Help? How to Attach Bed Rails to Interior Pillars?

[Corbury1492]

Hi - I am converting a 2014 144 sprinter passenger van (high-roof) to a "light-touch" (not full conversion) camper van. The idea is to make a van like a VW weekender - sleeps 4 people - but beds can be removed or stowed - so the van can be used for other missions.

The plan is to install 2 platform beds - one at about 18" above floor (just above the wheel wells) and the other at around 44" above floor. The upper bed rails will be across the windows. (see sketches). My question is how to bolt the rails to the "C" and "D" pillars of the van? Some people I have talked to have mentioned "nutserts" - other people have said this would not be enough and I need to weld a reinforcement plate to the pillar and then through-bolt to that. I'd also like to do the minimum removal and reinstall of interior trim (but I will do whatever it takes to get it done right).

The worst case load for each corner of the bed would be something like 500 lbs. (center of bed) /4 = 125 lbs. at each corner (dead load). Live load could be double that? Maybe? I'm thinking at least two 1/4" or 3/8" bolts for each pillar.

So - recap - how should I secure these to the pillars? Any suggestions would be appreciated.

Thanks,

C

 

[Inertiaman]

I am building a panel bed that attaches at the C and D pillars in my 144 so I can offer some suggestions.

My design uses, at each corner, 12 inches of L-track with an intermediate "shim" of machined PVC to conform the pillar curve to a plumb line. VHB tape between pillar and shim, and between L track and shim. Five 1/4" bolts through the L track and shim to rivnuts in the pillar. The upper three rivnuts are "Riv-Float" (search that term at McMaster-Carr) to permit off-axis bolt into the rivnut where the pillar is curved.

This spreads the load of the rails across enough surface and enough bolts that I'm content it will be robust. It also permits height adjustment of the rails, which are bolted to the L track using L track stud fittings. My L tracks are in the 27-39" range, but there is no reason a similar approach couldn't work at 44" or 18" other than the interference on the D pillar between 18" and 27" of the door bracket & corner brace.

For your situation, the lower bed is easier because the pillars are plumb from the floor to ~ 28". You also have the option of spreading the load to the floor through some sort of leg. Above 18" at the D pillar you encounter interference with the rear door bracket and a corner reinforcement, so you'll need to consider that. A crude solution is vertical 18" 2x4s abutted to the floor and also bolted to the walls/pillars though rivnuts, and the rails bolted to the 2x4s.

For your upper bed, the pillars are curving in significantly at the 44" point. The crudest solution would be 2x6 and three or four bolts/rivnuts on each pillar. Do some rough shaping of the wood to fit to the curve, and use Gorilla Glue or similar in addition to the bolts/rivnuts. Counterbore the 2x6 for the bolt heads so the bolts can be off-axis to the 2x6 and on-axis to the rivnut. Achieve horizontal attachment points for bed panels by notching or planing the wood edge, unless you are able to sufficiently shape the wood at the pillar interface to leave the 2x6 edge horizontal.

The D pillar attachments are the most challenging. At 44" you only have about 1.5" width or less to attach, so the one option for spreading the load is vertically. Also, the bolts are at the very end of the rail. If using a 2x6, three 1/4" bolts on 1.5" centers can reasonably spread the load, and with glue it will likely be sufficient, but not super confidence inspiring. This all assumes you are attaching to the wall edge of the pillar, not the much larger forward facing side or door facing side of the D pillar, which both carry their own obstacles to use for rail mounting.

 

[Inertiaman]

I replied before looking at your drawings. Interesting rail cross section. Where will you acquire such a channel extrusion? Aluminum or steel? Looks like you're assuming some welding (see a corner bead drawn at the rail/panel-stop junction).

 

[Corbury1492]

Hi - thanks for the great ideas.

I like the idea of the L-track - makes sense to spread the load with 4 nutserts. Do you think that the L-track stud connection will be strong enough? One L-track stud fitting per corner?

Also - what size nutserts are you using (I would really appreciate the exact part numbers - for float and standard). I was having issues figuring out what the metal thickness is and I did not want to order the wrong nutserts.

Also - here is a detail of the section. I was able to get 4 of these fabricated locally and powder-coated for $550.

Here are the finished rails:

I have not fabricated the bed panels yet - as I would like to measure and build them to the ultimate dimension of the installed rails (with a little space - not too tight).

 

[Corbury1492]

This is a great idea.

I sketched up what I think you are describing below. Is this what you are thinking?

And I guess you are using something like this:
http://www.cargoequipmentcorp.com/Wheelchair-Tie-Down-Sure-Lok-p/fe200739.htm

I might not use the VBH tape - because I'd like to be able to remove the shim (if I need to).

Thoughts?

 

[Inertiaman]

Your sketch does reflect what I was describing. Determining the shim shape was non-trivial. I used a 10" long contour gauge placed against the pillar and aligned against a contrived/temporary plumb vertical beam I clamped in near the wall. Its not a flat/slanting line, there is an arc to it. I then clamped the contour gauge so each little "finger" wouldn't move, and I measured the displacement from plumb at 1/4" intervals over the 10" length using a digital caliper. Then I entered those numbers in Excel and interpolated to get a list of 100 shim depth numbers across the 10 inch length. The lowest 2 inches of my L track require the same shim thickness as the last inch of the 10 (since the wall becomes vertical at that point) so I just extend the last depth numbers for 10 thru 12 inch points. The next step is to machine some PVC to this shape. I have a mini-mill that I can use, but I may just have give the numbers to a CNC guy and have it done.

My rails are 4" tall and 1.5" wide, so I have sufficient height to support two studs from the L track on each corner, spaced 2 inches apart. Your rails only have 2" height before the radius, so two studs is a problem. 1" stud spacing doesn't work on the L track, as the fittings can't be placed that close. 2" is the minimum stud spacing, at least with the studs I'm using, or with the ones you linked to above. I'd suggest welding a vertical extension plate at that point on your rails, so you could use two studs per corner, but that's a shame to re-work, given that you've already powder coated the rails.

The 3/8" studs themselves can easily support the load at each corner, so a single stud isn't a concern in that respect. My concern would be based more on structural rigidity. Twisting/torsion/shifting can happen more easily with a single point connection, as opposed to two points.

I suppose there is no harm in trying a single stud connection and checking it out. The same L-track/shim arrangement can be used for a single stud, or for two studs if you decide later that the rails need a second stud and perhaps you modify them to support that.

FWIW, here are the studs I used:
http://www.cargocontrolstore.com/single-l-fitting-with-stud-nut.html

And the track I'm using:
http://www.cargocontrolstore.com/series-l-track-and-mounting-holes.html

Cargocontrolstore.com was the cheapest by far for track and fittings. Its all Sure-lok products, same or better than most, so nothing sketchy despite the low prices. Shipping was fair.

 

[Inertiaman]

With L track you are largely confined to 1/4" bolts since the track base thickness isn't sufficient to support a 5/16" countersink (some exceptions to this, but not easily acquired). Also, the largest Riv-float inserts available are 1/4". Those two reasons are why I went w/ 1/4". The Riv-float p/n at McMaster-Carr is 93669A230 and the regular insert is 95105A143.

 

[Corbury1492]

Awesome - I will order those parts from mcmaster-carr - and the L-track.

I'm thinking that I have 2 options:
1. weld shim to rail - fasten l-track flat to pillar (with minimal shim to accommodate the curve). Then use one L-track bolt to hold it on (per corner). Down side is welding already powder-coated piece (but it is the back) and this relies on the welding angle being perfect.

2. use PVC shim - same as you are describing. Benefits are can tweak PVC with bandsaw and sand paper. Downside is that rails will protrude more into the space.

I leaning toward option 2.

Thanks for the great advice.

 

[312d]

i cant see anything, why?
please use the in house picture uploader, so they will stay in the fórum

 

[Inertiaman]

Downside is that rails will protrude more into the space.

Using PVC (or nylon, or dense hardwood) needn't add substantial protrusion. Just have the upper portion of the shim be as thin as manageable, maybe 1/8" or certainly no more than 1/4"??
With a 5" length of L track (and 3 bolts/rivnuts) or 7" length (and 4 bolts/rivnuts) the offset from the pillar (= thickness of shim) at the bottom of shim will only be about 1/2-3/4" if you can keep the top of the shim < 1/4".

 

[DieselFumes]

1. weld shim to rail - fasten l-track flat to pillar

Then your bed panels would need to be different widths if you moved the rails up/down.

2. use PVC shim - same as you are describing.

This is the only way to be able to use the same bed panels at different heights on the l-track mounted vertically in the van

 

[220629]

If the intention is to have equal spacing side to side using L-track and Rivnuts...

Why not install vertical sections of L-track which extend to the floor? That takes the down force to the floor. The L-track attachment bolts/studs to the Rivnuts can be screwed in to proper length and locked to length using a lock washer and nut tightened against the inside of the L-track. The bolts/studs would then be easy to custom adjust to act as standoffs.

There's varied solutions using L-track and E-track depending upon how you design it.

vic

 

[Corbury1492]

If the intention is to have equal spacing side to side using L-track and Rivnuts...

Why not install vertical sections of L-track which extend to the floor? That takes the down force to the floor. The L-track attachment bolts/studs to the Rivnuts can be screwed in to proper length and locked to length using a lock washer and nut tightened against the inside of the L-track. The bolts/studs would then be easy to custom adjust to act as standoffs.

There's varied solutions using L-track and E-track depending upon how you design it.

vic

This is a good idea - but I'm trying to:
1. Limit the modifications to the interior (at least for now)
2. Locate an upper bed in the window area - so the L-track would be tilted in - at that location (but I could shim the rails to vertical)

Additionally - at the sliding door c-pillar - there is a bump out up to about 30"(?) - so i would need to cut the l-track and re-route it in this area (to keep it in contact with the pillar).

 

[220629]

This is a good idea - but I'm trying to:
1. Limit the modifications to the interior (at least for now)
...

One inexpensive temporary solution could be using dimensional lumber. No fancy tools or alterations are needed. It could be easily removed when (if?) you decide to get more permanent.

Here's one thread.

https://sprinter-source.com/forums/showthread.php?t=39185

There are other threads where bed solutions are discussed. A search from the blue bar above will get them.

vic

 

[aboes81]

I used 2 inch angle steel (1/8 inch thick) for my bed rail. They are attached with one rivit-nut on each corner (on the c and d pillars). Then used a 2x4 as a leg between the wheel well on the rail. The bed is 43 or 44 inches high.

 

[Groovy2]

look at a basic steel bed frame -
amazingly simple and sturdy and many fold up -
make something similar -

 

[jsilver]

I mounted about 1/8" X 3"sheet steel to the pillars between the windows, screwed in (some rivnuts). Had welded angle steel between them, along the sides of the van. The guy who did it fitted the steel plate to the pillars, marked where the angle steel would be, and took the plates out to weld on the rails.

pics are in my album under bed rail mounting

John

 

[Corbury1492]

I mounted about 1/8" X 3"sheet steel to the pillars between the windows, screwed in (some rivnuts). Had welded angle steel between them, along the sides of the van. The guy who did it fitted the steel plate to the pillars, marked where the angle steel would be, and took the plates out to weld on the rails.

pics are in my album under bed rail mounting

John

I went looking for your album - and I found this thread https://sprinter-source.com/forums/showthread.php?t=36959
(still have not found the album)

Anyway - I modeled my rails off some rails that I saw on a buddy's Van Specialties sprinter (which I believe are similar to the Outside Van rails). I would have had the VS guys do the work - but I am on the east coast and shipping the van back and forth for a minimal amount of work would be crazy expensive. I've looked a little and I have not found anyone on east coast that does work like VS.

Anyway - I found a local sheet metal place - sent them the drawings and they fabricated the rails perfectly. They look exactly like the VS rails. Including powder coating it was less than $150 per rail. Now I am trying to figure out the best way to install them.

I will now try to find the album - thanks.

 

[GrayGhost]

Then your bed panels would need to be different widths if you moved the rails up/down.



This is the only way to be able to use the same bed panels at different heights on the l-track mounted vertically in the van

He could have the bed rails slide into each other to create a telescoping system that would accommodate different widths.

 

[220629]

He could have the bed rails slide into each other to create a telescoping system that would accommodate different widths.

The IKEA Skorva beams may work for that.

...

I made the frame with ikea skorva beams which are cool because they are telescoping/adjustable, and $10. You'll have to ask the "as is" dept for some skorva mounting plates because those usually just come with the beds.

The IKEA Skorva bed beams looked interesting so I did the Google.

SKORVA: Swëdish for "Go back to the store"

We assembled the bed from head to foot. It looked beautiful......then came this phantom "midbeam" the directions pictured. Alas, it was in none of the boxes that were required for us to build the bed. A phonecall later and a couple "wtf" moments later, it was decided:
1. No, i will not elect to pay 78 dollars for a 10 dollar part to be shipped to me within 3 days.
2. Yes, i will be driving back to Atlanta to walk in the store and pick it up myself.

https://www.flickr.com/photos/optikalblitz/3232592916/


Skorva Beams look like they would work with the notched 2 x 4's and probably other types of side wall supports. My concept would be to cut the Skorva beam ends off by about 1" each (for better thickness) so they can be set upside down into the 2 x 4 notches. Double check for the application as to date I have never personally seen a Skorva beam. It looks very promising though.

A Fast Pin could be used to hold the slip adjustment to the correct length and still allow the beams to be collapsed/shortened for storage.

Quick Release Fast Pin

View attachment 67098

After further reflection I believe that this is a better design for securing IKEA Skorva side to side.
Alternatively a single screw into the 2x4 pocket on each end of the cut down length, upside down Skorva beam will hold position and eliminate the need for a keeper pin.

I recall one member who used 3/4" plywood without any cross supports. Doesn't get much simpler than that. I don't have the link for that method.

To hold my bed platform plywood into place I use 1/4 - 20 studs with washers and wing nuts on the four corners (studs screwed into the 2 x 4). For the center sections I just drilled 2 holes straddling a few aluminum cross supports and tie them onto the cross supports with heavy cord.

vic

As always, clicking the blue arrow icon within any quote box will take you to the original post/thread.

vic