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harveyb258

H's 806 1:12 scratchbuild

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Hello guys,

 

I'll start this thread by saying a HUGE THANK YOU:thumbsup: to everyone for all the hard work that has gone into the research of this fascinating enigma of a race-car. Without their contributions, this build would not be possible and the whole world would be stuck with a lousy and innaccurate model (sorry protar/italeri)!!

 

I was originally going to post this in the "research and scratchbuilds" thread, but that's mainly showing how to modify the kit parts to make a convincing model. This will be a full-scratchbuild.....as such, I feel it deserves it's own separate thread.

 

So........... let us begin!

 

First, the chassis frame. As you know, the rails were a hollow construction formed from 2 C-shaped sections. I bought some 0,3mm tin sheet to do exactly that. However, this method was going to be very problematic in the fabrication. So plan B....I decided to get some 20mm x 3mm steel flat bar. A little OTT you may think, but this will be a full metal build (apart from tyres) and thus will be heavy, so I need the chassis frame to be very strong and stable.

 

First I marked out the steel using a metal scriber for the shape, allowing a few mm at either end to compensate for the curvature of the legs, then marked and drilled for the central beam. The frontal bends were achieved using the vice  and some grips. The next step was to curve along the length. I used a simple bending jig.....2 thickish (8mm) drill bits trapped in the vice. Very simple, yes....but oh so effective and without the need to anneal to stupid temperatures. The rear bend had to be cut half-way through with a hack-saw to get the shaper angle.

 

Next step was to mark and drill holes for all the cross-beams which are varying thicknesses of brass tube.

 

35936862110_d3fdfae4cb_h.jpg

 

36333364615_f174ac57f2_h.jpg

 

36333363955_3069694602_h.jpg

 

36333363535_be1cdfdbe2_h.jpg

 

36333363305_9da72254d0_h.jpg

 

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36333370985_0af20f9f3a_h.jpg

 

36333369685_f900aa0a56_h.jpg

 

36333368035_14ff33b4f7_h.jpg

 

Well guys, that's where things stand at the moment.

I think the next step will be cutting the legs to shape.....that won't be the easiest task by hand with the hacksaw.

 

Hope you all enjoy!!:D

 

Cheers, H

 

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Thanks Nick....over the years I've learnt to make the most of what I do have, it's saved me a lot of money! :D

 

Cheers, H

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For me it is to have the confidence to try. I am happiest in plastic and balsa because I assume I can't use stronger materials. I'm in awe of how you keep it all square and twist free. Perhaps I should find a couple of drills and have a play. Even cutting the steel daunts me! You can bet I will continue to watch with interest.


ATB

 

Nick

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Ambitious project and a novel approach Mr H. Nice reference drawing too.

 

In what scale are you working?

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Thank you Thierry, I hope to do it justice!

 

Time for an update methinks! As I predicted, cutting the steel by hand was, indeed, quite a task! It took 1.5hrs to saw each leg....I thought my arm was gonna drop off. So 3hrs sawing and then another 3hrs grinding, filing and sanding. I now have it looking more like a proper chassis. A couple of tweeks are still needed, but overall, I'm very pleased by the result!

 

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35974802600_2ae6a74d68_h.jpg

 

35563366903_275d963c69_h.jpg

 

That's all for now, folks!

I hope you like and thanks for watching!

 

Cheers, H

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A bi-metal blade in band saw would have cut the time by 4/5's! You got a beautiful result but at great cost of effort and time. Would be well worth the investment in a cheap off-shore band saw. With blade changes, great for hobby use, plastic, wood, metal.B)

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Hi guys.

 

I have a theory about the "tabs" we can see on our photo 1AA running underneath the chassis legs. After some discussion a long time ago on the "R and S"(research & scratchbuilds)  I think the general concensus was that they were a part of the floor-panel construction to give added strength.

 

After some careful studying of said photo, I now firmly believe that what we are seeing is actually the chassis leg construction. These "tabs" run the full length of the curve but not on the frontal straight bits.

 

35986622340_895670dc99_b.jpg

 

So....my theory is that the 2 halves were made as follows to aid in "rolling" the legs to shape......

 

35575112323_fa4948f880_h.jpg

 

What do you guys think? Could this theory be close to the truth? I would value the opinion of the experts out there! 

 

Cheers, H

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H,

 

Doh!. I have thought for a while that they were tabs (but attached to the floor plan); I had wondered why we could not see the edge of the C-section used for the frame and intended to model it; and had wondered how on earth you make a double C-Section work round a curve. However, it did not occur to me that they might be as you describe. Sounds plausible to me.

 

Extending your thinking a little further. Presumably both sections would have been modified in this way. They could only have been welded if the tabs lined up. which implies there should have been slots when viewed from above and below. Not sure that would have been great for stiffness. Perhaps they only did it on the inner C. I did wonder if the inner C would also have had lightening holes like some of the other cars of the era. I guess we will never know.

 

Still just goes to show that though I have an opinion I am clearly no expert!!

 

Nick

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Near Nick, 

Many thanks for your input. The thought process dictates that both halves would have to be the same.

The only top part of the frame that we can clearly see is the front straight bits ( which wouldn't need scalloping anyway), so, unless any evidence to the contrary turns up, which I seriously doubt, then I think that is the path I will choose!

 

Cheers, H

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Not an expert too, sorry, Harvey. Personally, I did not represent this detail on my build, but Hannes intends to do it...

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H

 

Your comment above prompted me to finally draw up a section of the chassis - from just below the cockpit. Result is show below based on photogrammetry from the photo you used above.

frame tabs

What you can see is the outer frame in red. The inner frame is green. I drew the tabs from the drawing on the inner frame only. There are several points to note.

 

The engine front view shows a chassis cross setion that is 3mm thick. From the photo the thickness appears closer to 6mm. It could be thicker I have not checked elsewhere. It could also be the thickness of the frame plus the undertray.

 

Second the tabs don't appear all to be the same size. However, it is really difficult to spot the edges precisely. More encouraging is that the distance for a tab plus a cutout is approximately 80 - 82 mm for each tab.

 

So tabs are about 50 mm apart and 30 mm long.

 

The cutout depth is difficult to measure but the 15mm shown above is plausible from the photo. Which would be less than half the depth.

 

Regards


Nick


 

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Hi everybody . After having a fight with my inner demon and chasing bad thoughts away I decided to contribute again.

I also believe these tabs to be a part of the chassis rails . We don´t even know if there were bottom panels besides the great sheet with the openings . This sheet reaches till the end of the fairing or the beginning of the heat shield  On the right side there´s the driver´s seat - no bottom panel necessary . On the left side there are 2 big oil tanks , there´s no additional panel necessary too . 

This car was constructed for race tracks with asphalt and the additional weight of a great bottom panel  has an impact on the performance of such a small engine  imho .Maybe some small sheets were added here and there like around the rear cross-beam or for stability reasons , possibly for the controlling of the air-flow. .

On engine  drawing 4 we can see the frame rail as 2 U-profiles . But this does not mean that the rails were  constructed with the same stability  in other regions of the chassis .

We cannot see tabs in the region of the massive engine suspension plate .But we can see 2 tabs in front of the bracket that keeps the brake cable in distance ( photo 1 AA ) .

In this region no bottom sheet makes sense imho .

These two tabs confirm Harvey´s theory that they were part of the rails ,maybe point-welded to the second profile .Maybe one of the two U-profiles ( or both ) was weight -reduced by removing parts of the profile .

Many greetings !  Hannes

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13 hours ago, harveyb258 said:

Excellent work Nick...I like what I see!!  Thank you!

Yes, Nick, excellent!

Glad to see you are back again, Hannes. 

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4 minutes ago, Olivier de St Raph said:

Glad to see you are back again, Hannes

I couldn't have said it any better myself...we have missed you!

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Hi guys!

 

A bit more progress today with the chassis-work to show you.

To create the "tabs" I used 0,5mm nickel-silver sheet, which I annealed first to soften it slightly.

I then marked out with a scriber and drilled 4mm ( working up from 1mm in 0,5mm increments) holes along the length at 6,5mm centres. In scale this is 30mm tabs with 50mm gaps.

 

36011951820_4442ab2095_h.jpg

 

I cut the strip in half , then filed to shape with a square file and carefully cut and ground the first piece close to the 3mm rail width. Laying the piece on a flat surface, it was very easy to tease to a rough shape with just my fingers.

 

36011952440_39c05670f0_h.jpg

 

Then a bit more teasing and I'm very close to the plans....

 

36011952060_95567a43d4_h.jpg

 

So, one down...one to go and then I can get them soldered in place.

More tomorrow!:D

 

Cheers, H

 

 

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Hi guys!

 

A day late with this update, but I had a problem. 

I have soldered steel rods before with no issues whatsoever (Cooper chassis), with just an iron, but they were only 2mm rods. This is a different ball-game as each leg is a lot of steel to heat up, so I used a torch instead. Try as I might, though, it wasn't to be. The solder didn't want to take at all....maybe I was using the wrong flux or solder , or both! Anyway I got fed-up of trying, so I resorted to good old 2-part epoxy. After being clamped up for about 18hrs they are now solid and have had a vigorous clean-up.....

 

36304596951_1f2300830d_h.jpg

 

36304596811_6cd6d2e8b4_h.jpg

 

I hope they pass inspection!

 

Cheers, H

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A wonderful detail (after much work!) but black paint will make it all disappear...:weep:

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On 08/08/2017 at 19:27, harveyb258 said:

Thanks Mr C, but I'm doing the unpainted test car, so no detail will be lost!!:D

 

Cheers, H

Very good idea, Harvey! I am sure your 806 will be amazing like that, especially because you use mainly metal parts scratchbuilt. I look forward to see that! 

Cheers

Olivier

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