77 replies to this topic

[MSwiss]

While posting on OWH in reference to some questions about the semi-unique Saturday night Hot Rod class at C/R, I came up with pics of something a bit different in chassis design.

I'm lucky enough to have a bunch of talented customers that are real gracious and generous, helping me out on various projects, making the tough slot car raceway business, a little easier.

Here's a Hot Rod chassis made on a 3D printer by one of my customers. It's a Chicagoland Raceway exclusive, but at the moment, they are not for sale.

He is also working on, IMHO, an even more exciting project, to be announced and possibly marketed.


Nice press fits for the bushings.


A super stiff motor box area with holes for screw-in FK motors.


The floating pod is "made into" the chassis. It is not removable. It has about .080" fore-aft movement, .060" side movement and a tiny bit of rocking action.


The front floating pod detail. Also shown is the neat crossmember that holds the lead wires.


As I was about to take the pics, I noticed my alter ego's name is even programed into the chassis. Also seen on the side pods, are the holes that will hold the glued-in pin tubes.

The complete car runs eerily quiet, with super-predictable handling. With hastily-added stick-on lead on the bottom of the car, this design won on its first time out in our Saturday night races.

[HarV Wallbanger III]

That looks cool, Mike. My AutoCad teacher has one available and said he would do a project for me to try it out. Now the $$ to get the mold done but it looks real cool now.

[MSwiss]

What I have shown is raceable, and as mentioned, has won a race. We're talking my flat track, soft walls and with Falcon II motors (still plenty fast in these zero downforce cars).

We haven't run one into a cinder block at the end of the straightaway yet.

[HarV Wallbanger III]

From what my teacher said the plastic is good but designed to see fit and fitment before the mold is made.

I wonder if you could boil it like we used to do R/C suspension parts to make them more pliable and not so brittle then that plastic maybe could hold up?? Is the chassis pliable in this state now, Mike?

[MSwiss]

While not quite "nylon-like", the chassis has quite a bit of flex. This was the original material.

Other materials were on the way but I haven't seen anything made with it yet.

This stuff is in it's ultra-early stages but I'm super-impressed on how good the performance is already.

[NSwanberg]

Stereolithography?

What is the polymer?

[havlicek]

That's cool as heck, Mike. It sort of reminds me of the plastic chassis cars from a few decades ago from what you said. They ran very quiet also and, while the scratchbuilt cars were better handling (at the time anyway)... I liked them. The old one were durable also as well as lightweight. The fact that it won a race out of the box will maybe steam some people's biscuits though. Next... an anglewinder!

-john

[MSwiss]

I'm not trying to throw slot racing a curve. I kind of envision this as possibly a good deal for IROC style house cars where the car stays on the lane and the race is truly a driving contest.

What's weird is I thought as I twisted a bare chassis, it wouldn't have enough bite and also, like the plastic anglewinder chassis Parma and others sold, years ago, the car might make a resonating sound like a speaker baffle. But just the opposite, plenty of bite and crazy quiet.

[Rick]

That is so SUPER KOOL! At the school I am going to learn Autocad, they have one of these 3D printers and it is, nothing less, than amazing to watch it build something. Real science fiction type stuff.

It probably took fifteen hours to build that chassis, on the printer, but a real-time prototype you can hold is so neat...

[flem1959]

Show us some pictures of the complete car and body.

[MSwiss]

Mike,

No disrespect, but I doubt these would be fast enough to interest you.

The body that goes on this chassis is the one behind the Cobra and uses 1 inch tall tires.

[Hworth08]

Looks good! An Eldon frame in a modern car. Well, an updated plastic frame anyway.

In a way the idea has a world of potential. Similar to the Aurora T-Jet frame. One chassis for every racer could result into a tuner/driver series. The T-Jets have had a big following this decade. The same is possible on 1/24 commercial tracks.

[idare2bdul]

What a great project! They had one of these machines at the California Skills USA State Championship this last weekend. One of their finished projects was a working clockwork, very impressive. The prices they have on these keep coming down but the one they had at the show was still $20,000.

[MSwiss]

It probably took 15 hours to build that chassis, on the printer, but a real-time prototype you can hold is so neat...

Actually 1-1.5 hrs. in the highest quality mode.
To be clear, whether it's set of eight-ten IROC cars for Chicagoland Raceway guys to race, or something that might be sold in limited numbers to the public, they will be made on the machine. It's not just to get a visual prototype.

What a great project! They had one of these machines at the California Skills USA State Championship this last weekend. One of their finished projects was a working clockwork, very impressive. The prices they have on these keep coming down but the one they had at the show was still $20,000.

IIRC, my guy mentioned something around $100K on the one he has.

[Ron Hershman]

OK, so the $100,000 question... what does it cost to produce one of these chassis and the chassis only???

[tonyp]

We have one at Trinity. It's older and uses a cornstarch type media. When you remove the media you coat it with CA glue and you have a perfect part you can use to test with. We made endbells, motor cans, suspension arms, and gears we could actually run. All except motor can of course.

Not sure what other media our machine can use, but it is pretty damn neat.

[Keith Tanaka]

A DIY kit for $1,495.

Not as accurate as the $20,000 machine, but a good low cost introduction to 3D modeling.

$1,495 DIY 3D kit

The Rapman in action:

Rapman video

Keith

[Keith Tanaka]

Or a Thing-O-Matic kit for $1,299.

Thing O Matic

Or the Cupcake CNC 3D machine kit for $699 (3.93"x 3.93" x 5.55" max. product dimension).

Cupcake CNC kit

Keith

[mdiv]

Mike,

Looks great!! Good luck with it, and I think I'd be interested.

-- Mikey

[Mike Patterson]

IIRC, my guy mentioned something around $100K on the one he has.

Mike,

Does "your guy" have the 3D scanner, too?

NEAT chassis!

[MSwiss]

No, unfortunately. Not at the moment. That's the first question I asked him when he first brought a chassis by two or three months ago.

I did talk with him for the first time in a bit, earlier tonight.

My earlier emails today did inspire him to knock out another chassis using a softer, more flexible material. He thinks it might work even better than the original material. He's passing it on to another customer to assemble into a whole car for this upcoming weekend. FWIW, he said it took 77 minutes to make.

He also added that technology on these is improving almost daily and his six-month-old machine is not nearly as spiffy as the latest available. He also mentioned hearing about a new material, that is very close to being available, that will kick this technology up another notch or two.

[68Caddy]

This is what I have been looking for, a 1/24 plastic chassis, or is it 1/32? If so, even better!

Nesta

[Mr. HP]

Mike,

Thanks for posting.

I’m the local racer/engineer with too much free time and access to a 3D printer (AKA rapid prototype machine). The design was done using Solidworks and the printer is an Objet Eden 260v. Build time is under 1-½ hours. The hot rod was my first attempt at a slot chassis, done mostly for fun and “shock value” with the local racers. With Mike’s input I have a few “more technical” designs with moving parts and tune-ability in the works for other types of slot car chassis (…and slot car parts). The material is a resin (comes in liquid form) with similar properties as nylon, except slightly more brittle. There is a large range of material options, elasticities and durometers ranging from 25 to 100 on a Shore-A scale still yet to explore.

The car exceeded all expectations on its first time out, just some stick-on led and it was ready to go. It even won Chicagoland’s weekly Hot Rod race by just a few feet over Sano Dave. And so far has proved to be very durable, however Mike’s “soft walls” probably have a lot to do with that.

Here a video of an Objet in action…

http://www.youtube.com/watch?v=pbjcfplk8Ig

[Rick]

WOW!

[John Miller]

Nice job, Steve.

John