220629]

Use 1 1/2" square tube instead of angles. You can notch the ends if you want.

Square or rectangular tube is very strong.

The ends can be cut to make an angle shape to fit the 2x4 slotted supports mentioned here in my previous posts. The modified ends will also maintain proper centering/positioning of the cross supports for a high mounted "floating" 2x4 or 2x6 side support.

As always the original post/thread can be accessed by clicking the blue arrow icon within any quote box. Clicking the quote above will take you to a more recent discussion with more bed support discussion.


vic

 

[220629]

There's been lots of discussion about deflection. I did some messing around with some material I have on hand.

My testing was very basic. I spaced 2 chunks of 4x4 on the ground 60" apart. I then used my 225#'s to put pressure on the approximate center.

A standard 2x4 dimensional lumber placed flat deflected, but held my weight while I bounced up and down in the center.

A standard 2x3 dimensional lumber placed flat deflected a bit more, but also held my weight while I bounced up and down.

A P1100 1 5/8" 14 gauge Unistrut channel supported my weight as I bounced up and down with no real deflection.

View attachment 68494

A Unistrut P4100 Unistrut on edge held my weight with some deflection while bouncing.

View attachment 68495

A 1x2 aluminum rectangle tube placed flat felt like it would bend before I put my entire weight on it, but it did take quite a bit of my weight. When placed with 2" edge up it supported my weight with bouncing and didn't bend.

A 1 1/4" garage door support steel angle bent with my weight on the center. No real surprise with as light as it is and no decking to distribute the loads.

Keep in mind that the above crude tests were with one only cross support and me putting weight on center section. Including multiple supports in your bed design with 3/8" or 1/2" plywood or particle board decking adds lots more load distribution.

I knew that the 2x4 used flat would be strong enough. To me the 2x3 was a bit of a wild card before my testing showed that it had sufficient strength.

Either style Unistrut set to the 1 5/8" dimension being vertical would be plenty strong.

I didn't have a 1 x 1 1/2" aluminum rectangle to test, but based upon how strong the 2" stock I tested was, I believe that a 1 x 1 1/2" aluminum tube on end would be strong enough.

Using angle stock does require a bit more caution depending upon how heavy the gauge is and how long the leg of the angle placed vertically. As Inertiaman pointed out in another thread, angle does have some advantages as to bolting and fastening if that is the plan.

For the occasional camper.

The cheapest cross supports to purchase would probably be the 2x3 dimensional lumber. By being placed flat the cross supports have only 1 1/2" or so taking away from under bed storage height. My concept with 2x3 or 2x4 lumber would be to set them into notched 2x4 or 2x6 side rails mounted to the side walls.

I would use 4 ea cross supports and 3 each deck panels. The outer deck panels would be 24" wide. The center one would be 32" wide for a total of an 80" long platform. Using 2 ea. 24" panels should work well for one 4x8 sheet good.

To ease installation I would fasten 2 each cross supports to the outer deck boards leaving cross support ledges for the center deck board to sit upon. The 2 end deck boards would set into place followed by the 32" center one. After a few deck screws are installed to keep things in place, you will have a simple bed support ready to use.

Keep in mind that this is a system. During my crude tests the stand alone flat 2x4 and 2x3 flexed with my full 225# on the center of the 60" span. The bed platform installed with decking as I suggest will not have noticeable flex during use no matter how active you may be.

vic

 

[PaulDavis]

Nobody seems to consider I-beams. They are stronger and lighter than almost other option, and simple to make. two 1x2" select pine or similar for the upper and lower beams, with 1/4 plywood, about 1-2" wide or another 1x2 for the vertical bar of the "I". Incredibly strong, very light. 1/4" plywood will require a router and a special router bit; using a 3rd 1x2 just needs glue + screws.

 

[Onefin]

Paul,
Do you have any images of the I-beams you described?

 

[PaulDavis]

Here are two images that show the lengthways i-beam I built for our bed.

https://sprinter-source.com/forums/showpost.php?p=328002&postcount=148

I have a router and the router bit but couldn't find the bit on the day I had to make the beam, so I used 3 pieces of 1x2 select pine, glued and screwed. This thing does not flex.

 

[Onefin]

Thanks for the info.
That seems like a very nice option to explore.

 

[avanti]

Good point about I-beams. As I understand it, the I beam is much more efficient per unit of material when the load is all coming from one direction. With downward loading, the top part of the beam is under compression and the bottom part is under tension, and the vertical part just connects the two. I though that square beams were only used when the load comes from two different directions. But, I'm no expert. is this oversimplified?

 

[PaulDavis]

An I-beam works partially as you note, but the good ones also rely on the fact that the middle/vertical is extremely stiff in the load direction. The load on a bed cross member (lengthways or sideways) is pretty much all vertical. I would have preferred to make something closer to a classic I-Beam with a deeper central section made of 1/4" ply, more similar to the the aspect ratio used in construction beams. But as I mentioned I misplaced my 15/64" router bit and was on a deadline, so I did the beam as shown.