APA project

[Fliger747]

I ran around (without mask) and carefully miked such items as the sight checker's station rail on the 5" mount and it comes out at a scale 1.13" in 1:120. I made a number of Jerry cans (copied without permission from a Whermacht utility can used in North Africa) which has three roundish handles, parallel, on top. These mike out at a scale .70" in 1:120. Very small handles and grab irons can be quite thin. Perhaps about .12 mm might be a practical limit.

In modeling there are no silver bullets, but we do have better tools to allow us to more closely approach an accurate miniature. The accomplishment is selecting the best technique that we can execute. 3D initially seems to promise push button modeling of great intricacies. Much is possible, but it is tempting to draw items which simply do not work with the current technology. Considerable experimentation and accumulated experience is required to develop an optimal part. It does get easier with time.

No model that I have ever been associated with has been perfect, or perhaps even approaching that goal.

Cheers: Tom

[Fliger747]

As an experiment I am printing some scale 1" (1:96) pipe rail, well supported standing normally and aligned vertically on the platen. I expect that the vertically aligned rail might print better, but take a while to finish. However numerous rail sections could be printed at once.

I just saw an advertisement for a new stronger resin but of course haven't tried it yet.

"Leccha" know how it comes out! Tom

[Fliger747]

The 1:96 1" pipe rails printed OK. Not of course the end of the story. One has to dry and cure these and remove the supports to fully evaluate the practicality. Maybe a bit "airy". I have found that after curing these do tighten and stiffen a bit. A shot of primer seems to help as well.

So far my evaluation is that with my current resin that the finished item, removed from the supports is too flimsy to maintain it's shape well. Phrozen has announced a new and stronger resin, perhaps advances in the technology will allow completely in scale rails, soon I hope?

Tom

[Fliger747]

David:

Thank you for the suggestion, I have considered that and I know in some larger scales that such brass stanchions are used. I expect the overall effect if accomplished would be less satisfactory than a slightly beefed up print. I have had trouble finding straight brass wire finer than .015" (.38 mm). Finer wire is available in coils but I have had trouble using this for rails. Current resins with a hole in the would be quite weak at that point. It would be possible to have a smaller pilot hole and then drill out with a very fine twist drill in a pin vice. One advantage of printing is the ability to have the rail snake around with bends not at a stanchion and replicate the actual stanchion spacing.

Regards: Tom

[DrPR]

I have a friend who makes HO model railroad "stuff" like saw mills and such. He told me how to get very straight wire off a coil.

1. Unwind the length of wire you want to work with from the spool. He does it several yards at a time.

2. Clamp one end into a firmly anchored bench vise.

3. Give a stiff jerk on the other end.

The result will be a very straight length of wire. I have tried it with copper wire and it works every time!

However, you need to experiment to learn the right force to use. Pull too hard and the wire will stretch and have a section with smaller diameter. Or it might break.

Phil

[Fliger747]

Phil:

Thanks, I have used that method but my beef with it is the coil wire is quite soft. There was a supplier of various bronze wires that I used for a while, though on a coil it could be straightened and was stiff enough. On this ship I have used a number of techniques, Wire stanchions in drilled holes with a wire top rail and thread for the intermediate rails, sprue glued together (fragile), soldered brass wire, 3 D printed.

Currently I don't think you will reliably achieve a scale 1" pipe rail in 1:96 but by the time you get to it technology and strength of resin may be better. Phrozen is advertising a new resin "ONYX" which is supposed to be stronger, whether it will be an improvement, who knows. However I do think you would find the resolution of surface detail pretty good. Files often have to be adjusted to fit the printing process and the size and shapes of the pieces involved. Definitely not push button parts yet.

Supposed to snow again tonight....

[Fliger747]

Wa Hail (a statement about a meteorological condition?) It did snow some 3 cm for our metric brothers.

I have a related project to the APA, a LSM, an open decked "ship" some 200 plus feet in length which would be a great place to park a plethora of invasion vehicles. The hull I made of aluminum over 55 years ago, stripped it down and beginning a major reconstruction. The Tank deck is back in place and I am experimenting with printing the main deck portions with 3D. Starting at the stern and working forward, the first piece mostly printed OK but needs the 20 mm tub beefed up and a few rail supports added. The main goal of this first piece is to test fit the piece in the hull where there is some curvature. The design goal was to have a little overhang such that it could be sanded flush for a perfect fit.

Scale is almost the same, 1:133, another catchy popular scale with a plethora of commercial parts... I guess that's part of the fun, making everything. The 20 and 40 mm mounts can be just slightly scaled down from the APA (10%).

Cheers: Tom

[Fliger747]

David:

This is generally true, though considerations can be that some parts can become too small to print well, railings etc. With very slight modification, thickening the shields and supports, my 1:120 20 mm Orlikons printed well in 1:196 and I replaced all the 20 mm's on Alaska with them. The 1:144 MK 37 that I did for Hank also printed well in 1:192 and I replaced the resin ones and commercial products previously on those ships though Alaska and Missouri used different models of the director. Sometimes it works, sometimes not. Probably the only items correspondent between the ships will be 20 an 40 mm, ready ammo boxes, oil drums for the smoke generator etc.

Cheers: Tom

[Fliger747]

Like Titanic, Randall deserves a little sister. As I had mentioned this is a hull that I crafted out of aluminum in perhaps 1964? I gutted it and made a new tank deck from trusty 1/16" plexiglas. Starting at the stern I am proceeding forward with printed sections. Currently two more sections are printing which will bring me up, almost, to midships. The trickiest alignment will be alongside the bridge structure where the sizing, and fit will be most critical as the outboard side is flush with the hull. A plethora of items to add after the hull level deck is roughed in. A few items printed integrally, gun tubs, vents and whatnot.

The existing hull is pretty good since I was a teen when I built it, but it's not perfect so each printed section has to be carefully measured and printed. Back then a computer took up a couple of floors over at the University and Bette Middler was still waiting for Dialing for Dollars.

Tom

[Fliger747]

40 mm Bofors barrels and 20 mm Orlikon in 1:133 for the LSM. Mount for the twin Bofors yet to be printed.

Tom

[Iceman 29]

Nice prints !

[Fliger747]

Thank you Pascal!

I have since printed the 40 mm mounts which came out well. With the size reduction from the units on the APA (10%) I was concerned the thin rails, seats etc might not resolve properly in printing, but they came out OK. With some fiddling, I should have all the port side of what the drawings refer to a the "superstructure deck" installed. Matching the curves of the existing hull with a printed item can be a little interesting and I anticipate some hand fitting.

Regards: Tom

[BB62vet]

Tom,

Those look good - one thing I've noticed is how the resin parts are not as flexible (such as in bending) as are the styrene parts. I guess the resin bulkheads could be bent if the thickness would allow it.

Hank

[Fliger747]

40 mm Twin Bofors, to be mounted on the LSM Forecastle (1:133). Also some 20 mm ready boxes to be sprinkled about.

Today I also designed the 40 mm fwd gun tub.

Tom

[BB62vet]

Tom,
Looking good - I can see that both of our printers are probably going to go up in smoke about the same time from overuse!!!!! NOT!!!!!

Will be interested in seeing how the tubs turn out.

Later,

Hank

[Iceman 29]

Tom,

Those look good - one thing I've noticed is how the resin parts are not as flexible (such as in bending) as are the styrene parts. I guess the resin bulkheads could be bent if the thickness would allow it.

Hank

The printed pieces can be heated a little with great care to fold them.

[Iceman 29]

Tom,
Looking good - I can see that both of our printers are probably going to go up in smoke about the same time from overuse!!!!! NOT!!!!!

Will be interested in seeing how the tubs turn out.

Later,

Hank

For the same reason I just bought a new Mono X at auction on eBay at a very good price. 25% less than the normal price.

[Fliger747]

Pascal:

Does a warm water bath work well for softening the cured resin?

[Iceman 29]

I tested it, I don't find it really conclusive, but I didn't have my machine at the time to clean the parts either.

The alcohol gives very good results with the machine. To reduce the cost, I buy 10 litre cans. I also decant the machine ( Wash and cure ) can from time to time, the resin settles to the bottom after 2 to 3 days. I recover about 90% of the alcohol each time, and add 10% more.

[Fliger747]

Today's minor efforts. Printed the new re designed MK 52 (I actually like it better) printed the last segment of the superstructure deck and started the bridge structure design. Cheers! Tom