Sectioned and Channeled Pocher Alfa Spyder

[Endeavor]

I only use white Superfine Milliput.  It forms a very strong bond both with the Pocher plastic and with earlier cured Milliput applications.  It is easy to carve and to sand and the surface can be polished to equal polished Pocher plastic. 

 

As you can see in the WIP photographs, it is a bit of a challenge to apply in very thin layers, but high points can be easily carved, filed, and sanded.  

 

The blue color you see in the photographs is Evercoat two part body putty, which is a good alternative for filling very small/ shallow imperfections.

[Codger]

While enjoying this presentation, the thought has come that this huge volume of work has many miles to go. I find myself trying to think ahead along with you, of what still needs to be done. Of course that's impossible without parts in hand but 'fun' for an interested observer. I'm certain it's less 'fun' for you and picture you covered in Milliput dust.

But surely another formidable task will be the correction of the fenders and runningboards, requiring sectioning, reshaping and relocating in several planes.

I've no doubt, after earlier photos, that you've plans afoot for this work and will solve the issues as effectively as you have so far. I just hope your resolve keeps up with the efforts required.

Many thanks again for this epic project.

C

[Endeavor]

 

To determine the final width of the rear of the body, I took a series of measurements along its widest sections.  The pencil line is just above where the rear wings/ fenders will come in contact with the body.  

 

The body flares outward from the deck down to this line and, from the line, the body flows inward down to the frame.

 

 

 

 

 

After determining how much wider the body should be at various points, I made styrene pads, varying from 1.5mm to 3mm, and attached them to the body.

 

 

 

 

 

Using the styrene pieces as guides, I applied layers of Milliput.

 

 

 

 

 

All through the process of adding additional layers, I was continually altering the contours of the body.  

 

 

 

It was not a precise or elegant process.

 

 

 

 

 

Slow progress.

 

 

 

 

 

I began to test fit the rear wings/ fenders.  As described much earlier in the thread, the rear deck of the stock Pocher kit is too narrow and the rear body flares outward from the deck all the way down to the frame.  The narrow rounded deck and the slope of the body sides are not only inaccurate in themselves, but when the rear wings are attached,  there is an enormous gap between the wings and the body which accentuates the inaccuracy of the model.

 

Correcting all of this is essential.  As you can see in the photographs below, I am making some progress.

 

 

 

 

 

This photograph shows how inaccurate the kit wings/ fenders are and the size of the challenge of building accurate wings.

 

 

 

The photographs below show the current state of the body.  Its dimensions and contours are close to being finalized, but much surface preparation remains to be done.

 

It is now accurate enough that I can begin the next task, which is to build new doors.

 

 

 

 

 

 

 

Edited February 17, 2019 by Endeavor

[Codger]

Brilliant idea making blocks as thickness gauges for putty. I should say 'another' brilliant idea.

 

Is the contour gauge useful at this stage for symmetry or too early yet?

[Endeavor]

A ruler, a digital caliper, and my eyes are my primary measuring tools.

 

I use the contour gauge to make the final measurements when I reach the point where I think the contours are just about correct and to confirm that the body is symmetrical.

Edited February 18, 2019 by Endeavor

[harveyb258]

Painstaking job, David, it's a pleasure to follow.

The result is well-worth all your hard work!! Keep it up, matey!

[Endeavor]

13 hours ago, harveyb258 said:

Painstaking job, David, it's a pleasure to follow.

The result is well-worth all your hard work!! Keep it up, matey!

Thank you, Harvey

[Endeavor]

One more asymmetry.

 

After rebuilding the right side front door jamb, I realized the right door was  too far forward by about 2mm.  I somehow missed this.

 

The photograph below shows both my first effort at re-building the right front door jamb and a line on the rear door jamb defining the material to be removed.

 

 

 

I began to remove the material with the flush cutting saw.  This first straight section was the easy bit.

 

The excess material on the lower part of the jamb was removed with a hobby knife.

 

 

 

The photograph below shows the door template set into its incorrect position, 2mm too far forward.  

 

This template will be used to build both doors.  Unlike the kit, the two door openings, door shapes, and door dimensions will be identical.

 

 

 

The rear door jam now in its correct location.

 

 

 

Below you see the template set in the door opening after the rear jamb was moved.

 

You can see the how much material must be added to the front jamb.

 

 

 

The photograph below is a work-in-process shot.  The completed jig saw has eight pieces.

 

The plastic came from the material that was removed from the cowl and spare wheel well.  Pieces were welded with solvent and will be reinforced later from the inside.

 

 

 

The rebuilt front jamb before any sanding, Milliput, or body putty.

 

 

 

Here is the template in the new door opening.  

 

There is still much work to be done.  The final dimensions of the door openings will not be finalized until the doors have been built and fitted.

 

 

[Codger]

Brilliant analysis, surgical cutting and paste.

Will doors have any curvature in either plane? If so, brass channel is helpful in making styrene hold those curves. My doors were made that way and no changes or de-lamination after two years so far.

[PROPELLER]

Brilliant surgery show, as usual!

Very nice to follow these advances...

 

Dan.

[Endeavor]

28 minutes ago, PROPELLER said:

Brilliant surgery show, as usual!

Very nice to follow these advances...

 

Dan.

Thank you, Dan

 

I am a an avid follower of your Avions Voisin Record thread.

[Endeavor]

19 hours ago, Codger said:

Brilliant analysis, surgical cutting and paste.

Will doors have any curvature in either plane? If so, brass channel is helpful in making styrene hold those curves. My doors were made that way and no changes or de-lamination after two years so far.

Thank you, Chas

 

Each door must have compound curves both at its top leading edge where it meets the cowl and a very subtle curve in the middle of the panel.

 

For inspiration, I took another look at the extraordinary construction of the doors on your Rolls.  The door sills on the Alfa are about 2mm.  The good news is that it does not have roll down windows.  I am thinking about using .7mm styrene and .78mm  (.03") brass flat bar stock.  The 1/4" X 1/16th" (1.6mm) flat bar stock you used would produce a door more than 2.25mm thick.  Of course I could widen the door sills or carve the doors out of a thick block of styrene.(?)

 

Looking at your thread today, I am reminded again of the loss we suffered when the links to your photographs were erased.

[Codger]

1 hour ago, Endeavor said:

Each door must have compound curves both at its top leading edge where it meets the cowl and a very subtle curve in the middle of the panel.

 

For inspiration, I took another look at the extraordinary construction of the doors on your Rolls.  The door sills on the Alfa are about 2mm.  The good news is that it does not have roll down windows.  I am thinking about using .7mm styrene and .78mm  (.03") brass flat bar stock.  The 1/4" X 1/16th" (1.6mm) flat bar stock you used would produce a door more than 2.25mm thick.  Of course I could widen the door sills or carve the doors out of a thick block of styrene.(?)

 

Looking at your thread today, I am reminded again of the loss we suffered when the links to your photographs were erased.

As always David, too generous. You brought back memories (and nightmares) of 'The Door Saga'.

But my question to you and your subsequent answer drove me to hunt through my build archives for applicable pix. In the vain hope that they might be helpful to you or anyone building a Rolls.

I apologize in advance for clogging your fabulous thread with explanatory shots. Feel free to delete them - or I will if you wish.

Unlike your meticulous, professional measuring  and planning, I accomplished my scratch built doors in my normal method; rather like Geppetto, hacking at wood blocks to make dummies. Way too late in construction, I failed to account for the prodigious warping of my Sedanca's tub. Pinched at the cowl (unequally) and widened at the rear door post with a roller-coaster curve diagonally across the doors - severe heartburn when you've gone to primer already. No choice but to toss out the kit doors despite drowning them in 185F water and twisting until fingers melted. Not good.

Here's what resulted.

You are right about the flat brass stock - but that was the final iteration. Seen here are the first two doors, made to shape using 3/32 C-channel brass, epoxied to the door's .030 skin (the upper, outer third of each door is doubled with .020 to form the color break).

#1 seen as paint test for the cream. The outers were both fine but each needed more study to get the inner sides right for windows and door cards.

Here is the inner side while trying to figure out the latching mechanism. Notice any difference in your advanced planning to mine?

Now here's the beginning of the final version using the flat stock. It was stronger but easier to bend to shape (without annealing) and had better epoxying area compared to the channel. The lower goes straight from the rear post to about half , then quickly tips inboard at the cowl. The vertical piece has a consistent curve from bottom to sharper at top of door:

Mocking up the window frames (3/32 channel and .040 Lexan) and latch. The outer door handle goes through the hole at latch and get soldered (yikes!) to the latch cam within. Solder iron  + nearby styrene = heart flutters.

These vertical shots clearly show what the poor doors had to twist like to match the body tub. Top down and bottom up views, the curves are dramatic.

 

The operational latch mechanism - after changing my undies several times:

The fully dimensioned works, in thousands of inch. The final door (#3), done both sides and each with different shapes. David did the much smarter thing by getting the central body symmetrical in the first place.

All's well that ends - OK...Color before clear. My next Rolls would have been better but that's just going to be speculation.

Thanks and apologies David for the hi-jacking of your thread but I hope even a bit helps you decide on your course of action on the way to this spectacular Spyder.

C

 

[Endeavor]

Chas,

 

Thank you for posting this.  As always, both instructive and inspirational.

 

In addition, these few photographs give those who did not see your intact thread a glimpse of what they missed.

[Codger]

I promise - no more soap operas in your thread...

[Endeavor]

 

Before building the doors, I did a bit more work on the door jambs.  The photograph below shows how I faired in a strip of 0.005" styrene to make the jamb level and straight.

 

 

 

My first attempt to achieve the correct contours of the doors was to epoxy brass strips to the back of the styrene panel. The strips were bent to shape and then epoxied to the panel.  The subtle and complex contours, combined with the problem that the epoxy was not amenable to my making final adjustment, forced me to abandon this approach.

 

 

 

 

 

I tried other methods, including combining brass strips, styrene pieces, and aluminum sheet.

 

 

 

I finally settled on building the doors by laminating an aluminum sheet between two styrene sheets.  The aluminum piece was bent to the proper shape prior to attaching the styrene pieces with two part epoxy.

 

Below is an aluminum door panel fitted and bent to the proper contours.

 

 

 

The door in the photograph below is constructed of the outside styrene panel bonded to the aluminum panel.

 

 

 

Below is the door seen from the inside.  The next step will be to attach a second styrene sheet, using the same pattern, to the inside of the door.

 

 

 

Below you can see the complexity of the shape of the door.  The photograph exaggerates the extent of the bends.  The biggest bend is at the top leading edge.  The bends in the center, bottom, and trailing edge are subtle.

 

[Codger]

David - I'm sorry my method was not helpful to you and you lost time because of it. Naturally, you came up with your own brilliant solution, which had I known it, would have been useful to me at the time.

 

Seems a good solution, but I imagine getting the inner panel to mate with the core aluminum which is curved away, concave, from it may be a chore. Doubtless you'll achieve it but show we students of your work how please.

[harveyb258]

Continued great work, David. I always look forward to your updates!

 

Cheers, H

[PROPELLER]

Great job Endeavour, as always!

Annealed aluminum I suppose, really easier to bend...

 

Dan.

[pg265]

Beautiful and very inspirational work!

 

Pascal

[Codger]

We really need a 'Coachbuilders Fourm' here. There are increasing numbers of highly modified and beautiful lessons in coachbuilding in large scales here. This is surely one of the most complex and accomplished. Exchanging methods of changes and tips would be inspiring and beneficial to aspiring builders.

I'd love to see a 'concours'  page of the most beautiful examples all together in one place on Brit.

 

 

 

I know,,,,,,,,,wishful thinking............

[Endeavor]

19 hours ago, Codger said:

David - I'm sorry my method was not helpful to you and you lost time because of it. Naturally, you came up with your own brilliant solution, which had I known it, would have been useful to me at the time.

Seeing your method was very helpful.  All part of the learning process.

 

Different models often require different solutions.  Unlike the Rolls, the Alfa does not have roll down windows.  You had the more challenging problem.

[Endeavor]

On 3/15/2019 at 5:40 AM, PROPELLER said:

Great job Endeavour, as always!

Annealed aluminum I suppose, really easier to bend...

 

Dan.

Thank you, Dan

 

The aluminum is just 0.35mm, so it was not necessary to anneal the panels.  At this gauge, without annealing, it has the right combination of being both workable and sufficiently rigid to force the styrene panels to conform to the new contours of the aluminum. 

[Endeavor]

The photograph below shows an alternative way to build the doors.  This is a good method, except that it is more difficult to make fine adjustments to the contours.

 

 

The new doors are taped in place.  The next steps will be to apply the inner styrene panels and spend considerable time adjusting the fit.

 

 

 

 

 

Below you see a scratch built door clamped to a cut down kit door.   The stock Pocher door has way too much curvature and this is a big contributor to the inaccurate bulbous look of the OOB model.

 

 

 

Below you can see how the new doors substantially alter the width and profile of the body.  You can also see that the doors do not fit yet.

 

 

 

The major body components in place.  Every piece in the photographs below requires more work.

 

 

 

 

 

[Codger]

This no longer looks like it came out of a Pocher box with the name Alfa Spyder.

The comparison of kit stock and your door is dramatic.

This mock-up is great incentive to press on - it will be an amazing transformation and totally unique replica of the original. One of one.

Unless you produce a transkit !