A4 Pacific Sir Nigel Gresley, O-scale

[Erik Zwaan]

Hi guys, thanks for your kind words and reactions. Regarding the longeron I would like to add that even with all the formers in place, the body is still flexible and can be twisted such that it will fit properly on the chassis. Not much tweaking is required though, the fit of the segments and formers is very well.
The trick is that the bottom of the formers remain free of the chassis by approximately 1mm once placed on the chassis, and that provides sufficient margin.

However, the way things look now, a major problem is looming ahead. The body seems to be longer than the chassis and to assess the exact impact, I have to start building and placing the cab first and then plot any mitigating action.

There are moments that this project comes awfully close to solving issues in real life projects. The only difference is a Total Investment Cost of 50 euros versus a mere 80 million euros....

And in such cases, project managers like myself tend to think in "challenges" rather than "problems" . Let's hope for the best.

Cheers,
Erik

[jenswtnm]

hallo eric,

i hade the same problem, i cut 8 mm in the first section after the chimey

best regards

Jens

[Erik Zwaan]

Thanks for the feedback Jens, indeed the body is approximately 1cm too long and as I have already assembled it, the only location for me to correct is at part 1, at the connection with the cab. Something to work on during the weekend, I hope.

In the mean time a short update; the body is almost done and the stack is in place. Final corrections of small gaps, color touch-ups and alignment of bottom edges still to go.

I detailed the flue gas outlets, by making inside funnels. The model itself provides a flat surface of the stack cover plate and by using the General Arrangement drawing of the locomotive it was not a difficult task to create a more realistic appearance. The collar around the stack base is approximately 2mm too short, which I solved by adding, what in my industry is called a spacer or spool piece at the back end of the stack. Anyway, a small strip of paper to close the gap.

Work on the cab has started, pictures will follow next time.

Also a picture of tacky glue and how the body looks like on the chassis. Slowly the locomotive takes shape .

Erik

[Erik Zwaan]

Worked on the cab last weekend, which is pretty straight forward. Trimming of the internal parts is necessary as it seems like the design has not catered for the thickness of the paper. Not really an issue but you need to be prepared to correct any internal or in between part.

Once the main body is placed on the chassis, with the cab as the fixed point of reference, you can see that the front side of the main body stands out for approximately 1cm. That's a lot and there are two ways to correct: Either cut out a section (as Jens has pointed out, the section behind the smoke stack, although I would opt for the one thereafter, which is part no. 5) or correct the first part at the interface with the cab.

As I already fully assembled the body I opted for the first part and built a few sections anew, to get a better insight how and what to correct. In the end I cut away some 8mm and made a hole in the first former, to allow the pointed front part of the cab to protrude, as this is the direct consequence of this correction.

The dry-fit shows a body that fits both to the cab and chassis. Likely minor corrections will still need to be made before I glue the body in its place, and I hope to finalize the entire assembly later this week.

Of all the small issues encountered up so far, this is the most critical one.

Erik

[Don Boose]

It's really coming along well, Eric! Great craftsmanship.

Don

[Tim Crowe]

It's a lovely shape

Waiting for the next update

Tim

[Richschindler]

Beautiful indeed. So streamlined, so well built!!!!

[elliott]

Moving along there Erik. Beautiful locomotive and great work.

[Diderick A. den Bakker]

Scaling mistake in the boiler...
My most humble apologies for what turns out to have been a scaling mistake. Apparently a lot of enlarging and making smaller again goes on during the designing process... Designer Cor has checked the body parts and the formers again, and has concluded that they are indeed slightly too large. There is a fairly simple solution: carefully cut away all the black cutting lines, build parts 1-5 and 6-10 (attach connecting strip to the front end of 5!). Then fit together loosely and check length against the chassis. Now cut the remaining few mms away from part 6.

For those who have not yet started: mail me your address, and I will send you the two new pages asap. If you bought a download version: mail me, and I will send the file in question. My mail: da DOT denbakker AT planet DOT nl

[Erik Zwaan]

Thank you Don, Tim, Richschindler, Elliott and Diderick for your comment !

Real life kept me busy last week so current progress is modest, however an important step was made: The body is now in place. I'll spare you the details but it took a lot of preparation to mitigate the scaling issue.

A few things I completed before placing the body:

• Small cut-ins in the body abeam the first segment and front windows of the cab to have a better fit at the windows. I'm considering of placing thin strips later on to hide the cuts. If you look at pictures of the real machine you will also notice interference strips
• Completing the inside lamination of the body with 200 grams paper, in between the formers. I left foremost former 7b out (more like a baffle), there's no need for that one with the internal reinforcement. The inside lamination helps to prevent "shining through" of the inside formers, due to the very frequent handling of the body.
• Alignment of the bottom gluing tabs. As you can see on the pictures I glued a laminated edge inside the body to neatly align the gluing tabs at the curved bottom rim. This also enhances stability of the entire body assembly.
• Enlarged the hole in the front former at the top side to make installation of the body to the chassis easier.
• Soaked the bottom rim of the body with white glue, to reinforce the edge and after drying applied paint touch-ups.
• As the curve of the body at front end (a difficult shape) does not mate very well with the chassis I applied a bit of construction kit to more or less close the gap but after installation of the body further correction is required.

Well, so far so good. It's not the best of my work i must say but given the circumstances not too bad ???
I'm currently in the process of finishing paint and glue touch-ups; call 'm the B-items on the punch list.

Finally a picture with front and rear wheels. Noting installed yet, just to get a feel how it will look like .

Cheers,
Erik