Roger's handcrafted 1:12 scale models

[Roger Zimmermann]

How to silver solder bushings at the end of the axle with  a hint of precision? I solved the problem by including tabs at each end of the axle and milling a groove into each bushing. The tabs are entering the groove without play, allowing to adjust the correct angle and position before silver soldering.
On the picture, both knuckle pins are ready to be put in service; they are at the right diameter to be without play in the bushings.
I can continue now by putting more "clothes" to the axle.

[Roger Zimmermann]

This front axle may not be very exciting, but I must do it! I first trimmed the part to be able to silver solder the upper flange of the H (or I) and gave its almost final shape. Now, I'm preparing the parts which will be silver soldered on each side to have the correct thickness. If my explanation is obscure, the picture which will come soon will explain better.

[Mike Macartney]

Hi Roger, A question. With silver soldering can the flux go off? I don't do silver soldering very often. Last time I went to silver solder some brass parts I made the flux up into a paste and brushed it onto the cleaned parts that I wanted to silver solder. When I applied the heat, the solder just went into small balls and just would not flow. The flux had been stored in a plastic bag for probably two years, maybe longer. Mike

[Roger Zimmermann]

Honestly, I never had a problem. Can it be that the flux you had was not a "good" one? When I review in my mind that last part I silver soldered, the flange for the front axle, I put a bit too much water and the flux was more like a liquid than a paste. I saw also the flux getting into balls but I assume that the brass was cleaned over the entire surface because the solder flowed as I expected. Next time I'm silver soldering parts, I will have the correct mix water/flux and try to remember how the flux is acting; I will report the results.

If Christine is here, she maybe can do a picture during the process.

The age of flux is not important: mine was previously stored into a paper bag for maybe 20 years or more! I have to say that I'm using one of the best product in the world: Castolin.

[Mike Macartney]

Thank you Roger. I think you have 'hit the nail on the head', yes I am sure I put too much water in the flux, and was too impatient. If I remember correctly, it was a small job that somebody in the village wanted repaired, while they waited, I rushed and did not take my time to do the repair. I think, possibly I cleaned it up and then soft soldered it.

[Roger Zimmermann]

Rushing for such task is never good!

[Roger Zimmermann]

To Mike: sorry, no picture when I silver soldered the parts below, but I did following to have a decent report to you: first, I mixed fresh flux to get a creamy solution. With the rod, I applied a generous coat of that flux. By heating the assembly, the flux tuned white like snow (although it's white when applied) and was boiling (this is the water). Then it more or less disappeared but in fact it went on almost all the surfaces. When the color of the joint to be silver soldered is getting almost the same color as the liquid solder, it means that the temperature is high enough and the tip of the rod can be put into the flame and will flowing into the joint. If the explanation is not enough, I will do some pictures with Christine; the best in my opinion is that you try yourself! Brass is not a necessity; 2 scrap of sheet metal can be used. Depending of what kind of alloy you are using, the sheet metal will turn dark red. My silver solder Castolin 1802 is about the lowest melting point on the market.

 

I can now show what I tried to explain recently. 4 filling pieces were more or less correctly adjusted to the existing axle. To help for the right location during the silver soldering, the pieces were riveted to the axle.

Now, I have to trim the assembly to the final shape; the second flange forming the H will be the last part which will be silver soldered. There will be several minor details which will be soft soldered as the are just for the fun.

Due to the intense heat needed, I'm glad that the bushings were mechanically stabilized.
 

Edited December 8, 2019 by Roger Zimmermann (see edit history)

[Mike Macartney]

Many thanks Roger for your description, it is very helpful.

 

The axle looks quite complex to make.

[Roger Zimmermann]

You are welcome, Mike!

Indeed, it's not easy to replicate cast parts. The only method is to divide  the assembly into simple elements and put them together. There will be a large amount of castings with this model!

[Roger Zimmermann]

The front axle is almost ready. Since the last report, I silver soldered the lower flange, added a sole or shoe (maybe there is a better word) at the location for the front springs, trimmed the whole axle and lastly added the four tiny pieces at each end of the axle. Two will get the grease fitting; the other two are staying closed. These four parts took a long time: I had to drill them, put a pin, drill the axle to accept the pins. Without that, I would not be able to soft solder them at the right place or the one soldered would get misplaced while soldering the one the other side of the axle.
What is missing? Again 2 tiny parts which are acting as a steering stop. Only when the brake shield will be done I will see the exact location; they will be soldered with the same method as the four ones, with a pin.
What is coming next? Logically, the knuckles. Here we go! 

[keiser31]

Wow, Roger! You make even the most complex items so perfectly to scale. I have been amazed since I saw your very first post. That looks like a real cast axle.

Edited December 12, 2019 by keiser31 (see edit history)

[Roger Zimmermann]

Thanks! I hope I can continue to amaze you!

[Laughing Coyote]

42 minutes ago, Roger Zimmermann said:

I hope I can continue to amaze you!

You always do. A true master.

[Mike Macartney]

Roger, the axle just looks incredible. I agree with keiser31 & Laughing Coyote. If you did not know the photos were of a scale model, you would think it was a full size axle.

[Roger Zimmermann]

Thanks Mike!

Modeling is just creating an illusion. It seems that I succeed with this axle!

[Laughing Coyote]

14 hours ago, Roger Zimmermann said:

Modeling is just creating an illusion.

Speaking of illusion, Where's that big quarter, Roger?

[Roger Zimmermann]

I do forget it too often because it's so heavy!

[Roger Zimmermann]

There are sometimes parts I don't know how to begin them. The knuckles are a good example. I did first the shafts but I had to modify my plan: the first idea was to have "bearings" in steel as large as possible therefore the hub would be rotating over the fixed very large shaft. This solution is not at all practical as I could not take easily the drum from the model.
Consequently, I did 2 shafts in mild steel and "bearings" in brass pressed into the hubs. The shafts will then be silver soldered into the knuckles. I then took the largest bit of brass I had, trying to machine all the needed details out of it. Unfortunately, I discovered that the bit is not thick enough! Therefore the attaching channel for the steering knuckle arm will be a separate element silver soldered to the main part.
But how to begin? Drill the hole to attach the shaft or drill the holes for the knuckle pin? I opted for the second possibility with the hope that the hole for the shaft will be at the correct angle to have the front wheel with a very slight positive camber.
As it can be seen on the picture (this time with the big quarter), there is still a lot to do!

 

When I began the wheels, I thought that I would need months to complete them. In fact, the job went much quicker than that. This is quite the opposite with the knuckles, they are still in fabrication. During milling, I suspect that the milling bit was not tight enough and went down. The result: a scraped part which can be seen on the left on the third picture.
As you may see, there is still some work till completion!

[Roger Zimmermann]

Finally, the steering knuckles are ready. There was a lot of machining, silver soldering and filing. I just have a regret: the steering arms are attached with 2 bolts to the knuckles; to have a flat surface for the head's bolts, a counterbore is provided at the knuckle's mounting point. Unfortunately, I cannot do that; I just could provide a flat surface. I don't know how this was done in production because the upper part of the knuckle is in the way. Maybe from the other side with a special tool?
What I still have to do is the device to adjust the play; the original knuckles having an upper and a lower ball bearing. Of course, my device will be just here for the show.

[John S.]

Roger, that is perfection! John

[Paulie9fingers]

Very nice, amazing work as always.
 

What is the bracket on the bottom of the spindle for ? I tried to search online to see what the factory ones look like but I had no luck.

[Laughing Coyote]

I just can't get over how you make this stuff. Always amazing! 

[Roger Zimmermann]

1 hour ago, Paulie9fingers said:

 

What is the bracket on the bottom of the spindle for ? I tried to search online to see what the factory ones look like but I had no luck.

Thanks Paulie (and the others too!)

the bracket is for the steering levers as you can see on that picture from a real car. This is how the knuckles are getting the input from the steering wheel.

[Roger Zimmermann]

20 minutes ago, Laughing Coyote said:

I just can't get over how you make this stuff. Always amazing! 

Thanks Martin!

Just come home and see how I'm doing it! Joke aside, it's nothing special. Just have the brain associated with small things and the corresponding tools!

[Paulie9fingers]

Thank you Roger

[Mike Macartney]

Roger, I think you could have been an excellent brain surgeon with your skills. To me, your work it is just amazing.

[Roger Zimmermann]

11 minutes ago, Mike Macartney said:

Roger, I think you could have been an excellent brain surgeon with your skills.

...but I don't especially like blood! The fact is that those people do wonderful things, helped with some visual systems. I still prefer to work on brass!

[Mike Macartney]

24 minutes ago, Roger Zimmermann said:

I still prefer to work on brass!

 

At least it doesn't bleed!

[Roger Zimmermann]

The knuckles are now ready with the addition of the adjusting device. Of course mine is not functional. You can see that the surfacer from the axle is already damaged. That's not a problem; in due time it will get a new coat. The goal was to cover the surfaces with are difficult to clean.  What's next? Well, Christmas is almost at the door!

Enjoy that period of the year!

[John S.]

Merry Christmas, Roger, to you and your family. You always have wonderful and interesting projects. John

[Roger Zimmermann]

Thanks John. Happy New Year!

 

What could I do next? Rather logically, the brake shields should logically be next because they are attached to the knuckles. But now, I'm doing the rear ones! Too much red wine lately? No! the reason is that the rear shields are rather simple and the front ones are more complex. The outside diameter is the same, that's all.
The dies I did are modified dies used for the Mark II wheel covers. Once the real shields ready, those dies will be modified to do the front ones, sparing that way a lot of material.
The dies are on the first picture.
The second one is showing my method to press the brass with the dies.
I was glad to see that the first shield went out without problem; the surface had some waves which could be almost eliminated by rubbing the high spots with a hammer. Unfortunately, the second shield developed a crack as you can see on the next picture. Doing another one is not a guarantee of success, therefore, I repaired the crack by silver soldering a piece of brass inserted into the crack.
The next operation was to shape the outer flange; unfortunately this picture is no good but both shields were already finished as shown on the last picture (only one was pictured). The flange is shaped with a hammer on the die as making another tool just for that was a waste of resources. A small hammer can do wonders!
Later, these shields will be adjusted on the rear axle; the 6 attaching holes drilled, plus a number of parts for the brakes will be added. I just can say that mechanical brakes are very complex, compared to the hydraulic ones. The bonus: I may have the brakes functional on all 4 wheels.

[Roger Zimmermann]

After the rear brake shields were ready, it was time to modify the dies to press the front shields. At first, I was thinking that the shape is easy; well it was the case to do the separate male insert. The female job was not that easy. The almost rectangular cavity could be milled, but the half round one was more difficult to get. Milling was not an option, at least not with my basic machine. I removed almost all the metal with grinding and finished it with a hand tool, shaving the brass until the insert was flush with the flat surface.
The male insert was then attached to the other die with a screw.
Then came the moment of truth: will the brass be torn as the cavity is rather deep? Nothing bad happened at mid way, but at the end it was torn at the end of the cavity. To repair it, I cut the damaged spot, pressed a bit brass, adjusted and silver soldered it. This repair took much more time than pressing the shield!
Now, I have to do the second one; most probably the same damage will occur; then I can show with a picture or two what I intended to explain.

[Paulie9fingers]

Very nice, what thickness is the material you are using to stamp the brake shields ?

[Roger Zimmermann]

Thanks Paulie! I'm using 0.3mm half hard brass (0.012"). I annealed the rear ones; I tried the first front one without heat. I annealed the brass just to finish the shield and, of course to silver solder the repair.

[John S.]

Beautiful work, Roger.

[Roger Zimmermann]

Happy New Year to all!
The end of 2019 was not kind with my front brake shields, I will relate it later. First I'm showing the various steps to shape the second brake shield. I prepared a piece of brass large enough; drilled some small holes to prevent too much damage, first picture. After 1/3 stroke, I checked how the metal is taking its new shape; no problem to report; this is the second picture. At 2/3 of the stroke, the metal is already torn at one end (third picture). Dies builder is a profession; probably there is a method to avoid the issue (choice of metal, various steps, etc.).
Once completely pressed, the damage is obvious, but smaller than with the first shield, fourth picture. A patch will be silver soldered anyway.
I began then to trim the center, to make the needed space for the knuckle. The first problem I encountered was with the shape of the recess at the top: I did the corner's cuts at 45° and I could not put the knuckle high enough! By looking at the pictures I have, I saw that the corners are at about 25 to 30°. I modified both dies to the new shape and I tried to rework the shields by pressing them again. No problem, the brass was soft enough to accept the new shape. Then, I could finish the aperture for the knuckle. I put a drum on the "assembly" (the shield being just pushed on the knuckle) to note that the drum is resting on the brake shield! What to do to get those 0.5mm interference away?
Well, the first step was to modify the ears on which the shields are attached by removing 0.25mm. More was not advisable because they were 0.7mm thick. Then, I modify the dies once more by carving the recess by an additional 0.2mm. Here again, I got no protest from the shields and no damage.
The third step I will do is to modify the inside of the drums to have just enough clearance.
I assembled a brake shield on a knuckle (fifth picture); I still have a slight interference; the drums modification will get rid of that.
While I was with the camera, I redid a picture showing how the flange are shaped with a small hammer; this is the last picture.

[Paulie9fingers]

Happy New Year to you too, quite a bit of work there

[John S.]

Happy New Year, Roger. All I can say is clean, your work is very clean.  I love how your subjects come to life. Always look forward to your post. John

[Roger Zimmermann]

During our short vacation in France, I took the raw material which will be the pattern to shape the frame and I began to work on it. It's 5mm thick, therefore, I cannot prepare it at home, I have no suitable vise. That piece of brass is 420 mm long or 16.6"
Back home, I'm continuing the brake shields by adding the various element to make the brakes operable.

[Roger Zimmermann]

Recently, I added a small shaft for a brake lever at the front brake shields as well as the insert for the bolt limiting the steering angle. One challenge was to drill a 0.4mm for the cotter pin. It's good to practice now because there are a lot of cotter pins on that frame! Then, I began the lever which will be actuated by a cable. I'm adding a picture showing the set-up for the front wheels; the picture is from a restored 1932 V-8 brake shield assembly, which is almost identical to the V-16 one.
 To replicate cast parts is taking a lot of time; I was aware of it! As I cannot cast small or large parts, I have to do them differently. The second picture is showing the lever and limiting bolt from the RH brake shield, + the parts which are constituting that lever: a shaft, 3 "bearings". The smaller ones are drilled entirely, the large one only up to the middle. The assembly is done with soft solder. After that, the final holes for the various pins/shaft are drilled. Finally, the width of the assembly will be corrected; to facilitate the construction, the "bearings" are larger (or longer if you like).