Manta Ray Chassis Brace

[Concorde]

Hi Guys, I have refurbished my original manta ray from 1992 for my son. Upon rebuilding with new parts etc, I realised there is a lot of (longitudinal) flex/weakness in the chassis front to back such that in a forward crash you have the following failures: 

1. the prop shaft compresses and buckles, or the bearings get a huge thrust load and get damaged.
2. the plastic chassis bosses that the top deck/tray screw into break/shear off
3. the chassis cracks/breaks due to the large amount of bending. 

Studying the large number of broken parts I still have from when I was a kid, I can see it is is real source of weakness in the car. 

So to cut a long story short, as an engineer I decided to design a bracing part. It worked so well I thought I should share it. It acts much like the top deck on the top force effectively completing the connection from the rear gearbox to the front. THe chassis is vastly stiffer in all directions and the prop shaft maintains the necessary longitudinal float even when compressed hard front to back. Here are some pictures:

   

[Concorde]

Here is another photo. You can see it connects the front gearbox to the top deck part to transfer the load during a crash. As a side benefit it also stiffens the chassis in twist. THe brace is secured also above the servo via a special and much stronger servo mount. I can make these parts available to anyone who needs them. They are printed in high impact ABS. 

 

 

[Concorde]

Here is a close up of the servo mount connection to the brace

[Concorde]

It also solves another issue with the DF-01 that is the steering arm mounts. I noticed on two of my chassis parts the boss had cracked away from the ribbing and showed quite a bit of flex movement when steering is applied. 

 

[Concorde]

Chassis bosses typically break here...

 

 

[Concorde]

As I am using the top force shock tower, I decided to add a modern style velco mount. It conforms to the manta ray body. No need for any body clips. 

 

 

 

  

[ruebiracer]

That sounds very logical and you designed some cool stuff! From my recent 4WD Retro race at the Tamico offroad cup, I saw several drivers facing breaks in their Top forces, which are converted to bathtub chassis by regulations. Also @wtcc5 had some breaks during a practice session on a similar car on Astro turf with quite high grip level. Your solution could be very helpful for these cars, as Carbon chassis plates are forbidden. 3d printed reinforcement braces still meet the regulations and the sprit of the cup and probably would increase the bathtub chassis life I guess!

But also every Sunday basher would only benefit from the reinforcements, as you say. With the upcoming Manta Ray rerelease, there would be for sure some interest for your design, I guess.

[svenb]

Very neat idea, well done

[Concorde]

Thanks for the kind comments. Yes, this particular chassis pictured has cracks around the steering bosses and also cracks around battery compartment (as I wanted to preserve my old childhood car). But with the brace it is now more torsionally stiff than my Top Force. I would say it tougher than the top force too. Does anyone know if this would fit the TA-01 and 02 chassis? 

[Ferruz]

Wonderfully done! I like the simple and effective design. A much needed upgrade for the DF-01 👍