JayW

Craig - uncommon how you can turn what looks like a mess into a miracle! Over and over.

Wolf - my challenge now is to generate as much and as great detail in my 1/18 corsair (and engine) as you are doing in 1/32! Great work sir.

Tail feathers look right on peter. I mean right on.

I wanted to get four cylinders complete and then post. But I think I am going have to leave the modeling for a couple weeks to address a Corona Virus risk, the details of which I will not bore you with. Except to say we have a family member who needs to be quarantined and I and a very old mother in law need to be away from this person for the incubation period at least. In so doing, I will be away from the man cave where my modeling happens. Should be OK - just a near term PITA. Now - work has been humming along on the cylinders. Let me show you. you see a major piece of tooling - a check fixture of sorts that assures exact positioning of each aft cylinder (I have a different one for the front row). And importantly it assures exact positioning of the intake and exhaust stacks coming from the back of the front cylinders. Note the pairs of protruding silver tubes. The white cylinder is not fully prepared (the fourth one I had hoped to finish for you). The other three are complete. More pictures: Included you see the valve guide tubes and tappets and the exhaust and intake stacks. Note how they joggle in towards one another, and squeeze through between the aft row cylinders. The lower pipe will connect to the intake manifold. The upper one will connect to the exhaust manifold. One day you will see these impressive details. Also included are the air deflector jackets that you see attached to the sides of the cylinders. That's all for now. Hopefully you can see how this is being assembled. Much of my time has been spent fabricating these fixtures, and I am not done. Once completed though, I can get repeatability for all the other cylinders coming down the pike. Take care, stay healthy, exercise social distancing, and I will post soon as I can.

Ah the picture:

Good observation. A reminder though that when you multiply the numbers here (.025 inch, .09 inch) by 18, they become large. Large enough to consider doing something about it. Landing gear hard points are very exactly tooled to the wing structure on aircraft. I am sure that was the case with the P-51. I am also quite sure the gear door cutout on the lower wing skins was tooled up well. Variation on the order of +/- .10 or so could be accommodated with the length adjustments of the door links. You could adjust for fair and gaps (wheels up), and you got what you got wheels down. It could be the doors themselves had a trim allowance although I have not seen in in the drawings.

Plumbers tape!!!! Hell yeah! Thanks. OMG - Imgur is giving me problems, so I will just have to describe in words. No pictures. Alright - I see a couple of things. First, it appears you have the gear door upper edge slammed up (or nearly so) against the lower surface of the wing. Ignoring the little tab that fits inside the wing contour, you should have a gap of about .025 inch (that is 1/18 scale). If you are able to reposition as described, that will contribute towards improving the mis-orientation of the links that you have described. And if you think about it, in real life if the door edge were slammed up against the wing skin, it would bind as the door closed. Needs clearance.... And, it appears to me that the aft lower corner of the gear door, in a side view, is approximately coincident with the outer diameter of the tire, maybe even a tad aft? That corner needs to be INSIDE the tire outer diameter by about 0.09 inch (1/18 scale), measured perpendicular to the strut. You can fiddle around with 102-33001 and you will see what I mean (side view zone 9). Like the picture on the left of the real thing - you can see exposed tire aft of the door; not so on the picture on the right. In other words, the door needs to swing forward a bit. That might be hard to do - the links want to place the door where they want to place it, if their lengths have been fixed. I seem to recall I had the same problem on Miss Velma and I lengthened one link and shortened the other (my rod ends were telescoping until the very end) which has the effect of swinging the door forward or aft some if there is any clearance between the links and the strut. If you can do it, then just eyeball that .09 inch dimension. Peter - I think that will fully resolve that little issue a couple of us see with the gear door orientation. I think I agree that per your rear view, the gap between the tire and the door is OK, so altering the length of the links for that purpose is unnecessary. And yeah - oleo extension had everything to do with the gross weight of the aircraft. You can just say she is fresh back from a mission with low fuel. It's fine. I hope my words-only description is self-explanatory. Man I feel vulnerable giving constructive criticism to the guy who is poised to blow away the modeling world with Lope's Hope. But IMO it's important.

Peter I have a question for you - Hose clamps. You have done a great job modeling these little details. My R-2800 has alot of hose clamps and I would like to do better. How did you do yours?

Oh my gosh - I wonder if this P-51 model is the new world wide standard for modelling accuracy. The pictures literally look like the real thing. Which is what we strive for. Congratulations. I'd like to see a side view (not oblique) from ground level in which to further assess the "sit" of the undercarraige. Can you provide? At this point, other than the superlatives, I suspect the main gear doors are a tad too far from the gear legs. At least to my eye based on the pics you have provided. I say this only because I have studied untold pictures of wartime Mustangs, and today's warbird projects and that is what I see. The doors are a little closer to the tires. I am pretty certain you have inspected photo's as well. Tell if you agree/disagree. The only way to change that would be to shorten the links, which may be very very challenging and not worth it. Do you know if your links are perfect scale with the real items? If so, then the attach points have some kind of error. And if that is the case, I would shorten the links anyway even if they are put a bit out of scale. After all, too late to modify attach points. I should however reserve final judgement until I see the side view, as any misalignment as viewed from the side can also affect this delicate relationship. I know what you went through rigging those gear doors - a very challenging task.

So Pete - can you give us an idea of what remains, and when you estimate crossing the finish line? You gotta be really close!

Never seen anything quite like this build. Each photo is the classic double take, mistaking it for the real thing. It is your talents that have done this - but I would submit it is the larger scale that allows that extra level of detail to be attained.

The front half of the crank case has been machined from acrylic, and detailed. It was not as hard as the aft half, because the aft half had the intake manifold ports. Here: Combine this piece with the aft half and it begins to look like a crank case: It is now time to sprout its blossoms (the cylinders). During my days off, I could not stop the little gray cells cogitating the problems ahead, which are many. Some involve the curved and formed pipes that make up the intake manifolds, and the exhaust pipes. So I attempted a little tuffy - the P & W provided exhaust stack for the forward row of cylinders - this part: Note it is actually a tube within a tube perhaps with the outer tube as an insulator of sorts (?). The outer tube has a weld fin along its length, and a flange near where it attaches to the cylinder head. And it is the "S" shape that makes it so challenging. I am going to use .125 inch diameter solder to make all these parts. This stuff: Now - the main reason I am using solder is because it can be formed relatively easily. I say relatively. This stuff is pretty stiff, taking alot of force to bend it. But once formed or bent, it has no springback, and unlike a tube, it has no thin walls that can collapse during extreme forming. I used .117 inch diameter on the Thunderbolt a couple years ago - that stuff was easily found in hardware stores. The .125 inch stuff was harder to find, and more expensive. It is also the largest diameter I could find commercially, and it actually is not large enough. For instance, a typical exhaust pipe on the Corsair, per drawing, is 2 11/16 inch diameter, or .149 inch in 1/18 scale. Although I cannot find similar data on the intake manifold pipes, by scaling various engine related drawings for Corsair and Thunderbolt, the diameter appears to be about the same as the exhaust pipes. Well - I have to use the 1/8 inch stuff; I have no choice unless any of you have any bright ideas. So - for that little exhaust stack prototype, I created a robust fixture, or tool, and it has to be robust: This fixture assures a fairly exact and repeatable final shape of the part. The solder was first lined with .156 diameter plastic tube, reamed to .125 inch ID, because it has to be slightly larger diameter than the rest of the exhaust piping. And then forced into an "S" shape with the fixture. It took a couple of tries with modifications made to the fixture. But it seems to work OK. I was fairly amazed the plastic didn't just split apart - it did not want to be formed into that shape! I now hope the fixture is robust enough to do this 8 more times. Here is the finished prototype part, which I think is good enough to just use as is: OK - must keep my eye on the ball. It is now time to finish the cylinders, including the air deflector jackets. That is what you will see next post. Thanks.

My thoughts exactly! The ultimate compliment.

And, the cylinder heads are finished a few days ahead of schedule: Big milestone. You can be assured, if you were not, that I am fully invested in this engine project, after all that monotonous toil. Next on the docket is to take a couple days off. I have been somewhat of an obsessive the last few weeks. When i am ready to go at it again, I think I will treat myself to something with a bit more immediate gratification, which will be the forward half of the crank case. Recall I have done the aft half already. Here is a shot of it painted up and with Meng nuts: The goal of course is to make the crank case look like this (found it on E-bay): I will post when that part is done. Then, some more tedium while I make the lower cylinder bodies (have already done one as you can see in the first photo). At the same time I will add air deflector jackets like these: I look forward to making a set front and rear - not so much the other eight sets! I know this is not very exciting but stick with me. Once I get the cylinders done, it's going to be one cool thing after another. Thanks!

To quote Peter: "The fork turned out OK". Being understated when in actuality you are a modeling tour de force is a quality I respect. Having scratch built a P-51 tail gear in 1/18 myself several years ago, I know exactly what is going on here. Fond memories - I really enjoyed that project. Mine was ground breaking I thought at the time. Yours is earth shattering. Now - have you fixed the tail gear extension/compression yet? Just like the main gear, this detail can be screwed up, and the major maufacturers get it wrong with regularity. Tamiya included. I am convinced when these guys put out a new model, they send someone out to a resto project and get every dimension they can think of by whatever meas they have. They use up their meager budget, come home, and wing the rest. Or something akin to that. In so doing, they either find a subject up on scaffolding with alighting gear fully extended, or they find one in a museum on static display with no air pressure in the oleos and the gear slammed down to the stops. Which leaves them wondering (if they even get that far) what the extension should be. With our access to Aircorps Library, we can do better. So visit tail gear installation drawing 97-34001, if you have not already done so, and get the fully compressed, fully extended, and static numbers. Then make an informed decision how much you want to extend the gear strut. And my apologies up front if you have already done so. And BTW, that drawing will give you good info on the position of the doors when open. Note it varies with gear extension, as the actuation links are attached to a bracket on the oleo assembly.