JCAD Karnage Jr. - MRC

[monkeyracer]

A few years back I bought an MRC at a local swap meet and started building the Tiny Terror TJ. I basically haven't touched it since May last year, and was starting to think about what to do with it.

Our local crawl shop (The Crawl Space - Arvada, CO) started a bi-weekly mini comp since the slick rock came out and I figured I would convert this back to a 1.9 Comp Crawler.

I ended up digging through my CAD files and found a version of my Karnage chassis that I scaled down to work with the MRC, and updated the file to the new comp rules and got a set made up.







Originally I was running some old G8 Flat Irons, but they just don't cut it for comp, so I picked up some rovers and made some new wheels for it. I designed a motor/servo plate to mount the full size servo and a small lipo. Also, the transmission needed a motor plate that would fit a 380 motor (running the xtreme 380x heli motor on sidewinder micro), as well as a cover to protect the spur (and quiet down the metal spur/metal pinion) so I made up some parts for that as well.

I like the stance; nice and low, aggressive look:







I've got some small batteries coming as well as some smaller wiring and connectors so I can wire this up right.

So, really this is kind of a "built" thread, but as we know with this hobby there is always something to tweak...

Hope you guys like it... Feel free to post any comments, suggestions or questions.

[Ghost]

it'll never work you need to send it to me for proper disposal, really digging the chassis and the low stance.
get it in the mail tomorrow the summer shootout is coming up soon lol

[Ghost]

also any chance that chassis going into production?

[monkeyracer]

Originally Posted by Ghost

also any chance that chassis going into production?

If there is enough interest, that is a good possibility.
Would probably end up having these cut from delrin or lexan.

[OTHGbronco82]

Originally Posted by monkeyracer

If there is enough interest, that is a good possibility.
Would probably end up having these cut from delrin or lexan.

I'd be down for one in white delrin.

[monkeyracer]

Originally Posted by OTHGbronco82

I'd be down for one in white delrin.

This would look pretty sweet in white delrin... At least to start, I would have to have all the same material, so I might start a separate thread to gauge interest and see what everyone wants as far as color... Keep an eye out for that soon. I'm thinking this would be an almost complete chassis set-up, just drop in your driveline and shocks/links...


I weighed this to see where I was at, and it is right at 2 lbs rtr. (1 lb. 15 oz. without the battery, which is 19 grams (.67 oz), so really just under 2 lbs total.)

I think I am going to try to get some wheel weights on the front axle though to get a better bias. These wheels will support weights as big as VP's brass knuckle weights, so I just need to make a mount for the knuckles I have and get them installed. I had 2 oz in each wheel in my old wheels, so I'd try to stick to around that amount...

[OTHGbronco82]

Originally Posted by monkeyracer

This would look pretty sweet in white delrin...

Plus people could dye it if they wanted to also.

[Ghost]

White would be good and there is always the option to dye it any color you want.

[monkeyracer]

Originally Posted by OTHGbronco82

Plus people could dye it if they wanted to also.

Originally Posted by Ghost

White would be good and there is always the option to dye it any color you want.

That's what I like about lexan, paint it any color you want, or just leave it clear... Talking to some cutters to get price quotes. Probably going to do white delrin for the first run and go from there.

Just made some knuckle weight holders for the GPM knuckles:



These are designed to work with the RC Bros knuckle weights and the mounts are placed to get the half weights clocked toward the front of the knuckle. I may offer these as an option, but would need to get a couple different knuckles to get compatibility down.

More to come soon...

[Ghost]

looks like they will also work with the losi pro aluminum knuckles also

[monkeyracer]

Originally Posted by Ghost

looks like they will also work with the losi pro aluminum knuckles also

Very likely. I would just need to get a hold of a set to test it out. The various designs are not much different with the MRC, with the exception of the high steer knuckles.

Losi:


Hot Racing:


GPM:


3Racing:



The Losi, HR, and GPM all look pretty much the same, and the 3R would likely work as well, but I wouldn't be sure unless I had some in hand.

I'll be going to a comp next Wednesday, so I can see what people are using and try out some fitment if possible.

edit: just noticed the GPM in the pic are a little different that the ones I have, but I definitely have GPM knuckles... hmmm...

[Elusive Crawler]

Ive seen this truck, it does work!

[oleminer]

Awesome looking rig!

Sent from my HTC6435LVW using Tapatalk

[creepr69]

what would the price be ? and how many preorders do you need to make this happen ? thanks Billy G

[monkeyracer]

Originally Posted by Elusive Crawler

Ive seen this truck, it does work!

IT works, but sometimes the driver doesn't...

Originally Posted by oleminer

Awesome looking rig!

Sent from my HTC6435LVW using Tapatalk

Thanks! I love the low look to this.

Originally Posted by creepr69

what would the price be ? and how many preorders do you need to make this happen ? thanks Billy G

That will have to be discussed in the upcoming vendor thread about it. I'll PM you in the meantime.



Last night I went to a small comp and did pretty well, placed 2nd. There were some tough courses, and the winning driver owns the hobby store that the comp was hosted at. I had a lot of help though from another new product coming VERY soon from JC Auto Design:



The above is the initial prototype. I have another prototype coming around the end of the month that will be closer to the production version. Myself and another driver will be testing these to make sure they are good to go, and should be ready soon for pre-order.

Also, I had another forum member send some other brand knuckles so I can design the weight holder for those. It looks like they are all just different enough to need a different design, but that's not a problem. You would just need to be specific about which knuckles you have when you order them. Also making some that fit the XR/Wraith knuckles, since that is what I am running on this now.

The chassis is also holding up really well and works great. The only problem I have been having is that since it is so low (and I use a droop setup) this is hard to flip back over. It just lies so flat you don't get that rocking motion to get you back over. Most people will use a sprung set-up, so that probably won't be an issue, but it's something to note at least.

I plan to have another update when the prototype comes in.

[EverettY]

Ahh you beat me to that front axle design Looks good... So XR splines on those? Is the servo mount built into the axle case?

[Szczerba]

All sorts of cool parts being made for this truck!

[winnerone23]

1.9 isn't dead or dying.. Its on its way back to the main show! (After it had a small break)

Axle looks like a good way to utilize better steering in the front and also to have a rear housing made for different ring and pinions for some UD gear ratios.... Cough, hint, cough, cough

[monkeyracer]

Originally Posted by EverettY

Ahh you beat me to that front axle design

Sorry

Originally Posted by EverettY

Looks good... So XR splines on those? Is the servo mount built into the axle case?

XR Splines, 6.5" Knuckle face to knuckle face. As shown above, I'm at 7.75" or so with those wheels and tires. I could do some more extreme offset wheels to tuck in more if I want, but I think this offset is what most people will have with their wheels.

Servo plate is a separate piece, and I'm not 100% happy with my servo placement, but that can be changed just by making a different plate. Also wanted to keep an option for the CF guys to make something cool there.

I'm going to try a centered set-up with the battery on the back links, so I will show what that would look like soon.

Here's a rendering of the axle so you guys can see some of the awesome built in to it:





The one in the background has the posts to mount the front plate, and the one in the foreground doesn't. There will also be a panhard version for the scale crowd. Built in truss with link mounts, and Tuff-Tubes (my name for the inner metal tubes) from the beginning. Axle case has screws that thread into nested nuts, and the C-hubs thread into the Tuff Tubes.

I plan on being able to offer custom widths, and custom configurations if need be. (For a reasonable price, of course)

Originally Posted by Szczerba

All sorts of cool parts being made for this truck!

I've got quite a few things planned for this thing, and most of them are right here in this thread.

Originally Posted by winnerone23

1.9 isn't dead or dying.. Its on its way back to the main show! (After it had a small break)

Definitely. I think the slick rock coming back (meaning that horizon will still have SOME parts for these) helps. They are fun, and definitely a different way to drive compared to the 2.2 and scale rigs. They can be an inexpensive way to get in the hobby and have a lot of fun in the meantime.

Originally Posted by winnerone23

Axle looks like a good way to utilize better steering in the front and also to have a rear housing made for different ring and pinions for some UD gear ratios.... Cough, hint, cough, cough

Yes, I plan on providing options for different ratios, but I would need to get a sampling of them to size and design them up. I'm highly considering making the rear axle with lockouts already built in. One less part to worry about breaking, cleaner look, more clearance... etc.

The other nice thing, as I mentioned above, is the width is narrower than if you did the XR mod to the existing housing. This way it's easier to stay under the 8" limit without having to hunt down the right wheels.


Any changes you guys would like to see based off what was posted above? I think I hit all the right points, but let me know if there is something you would like to see added, or changed. If it makes sense, it might make it into the final design...

[Ghost]

WOW talk about GREAT new stuff, looking forward to getting my hands on some of those cases, looks like a complete rebuild is on the plate for next season lol.
mini isn't dead it was just resting up for the comeback