Type 2 Ambulance - Pop top trouble

[WhiteWallForty]

So I'm having a bit of a hard time figuring out how to do this without the OG Sportsmobile roof. My idea is to build a subframe for the old school, spring loaded, pop top frame to sit in/on and then cut the roof of the ambo in half *(shown in pic below and) then piece it together that way, but I'm not sure how to attach the tent portion, seal it, or any of that... Has anyone ever done this?

[86Scotty]

The original SMB roof has wooden rails embedded in the fiberglass for strength. They run front to back. This is what supports the top that the frame sits on. I think that will be your biggest obstacle. You might have a roof that is strong enough but you might not be able to tell until you cut it. That is, of course, unless you can find out who made that ambulance roof and ask them how it's made.

As far as making the boxes inside the roof that the X frame moves within (I'm referring to what's attached inside the top of an SMB top), those are simple wood construction and not very complex. Have you looked at some of the top refurb job pics buried in this forum? I'm sure I have a few from years back. I have had a few tops apart.

A couple of folks here have put pop tops on Ambulance roofs and can probably help, but I don't know that it's been done to your style ambulance roof.

Paging @abitibi to the courtesy phone.

[carringb]

The main way that high-roofs got "popped" (mainly by Colorado Camper Vans) was to raise the entire shell. That allowed the fabric to sit inside the shell and attach to the roof opening, like the original SMB pop tops.

I don't think that will work on the ambulance roof however, unless you are able to cut out the entire steel roll structure.

If you bisect the roof like you picture, I think you'll need to mold flanges into both half. Getting the fabric to fit might be difficult with that concept.

Do you need the extra headroom inside? Or just more sleeping space? If it's the latter, what about just mounting a hardshell roof-top-tent up there, and cutting a hatch between the two?

[boywonder]

A few comments......


*EDIT.....after writing all this I noticed that you are just lifting the very top of the ambo roof..........most everything below still applies except for spring loads.



That roof looks like it's quite a bit heavier than a SMB penthouse; consider sleeving the crossbars, they bend all the time on regular SMB vans. Use .750 OD x .083 (or maybe thicker) wall DOM (drawn over mandrel) Cro-mo tubing.

If you can't find the tubing locally McMaster sells it. search for 4130 tubing.

Now is the time to sleeve, as once you get the mech on the roof it goes from a 2 banana job to a 7-8 banana job.


Consider replacing the existing 1/4-20 crap pivot bolts with shoulder screws and saddle spacers; the pivot bolts break all the time too. Do a search here for posts by "Pete" to find the latest improved design.


The roof blocks 86Scotty is talking about retain the crossebars to the roof inside, the front one is simply a fixed ""pivot" for the crossbar to sit in and the rear block allows the crossbar to slide forward about 10" when the top is up. Make the allowable slide length a little longer than 10" so the top can go fully up.

Look at the rails where the rear crossbar is bolted to the slot and the chain, it's also about a 10" slot.

You will need to crank up the extension spring tension a lot based on the weight of the top. Do you have the rear compression "helper" springs? Are they 12" long or 24" long?

I would consider mocking up a 2x4 frame on the ground and fastening the scissor mech/rails to it and then place your roof on that to make sure everything is viable before cutting a hole.

In the stock SMB roof, the canvas is attached to the roof via small screws around the perimeter through the headliner. This means that if you want to remove the headliner to add solar roof wiring etc the canvas falls around your ankles.

The canvas is attached to the metal van roof using 1/4" thick x 2" wide plywood furring strips with a zillion sheet metal screws and butyl tape between the bottom of the canvas and the top of the roof. If your roof is flat use one layer of 1.5" wide butyl tape. The econoline roof has channels etc and there are places where you need up to 3 layers of butyl.

You can buy the butyl tape from McMaster-Carr.

I made similar furring strips to attach the canvas to the top and then installed the headliner over them. This accomplishes two things:

The canvas doesn't fall off when you need to get behind the headliner.

The zillion perimeter screws are all hidden by the headliner; in my van the headliner is held up by the crossbar ceiling blocks discussed above.


Check out the beginning of my build thread for some useful info:


https://www.sportsmobileforum.com/fo...top-10808.html

[boywonder]

Originally Posted by 86Scotty

The original SMB roof has wooden rails embedded in the fiberglass for strength. They run front to back. This is what supports the top that the frame sits on. I think that will be your biggest obstacle.

^^^^^........now that I understand what you are trying to do......

[86Scotty]

Originally Posted by boywonder

^^^^^........now that I understand what you are trying to do......

Yeah, this thread popped in to my head earlier today and I started thinking that any ambulance roof probably has ribs and maybe even much more strength, but probably more weight. I'd love know what's in there.

I'm starting to think the bigger challenge may be what CarringB hinted to, how to achieve a lip around the top to keep water out, how to attach canvas, etc. If it's just thin cut fiberglass where he cuts it on the sides some structure will have to be added to even get small screws through for holding canvas and/or furring strips.

[2Fass240us]

I own a Type 2 McCoy Miller ambulance and haven't come up with a way to raise the roof (lol) that doesn't almost completely negate the point of owning a Type 2. The biggest reason is the rollover structure 86Scotty references. I'm further limited by the fact that I used that roll structure to support a 14' long x 5' wide roof rack.


Aside from the roll structure, the shape of the fiberglass ambulance topper is problematic because there's no great horizontal cutoff line. You're either too close to the drip tray or too close to the top of the topper because of emergency lamp location.


Neither of these challenges is insurmountable, but the juice may not be worth the squeeze and I expect you'd be faced with issues with watertightness even if you could pull it off.