Roger Zimmermann

Thanks Gerry for the picture. I'm not quite sure if I understood the spoke dimension: 0.012"? At scale 1:8, that's 2.4mm; almost like a spoke from a bicycle! Mines are more stable: 7mm; I will use brass rods of .6mm (0.024"). I have also the books from Gerald; however his method is not suitable for my needs. You will see my method soon!

Thanks Alex for searching parts! I save the pictures from most items. I have pictures from those items as assembled on the frame; it's always interesting to have them also as sole parts.

Well, Alex, let me continue the Cadillac project! Oh, by the way, only the emergency brake is functioning! The steering too, but with a lot of free play...

Thanks for your comments; it's a motivation to continue to relate this new adventure! Alex, you could go into the Avanti if I had a method to shrink you; unfortunately, you could not go very far as the motor is a dummy one!

In July 2019, I wrote this text in the Cadillac LaSalle forum. I did some changes here because some remarks are not relevant: When I was finishing the Mark II, I was thinking that it would be the last model. Fortunately, I'm still able to do something, but I will not tackle a 10 years project. Slowly came the idea to do something with Cadillac. One, if not the most prestigious model, was the V16. What I intend to do is a 1:12 scale rolling frame with the engine/transmission/suspension and steering. I would limit the MY from 1930 to 1933. 1934 have an independent front suspension; I have enough models with that type of front axle. My issue is to find enough documents/technical drawings and/or pictures to be able to conduct this project. Of course, dimensions are a must and I hope that one or more viewers have informations or could tell me who has some. If costs are involved, there is not a problem. Once, there was a V16 in Switzerland; I will have to research if the car is still in this country but most probably I will not be able to take from it all what I will need. Usually, shop manuals from that time have nice drawings from the mechanical features; this would be something to consider. Who will cooperate? Anyway, thanks for the help! I got some responses and suggestions. I got in touch with various people; a man from the Netherland promised me many pictures from a 1933 frame and engine he just restored. Slowly the idea came that I could go to that man and measure the frame. He told me that the engine and frame were already gone in North Germany at about 100 miles from his shop. If I wanted to et at the frame, I had to hurry because 2 or 3 weeks after, the body will be mated to the frame. As it was an unique opportunity to have that frame alone, I jumped to it. The car's owner and the body shop in Germany agreed that I would come and take as many pictures/dimensions. In between, I bought the repro shop manual from 1930-31, the one for 1932-33 and a parts book as I still was not sure which year I would choose. Due to the situation with the available frame, I choose to do a 1932 unit. Early August, Christine and me drove 530 miles one way to measure and take pictures from that 1933 V-16 frame and engine, just before the body was put on the frame. As usual when so many dimensions can be have, I forgot some essential ones, but I will survive. In retrospect, it was a fun adventure! We were one and half day at the body shop and we stayed a bit longer to see the countryside. We came back on Sunday because we had some commitment the next week. I began indeed with the wheels. On the 3 other models I did, there were just steel wheels reproduced in brass and, for the Toronado, with aluminum. This is quite different for this model: wire wheels. They are much more complex than usual wheels; this will be an adventure in itself! Due to other things I have now, I'm slow to begin the construction. I began the first part on September 8, a front hub, which is now in fabrication. The attached picture is showing it, but the part is not yet finished.

Thanks Paulie! The saga with the tires is the end of the Avanti story. I'm adding some pictures from the finished model. This thread is not yet finished: since some months, I'm busy with a 1:12 1932 Cadillac V-16 engine and frame. I will publish here what I already did with that new project.

Thanks Mike! My fingers are tiny tires levers!

My file was too large, this is the end of the tire's birth. The first examination is positive. The thin film at the junction must be removed with a cutter, picture 9. Then, the removal of the tire can continue, picture 10. By pulling gently at the outside diameter, the tire is coming out, picture 11. It’s now out and an examination is needed, picture 12. It’s perfect! I still have to remove the center, insert the white wall and install it on the rim, picture 13.

Thanks John! March 04, 2010 The birth of a tire After some failures, I believe now that I’m mastering the process, I did pictures during the birth of the tires number 4 and 5. One tire begins its life with 35 grams of transparent silicone, plus less than 1 gram of black paste and 3.5 grams of catalyst. The whole is stirred very well, creating a lot of air bubbles. Without waiting time, the mix is poured into both molds, picture 1. The embedded air bubbles are obvious on the picture 2. When done, the air must be evacuated. Yesterday, what vas unavoidable did happen: the shaft pulling the piston from the plastic air pump broke. I could continue the vacuum process with a device using water; it was the method used many moons ago with the Toronado tires. I remember that this method has one or two inconveniences: it’s using a lot of water for a long period and, when the operation is stopped, the water can enter into the desiccator, which was the case yesterday, wetting the silicone! I took away so much water as possible with paper and continued the process. After about 2 hours, the mix is no more liquid, more like a paste. At that moment, (time span : 5 to 10 minutes) both halves are put together and loaded with a maximum of weight to squeezed the excess silicone out of the molds, picture 3. When the product is set, (8 hours minimum), it’s the dime to the discovery ! First, remove the excess around the molds, picture 4. Then a small screw driver is inserted into a notch at the junction of both halves and use force to begin the separation of both halves, picture 5. With more strength, picture 6. Then, continue with the hands, picture 7. When one half is released, you can see that, picture 8.

Mike, I would have use the same method!

They are just stretched a bit without any adhesive. As the speed is very limited, they stay in place!

February 28, 2010 Success! The tire was taken out of the mold this morning; in fact, it was what I did first, long before breakfast! As the result is perfect, I can continue with that method. There are only 4 more to do ! Sometimes, I have trouble with chemical products. The white walls are a bit too thick; they are not flush to the black surface. No problem, I just mix again some white stuff and put the material into the mold. As I prepared too much, I put the remaining silicone into the freezer; at -18°C, it should not set. Well, it did not go that way: after one week, the “new” white wall is still sticky and the one which was into the freezer is set! As this new tentative is successful, I’m continuing the process. I did a picture when both halves were into the desiccator and began to evacuate the air. It’s impressive to see the surface of the silicone rubber when a significant vacuum is applied to the mix: one could think that it’s boiling! After 20 minutes at – 0.5 bar, the surface is getting calm and further pumping as no more effect. The cup into the desiccator has some more silicone to compensate the diminishing volume when the air is out. The trick is to catch the right moment to put both halves together. In retrospect, I suppose that the proportion silicone/catalyst was not right. I did another one which is now installed into the good tire.

Well, with the kind of work and experimentation you are doing, it's not a surprise!

Fortunately, the next tires were better!

No broken drill? I'm sure you had no idea some months ago how deep you had to go with hat engine!

Thanks Keith! Sometimes, by searching details, I'm coming across an interesting topic with bad pictures or good pictures but no explanation. I know that you most probably don't want to do a scale model, but if the pictures or text are too miserable, nobody will have a look at that. February 22, 2010 Good result ! This morning, I removed the half white tires (or positive molds) from the resin, picture 1. All is good, no bubbles, no major issue! In between, the odor in the flat went away, no war will be declared! You may wonder why there is a brass ring into each half mold. As the specific weight from the white silicone is near from 1, but I don’t know the one from the polyester resin; I suppose it’s higher than one. To avoid that the half white tires are floating into the resin, I added some weight to keep them down. February 27, 2010 Things are getting serious All what I explained before were the necessary steps to fabricate tires. Now, as the hard molds are ready, it’s time to make the first attempt to get a tire. The half forms are put together and attached with tape to avoid that the silicone is escaping. I did an aperture at the top to pour the silicone, picture 2. Honestly, I had doubts about the issue (one failure from time to time is keeping the ego at the right level, isn' it?): the silicone is too thick and is taking a too long time to flow down; the mix begins to set after about 1 hour. During the process to remove the air, I saw a lot of bubbles at the top wich would not burst. I’m not feeling well… This morning : I attempted to separate the mold from the tire which went without difficulties, picture 3. However, my fear was justified : a lot of silicone is missing at the top, picture 4. This tire cannot be used, but just for the fun, I put a white wall insert and assembled the tire on a wheel, picture 5, and I installed the wheel on the model, picture 6. I believe that the tire has a too large outside diameter, about 1mm. Maybe after some mileage, this will be down ! After this first attempt, I had to revise the method to get a good tire. At first I’m pouring the material into both half molds, picture 7. After about 2 hours, the silicone is almost set, but not quite. At this moment, I’m assembling both molds and squeezing the excess silicone with a lot of pressure. Some weight on the assembly prevents the upper part to lift and draw air, picture 8. Tomorrow I will have the answer!

Could you imagine cars built that way now?

Thanks John! I don't remember if I mention it before: this method is the one described by the late Gerald Wingrove in one of his books about scale models. I adapted it to my needs and what I have (had) sas material at disposal.

February 21, 2010 Ah ! Those plastic tools…The axle at the handle broke. Repaired. The axle at the plunger partially broke. Repaired. Sometimes later, the other axle broke; was repaired with brass. At the next break-down, I will have to replace it and buy another one in metal. Obviously those plastic pumps are just good for demonstration. It goes forward ! Yesterday, I was ready to pour some polyester resin into the negative molds, first picture. A piece of cardboard was shaped as a tube as a barrier for the liquid resin, sealed on a piece of flat brass with tape. Then I sprayed some wax to facilitate the removal from the brass. The second picture, just after the resin was poured. The green color is accidental, the resin is clear: to measure the resin quantity, I did a small spoon with brass; the chemicals into the polyester reacted with the brass and gave this green tone. THE question : how many air bubbles will be trapped into the tire’s grooves? The answer will be available when the resin will be set. I did that exercise into the flat because it was too cold outside to do it there. I could not wait for summertime !

Don't be so pessimistic!

In fact, I ended buying one in metal as this fracture was not the sole incident. This new pump survived the remaining tires and the ones from the Mark II. The metal ones are definitively worth the extra costs!

February 14, 2010 Yesterday, I poured some white silicone into one of the negative molds. The question was : will the product stick or not ? The problem with such a work is that the result can only be seen when the product is entirely cured, usually the day after. This morning : attempt to remove the positive mold from the negative one: The half tire on the right is perfect! At the top of the picture, there is something few would like to see at home: a syringe. This is needed to mix the catalyst with precision. No, I don’t have the needles ! At the picture’s bottom, you can see the product which will used to do the definitives tires. I did a test to see if the colo ris suitable because the ground product is clear like water ; a tinted product must be added; 1 to 4% are enough according to the manufacturer of the product. I poured a small quantity into one of the Toronado molds; with only a very small quantity the products is getting black, a nicer color that I had with the Dow Corning product (which is now extremely expensive, more than $ 300.00 for one kg). I’m doing now the other tire’s half. February 14, 2010 The breakdown! By creating vacuum with this hand pump, my hands are still OK, but not the pump ! Those tools in plastic are not worth…I will attempt a repair but I’m sure something else will go bad! By luck, I was at the end of creating enough vacuum…

February 08, 2010 Victory? It’s still too early to say it, but things are gook looking. The second half of the negative mold was done yesterday. Why did I wait so long to do that ? Well, I needed a releasing agent; I got it yesterday. All my attempts with silicone grease, soap or other products failed. What I got is a wax spray can ; this is needed to avoid that both parts are definitively glued together. This morning, I took away the tube. The surface which was contacting the steel tube is looking good. What will I find inside at the separation line, full of air bubbles? Indeed, the surface at a first glance is perfect. The product is also a good cleaner: even if I washed the brass tire before the job, the surface has some black traces. The spraying of the wax was not very good; I missed a small surface and the silicone stick together, but this small problem will have no effect for the rest of the job. The next operation: pouring the same product into both halves. For that, no error is allowed. otherwise, I will have to go back to the starting line.

What a job! I'm sure this truck will be way nicer than when it was new. I'm surprised by your method to shrink the metal. I don't know exactly how that process is working, but certainly is as effective as with hot spots. Do you have a dolly under the panel?

February 01, 2010 As I did know that the tire story will not go without difficulties, I did something else to let the things calm down, the rear license plate, for example. There are decals for that kind of job, but I don’t want to begin with a new experiment. Therefore, I did an « Avanti » name with brass and glued it on a black plate. Another small job I did: put some black paint are the right places. Here is one, installed on a wheel. The comparison between the new and the old one don’t need any comment.