'77 Excella 500 31' Off Road Build

[Mikebrady62]

Great progress Gary! Are you having mostly fun so far?

[GPurcell]

Originally Posted by Mikebrady62

Great progress Gary! Are you having mostly fun so far?

So far! still trying to figure out the best way to tackle this floor so everything lines up. Little stressful cutting up board as expensive as the Coosa lol

[GPurcell]

Got my order from Fastenal. I don't think my floor will be coming up anytime soon I love having the 6-lobe drive head too instead of phillips.

Truckasaurus - thanks for the tip on what to order.

[HRTKD]

That is one monster screw! Or you have really small hands. No, it's a monster screw.

[kidjedi]

Originally Posted by GPurcell

Cool something else to look into. I wonder how well the cork would stand up to dogs coming in and out all the time.

The answer: it won't. Take it from someone with a lot of experience with cork floors and dogs.

[GPurcell]

Originally Posted by kidjedi

The answer: it won't. Take it from someone with a lot of experience with cork floors and dogs.

Ok good to know. Most likely will lay the cork down and then some sort of click-lock flooring on top.

[GPurcell]

Originally Posted by HRTKD

That is one monster screw! Or you have really small hands. No, it's a monster screw.

Hahaha definitely a monster screw. Should be seeing how they work soon!

[kidjedi]

Originally Posted by GPurcell

Ok good to know. Most likely will lay the cork down and then some sort of click-lock flooring on top.

It's a bummer, because I'm a midcentury freak and I LOVE cork floors, but after 15 years with several kinds of floor (click lock at varying degrees of expense, rolled, glued tile, etc.) and three different dogs (Doberman - no issues, Pit/Boxer - destruction, Hound/Dobie mix (spaz) - absolute disintegration), I would never install them in an RV with that much traffic (at this point, I wouldn't even use them in a home unless it was a very low traffic area).

There is probably a better insulating material than cork to lay under LPV or whatever flooring you choose. A lot of the "sound mats" have decent thermal insulative properties, but I still think you'd be happiest with some polyisocynurate panels on the underside of the subfloor.

[GPurcell]

Originally Posted by kidjedi

It's a bummer, because I'm a midcentury freak and I LOVE cork floors, but after 15 years with several kinds of floor (click lock at varying degrees of expense, rolled, glued tile, etc.) and three different dogs (Doberman - no issues, Pit/Boxer - destruction, Hound/Dobie mix (spaz) - absolute disintegration), I would never install them in an RV with that much traffic (at this point, I wouldn't even use them in a home unless it was a very low traffic area).

There is probably a better insulating material than cork to lay under LPV or whatever flooring you choose. A lot of the "sound mats" have decent thermal insulative properties, but I still think you'd be happiest with some polyisocynurate panels on the underside of the subfloor.

Thanks for the info! Very much appreciate the honesty. I'll have to look into the polyisocynurate compared to other options.

[GPurcell]

Today was a big day.

Got supervised the whole time.


Anyways, test fitted the c-channel


Once the fit was checked, started cutting the Coosa.






Point of no return now




Started fitting the second sheet behind the first.


Here's where I decided to make us stop... I have found one downfall to the Coosa. While yes, it is stronger than plywood, it does flex some more.

With that being said, I have decided to get more angle iron and add floor supports between the outriggers for added rigidity. Do it once - do it right.





Also - so much room for activities with the belly pan above instead of below.

[Zcashio]

It’s looking good! Curious as to if you are still going to wrap the aluminum on the edges (skirts) so the frame isn’t “exposed”? Maybe you mentioned this but I couldn’t remember. Keep up the great work.

[kidjedi]

Shouldn't that Coosa joint be over an outrigger and cross support? Also, do you think the Coosa will flex even when it's fastened down? I'm wondering if that would take care of the flex and save you some work (and weight, though obviously at this point we know you don't really care about weight! )?

I'm getting ready to purchase some Coosa to replace the floor in a GMC motorhome, but I think there is plenty of support in that GMC chassis that I don't need to worry about flex. I am however thinking about cutting some access ports to store/access mechanicals in the belly.

[GPurcell]

Originally Posted by kidjedi

Shouldn't that Coosa joint be over an outrigger and cross support? Also, do you think the Coosa will flex even when it's fastened down? I'm wondering if that would take care of the flex and save you some work (and weight, though obviously at this point we know you don't really care about weight! )?

I'm getting ready to purchase some Coosa to replace the floor in a GMC motorhome, but I think there is plenty of support in that GMC chassis that I don't need to worry about flex. I am however thinking about cutting some access ports to store/access mechanicals in the belly.

That... is something I totally glossed over I may have to mess with it some more

[tbashin]

Post some updates on the off road frame.

[GPurcell]

Originally Posted by tbashin

Post some updates on the off road frame.

Updates coming. Been a little crazy past couple of days.

[GPurcell]

kidjedi - I will be cutting down the boards like you suggested so the joints land on a crossmember.

However - I still will take the time to weld in some more supports. Just feels like the right thing to do.

[HRTKD]

Playing Devil's Advocate here...

Do you really need supports between the outriggers? Once the the trailer is finished, how much foot traffic is there at the edge of the trailer? Most of the edge of a trailer has cabinets or other "stuff" on it, that would span the existing supports.

I don't know how the shell is attached to the frame. I assume that it will attach at the outriggers for sure. But could you also put a screw between the outriggers up into the shell? That would add some support to the Coosa board.

[tbashin]

Originally Posted by kidjedi

You probably already know this, but be aware that there actually needs to be some flex in the frame or you will start popping rivets and possibly creasing panels. I've been researching building a frame from scratch for a couple months. My original thought was "as solid as possible," but evidently that's not the way to go; there needs to be quite a bit of flex for these monocoque designs. I'm also looking at "deck over wheel" possibilities, but I don't want to increase my center of gravity too much (though I do want to raise everything quite a bit to increase clearance by as much as possible). I am also looking at water tank solutions mounted inside the cabin, both to minimize damage from below (rocks, logs, etc.), but also to keep things from freezing in the winter. I am aiming for a Colorado high altitude winter build, so everything needs to hold up to remaining in use at sub-zero temps.

Interesting. I see this mentioned often but I don't get it though. I can't figure out how the monocoque structure needs to have flex or it pops rivets or could buckle.
I would think that being more structurally rigid, it would prevent the flex that causes these issues.
It seems every time I've seen a post of an AS buckling or rivets popping it was because of too much flex or a hard jolt. Rivets were popped by hitting rough roads or trailer twisting, or due to too much WD force, etc.
Buckling of panels, I would think, can only be caused by displacement of the supporting structure in some way, such as when a wrecker tries to pick up by the rear or extreme tail drag situation, etc.
I can't wrap my brain around how more rigid frame would not help maintain the overall integrity of the structure. A properly cushioning suspension being part of the build.

[GPurcell]

Originally Posted by HRTKD

Playing Devil's Advocate here...

Do you really need supports between the outriggers? Once the the trailer is finished, how much foot traffic is there at the edge of the trailer? Most of the edge of a trailer has cabinets or other "stuff" on it, that would span the existing supports.

I don't know how the shell is attached to the frame. I assume that it will attach at the outriggers for sure. But could you also put a screw between the outriggers up into the shell? That would add some support to the Coosa board.

I'm going to be doing that on top of adding more supports.

[GPurcell]

Got some more angle iron. 1/8" 2x2.



Each outrigger will get one support except where the door is. Cut out two for that.



Also decided to cut out one more set of outriggers for the rear of the trailer. It's under where my bed will be but decided that it would be better safe than sorry. One more attachment point too.