I'm too old, they won't take my sperm. My boys are fine where they are, they are enjoying the rest after many years of abuse. :lol:

Been trying to make a few drawings of what I want to do but it's kind of hard without having the actual truck in front of me. And I'm doing this in the middle of packing boxes because we're moving in three days. Anyway, here's what I have for now. Many adjustments and modifications will need to be done once I get the truck and I can physically check if things will fit. From what I have now, the size of lipos would be limited. I would try to fit the Losi Muggy steering bell crank in there, secured to the bottom plate. I would like to use the E-Revo tranny but it needs to be positionned to the front a bit so I don't know yet what to do about the center shafts.
I thought of making the top plate out of 3 mm CF, the bottom plate out of 3 mm thick T6 6061 aluminum and the rails from Delrin blocks if I can get a supplier from the web. I would need to buy a new tool to make the rails, a band saw. Been wanting a band saw for a long time and never got around to buying one. Here's some pics.

Lower plate
http://i177.photobucket.com/albums/w...sis_plate1.jpg

Upper plate
http://i177.photobucket.com/albums/w...sis_plate1.jpg

Rails
http://i177.photobucket.com/albums/w...sis_rails1.jpg

Bonus pic
http://i177.photobucket.com/albums/w...l_concept1.jpg

Here's a second concept with straight chassis rails that should be much easier to make and separate front, middle and rear skid plates that overlap each other in the middle. I made it into a little movie.

http://i177.photobucket.com/albums/w...l_concept2.jpg

Looking good so far. I should have those XXL dimensions for you in a couple days.

So now your only solid piece front-to-back will be the upper plate. Everything else is in three sections. I'm not sure, but will the CF plate be able to bear the brunt of the forces, or will it be a weak point?

Here's my thought: You could make the lower plate a single piece Al plate from front to back, but more narrow than your present center section (just as wide as the widest parts of the top plate. Then you could add CF "wings" in the middle as battery trays. If that makes sense.

JThiessen, thanks, it will help a lot.

brian015, yes what you explained made a lot of sense. This last concept was to try to have simpler chassis rails, they are basically bar stock cut to size and drilled in the right places for screws and bolts. They would be so easy to make and so much cheaper in price for the raw material. A solid one piece lower plate was in my first concept but I thought that having a separate front, middle and rear is also interesting. The front and rear plates usually wear out faster than the middle, when they need to be replaced then you don't have to replace the whole bottom plate. Even though they are separate, they do overlap each other which brings more stiffness and strength to the chassis as a complete unit. Also, I plan to use long M4 screws that go through the bottom plate, the chassis rails and the top plate with a lock nut on top to sandwich everything together and lock every part as strongly as possible. I'm still just playing around with ideas so keep on giving your feedback, it will definitely help me to come up with a final concept.
And please tell me if you see anything that couldn't possibly be done because I still don't have the truck, I'm just figuring out stuff just by looking at pics from other builds and exploded views.

Since you and I are doing the same thing right now, some details that I see as tough to overcome:
1) Replacing the rails. The rails taper up and in the back on the bottom (I believe the front is just a taper inboard). This taper interfaces with the bulkhead support/mounting plate. Nailing this part down will be tough via reverse engineering. Not impossible though. This is the only reason I have chosen to keep the stock rails.

2) I also think the three part chassis might prove to have too many joints over time. I really think that having a continuous member from front to back is very critical to the flex and structural rigidity of the chassis.

If you are going to make a one piece bottom chassis, you could keep it flat to avoid the the taper issue. Or, get a muggy chassis and mod that to your needs.

MC - check my thread. I put up some new pdf's of the plates for ya. http://www.rc-monster.com/forum/show...781#post355781

Thanks JT that's great.

Alright, a front and rear skid plate, overlapping a center bottom plate, with two ''one piece'' chassis rails and a top plate with XXL specs. I can't wait to get the truck to see if this is doable.

http://i177.photobucket.com/albums/w...s_concept1.jpg

Those one-piece rails are going to be your most difficult fab work. I wonder if they're worth it. The weak point in your three-piece lower plate is obviously at the joints (and what you said above about sandwiching all four layers at that point with M4 screws sounded semi-convincing to me :wink:). And it's at that weak point that your one-piece rails have their kinks. I'm not sure that turning your previous three-piece rails back into one-piece rails is going to add any rigidity to the chassis. I imagine the kinks in the rails would allow the rails to bend up and down at that point (where straight rails would not). So, I don't know if it's worth all the effort to make them.

Those are my thoughts trying to imagine how it would work when stressed - I don't think the one-piece rails would be a great advantage over the three-piece rails in reducing the stress on the CF top plate.

My vote: try your previous plan (3-piece bottom plate and rails) and if it fails go for a one-piece bottom plate.



So - when are you expecting to get your truck? (or is this just an elaborate thought-experiment? :lol: )

Look at your chassis from the side. Now imagine a load being applied from the top. The chassis will bend downward in the middle, forming a "U" shape. With a solid piece running from front to back, the stresses in the chassis are linearly distributed through the member. When you have changes in shape, those stresses are passed through the most direct path. In your case, it will be through the fasteners and the holes for the fasteners. Now remember, you are looking at it from the side....you only have a single fastener line when looking at it from this direction. All those stresses are going to be passed through that fastener, and the thickness of each SINGLE piece of material. I'd predict an immediate failure - first at the bottom most piece - it will try to pull the fastener forward though the hole. The fastener being harder, will tear through the aluminum. Give your self at least two fasteners at each joint when looking at it from the side, maybe three.

For now, it's just trying to come up with a nice electric conversion that looks factory made. I really want the LST, when will I be able to get it is unknown :neutral: We just bought a new and bigger house and we are still unpacking from the move three days ago :yes: Lots of work to do around this house but I still want to squeeze this truck in.
As for the three piece bottom plate, it is no different than the stock truck, the XXL uses a rear and front skid plate and a middle one that are not touching each other as far as I know. They all look separately secured to the chassis rails. What I show in the last movie are three bottom plates that overlap each other to form a flat bottom. This is because the center plate would be lower than the stock one. At the same level with the front and rear plates. The center plate also houses the batteries so the lower it is, the better for a low CG.
With the help of a band saw, the one piece chassis rails should be fairly easy to make with a bit of planning. The hard part might be to find the raw material to make them at a reasonable price. I still don't know how high the stock chassis rails are, if they are 1.5 inches high or less, I should be able to find material to fabricate at a good price. If they are higher than that then I might have some difficulties.
Thanks for your feedback, I appreciate it.

On the stock chassis, the plastic rail and the top plate do all the load carrying. The center plate keeps the lower rails from spreading apart when a load is applied. The front and rear skids aren't part of the equation.

The stock rail is something around .983 thick in the center - I havent measured the ends. Probably somewhere around 1.25" or so.

I went back and looked at your vid again. For some reason, I thought that your center rails were three piece.....sorry!

What CAD are you using? I might be able to send you my CAD files.