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Pocher Rolls Sedanca


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Some thoughts on classic Pochers...

As you've read, I'm heavily involved in the body alignment phase of construction. The Rolls body has many elements front to rear which must all work together to produce the beautiful lines of the car. If you assemble the kit as delivered, none of those elements will be in the right places.

Paul Koo's excellent DVD is essential for pointing out things that would take any builder much longer to figure out without the guidance.

But I learned that you should use that only as a starting point and relentlessly check every dimension, fit and fastening location - before committing to final attachment and paint / upholstery finish.

Here's my observations and example:

The key is to get the rear wheel centered correctly in the fender opening-that's the primary goal. Pocher's attachment location puts the wheel way back in the opening because the rear fender (attached to the body) is too far forward. That looks goofy. If you put the trunk box in place, there's a big gap between it and the back of the body.

So Koo says to redrill the body attachment hole (to the chassis) forward on the body by 5mm if you have an early kit or 3mm for a later kit. (This because Pocher made the hood lengths too short on the early kit and 'corrected' it on later kits. Their 'correction' is different than, say, Tamiya's correction...)

Well, good starting point but if I had blindly drilled the hole where advised, I'd have a wonky rear wheel placement. Constantly moving and checking, I decided to start at the very rear. Putting the trunk in it's correct location, then placing the body rear right against it located the rear fenders correctly over the wheels. I pinned it there. I had to drill my location 7mm forward, not the Koo-recommended numbers. Every Pocher is different.

Then I taped the windshield cowl unit in place. Then onto the adjoining pieces, the four parts of the hood. The hood tops fit perfectly between the grille shell and the cowl. I mean perfectly. But, the hood sides are 1/8" (!) too short.

Now that I can live with because it's a simple matter to add styrene and blend in to extend them. The front fenders, being totally detached from the body are not affected. Another key is that I spent a great deal of time earlier getting the radiator dead vertical to the chassis providing an 'anchor point' for the front coachwork.

Of course this required trimming and fiddling with the floor board and chassis many times but I won't bore you with that.

So for best results and a pleasing model, don't be in a rush and take nothing for granted with a Pocher.

382Medium_zps401f44f5.jpg

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I just finished reading this from the beginning and all I can say is...

Wicked Pissa!

And after seeing what you are going through, I now know for sure that I will never build a Pocher kit. My PTSD could never stand the stress.

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Thanks Neil but this is cake compared to what you've been through.

My hat's off to YOU Dude... ;)

EDIT: Don't read my next post without a good bottle of wine in hand..................

Edited by Cato
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One step forward-12 back...

I have been unexpectedly busy the last week but nothing shiny to show off here. I am always my own worst enemy.

Previous posts have shown the body alignment phase and I was pretty happy, having discovered the demons pointed out by Koo and 'corrected' them to the best of my feeble ability. Errrr, not so fast.

Famous for viewing things the next morning with a critical eye or 'eureka' moment, I found niggling little fit issues. Remeasuring and plotting better attachments showed me I had things wrong earlier.

The deal with Pocher Rolls' is to get the rear wheel centered correctly in the fender opening. So you have to relocate the body aft. That changes the hood, cowl, floor and trunk positions.

Without further whining, here's what I had to do to get the critical correct proportions;

Section 6mm (!) out of the trunk box and lid.

Move the body back 6mm; redrill it's locating holes accordingly.

Move the separate floor back also.

Notch a slot in the floor because the rear crossmember prevented it from seating flat onto the chassis.

Make locating 'stops' to center the floor onto the chassis, matching the new body position.

The trunk, top cut in center because it has compound curves on all sides; The box, cut at the back edge and reinforced with inner braces and top and box having all the 'graining' texture sanded off-it will be painted not upholstered; the floor with the slot cut into it for the crossmember. The big rectangular opening is for the battery box which is completely hidden anyway. The seat covers the top of it and the new wood floor will cover the bottom.:

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Two styrene rods used to center and stop the floor at the rear:

385Medium_zpsfde3b5f8.jpg

The floor in place with the levers correctly centered in their opening and it centered on the chassis:

386Medium_zps70dd11f8.jpg

Frequent on / off placement of the body and parts confirmed I was finally on the right track. Trunk fit perfectly with no bind, wheel centered in rear, levers in correct place and everything the same on both sides.---Wait a minute, the ruler revealed the wheelbase was different by 1/16" on one side. Loosening the spring perches allowed enough shift to correct that. Now the wheels were centered (in the rear) on both sides.

Home safe? Ahhhh, not yet. What's bothering me now? I should be polishing its glass case and swilling champagne...The ride height, that's what.

Initially pleased that the PE springs lowered both ends in a scale pleasing manner for that '30's rakish look, I wasn't yet happy. So I made 1/16" shims and placed them between the front axle and the spring on the perch. Raising the front gave nice tire clearance but a great low look, combating the Pocher buckboard stock placement.

The rear benefited from 1/16" shims too but the rear axle is above the spring. So placement there raised the axle, thereby lowering the car. Just a bit. Maybe I'd like more but this is certainly acceptable and I can't find a way to lower the rear further so this is it.

Seen here, the front before modification and the rear after. Notice the trunk tilted back a bit? Not anymore after sectioning. An inner wheelwell panel will hide the gaps and make it even less noticeable. Better pics later on, more work to do. Making 2mm studs to anchor the floor and to attach the floor to the body side flanges. At least everything is where it should be:

363EMedium_zps0ff32be2.jpg

Honestly, you CAN build a Pocher right out of box, with just the 'normal' amount of difficulties and have a KNOCKOUT model. I am cursed with a vision which drives me deeper into the abyss of endless nit picking and fuss. I am pushing my personal envelope. With a Pocher classic you need to be part detective, part engineer, part inventor and completely nuts. I am only the latter.

But I AM getting what I signed up for... banghead.gif

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Looks good to me. Do you have a side shot of the actual car to show what you are trying to achieve?

The actual car with this coachwork and fenders does not exist to my knowledge.

But here is a similar Pocher Sedanca courtesy of the Paul Koo reference material.

This is built with all Pocher parts as in the box, with stock Pocher ride height:

STOCKMedium_zps2cbd1f5c.jpg

I sought the kind help of a professional graphic artist and this is what the same car looks like lowered to my spec, in Photoshop:

LOWEREDMedium_zps918c2f96.jpg

I now have the same front aspect and almost the same in the rear.

The difference is dramatic.

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Looking at your model photo in the front the fender is a lot closer to the tire and the back is pretty close to your modified picture. I think the front beihg so closecto the tire makes the back look at lot higher. If you raised the front up to be closer to your modified photo it would look better. Also it would give the front some room for suspension travel.

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Looking at your model photo in the front the fender is a lot closer to the tire and the back is pretty close to your modified picture. I think the front beihg so closecto the tire makes the back look at lot higher. If you raised the front up to be closer to your modified photo it would look better. Also it would give the front some room for suspension travel.

Well yes Bob, you are correct as I explained in post 559:

"Seen here, the front before modification and the rear after. Notice the trunk tilted back a bit? Not anymore after sectioning. An inner wheelwell panel will hide the gaps and make it even less noticeable. Better pics later on, more work to do. Making 2mm studs to anchor the floor and to attach the floor to the body side flanges. At least everything is where it should be".

As explained earlier in that post, the modification was to raise the front axle 1/16" with shims.

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Sorry missed the part about the front. Curious to see what it looks like with the changes done. Like the concept that you are shootijg for.

I had to strip it now of wheels and body to continue work. it's back on the work stands. After a while, I'll have to reassemble to confirm all is well. I'll surely post that.

It will be very close to the P'shopped picture above - the front is just like it, the rear a tad higher. I like it now.

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The (under) floor...

Another probably frivolous detail, the under side of the cabin floor. RR covered it with planks. Herewith, my interpretation. 1/32" aircraft ply, fresh off the Dremel jig saw. Five sections, just layed in place, no adhesive. Needs staining, lining (the separate planks) and rivet heads on the outer edges.

You can't tell but that kit floorboard has been heavily massaged for fit, with bits removed and holes redrilled.

What's a few more hours piled on??

387Medium_zpsc124b3cf.jpg

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A Pocher myth (among others)...(Tip alert!)

Much has been made in Pocher builds of the fact that screws comprise much of the assembly. This much is true. It has made purchasing a partial-built Ebay model a money saving occurrence compared to sealed-box kits. Take it apart and do it your way.

Due to the continual need to test-fit parts and dis / re - assemble many times, this becomes a liability given the quality of the fasteners Pocher provides. Also, some of the arcane joining methods of the panels and parts, plus the sheer weight of the lumps compound the fragile nature of the assembly. Glue is to be encouraged wherever possible after component adjustment and finishing.

Wishing to have a sturdy model that will long outlast me, I searched and found superior methods to attach parts.

First a follow-up: here's the floor planks, stained, scribed and lined which comprise the exterior floor. Only rivet heads still needed and they are 'silk pin' heads as described by my Chief of Sewing.:

388Medium_zps70d1e4ef.jpg

Here's what I'm talking about; the long and short screws provided. They are ~.060 in diameter, either too long or too short, have too coarse a thread for the strength needed and have brittle head slots which splay open even with the finest screwdriver. Many of these need to be 'melted' into place as the holes in the styrene are all too small and the plastic too brittle. Then when you test-fit a part held together by them 4 or 10 times the holes are buggered and they are holding nothing. Crying yet?

Also seen here is the best answer I've found; 2mm threaded rod, ~.075" diameter:

389Medium_zps331616f5.jpg

I've found that drilling and tapping the holes with a 2mm tap, then making a stud from the rod of the correct length, allows a 2mm nut and washer to clamp much better than the wonky screws.

Seen here is another viable solution; a 0-80 hex bolt, about .055" diameter. Yes it's narrower than the screws but by tapping the too-small holes for 0-80, you now have a hex head (and I hope you bought the hex driver!) which will not deform. Plus you have a much finer thread than the screws to really get a secure join.

390Medium_zpseb4cfa6c.jpg

Finally, here's a very problematic area on my Rolls which is now no longer such; the join between floorboard (shown) and the body side panels which are big, ungainly and fragile. You tap the hole, make a stud, CA it in place neatly, slide the body flange under the washer and nut, then tighten the nut. The clamping is far superior to the screws and I can now test fit like a crazy man right up to final paint without fear:

391Medium_zpse7c251cc.jpg

Now I know that a thousand of these have been built without my Rube Goldberg inventions. And they are fine models. But as I said, I think a permanent, strong structure is most what I'm after.

I offer these boring-to-read tips in the hope that even one current or potential builder finds merit in them to go the extra bit of work and expense for a secure model-especially if you're as nuts about the subject as I am.

In fact, I wanted the model sturdy because I'm making provision to take it with me when I leave for my extended nap... B)

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Why do you say that a screw with a finer thread would create a stronger bond? Wouldn't a finer thread be more liable to get stripped, especially in plastic? In my experience, fine threads are only good for machine screws, whereas coarse threads are best suited for wood, drywall, and plastic. Or does the courseness of the threads really matter anyway, since most of the work is being the done by the nuts clamping it together?

I'm sorry I've never commented before, even though I've been following this thread for months. Your reengineering (hey, it's not often you see two double 'ee's in one word), scratch building, and detail work are just incredible.

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Thanks for your kindness and comments Andrew.

But I make no pretense to be an engineer. I'm just reporting things I've found to be more effective than what the kit gives you.

I've found that the more threads per inch in the hole depths I have to work with, has been a closer fit after repeated cycles of tightening / loosening (which the kit design makes necessary) than the screws. The parts remain secure.

In a couple of places, where possible, I've even 'sistered' plastic sheet behind a hole, drilled and tapped, to make the fastener purchase deeper in solid material.

Plus the other big reason to use the thinner, finer bolts is having a non-deforming hex head rather than the taffy screw heads which go to junk with repeated cycles.

What doesn't help is the three decade old plastic; the brown, clear and gray are ultra brittle and the black is like hard tar. As example, look at what I went through melting the wheel spoke nipples into place because the plastic fractured under pressure. I'm still twitching from that one...

Make no mistake, 80 TPI requires care in handling regardless of its apparent benefit. I have many 00-90 bolts in many places too-the clevises for instance. You can't cowboy any of this stuff around.

The whole build is truly the cliche 'work in progress' and I've been improvising every step of the way. I can't remember a single place where I didn't use different material, fastener, adhesive, or joined part A to part B just as the kit comes. :wacko:

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I appreciate your humility, as I think there is not nearly enough of that trait going around these days. However, I do believe that anybody who can face a mechanical problem and can conceive and execute an effective solution is an engineer. You, sir, are an engineer. Don't let your humility hide that from yourself.

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I appreciate your humility, as I think there is not nearly enough of that trait going around these days. However, I do believe that anybody who can face a mechanical problem and can conceive and execute an effective solution is an engineer. You, sir, are an engineer. Don't let your humility hide that from yourself.

And you Sir are an articulate gentleman and a scholar. I have miles to go with this thing; please hold the bouquets until I make something good out of it.

I am not worthy... <_<^_^

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