B1M bolt-in mid motor conversion kit

[lmw94002]

You could always to the racing cut-down tub w/ nice edges to remove that notch... a bit of work, but solves the ugly notch in an otherwise nice tub.

Do you know if you can get those battery cup source files anywhere? It'd give me a good reason to try to get my 3D printer up and running again. lol

[mk-Zero]

Yeah, I'll cut the sides down eventually, just too lazy and wanting to concentrate on the mid-motor conversion itself for now.

Sorry, I generally don't make my source code files available. If you are interested in a set, you can find them here https://www.shapeways.com/product/ZH83HYQNQ/rc10-transverse-shortie-pack-battery-cups?optionId=59794612&li=shop-inventory

[mk-Zero]

Runner status!




Took it up and down the street a couple times last night. That weight distribution seems pretty sweet, it just takes off like a bat out of hell, no wheelies.
I need to rebuild a the shocks and the diff and glue up some new tires then I think it will be ready for the track on Thursday. Guess I need to figure out what I'm doing for a body too. I'll use b5m wing mounts for the wing.

[mk-Zero]

Well, thanks to Photobucket this thread is completely f***ed now... I'll see about fixing some of the pics later.

Anyway, I crappily (is that a word?) painted a body, and glued up some new Dirt Webs and took the car to the track last night (indoor clay). Once I got the tires a bit broken it the car was fantastic, considering some setup challenges. I'm running World's CVAs in the back, and as you all probably know they are too short. So I ended up putting tons of spacers in my rear shocks and running very little droop, which made the back end a little loose. Also, rear springs were a bit too stiff. Aside from those setup issues the car was a blast to drive. I didn't even end up driving my 44.3, I just wanted to keep driving the 10M all night. The car has tons of steering and jumps very level and is easy to control in the air. I was keeping up with modern cars with good drivers later in the evening as I got used to the car and the tires broke in. With some dialing of the setup and some more "seat time" with it it's going to be an absolute beast.

So far the conversion seems very durable. I had many a horrific crash including lots of cartwheels (when I was getting used to the car and the tires weren't broken in) and everything survived perfectly.

The best thing to me is that I didn't have to drill a single hole in the car or make a single cut to any original parts including the pan. I could switch the car back to rear motor and no one would ever know it had been a mid motor at some point. That was my goal, I think I managed to pull it off

[mk-Zero]

Here's a video I made of the project.
I got some softer rear springs (black) for the back and put in some lighter oil in the rear, we'll see how that affects handling. I also added extended front axles.
It's funny, the car has so much less weight on the rear axles compared to a normal RC10 that even with the very soft black rear springs and the collars all the way up the rear ride height is still a bit too high. I'll probably have to go in one hole on the rear arm shock holes to soften it up a little more. I'm taking the car to the track again tomorrow night, so we'll so how dialed in I can get it.

[lmw94002]

That is an awesome video. Love seeing it all up close like that.

As for rear suspension / ride height... with so much weight moved forward, would you consider using a slightly shorter shock shaft and/or shorter shock body? I'd love to drive that car and compare it to a regular RC10 at the local track.

[mk-Zero]

Thanks, glad you liked the video.

I'm not sure on the rear springs and shocks, I need to drive the car more and see what it needs. On the bench, the black rear springs "feel" about right, other than being a bit long. If anything on the rear shocks I would want to go longer with a taller tower to give me more room to reduce the preload on the springs. We'll see.

[GoMachV]

The Facebook crowd is enjoying the video.

All except one person, who is asking "why". Lol. Always gotta be a troll or two

[jwscab]

video looks great. I was thinkin maybe there should be some kinda rear brace to tie in the chassis tail to something......

[mk-Zero]

Thanks guys. I'm going to design a rear brace to reinforce the motor guard. It will use two tubes like the front braces. Maybe I'll design them today or tomorrow and make some this weekend
I had a similar brace on my B1M project, I'd post a pic, but, photofuckit...

All except one person, who is asking "why". Lol. Always gotta be a troll or two

Why? Because I can

[lmw94002]

Yeah, more tubes... to be anodized and can look slick if the front and back match.

[JK Racing]

Why? Because I can

Agreed....

[mk-Zero]

I had a good outing with the car last night. And again I was having so much fun with it I didn't even drive my 44.3. Poor thing
Anyway, the setup is getting really good. It now has proper droop and softer rear springs and oil and so the back of the car is much more stable. But it still turns really well. Here's a video of a friend who's a much better driver than me driving it. He wants to build one now

[lmw94002]

Looking good. Sounds like the back end might be slapping the ground though?

[mk-Zero]

It's possible that it was a little. Hell, my 44.3 slaps the chassis from time to time. The suspension could probably stand to be a little stiffer, but the car is well-balanced now front to rear. I'll keep messing with it.