# Building a 3D-printed sprint car



## carlos.arista (Nov 26, 2014)

Hi guys,

I'm Carlos, new to this forum. I work as an engineer for Ford in Mexico.

For some time I've wanted to build a 3D-printed slot car and see what can be done with the technology. I really enjoy sprint car racing so that's what I will base the model on. I'll be posting updates of the development here and hope I can get some advice from the experts as well 

I've started with the frame which is a very simplified version of an actual chassis. 1/32 scale. It will require precision to fit a motor there...


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## slotcarman12078 (Oct 3, 2008)

Looks cool already!! Welcome Carlos! :thumbsup::thumbsup:


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## carlos.arista (Nov 26, 2014)

Thanks! I enjoy this forum, been visiting for a while now.

The basic layout of the chassis is now modelled. The wheelbase in a sprint car is between 84 and 90 inches which translates to 66.7mm - 71.4mm in 1:32 scale. We'll give it 72 to try and give it the best possible stability. 

The space for the motor will be tight indeed but still possible to fit without going out of scale. 



















Gas tank is now modelled and will allow to finish the design of the rear frame:


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## carlos.arista (Nov 26, 2014)

I hope to make some good progress during the weekend. I'll be busy following WEC in Brazil as well...

Question. Does it make sense to make holes for the crown gear on either side of the chassis?

The frame and chassis now have their respective fixing points. I'll get a second chassis built with a stiffer setup in case this combo flexes too much. 

The rear frame is now complete and the gas tank will attach to it, with a small guide on the bottom simply to keep it from moving. Body panels are next...


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## alpink (Aug 22, 2010)

I am impressed !


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## slotcarman12078 (Oct 3, 2008)

Seriously cool!!! I played with a much earlier version of "Cad Cam" back in the late 80's. It was before 3-D and was dinosaur compared to what can be done now... Everything we did was backed up on tape and the main computer was the size of a bedroom closet! :lol:


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## carlos.arista (Nov 26, 2014)

Body panels are now finished. I went for a design that looks similar to Kasey Kahne's cars which in my opinion have the classic sprint car look. They should be easy to install on the frame. Exhaust pipes will definitely be a challenge, not sure of how to solve that one yet...


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## slotcarman12078 (Oct 3, 2008)

Unreal!!! :thumbsup::thumbsup:


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## carlos.arista (Nov 26, 2014)

Thanks! The design of all printed parts might be finished this week. Sourcing the rest of the components will take a little more time though. Especially tires and wheels. Any suggestions? It's not too easy because the rear tires are quite big. Something with a diameter of 22 or 23 millimeters and 15 - 16 millimeters wide would look pretty cool. Fronts should be easier.

The exhaust pipes are now finished. They'll need to be installed with glue to the side body panels. Probably epoxy to make sure it stays there forever. 



















The front wing is finished as well. It attaches to the frame, so the car can have use both configurations, winged and non-winged:


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## bobhch (Apr 22, 2007)

Holey Crap that is Cool....Nice Man!! :thumbsup::thumbsup:

Bob...digs race cars like this...zilla


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## RiderZ (Feb 19, 2007)

Print it and they will come.


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## slotto (Feb 9, 2010)

you are killing me! send it to the printer!


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## RiderZ (Feb 19, 2007)

Right-can't wait!


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## carlos.arista (Nov 26, 2014)

The rear wing is now designed, so time for printing! The weight is a concern here, mainly because it significantly raises the center of gravity. It is placed as low as the looks allow. On high speed tracks however it should provide downforce and be useful. It has a steep angle of attack and a gurney flap. The printed component should have a weight of around 6 grams. The supports are designed to flex and keep the wing in one piece during heavy crashes.

It'll be interesting to see the difference in handling of the car with and without wings. Initially I believe it'll be faster without them. Could depend on the type of track I guess...

So all printable components are ready. I won't make an interior mainly because I suck at modelling organic stuff. There should be nice figures that fit into the cockpit.

It's also time for sourcing the proper components. Any suggestions for rear wheels and tires? I've always used aluminum wheels and rubber tires but I haven't been able to find the proper size. Pro-track products look nice. Are their wheels and foam tires a good option?


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## slotcarman12078 (Oct 3, 2008)

Looks cool as heck!!! I would suggest going aluminum or brass wheels as the extra weight will help offset the upper weight. I have no experience with larger scale stuff, but I would assume you would want the tires to slide through the turns. The only thing I could see as a major improvement would be a steer-able front end, so as the car drifts through the turn, the wheels in front show proper steering to compensate. All over a gorgeous body, and can't wait to see one printed out!! Don't get in trouble with work!! :freak:


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## Full Flaps! (Sep 26, 2010)

Excellent rendering Carlos! 
I'm not involved in slot cars, but diecast cars, 
and I too am excited with the possibilities of 3D printing in the development of them. 
As many diecast cars developed in the traditional way leave much to be desired in terms of modeled accuracy… 
I look forward to seeing your finished product! :thumbsup:



___________________________

_www.nongmoproject.org_


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## slotto (Feb 9, 2010)

Even if it's top heavy, it will make an awesome display piece.
Just knowing you designed and built it yourself.
You should be proud !


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## carlos.arista (Nov 26, 2014)

Printing is in progress. There seems to be a long queue at Shapeways so they'll be leaving on January 10th, apparently. They have really cool colors for nylon plastic, we'll see how they work on the car. 

Thanks for the tips! Regarding tires and wheels, I'll do some testing with NSR products as there is a wide range available here. It should give good information on what compounds to use, width, etc. Maybe we can add some weight to them and see how it reacts. It should be easier to find the perfect combo after this. The chassis can receive some lead weight in front of the motor, I think this will help a lot. 

@FullFlaps Check this out: http://www.popularmechanics.com/cars/news/vintage-speed/3d-printing-can-now-re-create-an-entire-classic-car-15566080

@Slotto Thanks mate, I appreciate it. I'll only be happy if it becomes a proper little racer though!


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## frank9129 (Apr 2, 2007)

Carlos,
I just started reading your thread. OMG you car is going to be kool.
I have been racing Grabber Bandits which are converted die cast Sprint cars.
I can't wait to see you finished product.
Frank


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## carlos.arista (Nov 26, 2014)

Hi Frank, thanks mate. 

That sounds cool, are these in 1/24 scale?

Where can we see some pictures?


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## frank9129 (Apr 2, 2007)

Sprint Bandits are pull back toys. With the wing they are 4 1/4" high, 3" long, and 2 12" wide. The chassis for these cars have gone through several changes. First try was to glue the motor to the chassis, cut out for the gear, and glue in the bearing and rear axel. The second try was to use 1" aluminum channel. The motor was glued into the channel, the bearing and axel are also glued. The third try was great, a chassis was built from brass and covered all the bases.
I am trying to find the pictures of the builds. Wish me luck, my computer crashed and sis several flips over the fence.
Frank


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## frank9129 (Apr 2, 2007)

Carlos,
send me you e-mail and I can send you a file on the build. It is from another and I can not post it with out their permission.
Frank


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## frank9129 (Apr 2, 2007)

Carlos,
I can't post a picture to this tread. However, I have started an album. Check it out. There is a Gripper Sprint Bandit.
Frank


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## carlos.arista (Nov 26, 2014)

Oh cool, I hadn't seen those, how do they behave?

Upload your photos in Photobucket and you should be able to post them here, but if you wish you can send me an email to [email protected]

Regarding the printing, 3 out of 8 components show as completed. Hopefully the whole package ships at the beggining of next week. We already have a couple of wheel/tire combinations to install on the car and get it up and running!


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