Roger's handcrafted 1:12 scale models

[Roger Zimmermann]

The rough work is done on the tire pattern. The face towards the rear of the lathe will be refined with an hand held tool. This is the best way to get a smooth and regular surface. Because of the white wall, the other side will be handled differently.

 

[Luv2Wrench]

I wasn't sure if it would work for you but since the procedure isn't all the well know I thought I would mention it.   I really enjoy your work and I'm very thankful you keep taking us on this journey!!

[Roger Zimmermann]

The rear of the tire is almost finished. As you can see, the shape was done with a cold chisel. When I did the picture, the lathe was not running because  both hands are needed to work correctly with that tool. I'm using the slowest RPMs; with the correct angle and position, the quantity of metal which can be removed is impressive.

[Roger Zimmermann]

The tire pattern main element is ready. Most probably, by looking at the attached picture, you will not understand why the front of the tire has this strange shape. This is my way to add the large white wall: it will be a separate element pushed into the black rubber. I did the same with the Mark II's tires with one major exception: the tire's name will be on the white wall. For the Mark II, I did a negative mold and I could directly do the white elements. As I cannot engrave the tire's name into the brass, I will to make a positive form; with that done, a negative mold can be created. It's just one step more...
For the moment, the next step is to add the profile on the thread.

[John S.]

Roger, I really appreciate the hard work and dedication you put into all your projects. Just great work! John

[Gary_Ash]

Roger, as you had stated back in the Avanti model work, a 3D printed master would get you finished more quickly and maybe with more detail.  Just for fun, I put together a 3D model of a 7.50-18 tire with zig-zag tread, 32-inch o.d., 7-rib tread, tread width 6.25 inches, and section width 7.5 inches.  I didn't letter the sidewalls, but it could be done.  What scale are you working at? 

 

Actually, a 3D mold for the tires could be printed out.  I made the tread depth 0.5 inch from the 32-inch o.d., don't know if that would lead to problems removing a cast tire from the mold when scaled down.  

 

Edited December 6, 2021 by Gary_Ash (see edit history)

[Gary_Ash]

I added the Firestone logo lettering.

 

[Roger Zimmermann]

Thanks Gary for your input. This is correct: I'm sure that a 3-D tire would be better, with a more complex thread and more scripts on the side. Quicker too, but for what? Doing a 3-D tire would not be "my" tire, but the one from a machine. I just could go shopping and buy what I would need! In short: this is not my conception of modeling. More and more people are using those fancy method to build various objects; it would make sense to build missing parts from a real vehicle, especially if the shape is complex. 

I'm most certainly "old fashion" with my thinking or philosophy; at the end, what I'm doing and the way I'm doing it must please me!

[Gary_Ash]

Roger, I wasn't wanting to take away from your enjoyment of your projects, and you do them exquisitely.  I just wondered if I could actually draw a detailed tire on the computer CAD system and print out such a thing on my $175 3D printer.  I learned a lot about what goes into the design of a tread pattern.  I did print two blackwall tires, one with the Firestone lettering and one without at 1:12 scale.  They are too large for my 3D-printed 1:24 scale model of my 1932 Indy car, though the full-size car has 7.00-18 tires, not much smaller than the ones you are modeling.  Using the 3D printer is pretty easy but learning the CAD software takes a long time.  I think that is what prevents many people from using 3D printing for making car parts.  It is easier to learn for those of us who trained as engineers, learned how to do drafting with a T-square, triangle, and drawing board, and learned to read and use mechanical drawings during our working careers.  On the other hand, I am much less skilled than you are at operating my small lathe, so I tend to use other machines to make things. 

 

These tires are done in hard PLA plastic.  I did upload the CAD file to i.materialise.com to see if they could be printed in a rubbery-like compound.  They can use an HP fusion jet printer to print gray rubber, then dye it black.  The estimated cost was $33 per tire - less than real tires but still pretty expensive.  But, one printed one could be used to make a mold to cast others cheaply from urethane.  The Firestone lettering at 1:12 is on the borderline of what is possible with fine detail on my inexpensive printer, though I didn't print at a slow enough speed for best resolution, but commercial printers can do much better.  Printing a tire with whitewalls would be a challenge, might have to be done as two separate pieces, as you are doing.  I'd be happy to mail a tire to you.

 

3D-printed 7.50-18 Firestone tires at 1:12 scale.  Printing time is about 4 hours per tire.  Material cost is less than $0.50 each.

 

3D printed model of 1932 Studebaker Indy car.  Printing time was three days.  I paid a lot of money to a Ukrainian company to create the detailed CAD file from hundreds of photos and some of my CAD files, took them many weeks to complete.  

[Roger Zimmermann]

Well, Gary, you are quick! Anyway, way quicker than with my method! What you don't know: I did no like the overall dimensions from the replicated tires one can buy. I ended with an overall diameter over 32.6" (at 1:1 scale) and a section width over 7.85". This is a typical Swiss compromise: not what the actual real tires are, and not what the theoretical dimensions should be! If you take those dimensions at 1:12, the tire you could do will still not fit your 1:24 Indy car! 

With my antique method, I should get a better rendering from the Firestone lettering. However, as you are writing, the quality of the printer is certainly a non negligible factor.

Please don't let do a tire from that company because it will certainly not fit my rims. My design is particular dimensions wise.

With a 3-D printing, the white wall will also be a separate inserted part. Everybody is cooking with water!

Nice scale model from the Stude Indy car. I can imagine that the file was costly, especially working from pictures. 

You will see the next few days/weeks/months the birth of my tires with the method first developed by Gerald Wingrove.

[Gary_Ash]

Roger, you expressed concern that a 7.50-18 tire was not 7.5 inches wide.  The nominal sizes assume that the cross-section of the tire is round.  The tires of the 1930s had a height of about 90% of the width.  Older balloon tires were closer to round.  So, if the sidewall height is 7.5 inches on an 18 inch rim, then the tire diameter is about 18+2x7.5=33 inches.  The tread thickness may add some to that.  So 7.5/0.90 = 8.33 inch width.  Change the section ratio, and the actual tire width changes.  Tires of the 1950s and 1960s had ratios of about 0.82, modern cars are down to .6 and less.  

 

I didn't think you would actually want any 3D-printed tires, I knew they wouldn't fit your rims, I just did it for fun.  But, I'm still happy to send you one for inspection or use as a toy for a cat.  One nice thing about the 3D printer, though, is that I can use any number to scale the CAD drawing, whether full size, larger, or smaller, so I can easily use the same CAD file for a 1:24 size tire or 1:3.1415926 scale.  The real limit is that my printer will only do a part that fits in a volume 8" x 8" x 10" high and the minimum wall thickness must be greater than about 0.3-0.5 mm for the part to have any strength.  Some commercial printers can now do parts 1 to 2 meters wide.  I did have some parts commercially printed direct-to-metal for Edinmass for his 1917 White.  These were about 8 inches long, made with sintered stainless steel powder infused with bronze, came out excellent.  

[Buick 59]

Roger,
 

Watching your progress is an absolute joy, especially since you continue to use traditional modeling methods which can only be performed by true craftsman.

If you were making your model using a 3D printer there would be little joy watching your progress, and the end result, which might look superior to the uninitiated, would be devoid of the craftsmanship that make your models works of art.
 

Thank you for continuing to share your work... it is truly inspirational!

[Roger Zimmermann]

16 hours ago, Gary_Ash said:

Roger, you expressed concern that a 7.50-18 tire was not 7.5 inches wide.  The nominal sizes assume that the cross-section of the tire is round.  The tires of the 1930s had a height of about 90% of the width.  Older balloon tires were closer to round.  So, if the sidewall height is 7.5 inches on an 18 inch rim, then the tire diameter is about 18+2x7.5=33 inches.  The tread thickness may add some to that.  So 7.5/0.90 = 8.33 inch width.  Change the section ratio, and the actual tire width changes.  Tires of the 1950s and 1960s had ratios of about 0.82, modern cars are down to .6 and less.  

 

 

Gary, I'm doing a different calculation: if the tire is 7.5" wide, the diameter will be: 7.5 x 2 = 15 x .9 = 13.5" + 18" = 31.5" The width is staying a 7.5". That's my understanding of the bias-ply tires. Reproductions are "oversized" maybe to fill up the wheel arches better. Remember the experience with my friend not being able to put his 6.70-15 into the spare wheel well from his Corvette. This was not an issue during the fifties and sixties. Only now.

It's much easier with radial tires (or less confusing): the width is given in mm and it's the actual width of the tire. For the outside diameter, the usual calculation depending of the ratio will give a correct result.

About the tire you did: if you insist, why not? I'm giving to you my home address with a PM. Thanks in advance!

[Roger Zimmermann]

15 hours ago, Buick 59 said:

Roger,
 

Watching your progress is an absolute joy, especially since you continue to use traditional modeling methods which can only be performed by true craftsman.

 

Tom, thanks for your comments! Don't worry, I will either continue that way or...quit. I will never buy a different equipment because it does not correspond with my vision of modeling.

[Roger Zimmermann]

To do the thread, I choose to fit 7 bands, even if the Firestone has 8. Why? Because I have to split my tire in the middle; the separation line will be on top of the middle band, which is easier to clean.
I cut 7 bands a bit longer than the circumference to be on the safe side. I did 3 assemblies by soft soldering twice two bands and one assembly with 3 band. This will shorten the machining a lot.
By looking at the original tire's thread, I saw that the zig-zag is not at 90°, but approximately at 120°. The milling tool on the picture as an angle of about 110°, good enough for my purpose.
As the head stock from the lathe was in the way, I had to remove it. Of course, I can only machine the brass which is secured with the jaws. After about 45mm, I have to position anew the assembly, taking care that the pitch is still correct.

[Randiego]

Roger,

 

Looking at Gary's tire that he printed, it is much like the item that I tried to make.  But no dig at his skills or efforts.  He is commendable in that he took the initative to venture into building you a tire.  Hats off to you Gary.  Your hearts in the right place.

 

My brother gave me a 3 D printer to get my feet wet in this new technology.  I found out that the time it took to learn the system and start the design process consumed too much of my time. It takes a lot of time to be proficient that I do not have the luxury for right now.  Plus the quality  of the part(s) left a lot to be desired.  I realize that the printer that he gave me was not an expensive one, just one to "whet my appetite" and get me going in a new field.  Well, like you, I am too old a dog to learn (or want to learn) new tricks.  I really  do not like computers other than communication tools, bookkeping, and simple programs that do not tax my abilities. I haven't even mastered the skills of Photoshop!  And with the new photography  methods, that is an important tool to clean up or modify pictures. 

 

The new generation of upcoming "modelers" are doing a lot with their 3D printers, but nothing replaces turning brass, soldering parts together, filing and sanding, fabricating bucks out of blocks of wood, bending wire and soft metals to fabricate part(s).  I am sure that if you invested in a high dollar machine, the quality  of the part(s) will be much better, but I am not in the market for a $2,000.00 to 4,000.00 printer.  Guys like Jay Leno have a hi dollar, state of the art, 3 D printer that they use to make unobtainable parts for their car restorations,  BUT, they have the budget for that very expensive machine.  Plus, most of the time, they make the part, or plug  to be sent out to be cast, and then it is sent back and his inhouse machinist finished the part.  But these are 1:1 parts, not 1:12 parts.  Like you said, Roger,  you are departing from machining and fabrication skills and are replacing them with programming skills.  A whole different field of "modeling".   

 

We have reveled for over 12 years watching you perform your magic with metal and that little Emco lathe.  It has given me vast pleasure to follow along watching you confronted with various problems and then the "light bulb" goes off and whammo, you come up with the solution.  We are all appreciative of your masterfull creations.  What really  amazed me the most is that not only did the Continental look IDENTICAL to the 1:1 auto, but the damn power windows, lights and seats FUNCTION!  Now 3D print that ! !

Give me the good old days of traditional model making, Roger.  As always, an awe inspired fan!  

Randy 

[Roger Zimmermann]

Well, Randy, this is when a good 3-D printer would do better than me. Just see below!

 

When I began the planning for the "mother" tire, I felt that the zig-zag thread was a good idea. Now, I hate it! The pitch was small: 1 mm. The tire without thread was not flat, but convex. At first, I soft soldered the middle band. As the brass piece is rather heavy, it took a long time to heat the brass to solder the band.  Once soldered, I had to remove the excess solder which was into the zig-zag, which took a long time. Then came the positioning of the next band. Ideally, the spikes should face the recess from the first band. As the milling was not creating a 100% exact pitch, I began to get in trouble, plus the fact that the next band is slightly shorter due to the shape of the tire. The first two bands positioned at each side from the first one were not too problematic but the next two were that bad that I did 3 pieces for each trying to have the correct figure. Finally, both at the outside of the tire have been soldered without looking too much at the other ones, except for the spacing.
The picture is showing the master tire after the last soldering operation; the plier on the right was used to rotate the tire during the soldering. I will now have to clean the assembly and trim the sides, with the hope that the thin bands will stay soldered.
In conclusion, not my best tire pattern. 

[Pat Hollingsworth]

I imagine that getting that tread arrangement gave a lot of men at Goodyear Rubber fits as well Roger. I never thought of the little differences in circumference causing the trouble but it sure does when one thinks about it.

I had an old friend that was a tire recapper. I bet he'd have known all this stuff. He did a set of 'period' caps for my old '36 Ford back when these things were far scarcer. Use an old commercial vehicle pattern he referred to as highway commercial. Long time back.

And, I know the soldering of such different masses of brass is a challenge. But, you've done plenty of that before- successfully. I admire all your work as much as the final product. 

[drhach]

Roger, would this be a case where using epoxy might be a better approach to attaching the treads? You certainly wouldn't have the heat issues and probably would have a little more working time. 

[Gary_Ash]

I wonder if the real tire molds produced a tread pattern that was nearly flat as tires came out of the mold.  Once a tube was inflated inside them, they would change shape and produce the slightly rounded surface we are used to seeing.

 

When I looked the tread patterns for the Firestone tires on the Coker site, I counted 144 zig-zags looking at the sidewalls.  The treads seemed to show about 120 degrees for the zig-zag angle, as Roger has used.  To make the tread pattern work in the CAD model and still leave space at the bottom of the ~1/2 inch tread depth, I had to taper each of the 144 zigs to aim to zero at the center of the tires (R=0). I don’t think Roger’s strips have that taper, might be a reason why they are tough to form around the “carcass” of the tires.  I think it’s very impressive that he has made the master tire so well. 

[Roger Zimmermann]

On 12/16/2021 at 10:31 PM, drhach said:

Roger, would this be a case where using epoxy might be a better approach to attaching the treads? You certainly wouldn't have the heat issues and probably would have a little more working time. 

This is a legitimate question. I discarded this method because not practical: it's not possible to glue the band(s) at once, only one inch or 1 1/2" Till the epoxy is cured, I should wait with the finger on the band to avoid unwanted movement. Then the next inch or more...The most important soldering is at both exterior bands: it must be done on all the outer circumference to fill up the possible void between band and main part. Would epoxy be strong enough to resist the final machining? Maybe, maybe not! 

 

@ Gary: Tire manufacturing is to me a black (pun intended!) science. I saw many pictures how this is done, but I should see it myself to really understand it. It could be the the mold is flat, maybe not.

You had time to count all those zig-zags! In my opinion, there should be more, but I will not count them!

You are right, all band were done the same, creating the issue I related. I did the same on the 3 previous master tires, but on those, the pitch was greater and the distortion not readily visible.

Edited December 18, 2021 by Roger Zimmermann
Comment added (see edit history)

[Roger Zimmermann]

Finally, the tread is not too bad. As for most every bias-ply tires, there are ribs on the side. When looking at the Firestone picture, the side ribs are in phase with the zig-zag from the tread. I decided that it would be foolish to attempt it; I'm just doing about 160 indentations without trying to match the zig-zag; there are about 215 at the outer circumference.

[drhach]

Good point about the wait time for the epoxy. I guess every process has it benefits and its compromises.

[Roger Zimmermann]

6 minutes ago, drhach said:

Good point about the wait time for the epoxy. I guess every process has it benefits and its compromises.

Said another way: everybody is cooking with water or each coin has two sides!

[keiser31]

I am always so impressed by the incredible details of your work/art, Roger! Thank you so very much for sharing these steps.

[Roger Zimmermann]

The main job of the brass tire is over. As I wrote earlier, the manufacturer's name will be on the white part of the tire. I'm happy with the Good Year tires I have on my models, negligible wear, not noisy, no cracks and still supple after all those years. I will however change the manufacturer by using the Firestone name. 
I had the foolish idea to make separate letters in brass; some would be easy (i, t, n); e, s would be more difficult. I began with the "F" just to see that the crisp angles are something I cannot do with the tools I have. An engraver could probably do them all, but it's a profession for itself with very specific tools I don't have. 
I will therefore come back to the old method I used with success: paint.
I'll need now material to continue with the tires: silicone and some brass to do the mold for the white wall. I will not bother suppliers before the end of the year; I'll look next year for that missing material. 

[Roger Zimmermann]

Sometimes it's better to put something on side and continue with it later. It's now happening with the tires, I will resume this adventure later.
As there are still plenty things to do, I'm not "jobless"! I'm continuing with the distributor. There will be plenty to do...I began with the support. I wondered first why this support was so long; after a while I understood that a shorter support would interfere with the fan support. Fortunately, my dimension estimates/calculated are not too far away, there is just enough space between both supports.

[Randiego]

Roger,

The master tire for the mold looks great.  Only  you, or a tire designer/engineer at one of the tire plants would notice the small differences in your "master".  The rest of us (the public) would not catch that issue.  Our eyes will be drawn to the rest of the surrounding car.  There is a lot of detail that will capture the interest of the viewer of your Cadillac.  Only you , and a very select few, will ever know the difference.  

 

There is so much to see and admire on your cars that it would take a trained eye to catch any mistakes that are present.  Joe Public will not be aware of the descrepencies with the tire(s).  One can look at the model for hours admiring all the details and never know the difference in the models tire vs. the 1:1 version.  Hell, Roger, I have brand new tires on my vehicles that have flaws right from the factory.  Sometimes they do not show up until I am back in the tire shop for a balance or rotation.  90% are cosmetic. 

 

I will be  waiting to see the finished tire.  I bet it will come out as great looking as the tires of the Continental.  Excellent work as always.

 

Randy                                                                                                                                                                                                     

[Roger Zimmermann]

The ignition system from those engines were a bit different than the ones from the fifties-seventies. The distributor houses indeed two ignition systems, one for each bank; two ignition coils are also used. Once the ground setting was done with the pointer at the flywheel, it was also possible to advance or retard the timing in degrees thanks to a scale attached to the distributor support. A pointer, integrated to the distributor itself allowed to get the desired setting as shown on the first picture. 
With 16 ignition wires, it was certainly easy to have a cable mess. To avoid it, an organizer was integrated at the base of the distributor. From there, the wires went into a tube and emerged from it at the desired location. 
The organizer and the lower plate locking the distributor were chromed and assembled with screws or rivets. To avoid the proliferation of small parts, those items on the model are soft soldered to the main body; this assembly will be chromed and what originally was not chromed will be painted.

[Buick 59]

Incredible!

[Pat Hollingsworth]

Those Cadillac engineers were mechanical artists. It's a fitting thing than another artist is replicating their masterpiece. Thanks for the Christmas present, Roger. 

[Roger Zimmermann]

The last tiny parts to the distributor were added yesterday, just at time for the year's end. It was however too late to make the update, but today is an appropriate day for that: it let time to evaporate the alcohol absorbed the evening before!
The distributor cap is attached to the body with two strong springs. My rendering of that is rather crude from very near, but by looking at a distance the illusion is almost perfect.
Like all distributor caps, the central plot is from the ignition coil's secondary circuit. On V-12 and V-16, there is a second plot for the other coil. Under the cap, there is a ring to conduct the voltage at the appropriate spark wire via a specific rotor.
On the real distributor, there is an oiling provision on the side for the cam. This is also replicated on "my" distributor, as well as both contacts on the side going to the primary circuit of the coils.

[Laughing Coyote]

Looks awesome as usual!  Happy New Year Roger, looking forward to another year of great craftsmanship as this project progresses.

[Roger Zimmermann]

Happy New Year to you and all the other people! Thanks for your comments...

[Paulie9fingers]

That looks amazing, Happy New year to you too Roger, and everyone else.

[John S.]

Roger, just beautiful work. Amazing, just amazing!!!!! John S.

[Randiego]

Very nice, Roger.  A very happy New Year to you.

[Buicknutty]

 In all of the years I've been following your work you never cease to astound me time and time again. Beautiful work and craftmanship.

Keith

[Roger Zimmermann]

At the end of the year, I did both ignition coils and their support. Those rather easy parts were finished when I began to look at restored cars. Something catch my eye: the ignition coils are not behind the fan, they are located at the the radiator!
The coils were wrongly installed on the fan support when the frame and engine came to the Netherland to be restored. As Johan did pictures from all the elements before he began the work, I was fooled by those pictures!
Those coil's supports will be removed and, in due time, the coils added to the radiator.

[Roger Zimmermann]

When I don't know how to do a part or no envy about it, I do continue with something else until either I don't know with what to continue or the desire to have an element finished is haunting me!
The brushes covering bands for the generator and starter motor is a perfect example. It seems easy to do, but indeed I pushed back their fabrication. It took me a while to do the first one because I was not at all motivated. Finally, the task was not so bad: a band of brass 0.01mm thick, with one rolled end, then a small attaching latch soft soldered at the right place and voilà! At first, I intended to rivet the latch like the original parts but opted for the soldering. Less chance for a disaster doing so!
The second band came not so well as the first one, but still usable. Those parts will be chromed.
By pulling at the latch, the band can be removed like the original one.