A-Main Bullet Fwd 4ws RC10 conversion Tribute build

[jwscab]

where is the double kick-up that you keep referring to? is it a double kick up front? It's hard to see from the manual.

[Phin]

There's one bend between the trans and arm mounts and another after the arm mounts to form a bumper. In the drawing the bends are the two vertical lines at the front end to the left and right of the arm mount holes.

[GoMachV]

I need to pick up a protractor today and see what the angle needs to be, then ill bend the second bend up front and see how that goes!

Phin, your eyes are a lot better than mine I was so excited how well it fit I didn't even notice the spacing was off. I think the kick up is a lot of that tho, I will reduce it a bit and see how that changes the spacing

[Coelacanth]

Looks great so far. For the record, what's the ballpark for an acceptable kick-up angle, and I imagine it would be slightly different between a 4WD, RWD and FWD car?

[jwscab]

OK, I see. So you could make a single bend, and then add a bumper with a bend on it, would simplify your chassis requirements, especially in custom carbon material.

I'd say the kick up is between 10 and 15 degrees, not much more. More like a 4wd buggy than anything else. I'd probably pick 10 or 12, it's not like you need to design to win a world championship or anything.

[GoMachV]

That's the current hurdle. I'm bad with numbers but the Maxxum had a very shallow kick up, as did the few 4wd buggies that had kick up. About half of a typical buggy. IIRC a CC chassis is 20degrees, I'm guessing 10 degrees would be fine. Once the alloy chassis is made and bent, I'm thinking the blanks could be used as a mold for a few carbon chassis. I have a local shop that deals with composites and should be able to help.

[GoMachV]

OK, I see. So you could make a single bend, and then add a bumper with a bend on it, would simplify your chassis requirements, especially in custom carbon material.

That's the battle though. This is a tribute and we all want to keep it true to the original. I could have made the towers with proper geometry, big bore shocks, stealth trans, etc...but it wouldn't be true to its heritage. We are aiming for the 2 bends in the finished product, hopefully it will be a carbon chassis but I'd prefer aluminum bent properly and laminated with a carbon sticker over the other options if carbon fiber doesn't pan out.

[fredswain]

Most vintage 2wd cars up through the B3, XXX and most of the old aftermarket chassis were 30 degree kick. The original JRX2 was 20. The modern cars are generally 25 but the 22 is adjustable between 20-30. 4wd cars generally fall in the 7-10 degree front kick range.

[jwscab]

eh, i don't think anyone would fault you if you made the second kickup part of a separate bumper, but anyway....I think I remember seeing the yokomo 870C bulkheads from RPM listed as 12 degrees caster. that chassis is flat and the kickup is accomplished with the bulkheads. just pointing out a reference.

[Coelacanth]

Most vintage 2wd cars up through the B3, XXX and most of the old aftermarket chassis were 30 degree kick. The original JRX2 was 20. The modern cars are generally 25 but the 22 is adjustable between 20-30. 4wd cars generally fall in the 7-10 degree front kick range.

So generally speaking, 4WD cars require less kick-up? That's good to know, and it's exactly what I've noticed with most cars these days. The RWD's have a more pronounced kick-up compared to 4WD's, which is very slight. Thanks for the info Fred.

[GoMachV]

Yup, which is also why the mip 4-10 was so oddball, it had 2wd geometry up front. Most 4wd are slight or no kickup and caster is added at the wheel.

That's a good point about the yz10 bulkhead, and as I have seen yz10 using kyosho carriers, angle-wise it should be a good starting point.

[GoMachV]

Well, the kickup was closer to 18 degrees lol! I Kicked it back down to 10 and built a brace to keep it there, and put a 15 degree bend in the bumper. Once the PVC glue cures ill put it back together and see if the clearances between the tower and trans opened up much. The tower I prototyped is 1/16", so we will need a bit more room there anyway!

[Phin]

10 degree should be what you need to put the tower 90 degrees but I don't know if that will be enough to get the arms swept forward like in the manual.

Still recouping from the weekend so haven't gotten a chance to fiddle with the drawing. Should get to it later on tonight or in the morning. I'll also try to do the bellcranks and add the battery cup and servo mounting holes.

[GoMachV]

Well today was not very productive but I do have the kick at 10 degrees now and 15 degree at the bumper. Here are some pics so you can see where we are at. The clearances got better but the bones are for the most part straight not swept.

We're getting there!

[SFC K]

Looking good!