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CrazyCrank

Pocher Bugatti T50 Coupé de Ville: a resurrection

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Thank you very much, @Roy vd M.

 

This afternoon, despite of stage fright, I've opened the eye at the top of my lever.

It is even more fragile now, and I'll have to be very careful for the next step (parting the lever of its bar, and rounding the bottom on the miller)

 

30420677957_6ec2825d0a_z.jpg

 

Stay tuned for further developments :)

 

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Job completed for this part, front brake lever !

 

45320705282_4e724ec17a_z.jpg 44457162505_443611e7cf_z.jpg  44457162495_5f4284c22e_z.jpg

 

44457162465_7f79464afb_z.jpg 30431269427_bc57739fb1_z.jpg

 

 

Nevertheless, I'm not perfectly happy with it 😥, because, as you can see, the top of the eye at the top of the lever is a bit flat, not rounded.

 

It occurred during the milling process, due to a mistake I've done with the zero point of the X axis 🙄, and so, the eye has been shortened accidentally .

To compensate this error, I've filed the eye in order to get a better aspect, but doing so, I've drastically  reduced the thickness of the metal, and that have probably weaken the eye.

So, I wonder if, when I place the hook of the front brake cable in this eye,  it will have a sufficient tensile strength fro keep for breaking when I tighten the cable ? 🤔

 

For the next days, I've planed to machine two identical levers, using the same method, avoiding to make the same mistake, and I hope to get more resistant eyes.

If not, I will redraw my levers, in order to get a thicker , and so more resistant, top part.

 

Stay tuned if you like, and thanks for watching :)

 

 

 

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Good evening chaps :)

 

Finally, the CNC miller, though pleasant to use, is a rather difficult to master tool,  and I've had a lot of issues and disappointments today.

However, I've produced some clones of my first part, among which two seem usable, and whose eye is thicker and so, more resistant.
It remains a lot of work to do to give them a nice and identical (in terms of dimensions) aspect.

 

43574659850_b0ce102f09_c.jpg

 

Stay tuned if you like and thanks for watching :)

 

 

Edited by CrazyCrank

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Never mind, Thierry, you can always sell the "duds" on flea-bay:D

 

I know, for a fact....you ain't putting ANYTHING on that car that's not perfect....and so do you.:lol:

 

Cheers, H

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You're right @harveyb258, without claiming perfection, I always try to get as close to it as possible, however avoiding to imitate Icare.

So, I only need to be VERY happy with my parts, and tonight, I think I've reached this goal with my two last tries on this f..... levers 😜

 

All the first attempts, though nice or acceptable they seem to all of you, have manufacturing defects.

 

First of them, the one I milled with my Proxxon MF70 before modifying it in a CNC tool: Obviously, it has the right shape, the right thickness and resistance of its top eye, but, it's much too short !

 

The second one, the first whose draft has been entirely machined on the CNC miller is quite "perfect", but its eye is too thin and so, could break when I tension the brake cable ! (It's the first on the left on the previous post's picture)

 

Several other tries have failed because of numerous mistakes I've done with my CNC program, by lack of experience or careless errors. I won't show them, they have jumped to the trash.

 

The third and forth one (the second and third on the right of the previous post's picture) and the fifth one seem acceptable. The eyes are thick and resistant, but the large holes at the bottoms seems not to be well centered.

In reality, when I drilled these holes, they seem perfectly centered... on the side I was working on !

But on the other side, the holes were offset and not centered.

 

The reason is that, on this milling machine, there is, when it's used as a CNC one, a quite excessive backlash (See here please, what is backlash ) on the Y axis, and, as I was milling the sides providing cuttings of 0.5 mm each (12 cuttings to reach 6 mm depth), each cutting has been slightly-off the previous one; and so the section of my part has not been rectangular but a bit parallelepipedic with inclined sides. And then, when I've drilled on the center of a face, the hole wasn't rightly centered on the opposite side !

 

See the sketch below (Of course, I've grossly exaggerated the phenomenon, to illustrate my explanation).

 

30494182227_d3cb9f307b.jpg

 

There's actually no (simple and not too expansive) way to correct the backlash on my miller. I've some ideas to do it , but that means radical changes on hardware and software.

 

To reach my goal with theses parts, I've had to think a lot, make several tries, and finally I've decided to mill each face (in fact, two right-angled faces), in only one cutting of 6 mm depth.

That supposed to give the milling work a very low feeding rate of 6 mm/min (instead of 120 !), to avoid breaking the part or the tool (2 mm end mill), and to generously oil the tool and the brass bar during the process !

 

But it was worth it ! Because I got as from the first attempt, these two parts, absolutely identical before filing and sanding:

 

The left one is what I got only with the CNC milling job, before cleaning and filing (the draft)

The right one is what I got with its clone, after filing and sanding.

As you could see, the eye, even after filing, if frankly thicker and resistant, and the holes are centered (trust me please, it's the case too on the opposite sides)

 

43617637450_dfd0ecb98b_z.jpg

 

And now, a family picture: from the left to the right, the older until the two last ones I'm very happy with !

 

43617842910_c520be804c_b.jpg

 

Obviously, it remains a lot of work to do on this two levers to get them nice and identical, but it's an easy job. The hardest stuff has been done 😎

 

Stay tuned if you like, and thanks for watching :)

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Good evening, my friends

 

A little progress tonight.


I've milled the rough of the first rear brake lever, in the same way as for the front ones, using the milling machine in CNC mode, keeping 0.3 mm margin around the part, in order to finish it with sand paper and files.

On the miller:

 

44565787425_e005a943fa_z.jpg[

 

The rough:

 

30539490757_49d42908aa_z.jpg

 

31605609338_0e233aa18f_z.jpg


After filing, sanding, and polishing, and before separation the lever of the brass bar:

45479857721_3589db377e_z.jpg

 

45479857561_351a6ed9d7_z.jpg

 

44566024145_db79958741_z.jpg

it's really a tiny part:

 

45428619762_10b42f4063_z.jpg


Tomorrow evening, after my medical job, I've planned to separate the lever and finish it, and then. to mill an identical second rear brake lever.


Stay tuned if you like and thanks for watching :)

Edited by CrazyCrank

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Hi chaps

 

Day's production:

 

A rough for the second rear brake lever, and another for a third front brake lever (one of those I've machined and considered as good, is too thin relatively to the other, so....)

These two parts are not finished, of course.

 

43769368880_d5c6d63512_z.jpg.  45586870761_908e1a7757_z.jpg

 

And a first try for a Diy shock absorber's lever: this part look like a rear brake lever, but is less high of 2 mm, is finer  and shorter, and has a hole M0,6 at its bottom end, in which a M0,6 screw and bolt ha been placed. the bottom end is normally split

And on the real car this screw is used to tighten the bottom end of the lever around the axle, stretching the split.

The split has been simulated by an 0.5 mm wide and depth engraving,

The top eye is 0,6mm drilled and is not opened.

 

This part need still a lot of sanding and polishing before to become acceptable, but with these pictures you could  get a rough idea of what it will look like once finished

 

44861996644_2c2d4f6801.jpg  30645703387_7b75d5b89d.jpg

 

45586872021_9fda0736c4.jpg.  30645701627_3b3d50fb30.jpg

 

Comparison between a rear brake lever and a shock absorber's one:

 

43769369370_d3c996af06.jpg

 

It remains to machine 3 other levers, and it's a a lot of work (3 hours each at least)

 

Stay tuned if you like and thanks for watching :)

 

 

 

Edited by CrazyCrank

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Hi Gentlemen

 

I've not yet finished my two brake levers (only milled the roughs) nor my damper's levers.

 

But today, while driving my car,  I've had an idea to cut very small sprockets 5 mm diameter to replace those I'd placed against the front brake's chains, because I'm not ever happy with them (one is metallic, the other made with plastic)

So, using the lathe and the miller, with the help of my dividing rotary chuck, I've cut 12 teeth around a 5mm brass rod with a 1mm bit, each tooth separated from the following one by 1.3 mm on the perimeter (30°), and I've got this first try.
I have to refine the technique in order to get nicer and much regular sprockets, but the result of my thoughts and first test is quite encouraging.

 

43821162850_a234715829.jpg

 

45588634442_797db6a999.jpg

 

To improve the technique, I've several ideas

For instance, cutting the teeth on a 5.5 mm rod, to get M1 holes, and then mill gently 0.5 mm on the periphery to get my 5 mm sprocket

 

Stay tuned if you like, and thanks for watching :)

 

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Good evening chaps

 

The work goes on...

 

Hereunder the set of parts I've machined or built for the front brake system, and some other parts that have to be finished

Sprockets are done, one chain has to be assembled, and, if I have the courage, I'll build 2 more chains in order to be the closest as possible of the real car.

 

44739596585_ed3396a4f6_c.jpg

 

Stay tuned if you like and thanks for watching :)

 

Tomorrow is the first birthday of my preferred and beloved scale model...my grand-daughter Emma 😍

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Well, ya know that I'm well-and-truly-hooked, don't you?

 

Keep it up, Thierry...your work is a pleasure to follow!:thumbsup:

 

Cheers, H

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Thanks a lot @Roy vd M.

 I hope you sit down at the bench as soon as possible, because I can't wait more to see your Delage project progressing :)

 

And yours, too much more for me, @harveyb258

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Incredible work and patience.

Totally gobsmacked.

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Evening chaps

 

Preparatory work for the front brake lever system...

 

I've purchased on Ebay new brake drums and I'm following @PROPELLER 's method to enhance the braking system..


I'm however wondering if It would be possible to combine his method and the Pocher's one, in order to get working brakes and always tightened brake cable.

At the moment, I've turned on the lathe a shaft for the lever and a shim that will be interleaved between drum and lever.

The outer end of this shaft has received a 0.8 mm wide groove, in which the M1 bolt will cross, locking the shaft and the lever against the drum.

Later, I'll work on the inner end of the shaft to make a mechanism which ensures the lever to be inclined forward.

 

Some pictures blew to illustrate my little job:

 

31153304367_afa1186b89_z.jpg  31153304147_4540968455_z.jpg

 

46092477521_87eeee915b_z.jpg  31153303607_d80ae28476_z.jpg

 

32221144618_e9868a43c1_z.jpg 46042241882_c7b2b3b883_z.jpg

 

Stay tuned if you like, and thanks for watching :)

 

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Great work as always.

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CC I had just started to read the thread and I was shock with the impresive capabilities you do have for the construccion of this model, You have demostrated to have tremendous skils and hand capabilities to do what you had demostrated to build with such detail and originality.

My full respect for you!  Even you mention in the thread you say that you are learning (with no dought) but you are perfecty qualified as a MASTER with what you have show to all of us.

Hat's off too, you deserve it.

 

Keep updating us with the great work you are doing.

 

My best regards!

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CC, it looks that your way of living is in machinery, due to the way you manage to solve the construccion of some of the parts, like the exhaust, levers, etc. How did you got such of a background? 

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31 minutes ago, Miguel Rivero said:

CC, it looks that your way of living is in machinery, due to the way you manage to solve the construccion of some of the parts, like the exhaust, levers, etc. How did you got such of a background? 

 

Hi Miguel...

First of all, thanks a lot for you kind words, most appreciated :)

Concerning your question, I'm not sure to understand correctly what you meant, could you precise please (in spanish if you want) ?

 

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2 minutes ago, CrazyCrank said:

 

Hi Miguel...

First of all, thanks a lot for you kind words, most appreciated :)

Concerning your question, I'm not sure to understand correctly what you meant, could you precise please (in spanish if you want) ?

 

How did you got the expertice to build such parts like the ones you describe in the thread?

You do CNC machinery, as well as bending tubing among other thins.

 

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1 hour ago, Miguel Rivero said:

How did you got the expertice to build such parts like the ones you describe in the thread?

You do CNC machinery, as well as bending tubing among other thins.

 

I don't know exactly, Miguel !

I study other's builds, I look, I think, I've a passionate love for maths, physics and technology. I've eclectic tastes, and overall, I'm very curious.

When I've seen, here and on other forums what some people were able to do, I wanted to try myself to reach such amazing results.

Concerning the use of a CNC milling machine, I needed it to machine curved parts, or several identical parts, so, I've given myself means to do that... I read up on CNC, I've purchased components, study how others had built their CNC machine, and hen built mine.

The Internet provides a wealth of informations for anyone who know how to search !

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