tube frame for b4

[damian]

hi

i know the b4 is not quite vintage but i have read around a couple of forums and i like this one best.

i have always liked the tube frame/ sand rail type of look so i though i would give one a go.

since i just got my hands on a b4 i didn't want to completely rebuild it so i decided on a detachable sort of body frame thing.

i have done some brass soldering before so i will use that.

first i wanted to mock one up so i cut some 6x6mm pine strips and got to work with the saw and hot glue gun.

i wanted the entire thing to attach with one body clip so i made it with two of the frame rails locating in the rear shock tower and a body clip at the front.



good old hot glue





this is the single body clip. there is a copper nail coming through the wooden frame and through the stainless skid plate.



couldn't find any suitable sheeting so just wrapped it in an old t-shirt to get a sense of the form.



the most challenging part is having a self supporting rear end to allow the frame to come off as one. the boddy needs to slide forward 6-7mm to release from the shock tower so the rear end is slightly large.

i brought it out for a spin and it is pretty strong (couple of rolls)

the main problem is that is make the buggy look like it is squatting in the rear so i need to give of a bit of a forward lean for the next version.

so that is it for now. will have to get some brass tube and go from there.

on another note here is some thing i think is of great interest i this hobby. it is called polymorph. it is a plastic with melts at 62 celsius. you boil it in water and then shape it by hand or force it into a mould. it is very strong like a nylon. here is a replacement batter cover for my radio. took about ten minutes and clips in like the original

[MayorRC]

Intriguing, I've actually considered piecing together a B4 in a sand rail type style as you have above. Is the wood a mock-up, or do you plan to make it out of metal? Nice work!

[damian]

yes the wood is a mock up. i am working on a brass one now. because the frame is in addition to the regular chassis i would prefer the weight of aluminium but it seems a pain to weld or solder.

the wood one is actually really strong and light. i may make a new wooden one with neater joins.

the brass one is nearly done and weighs 160g while the wooden one is a mere 40g.

[damian]

an update on the brass frame. ran out of brass so it's stalled just now.



when i ran the wooden frame i gathered loads of dirt in the chassis so designed this frame to fit over the stock body to keep dirt out.







i quite like the asymmetrical rear end as the transmission is asymmetrical. in the last picture you can see the slipper nut cover is white. i made this from polymorph as i got the car with no cover.



at the rear i used different sizes of brass so i could drill right through for extra strength compared to a fish mouth joint. be cause the rear end hangs out the back unsupported strength is more important here than elsewhere.



this is the key to the whole thing. these two lugs fit into the rear shock tower and hold the whole rear of the frame in place with the front held by a body clip.

thats it for now till i get some more brass. i am also thinking about sheet material to enclose the whole thing. im thinking polypropylene sheeting for durability.

[kevin107]

That looks like it's coming along nice. I have always loved the look of sandrail buggies.

[teman]

Nice work Find someone with a vacuum former to pull a body out of lexan, you basically have the "mold" for it right there

[damian]

i wish i had access to vacuum former. i used one a lot in college. i would need to cover it with something solid enough to resist the vacuum to get flat sides. i am hoping to work up something from flat pp sheet. btw i dont know why rc bodies are not made of pp. i have vac-formed it in to hemispheres which can be inverted. you just cant crack or tear it.

[teman]

You might be able to cut "body" parts out of lexan and attach them individually somehow either to use directly or in forming?
I don't know of any local forming guy either, I'd dig to have some undertrays made

[damian]

couldn't for the life of me find any plastic sheet to buy so i bought some a4 document folder things with pp covers.



trying to figure out how many panels to divide it into.



working in cereal



assembling the pp sheet.







so that is pretty much how she looks. i think i would like it to be a little slimmer in the middle but i really wanted to fit the stock body under there especially as i might bring it to the beach.



i know from previous experience that you can't glue pp too well so i went with a melted stitch rivet. i poked a soldering iron through and then flattened the molten plastic with a piece of metal. this is the bonnet (hood) attaching to the side. the roof is cut out attached to the right side piece and melted onto the left side. both sides are melted to the bonnet.

[THUNDERSTRIKE1]

The pp sheets give it that original sheetmetal road warerior look.Lookin great so far.DON

[damian]

yeah in the past i have not liked using that soldering iron method but it actually suits the body. the "rivets" could be used all over the place.

[biff85ta]

You could have just wrapped it in fleece and coated it is resin.

[fireguy14]

That is outstanding!! Very nice work indeed!

[damian]

so i brought these monstrosities for a test today and realised i have un matched wheels. so i did a light light editing and was wondering is it possible to dye white wheels to this pro-line yellow?

[damian]

i have a question about weight.
what is a decent weight for a b4?
with a 5000mah 2 cell and normal body it comes in at 1580g.
with the brass frame it is 1770g.
i know that is a pretty hefty weight increase but for bashing the brass frame looks much cooler and protects the shock towers a lot.
does any one have a b4 to measure?