3D Printed 1/32 Vintage Asphalt Modified Coupe

[Vintage 1/24]

Yes, back in this era the dirt and asphalt cars had not really diverged yet. The *All Star League* ranks would provide a great build list of cars to create - which included both dirt and asphalt cars and venues.

I eyeballed up 3.5 inches for the wheelbase. Later I checked the wheelbase of a '37 Chevy Coupe and it was 112.25". Diving by 32 that is 3.5" within a few thousandths - sometimes things just work out!

The minimum wheelbase for the Modifieds was 110" by the rule book - and I think it makes sense to commit to true scale - the Jarzombek offset coupe wheelbase was a tad longer I will adjust this chassis in version 1.1 for starters...

I haven't decided on how or what to sell. Being a plastic chassis, and the lack of Modifieds in the 1/32 scene, makes me think it would be a good fit for the 1/32 home racer.

I am thinking about what to make, adjustable wheelbases, universal frames etc. but each 3d print is a unique event, there is no tooling or molds to maximize the use of... So it would be easy to make variations - wheelbase - bars etc.

I am creating '35 and '37 Chevy Coupe bodies right now - and it looks promising. I will do more body styles if that works out. I haven't seen many 1/32 coupes for Modifieds ('35-39 Chevys, '37-40 Fords, plus Pintos, Vegas and that kind of stuff) available in 1/32, so I am making one (to start). In this case I may go for a generic master for the '37 Chevy coupe that will be cast in resin for the necessary cost savings and convenience - with the enduser hogging out windows and trimming fenders and body work as needed to replicate specific cars.

I just threw on some gear to test the chassis, and I question the guide setup - I went to the big Parma guide shoe because I had it, but maybe a smaller setup makes sense. The motor mount is fine so far, but I will be adding heft there and in other areas - again this was the very first test print.

But given the bodies I am working on, and the ease of changing the chassis around, I could fairly easily make something *very close* to the Buzzie car you have shown!

[ccobra]

I've use the ABS extrusion printer on my chassis and have found that I need to make the flag mount at 3/16" thick to prevent it from breaking. This was shown as a weak point when I ran an analysis on the chassis. This also showed me where the flex points were in the frame and these points could be moved to get the chassis to handle better. I also make the motor mount plate attach to the rear drive area like one of the motor mounts that Harry uses. With the Parma motors, Deathstar, I also support it in the front. The flags I use are either the Parma, Slotit, or the Professor Motor types. Now all I need to get is my printer going again for the print head quit on me. Now that is one interesting frame and once I get my printer going again, I've got some ideas for a chassis to place under a Chevy two that I got from the Doctor.

[smithspeedway]

Have you thought about using off the shelf metal components to reinforce key stress points? Several manufacturers make guide tongue braces.

[btaylor]

Those chassis are a work of art, I believe there will be some Modified Coupe body's available to the interested in the VERY near future. I now have the early thirties coupes and there are more on the way that I know of. I am sure they will be posted soon.
I know of at least two sedans, one early and one late 30's as well. Keep us posted on the availability of this chassis please!
Bob

[Vintage 1/24]

[slothead]

Love that 35 Chevy modified! This is going to get me back into building oval cars again.

I guess the ideal location of the guide can vary, but my sweet spot was 1/2" in front of the front axle for 1/24 scale cars. The handling characteristics of the triangle formed by the guide and rear wheels matters more to me than how visible the guide is. In fact, for a great looking and handling car I'd go for a long brass drop arm for the guide that included the motor & mount that pivoted at the rear axle bushings. The weight of the motor would keep the guide planted in the slot, and the rest of the chassis and body would float above it with that weight planting the front wheels to the track. If you picked the car up by the body or nerf bars the guide could hang down 1/4" to 1/2", isolating the body vibrations from the running gear.

Sitting on the track this car would look just like your mock-up, with a full 3D chassis riding above the drop arm. I'm looking forward to starting a 1/32 build like this when you have a body and chassis I can buy.

Thanks.

Slothead

[chris]

What a fantastic project! Just read these posts and I'm gobsmacked.

Brilliant stuff.

Chris.

[btaylor]

"The 3D scanned '37 Chev Coupe that Shotgun posted is unavailable - Are you going to master that and cast it from a two-piece mold?"

I wont be casting from Daves 37, that was his design and execution,and i try not to replicate other peoples Bodies unless i have their permission. I am sure when he is ready to release a version of that body he will let us all know.
As it stands, I only have the Confederate Coupe body and the 33 Chevy eagle coupe that is being molded right now.
I hope to add a an early 30's and late 30's sedan to the mix soon as well.
Bob

[GTI]

Vintage,

In regards to the guide placement. I recently soldered a collar on the modified chassis that you built. Ground a part of the front of the collar so that I could use a slot-it screw guide. The set proved quite good compared to the professor guide normally used. So I think that is a definite option to guide placement, softer braids and most people with 32nd cars have these and braids etc... available.

[Vintage 1/24]

[HomeRacingWorld]

"so scale wheels/tires are important I think"

I second that emotion.

I am quite happy with the CB Design look so far.



15X10 with 22166FF.

But I can see on other later bodies you would want larger or smaller diameter.



CB Design makes a 17 sized series of wheels. 17x10, 17 x 11. Even a 17x8 which would work well for that occasional "pony wheel".







This is if you want larger.

IF smaller is desired they make a "F1 wheel" I call a "Modified".



It boils down to compromise. These wheel sizes have been the standard for quite awhile in our hobby.

Making a new size wheel is a great idea....but getting after-market tires for it is not. Some manufactures do not care about such things, but to ignore the enthusiasts who are involved in racing and wanting the performance/choice of a different tire is not something these enthusiasts appreciate. Often then, they replace the wheels with something as close as possible to scale so they can begin using the tires available.

Or others who don't want to do that, then have to wait and hope that a mold is made for our wheel and that the tires look and fits the way we like.

I must stress how fortunate we are to have people like Paul Gage who is not afraid to create new sizes/molds when he sees a need.

Nothing takes away from the visual appeal of model more than the wheels to my eye. Yet I also have that "wiggle room" where if it is close and seems to capture the essence of the car, I am happy. Such as the Steel Wheel from CB Design. It looks very good. Is it a perfect match for every steel wheel used back then? No, of course not. But it looks great to me on the models and so I am pleased. Others must be too as it's kind of popular.

If I were going to make a new wheel, I would do my testing with prototypes, get that size I want down perfect. Then compare it to wheels already in the hobby. See how close they are to determine if I really need to make a wheel size that is not supported by current after-market tire makers.

If I did feel it was important enough to make, then my next email would be to Paul Gage. Find out what it would take and how long it would be to get them to market. He does this a lot for other major brands when they introduce a new wheel, so I would imagine the same would be done with my wheel.

Anyway, sorry for the long post. Not everyday we have new products being talked about for oval racing, and I get a little excited :)

[Vintage 1/24]

HomeRacingWorld-

Thank you sir!

Very informative post - actually I am not *trying to reinvent the wheel* here, but trying to find the best scale match for that 'Firestone 500' type modified wheel/tire setup.

It is in the realm of possibility to make a unique wheel/tire, but there is so much stuff out there already, that there is likely a road to this setup, and by the look of the sidewall profiles alone the Paul Gage stuff is the way to go.

I figure true scale for a 15" rim would be 12mm so that seems like something to persue. I see PGT already offers sizes to fit even the smallest Parma type wheels/hubs (down to maybe 10mm), I think Pro Track comes in like 12-14mm, and there are makers like Sonic that make similar sizes, all for the commercial market, available as needed.

But yes, it may be that it doesn't have to be perfect scale - sometimes the wrong size will make more sense in function or to fool the eye; there is 'art' in artifice. Actually, I really like the look of the setup you posted.

The caliper dimensions on the 17mm wheel/tire were useful; this is a battle of millimeters after all. I wonder how the 15x10 and 22-16s would measure out? Again, I like this look.

I wanted to start with what would be the perfect pie in the sky match, which my calculator is saying would be a 12x12 rim with a "PG style" 20-14 or 20-16 tire? It would be ideal to have perfectly scaled asphalt modified slicks on a perfectly scaled car - but those 15x10 and 22-16s look very good.

GT1-
I should have answered before, but I would like to see that guide flag setup - I am thinking that It might be the right guide mount for this car. I understand it is a pretty popular setup.

[RichD]

The diameter of the visible part of a 15 inch wheel is actually 16 inches, so a 12mm (.5 inch) diameter wheel would be perfect. The 14mm series CB Design wheels are about the right diameter, but they are all too narrow for those steamroller tires except for the F1 size. The 15mm series would be equivalent to 16-17 inch 1:1 wheels, but I think they look OK and a variety of resin inserts are available for that size.
There is a chart on the Slot Car Corner site that has the actual dimentions of all of the CB Design wheels. http://www.slotcarcorner.com/wheelchart-combo.pdf

[GTI]

Vintage, I sent you an e-mail regarding the guide with photos. Wasn't sure how to get that done here. Hope it helps. Looking forward to this project, good luck and have fun!

[Racie35]

How many pieces are glued together to make one of these?