Scalextric DPR Compatible Chassis for SCX NASCAR CoT (Ford Fusion)

[MrFlippant]

Scalextric DPR Compatible Chassis for SCX NASCAR CoT (Ford Fusion)

https://www.thingiverse.com/thing:5322295

A good friend switched from SCX Digital slot cars to Scalextric Digital, but had a large collection of SCX NASCAR cars, including several that he customized the livery on. He didn't want to give up using those bodies, but converting an SCX Digital chassis to plain analog or Scalextric Digital isn't as straightforward as for other brands. I offered to help, and this is the result.

Note that the purpose of this chassis is to use AS MANY ORIGINAL PARTS AS POSSIBLE, so that the parts from the SCX chassis can simply be moved over to this new one. The only thing needed is a standard analog type guide, the wiring loom for DPR chips, and the DPR chip itself. The motor pod from the SCXD chassis can just be popped out of the old one, and popped into the new one. The front wheels can be easily moved as well, using the stub axles clipped to the original chassis.

I did my best to mimic the front splitter/grille area of the CoT (Car of Tomorrow) cars, but with some minor changes to make them easier to print. A little bit of paint might be needed, depending on the original car. While this chassis was measured from, and tested on, the Ford Fusion model, I'm told that all CoT chassis are the same, so this should work under any SCX CoT body. A clean print should not require any modifications to work, but there may need to be some trimming of the chassis or body for optimum fitment.

Supports are needed for some areas, but the screw holes/posts are designed not to need support on the inside. If you use PrusaSlicer, definitely make use of the pre-supported 3MF files I've uploaded.

Per the license, you are free to print these for your own use, but I do not grant permission to print them for sale.

[Wet Coast Racer]

That's tidy work, Greg!

How's the flatness on them there chassis?

[MrFlippant]

That's up to your printer. Mine are pretty dang flat. Did you need some, or can you print your own?

[Wet Coast Racer]

My question is entirely academic. What I know about 3D printing would fit on the head of a pin!

I'm simply interested in how these 3D chassis compare to the 'original' factory chassis from China. I know that Maurizio would always recommend flattening these and wondered if any similar process was being followed by you 3D folks as a tune up tool. Or if it were even possible.

[MrFlippant]

It's certainly possible. Filament printing uses thermoplastics, just as injection molding does. As such, if a filament printed chassis went out of whack, it could be worked back into flatness using heat/cool techniques like people do for injection molded chassis. It's important to know what material a chassis is printed in, though, as some materials have a lower melting point, and boiling water would not just make the pliable, but completely collapse. That said, injection molded parts are quite often done in ABS. I can also print in ABS, and it will have the same properties as an injection molded part, aside from the layers. I can't tell you exactly what every production chassis is made of, though.

Filament 3D printing (aka, the "hot glue gun" style) is done onto a plate that is SUPPOSED to be perfectly flat. As such, unless the person has some crazy printer that will compensate for a totally out of whack print bed, the print will ALSO be completely flat. Well... unless they're stupid enough to pull the print while it's still warm. Speaking of which, that's why injection molded parts can sometimes be deformed... they're still warm when they land in the pile of parts, and if they don't cool off fast enough before something else deforms them (landing on things, other things landing on them, etc.) then they'll deform too, and we end up boiling them. ;-)

So, the end result of a filament printed chassis, or any 3D printed chassis done in a properly calibrated and maintained machine with a competent operator, is a perfectly flat chassis.