50 replies to this topic

[rvec]

Wouldn’t it be great to have a series of individual/team races depicting the famous rivalry of the 60s between Ford and Ferrari. I am not talking about GT40s vs Ferrari P3s and P4s but the rivalry for the GT championship. The GT class was designed to pit specially prepared “production” cars from different manufacturers against one another. The 64 and 65 seasons became a battleground between Ford and Ferrari. The Cobra Daytona against the Ferrari 250 GTO; both iconic cars
As I considered this series, challenges came to mind.

• In real life, both cars were rather short and narrow.
• Slot car versions in 24 scale would be shorter than our typical sports car and few have chassis set up for such a short vehicle.
• Narrow vehicles would not handle great as slot cars
• Neither car is readily available as a plastic model kit in 24 scale.

With time on my hands, I decided to explore the idea of printing one of each of these cars, making a mold and then casting several of each. Surfing the internet I found a 1/28 scale print file for a Mini Z Cobra Daytona. Finding the 250 GTO was more of a problem. Although I found several, owners of detailed models wanted in excess of $100 just for the print file. Finally I located a somewhat suitable 250 GTO for no cost (unfortunately I will have to modify the printed model before molding). Below are images of the print file results

 

 

 

 

Since I do not have a 3D printer, I sent the print files to Cloud Craft, a 3D printing vendor https://craftcloud3d.com/ . The vendor allows for scaling the print file. I scaled both up to about 1/20 scale. This made the length of both cars nearly identical at 7.79 inches in length, 3.25 inches in width and 1.98 inches in height. The vendor also provided a choice for the print material. I chose resin. I am waiting for the printed models to arrive.

 

In the interim I am working on casting a very light model that is strong enough to survive the rigors of slot racing. A slotblog member suggested I slosh a very light cast and reinforce with carbon fiber. I should have the materials in hand within a week and will try this method out on a new cast of a GT40 MK IV

Once I prove the concept, I will test the models in upcoming races to determine their durability. If they pass muster, I may suggest a series for a club and cast 6 of each for slot racing. Stay tuned.
 

[Larry Horner]

Great idea Rich as these are two of my favorite cars too and as a fellow 3D print hobbyist, I love your process. Obviously once you have a digital model, you can scale it anyway you like to get just the perfect size for a slot car. Be sure and post your printed models back from Cloud Craft.

[rvec]

I will but it may be several weeks before they arrive in the US.  (The source that was most inexpensive was from China)

[Alchemist]

That is an excellent project Rich!

 

I'll stand first in line to place my order with you Rich!  LOL

 

Looking forward to your progress.

 

Ernie

[rvec]

Since I ultimately want to run a series, I certainly don't want the cars to look alike.  As far as the Cobra Daytona, there are at least four liveries I can choose from.  In 64, only Shelby ran the Daytona. The color was a light metallic blue. In 65 the Shelby color was a dark metallic blue with white stripes.  The cars were farmed out to teams in Europe in 65 for the European races (Shelby was ordered to concentrate his efforts on the GT40 program).  There are at least two liveries here  - Scuderia Filipinetti and ford France. 
 
As far as the 250 GTOs are concerned there are many liveries including the red factory cars.
 
See below for images
 

 

 

 

 

 

 

 

[HarV Wallbanger III]

Great time in history! I would love to get 1 of each!

[rvec]

As mentioned in the original post, I plan to have a third party print the 3d files for both cars. I will then modify the prints as necessary. Molds and then casts will be completed for both cars.
I just completed the Cobra Daytona and Ferrari 250 GTO “blueprints” from their respective 3D print files (See images below). Note that I have drawn the wheels. The rear wheels are an inch in diameter. The front wheels are 15/16 inch in diameter. The Daytona looks great. The only thing I might attempt is to make the front wheel openings a bit smaller.
 
The Ferrari GTO will need some work before it is ready for molding. The first thing I noticed is that the rocker panels were missing. I added these in the drawing. Next, the model decreases in width starting near the back of the door. The actual car has a bulge to accommodate the rear wheels. It will take quite a bit of work to create fender flares that look accurate. The new material shown in the top view is a start.
 
As mentioned in the original post, the purpose of this project is to produce two equally matched slot cars so that the dual between Ford and Ferrari in “scale’ will be as close as possible. The files for each car were scaled up so that the width of both cars was 3.25 inches (For the Daytona this resulted in a scale between 1/20 and 1/21). The following table shows the dimensions of the resulting models (all measurements in inches). As one can see, the dimensions for both models are almost identical.
 
 

 

 

[rvec]

I received the resin prints from the third party. The detail is and materials are quite good.  Unfortunately the Cobra Daytona was printed in the wrong size. I contacted the vendor who said they were sorry for the error and would send the Cobra to me reprinted at no extra cost.  Below are images of the resin prints.  As noted above, the 250 GTO will take some work to prep before a mold is created while the Cobra Daytona coupe looks good as printed (I may change the size of the front wheel openings on the Cobra before creating a mold)
 

 

 

 

 

 

 

[Revtor]

cool project!

 

the moldmaking process has so many possibilities..

[Martin]

Hi Rich, love your enthusiasm, great project. My question is why you did not take a Revel or Carrera  Ferrari GTO 250 or other brand and a K&B Cobra and mold it? You can even throw in Corvette Grand Sport to add flavor.

 

Were you looking for a wider/ bigger cars or were there other reasons?

[rvec]

Hi Rich, love your enthusiasm, great project. My question is why you did not take a Revel or Carrera  Ferrari GTO 250 or other brand and a K&B Cobra and mold it? You can even through in Corvette Grand Sport to add flavor.

 

Were you looking for a wider/ bigger cars or were there other reasons?

 

The reason I scaled up the STL files is because I would like to run these cars in our Sports Car class (as well as having  class for them by themselves).  The Sports Car class is for production or prototypes with a max width of 3.25 inches. In real life the Cobra and GTO are quite narrow and short by today's standards. By scaling these up they will handle better. Also, most of the guys already have Scholer or other H-Bracket chassis for 1/24 Sports Cars.  All that will be necessary to run the Cobra/250 class will be a body change. No additional money will need to be spent on a chassis 

 

The STL files were procured on the internet. If I had plastic model versions of the cars and a good scanner I would have scanned the plastic models and scaled them up for printing.  If I had a 3d printer I might have printed them myself and then created a mold. I would buy a 3d printer if I thought they produced good quality plastic model replicas. So far I have not been impressed with the 3d prints I have seen from personal 3d printers.  As I mentioned in the post, I used an outside service called Craft Cloud (Craftcloud – 3D Printing & Price Comparison Service by All3DP ) to print the models in resin.  The quality is quite good.  The Cobra Daytona will take very little work but I wish I could have started with a better file of the 25O GTO

[Martin]

Thanks for taking the time to reply.

If the bodies are closer to 1/20 scale what size will the wheels and tires be to look correct do you think? 

[rvec]

The GTO came with resin wheels. They measure 1.125 inch rear and 1.0625 front. Note the the "blueprints" shown above illustrate both cars with wheel diameters of 1 inch and 15/16 inches for the rear and front respectively as well as .05 inch ground clearance.  We use 1 inch rear and 15/16 front in our Sports Car Class  This way the guys can just swap bodies for either the Sports Car class or Daytona/GTO bodies. Note that he wheels look pretty good but I may make the wheel openings a bit smaller on the Cobra before molding

[Alchemist]

Hi Rich,

 

This project of yours continues to be very exciting to me!

 

Thanks for keeping us informed of the progress.

 

Ernie

[rvec]

It has been a while since I posted on this thread.  I recently received the third party print of the Cobra Daytona in the correct scale.  The scale is about 1/20 so it would fit our existing sports car chassis. The wheelbase is about 4 1/8 inches and the width is about 3.15 inches. The car is shown with 1.06 inch rear and 15/16 inch fronts (this is so that the chassis that the guys run sports cars can be used with a simple body swap).  BTW - the photos seem yellow but the car is actually white

Below are some images.  The chassis is a Scholer with a 2NASTE front end. The only things I am thinking about doing to the body before molding and casting are to sand and fill the "side pipes" and make the front wheel openings a bit smaller so the front wheels don't look so small.

 

BTW - I still have to fabricate a front pan for the chassis
 

 

 

 

[HarV Wallbanger III]

Interested in these....

[rvec]

It has been some time since my last post on this thread. The reason it has taken so long is that I have been working on finishing my run of five GT40 Mk IVs in resin and doing some home projects.

Now my focus has shifted back to the Cobra Daytona coupe. The original model needed a bit of work before making the mold. After sanding and filling the “side pipes” and filling in the front wheel wells (this was done so that I could cut a smaller opening than the original model so that the 15/16 front wheels would look better in the wheel opening), the original was ready for molding.

The mold box was built and the model centered in the box. The model was affixed to the bottom of the mold box with a large wood screw (to insure that it would not move during the molding process). The mold rubber was mixed and poured as directed. Below are a few images.

The next steps are to rebuild the mold box to give the mold some support and pour the casts
 

 

 

[rvec]

Made some significant process over the past several days.  First, I fit the proper motor and gears to the chassis (Proslot 16D, gearing 10/52). I tested the chassis with a old Ferrari F50 I had laying about.  The car was an absolute screamer.  Then, yesterday, cast the first body.  The detail is quite good and I am very happy with it.  It could be  bit lighter but I think it will do fine.  Next, I will reinforce the body with carbon fiber and test.  Below is an image of the cast.

 

 

[rvec]

Here are some images of the chassis, the F50 "mule" and the Daytona mounted on the chassis.  I did some testing and the Daytona is a bit slower than the F50.  I think the Daytona times will improve as windows are cut out and replaced with .005 lexan, then maybe a bit of weight tuning.  I will keep all posted.
 

 

 

 

 

[Lou E]

Very cool idea and even cooler that you are making it happen, great work!!

[rvec]

Very cool idea and even cooler that you are making it happen, great work!!

Thanks. Its all about trying something new. I am relatively new at molding and casting and it has been a fun exercise.

[John Luongo]

outstanding work! i remember watching these race at daytona. that body work was so much faster, they could keep their revs down a bit and still keep up with the Ferraris. remarkable difference for just a design/body change. well done!

[rvec]

outstanding work! i remember watching these race at daytona. that body work was so much faster, they could keep their revs down a bit and still keep up with the Ferraris. remarkable difference for just a design/body change. well done!

 

Thanks John,

Still have to do some work on this first prototype before I am happy with it.  I should have some time to concentrate on the project soon

[rvec]

I just finished with the body reinforcement and paint.  All that is left is the deals and a clear coat
 

 

[rvec]

Finished except for the stripes.  I will do the striping after our race on Monday.  Below are images

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