Thoughts on my design

[wlivesey]

Ya know...and it's just an idea...you could do a trolley top. It would open up a lot of space from the front to the rear depending on your design. This is what I've done, but the principal/engineering can be modified to suit your needs, and I don't think the work would be that much more than trying to do a lift top, and the + is open the door and it's there, doesn't need to be raised. Doug

Doug's trolley top is looking more appealing every day... Not giving up yet though...

[angib]

I plan on using some sort of latch on the inside that would pull the folding sections together. That should, in my thinking, ensure a tight seal.

Bill, the only reason for using an aluminium strip was because it's fairly thin - a wood 1x2 could be used instead but that means the pop-up roof has to get bigger to fit over the extra width/length - it's only 1.5" more (3/4" either side/end), but you'll be running out of a spare 1.5" very soon......

I can't see that your latching idea will work at all - you need, let's say, a 1/8" clearance between moving parts, plus the amount the seal is compressed, so that's something like 1/4" of movement needed. Now near the top of the 'walls' where they're free to move, that's no problem, but down the bottom you're trying to flex the hinges sideways by that 1/4" and that won't work (unless it rips the hinges out).

There's always some (maybe a lot), and it will end up inside when the mechanism folds, no matter what seal you use.

That's why a step is needed around the base of the 'walls'. I reckon a 1/2" or 3/4" step is sufficient. I've sketched it out here in cross-section:



But of course that's another 1/2" to 3/4" that has to get added to the depth of the roof - in reality the roof has to be at least 5" deep, so it's no longer the shallow 1-2" that Bill had in his illustration.

I knew this could be complicated but it seems to be getting more complex every day.

Nope, it ain't started getting complex yet - there's much worse yet to come!

Next you will need to look at each joint and work out how to seal it effectively. When you do that, it's likely that you will need A to overlap B - which means that A is now bigger than B and that means A will hit B as it folds down, or else C will hit A. And so it goes*.

And once you've got each joint sorted out, you then notice at that the points where the joints meet, there is a 1/4" hole. Now you can forget about this.... at least until the day you're sleeping underneath that hole in heavy rain.

One thing that's worth considering is that it isn't really necessary for everything to hinge into place - you already have a loose roof that you're just lifting with your hands, so why not just lift two of the side/end 'walls' into place by hand? This might allow the roof to be much simpler and/or more watertight.

Andrew
*In memory of the late Kurt Vonnegut, of course.

[jeep_bluetj]

I'm absoutely in love with "transformer" trailers -- I think about pop-tops alot.

One simple way to handle the original "all solid" top so that it'll seal when up is some canvas (or vinyl or whatever). Won't BE a tent (you have hard walls inside) but the tentage goes from halfway up the poptop to the outside of your raised portion. (I'd draw a pic, but don't draw as fast as you guys)

When down, the tentage folds down inside. When up it provides the seal.

Downsides are:
1. It's tentage (I HATE tents.... ) And may not be visually pleasing.
2. Likely rules out windows in the top part.

[wlivesey]

the tentage goes from halfway up the poptop to the outside of your raised portion.

I see, like some sort of boot around the bottom to keep water away. That makes since - It seems like a simple enough design. I think I've just about got this design worked out. I'll post it soon to see what everybody thinks.

-Bill

[wlivesey]

I'm absoutely in love with "transformer" trailers -- I think about pop-tops alot.

Me too... I've got a couple other ideas up my sleave that, though probably unreasonable for the most part, will make a neat concept ttt.

[wlivesey]

I think I've got most of the poptop problems work out. Though it looks almost the same, I started over on the design and included seals and latches. Now, every seam has a seal, and the panels fold down on each other without droppping down into the cabin - I'm hoping this will help minimize the amount of water that could be allowed into the cabin if the windows are wet when they are closed.

I've got one more problem I see that I would love some help with. The rest of the poptop is pretty slick, I'd like a slick solution to this problem as well... How should I secure the roof to the panels in both the up and down positions? The up position should be pretty easy. Spring latches should work fine. The down position might take some creativity to come up with a nice, easy to use solution. Here are some pics that should help explain the problem.

First the animation of how it works... Notice the roof is free floating...
<img src="http://docs.google.com/FilePage?id=dfs967x9_25dwjc58c2">

Here is how it looks from the top when folded down. I made the roof transparent to make it easier to see the folded window panels.
<img src="http://docs.google.com/FilePage?id=dfs967x9_27fr84f9ff">

Here is a picture of how things look from the inside when the poptop is down. Notice the latches and stoppers to support everything. (I may do away with the stoppers and just use the latches.)
<img src="http://docs.google.com/FilePage?id=dfs967x9_29rkpskcds">

This is a picture with the only access to the roof highlighted in yellow. When the poptop is down, I need to be able to secure the roof so it doesn't blow off while I'm driving down the road. Any ideas how to secure everything?

The spring latches at the sides can secure the bottom panels down, but the panels above them and the roof itself are just resting on top at the moment. I need to be able to hold everything down. I've got a couple of ideas but I want to see if anyone else has a better idea.
<img src="http://docs.google.com/FilePage?id=dfs967x9_31cfgb35dd">


If you've made it this far through my post, thanks for your interest!

-Bill

[jay]

this is a fantastic planning exercise and the graphics are excellent. if it gets into production there should be a documentary made!

[wlivesey]

this is a fantastic planning exercise and the graphics are excellent. if it gets into production there should be a documentary made!

Thanks so much! With all the effort that's been contributed by this community I feel like I owe it to you all to see it through and build my PopTop design. I'll definately take lots of pictures and post everything here for all to see.

-Bill

[wlivesey]

The design above is using 1.5'' thick insulated walls and roof. Just for fun I made the walls .75'' thick (I figure .75 ply could be used, uninsulated), this dropped the total height of the poptop to 3.25''... Much lower, now. I like that but I don't know about going uninsulated.

[bobhenry]

Bill , It appears you have a 4" x 8" +/- opening past the walls to the roof. If a 4x8 block the depth of your 2 wall thichnesses ie 1 1/2" was attached to the roof and a large comfortablt lift handle was mounted on it it would help you control the roof as you lifted. This block would act as an alignment pin to center your roof correctly. The addition of 2 window sash locks would lock the roof down to the bottom set of walls. You might want to look at sash locks instead of barrel bolts to latch down the wall sections as well.

[wlivesey]

Bill , It appears you have a 4" x 8" +/- opening past the walls to the roof. If a 4x8 block the depth of your 2 wall thichnesses ie 1 1/2" was attached to the roof and a large comfortablt lift handle was mounted on it it would help you control the roof as you lifted. This block would act as an alignment pin to center your roof correctly. The addition of 2 window sash locks would lock the roof down to the bottom set of walls. You might want to look at sash locks instead of barrel bolts to latch down the wall sections as well.

Good, it looks like the pictures help show the problem... My concern with that idea is that the block, I'm assuming, would be attched to the roof. That would limit headroom. Unless, ofcourse, the block could be removed once the roof was up.

Sash locks are a good idea. I was thinking spirng loaded barrel bolts would work too though.

[angib]

You've now got a perfect duplicate of the pop-up roof of George Teague's Compact GT - he just put latches on the outside, which is a KISS solution.

Andrew

[Miriam C.]

You've now got a perfect duplicate of the pop-up roof of George Teague's Compact GT - he just put latches on the outside, which is a KISS solution.

Andrew

I guess there aren't too many ways to do that where it works well. Great Animation though. I would still love to see it built with all the little detail photographed. This will be a fun one to watch.

Can you do some kind of cable release/pressure close thing. That might make it easier for shorter people to get to. Might make a sealing issue again too.

[wlivesey]

You've now got a perfect duplicate of the pop-up roof of George Teague's Compact GT - he just put latches on the outside, which is a KISS solution.

Andrew

Well what do you know... It is remarkably *identicle*. The only issues I have with latches on the outside are appearance and security. Neither of these are big isuues, though.

[wlivesey]

Can you do some kind of cable release/pressure close thing. That might make it easier for shorter people to get to. Might make a sealing issue again too.

I was planning on using piano hinges. I wonder if there is any type of spring loaded hinge that would make it easier??? Maybe a gas strut??? That's getting too complicated, I think. I'm all for a simple solution if one can be had.