Making a carbon fiber chassis the novice way

[JosephS]

So I had not really noticed before but the t2 rear bulkhead has guides on the side.

I had to re cut the sides of the chassis so the the top of the bump actually fits over the chassis.

Now I am onto the nerve wracking step of drilling.
I have not had to ever precision align multiple holes. I need to get the distances right on each part so they will attach correctly, then as well align each part so that I don’t misalign the suspension.

I’m clamping the donor chassis to the taped up back and I’ll draw the holes first to see how well I do lining it up.

[JosephS]

All measured up right but off by off by a 1/16 on the marking.

I was measured the chassis but drew marks from the traced edges instead of re drawn from the center line.

Easy enough to measure again. Better to tape again then drill twice.

I am assuming that all of the dimensions of the car are done to the 1/16”

[JosephS]

Thinking about it a bit I actually need to make sure the nose piece fits properly and that will have to define the centerline of the car.

The holes I sketched yesterday line up with the holes on a donor nose plate

The chassis is quite rounded inner corners. I used a file and squared them off a little so the nose pice can fit flat on the chassis

The piece fits in and clamps flat with almost no pressure.

I am going to test fit again with a better nose plate then drill out the holes. I have some concerns that the extra thickness of the play will cause issues with the steering mounts but I’ll have to see when it’s all mounted up.

[JosephS]

Getting there. Long hours at work have kept me from finishing this all up.

I finally drilled out most of the chassis holes.

I wound out making a mistake drilling out the nose plate holes. Just a bit off center. Some jb-weld is being used to fill in the holes.The bottom of the holes will be in the counter sink area and top will be under a nose plate. So I don’t expect this to be visible when built.

[JosephS]

All the holes on the bottom of the chassis are now in place except the servo mounting and antenna hole I used a 1/2 drill bit and a file to make the square opening.

[JosephS]

Trimmed up. Rear bulkhead head notched cut. So far things are mounting up and lining up like they should.

Just need a 100degree countersink then to do the cosmetic finish.

[JosephS]

Visual representative of different CF finishes

https://dragonplate.com/dragonplate-finishes

https://diyblog.commonfibers.com/blogs/process/wet-lay-up
https://diyblog.commonfibers.com/blogs/process/hand-trimming
https://diyblog.commonfibers.com/blogs/process/surface-and-edge-prep
https://diyblog.commonfibers.com/blogs/process/clear-coating
https://diyblog.commonfibers.com/blogs/process/buffing-polishing

[JosephS]

Getting there
Holes counter sunk and parts test fitted.

I misdrilled the servo mounting holes then counter sunk them. Should have mounted the nose plate and drilled the first hole though the plate.


The extra thickness of the chassis is causing rubbing from the nose tubes on the steering. I’m going to find the right mount depth an route a small groove in the chassis to make everything clear.


I’ll think a bit how to make that look acceptable.


But the car can drive now if I put electronics in it.

I just need to trim a bit behind the rear bulkhead and then drill the holes in the side of the chassis.

[Dadio]

Looks very strong

[JosephS]

It’s taken a bit but the holes for the front braces and rear braces are in. Now it’s about seeing if I can make this pretty.

[JosephS]

Looks very strong

it's pretty beefy that is for sure, though the original t2 chassis isn't far off. I'm not concerned at all about running it. I don't think it's going to crack.

[JosephS]

I did the patching to pieces of the chassis that were not quite right by mixing carbon dust with epoxy to form a paste and putting that in any holes, scratches and miscuts. The pattern get broken but is an absolute color match. So this is pretty forgiving to work with

I set up the final dressing coat of epoxy for the outside.

I found it saves a lot of effort to use syringes to mix the proper amounts of epoxy for small batches

The kind of resin used for laminating epoxy is very thin and will run right off most surfaces. So I mixed up 20ml of lamination epoxy and added 30ml of 5 minute epoxy to create a thicker epoxy that will stick to the sides of the chassis.

Hopefully that does the trick and I’ll have a coat of material that I can sand down smooth.

I let the results cure over night and did a light sanding. It takes a few days for the epoxy to cure fully solid, but this let me see about what I was going to get. Epoxy was ok on the bottom, but didn't stick to the sides well enough to provide that glass like look.

The chassis was made with some high spots on the curves, making the area next to them low when sanded out.

I'm not going to try for the glass look on the sides. I think I have enough epoxy on them for function. I'll sand as flat as I can but there is going to be some texture in that.

The outside of the chassis is pretty easy to finish off, but the inside will be harder. I will need to apply some additional thin epoxy to the inside of the chassis to fill in some minor de-lamination. I'm going to go as lightly as I can. It's very difficult to smooth and remove excess material from inside the chassis. I'm going to wind up with a highly textured inside of the chassis.

[JosephS]

I have the chassis just about as flat as I can.

I think I have taken this to the edge of what my skill can do. As I complete each sanding pass I seem to tear a hole in the carbon fiber. Not a wear spot but an actual tear.

I’ll mix up some 5min epoxy and use a toothpick to fill this and stop trying to make it better.

It’s nice looking and a tad lighter than stock. 4.8poz vs 5.7

B63FB192-3DB5-4184-A84F-BA24AF89DB0A.jpeg (22.34 KiB) Viewed 855 times

B63FB192-3DB5-4184-A84F-BA24AF89DB0A.jpeg (22.34 KiB) Viewed 855 times

B57D8906-02B2-476C-9482-A07C705263A1.jpeg (19.72 KiB) Viewed 855 times

B57D8906-02B2-476C-9482-A07C705263A1.jpeg (19.72 KiB) Viewed 855 times

Now just some pin hole repair, clear coat and polish are left

[JosephS]

All clear.

[JosephS]

All done.

I actually started a carbon fiber project and ended up with a working chassis