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Mid Motor Low CG Spec Carpet Monster

Posted: Fri Jan 17, 2020 9:17 am
by MotoObscura
The goal of this project is to make a dedicated racer so I can stop breaking parts on my original Worlds Car :shock:

I will be using a re-release worlds car as a donor, though admittedly few parts will be carried over.

Here is the plan:
-custom Single piece 1/8" 6061 aluminum plate chassis with narrow front end
-Mid Motor laydown transmission from a B6.1 with gear diff
-4mm carbon fiber shock towers front and rear to mount to truck front end and B6 transmission bulkhead
-Mounting for low profile shorty LiPo
-Traxxas Bandit RPM front and rear arms with Niki's rear arm mounts
-B5M wing mounts
-C hubs, knuckles, V2 shocks, and rear axle carriers from rere worlds car
-B4 wheels to try to keep width legal

Buckle up, things are gonna get weird.

Image

Re: Mid Motor Low CG Spec Carpet Monster

Posted: Fri Jan 17, 2020 9:23 am
by KidAgain
Sweet I love projects like this

Re: Mid Motor Low CG Spec Carpet Monster

Posted: Mon Jan 20, 2020 6:46 pm
by MotoObscura
Look what showed up today 8)

Image

Original worlds tub weighs about 5.5oz, without the nose plate. This hunk of aluminum weighs about 8.5oz, so hopefully I won't need to use as many chassis weights.

Time to countersink some holes and bend the nose.

Re: Mid Motor Low CG Spec Carpet Monster

Posted: Mon Jan 20, 2020 7:28 pm
by mikea96
Those look nice!

Re: Mid Motor Low CG Spec Carpet Monster

Posted: Mon Jan 20, 2020 9:07 pm
by MotoObscura
Image

Here's where I'm leaving it tonight. I need to order a few hinge pins and longer turnbuckles to fit the RPM arms, as well as figuring out a battery mounting solution for the shorty pack.

Re: Mid Motor Low CG Spec Carpet Monster

Posted: Tue Jan 21, 2020 6:45 am
by Headling
Looks great so far, did you make the chassis??

Re: Mid Motor Low CG Spec Carpet Monster

Posted: Tue Jan 21, 2020 8:36 am
by MotoObscura
Headling wrote: Tue Jan 21, 2020 6:45 am Looks great so far, did you make the chassis??
I designed the chassis and had it laser cut from 1/8" thick 6061 aluminum.
I countersunk the holes and bent the nose with a vice mounted press brake to about 25°

Re: Mid Motor Low CG Spec Carpet Monster

Posted: Tue Jan 21, 2020 9:52 am
by XLR8
nicholasdivitto wrote: Tue Jan 21, 2020 8:36 am
I designed the chassis and had it laser cut from 1/8" thick 6061 aluminum.
Very nice!! 8)
Was the chassis plate laser cut at your place of business or by another commercial service provider? Link? :D

Re: Mid Motor Low CG Spec Carpet Monster

Posted: Tue Jan 21, 2020 1:26 pm
by MotoObscura
XLR8 wrote: Tue Jan 21, 2020 9:52 am
nicholasdivitto wrote: Tue Jan 21, 2020 8:36 am
I designed the chassis and had it laser cut from 1/8" thick 6061 aluminum.
Very nice!! 8)
Was the chassis plate laser cut at your place of business or by another commercial service provider? Link? :D
Cut by theses guys:
https://sendcutsend.com/

Re: Mid Motor Low CG Spec Carpet Monster

Posted: Tue Feb 04, 2020 8:44 am
by MotoObscura
Not a lot of progress made in the past week or so, but I did buy some B44 CVA shafts and the seem to be a good length for the Bandit rear arms and mounts. After taking some eyeball measurements, it looks like the front end is going to be too wide by about 10mm, so more than I can remedy by modifying the front axles and carriers. I think I'm going to have to design a new front bulkhead that still mounts like a 10T but is a little narrower.

The single piece aluminum chassis plate is now available for sale on my website.

Re: Mid Motor Low CG Spec Carpet Monster

Posted: Tue Feb 04, 2020 9:43 am
by jwscab
apologies if this is where you got the info and you know all about it already:
check this listing over, it appears its the same build list you have there.

Front end:
-10T kickup ASC7305 and bulkhead ASC7207
-Inner hinge pin ASC7209
-Front arm RPM80492
-Outer hinge pin ASC8423 or ASC7357
-Caster and steering block ASC6210 + ASC6225
-T3/B3 front axle ASC7221
-B4 Front wheel ASC9588 or ASC9688

this is from Niki's rpm style build, he does mention the wheel nuts fall outside of 250mm width
https://www.rc10talk.com/viewtopic.php?f=35&t=40129&p=451764&hilit=rpm73282#p451764

Re: Mid Motor Low CG Spec Carpet Monster

Posted: Tue Feb 04, 2020 9:55 am
by jwscab
btw a quick bulletproof solution would be to run dynotech klien front arms. no redesign, just bolt on.

Re: Mid Motor Low CG Spec Carpet Monster

Posted: Tue Feb 04, 2020 1:14 pm
by MotoObscura
jwscab wrote: Tue Feb 04, 2020 9:43 am apologies if this is where you got the info and you know all about it already:
check this listing over, it appears its the same build list you have there.

Front end:
-10T kickup ASC7305 and bulkhead ASC7207
-Inner hinge pin ASC7209
-Front arm RPM80492
-Outer hinge pin ASC8423 or ASC7357
-Caster and steering block ASC6210 + ASC6225
-T3/B3 front axle ASC7221
-B4 Front wheel ASC9588 or ASC9688

this is from Niki's rpm style build, he does mention the wheel nuts fall outside of 250mm width
https://www.rc10talk.com/viewtopic.php?f=35&t=40129&p=451764&hilit=rpm73282#p451764
Yup, that's where I got my info from, but it seems that a little more than just the wheel nuts will fall outside of 250mm.

The reason I'd rather stick with the RPM arms and design a new front bulkhead is because in my mind, the arms are the most likely thing to break and I'd like a relatively cheap (like $10 for a pair of RPM Bandit arms) replacement option that could probably be found at a hobby shop in a pinch. Nothin against Klein arms though, that would probably be the path of least resistance.

Re: Mid Motor Low CG Spec Carpet Monster

Posted: Tue Feb 04, 2020 2:20 pm
by jwscab
the klien arms are pretty much indestructible. you are much more likely to crack a shock tower, which will likely have to be custom in order to use a narrow bulkhead, so kind of a rock and a hard place to be honest......


could probably get away with just trimming the center out of the truck bulkhead to make it easy to narrow up.

Re: Mid Motor Low CG Spec Carpet Monster

Posted: Thu Feb 06, 2020 9:05 am
by MotoObscura
jwscab wrote: Tue Feb 04, 2020 2:20 pm the klien arms are pretty much indestructible. you are much more likely to crack a shock tower, which will likely have to be custom in order to use a narrow bulkhead, so kind of a rock and a hard place to be honest......


could probably get away with just trimming the center out of the truck bulkhead to make it easy to narrow up.
That's true, maybe I'll pick up some Klein arms to play with. I'd still like to investigate the possibility of an even narrower front bulkhead that still mounts to the standard truck kick-up plate.

I'm designing my own front shock tower for the narrow bulkhead and V2 shocks, rear tower too since it needs to mount to the B6 transmission case.