eTraxx

About Me
Live in South Carolina in a small town right outside Camden. I am retired from the US Army – 1969-1972 Vietman(18mo) and Ft Huachuca AZ a a 72B; Machinest for five years; Ran Model Railroad Hobby Shop (Best job ever); Apartment Renovator; 1987-1999 Ft Hood TX, Saudi Arabia/Iraq (Desert Shield/Storm) with 3/32 AR, Germany with 1/70 AR and 1/67 AR; California with 1/40 AR and Korea with 1/72 AR (1st Tank) all as a M1/M1A1 Armor Crewman; 1999-2006 with Army Reserve as a 55B/89B with service in Baton Rouge LA (great food by the way) .. Kuwait, Afghanistan and Uzbekistan (few days each of the last two).

Now .. I’m retired and happy with life (well .. other then not being wealthy and having a bevy of throng clad young-things running around the house)

Power and Paints
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Didn’t accomplish much today. Went to a TCA meet and picked up a non-running Atlas 0-6-0 Diesel switcher for $5. Worth it to me as I want to turn it into bits and pieces ..

Dropped by New Brookland Hobbies then and picked up some Floquil .. Aged Concrete, Dust and Grime .. so in the end .. not a bad day.

Foaming …
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Experimenting a bit here. I cut three pieces of foam to fit into the corner and between the structures .. then hot-glued them together. What I want to do is carve a hilly slope that connects the two into the backdrop.

The ‘method behind the madness’ is to give the impression that the buildings are built on very un-level ground. Retaining walls inserted at the appropriate locations and winding steps and roads should help. The slope itself will be rubble and dirt with perhaps a little grass. There’s not much room really but should be enough with trees against the backdrop to hopefully (and magically!) blend the scene into the backdrop. I’m thinking though .. that this will be pretty much an example where forced perspective may work since the buildings form a view block and restrict the view .. so that might work better then if it was out in the open.

Just how well that works is still to be seen. I’m thinking though .. that if that little bit of foam is left ‘loose’ .. then like the buildings, it can be taken to the workbench for detailing.

Structure Arrangements
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Maintenance Shed etc.
With the Maintenance Shed finished I need to place it. The Critter Shed was placed on a piece of Styrofoam so it was the same height as the track.

I cut out another piece of foam the same thickness for the Maintenance Shed to sit on – then another thinner piece. The idea is a little vertical movement there to make it interesting. I’m thinking that  a rolling hill between/behind the buildings that blends into the backdrop would work .. I think.

If I do that – it gives me opportunity to have retaining walls of various shapes and sizes.

Narrow Trak 12
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Great Weekend
Last Friday and Saturday I attended the Narrow Trak 12 meet. This is an annual model railroading narrow gauge and logging convention in Transylvania Co., NC. It’s not very big .. but was fun. Mostly clinics.
Clinics
MMR Ben Bartlett’s clinic was on Constructing a Laser Kit. He used Motrak Models’ HO Scale MOW Shed as an example, covering basic construction methods.
Johnny Graybeal gave clinics on the Eastern Tennessee & Western N.C. RY and Steam Shovels of the Narrow Gauge;Matt Baumgarner talked about the Ritter Lumber Co., in Mortimer, N.C.; Gordon Fewster gave clinics on Small Control Panels and Scenery; Yvonne McCall-Dickson on the Carr Lumber Company (interesting in that the buildings had been right outside where the convention took place); Jerry Ledford on Western Carolina Logging.
Tom Yorke gave a clinic on Working with Balsa-Foam
Models
Dioramas
Ha. There were only two .. my clinic model and the one from Tom York. He’s building a Gn18 operating diorama. This is the first part of it (his clinic on carving balas-foam was on the entrance).
Motive Power
The large tank engine in On18 was from Tom York; I believe the two ‘home builds’ were also by him and in On18. The other two engines were both HO. The one with the powered pulleys (they DO have a name .. I just forget what you call them) was very nice as was the Climax. I believe they were by the same person but managed to not get it which is a shame as they were very well done. The smallest was the Nn3 Shay shown with the penny. This had a note that it was produced using RP (Rapid Production .. aka .. 3D printing). Again .. I didn’t manage to find out who did that .. would have liked to talk to him about it.

Brick – FAIL!!
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I wanted to see if I could make a mold so I could cast bricks in 1:48. First thing I model a standard brick in Sketchup including a 3/8″ deep frog.

That was easy enough. There are all kinds of different sizes of bricks when you start looking but the 4x8x2-1/2″ shown here is near enough a ‘standard’ or ‘common’ brick.

I arranged 11 bricks by 10 bricks in a grid and then surrounded them with a wall and a base. The idea was to create a master that I could pour RTV into and create a nice mold.

I wanted to test out WSF as a material – I haven’t done so in the past as I’ve kept myself to using FUD.

WSF – or – White Strong and Flexible is a laser sintered nylon plastic. It’s high strength is offset by it’s medium smoothness and less detail then FUD.

So. Here’s what I got. Hmmmmm. The minimum embossed/engraved detail that WSF can be printed at is 0.2mm .. about 0.008″. If you look back at the first illustration with dimensions that 4″ full-size brick width is 0.075″ in 1:48. That 0.008″ minimum detail is a full 1/10 that width. That means I got bricks with rounded edges.
A close-up of the RTV mold and a couple tries at casting bricks shows the results.

There’s a couple of things that can bee seen in this photo:

  • Pin-Holes in the RTV. That’s one of the things that I will fix at some point. The RTV needs to be de-gassed in a Vacuum chamber. I have the vacuum pump and need to purchase a couple more items to build my own vacuum chamber.
  • The bricks show well the rounded edges. Those edges would be much less if the master was printed in FUD – but that would be quite a bit more cost then the WSF print. I wanted to see how well the WSF printed and am confident that it would probably be fine to represent something like a truck sideframe.
  • The yellowish colored bricks were cast in Durham’s Water Putty and the reddish colored bricks is a plaster’ish floor leveling compound colored with Terra Cotta cement color. Neither of these made good bricks.

The bricks were a ‘FAIL’ IMO .. pretty much. If they would cast better I might could use them as old bricks. I will still use the mold to experiment with other materials to see if I can some nicely cast bricks from it. One problem is if you look close .. the backs of the bricks .. the side opposite the frog is slightly dished on many of them. That’s simply that the plaster didn’t completely fill the brick mold and surface tension pulled the edges up. I need to play around with it but I think that the answer is that I need to overfill the mold and at some point I need to scrape across the surface.

Small Dia Threaded Rod – Pt 2
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I was curious as to the actual size of a 1:48 scale 1-1/4″ Acme threaded valve stem .. 5 tpi .. would be. In the drawing the major diameter of 1-1/4″ is reduced to 0.026″/0.661mm. The various dimensions are shown .. all of which are below the minimum detail that FUD can be printed at. The red square shows that minimum size .. 0.1mm

Im not necessairly saying that I have to print in FUD .. but that was the first thing that came to mind.

Using that minimum 0.1mm for FUD I drew out the best that I could possibly hope for if I printed this in FUD. The therads per inch end up around 2.5 .. twice as coarse as the scale version but I think would look fine if the printing was possible.
Is this possible? Not sure but I kind of doubt it .. at least for printing in FUD. The minor diameter of 0.461mm is below the 0.6mm minimum for a ‘wire’ when printing FUD. It *might* slide by .. but would be ‘iffy’.

What I was looking for was some basic dimensions that I could work toward. I would like to go another route and create some rollers with the thread on them. I could possibly use them to roll the threads onto a length of small dia solder. Not too crazy .. that’s how bolts and screws are mass-produced .. the threads are rolled into a metal rod with dies. The problem is .. what to use. The example above is using FUD .. but that is too soft, brittle, weak to act as a die .. even for solder (at least, I believe so). There is Stainless Steel at Shapeways but the minimum detail is way too big for this – 1.0mm .. ten times that of fud.

Small Dia Threaded Rod
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When I was trying to design my 6″ gate valve I ran into the problem of – where the heck do I find something small enough to look like a valve stem for something that small. I found a chart for Kennedy AWWA Gate Valves where they show the stem dia for a 6″ valve is 1-1/4″. In 1:48 we are talking about a threaded rod that is only 0.026″ dia. Woah.

Very small dia threaded rod can be found. You can purchase #0000-160 (0.021″ dia) .. for about $50 a foot! I saw that and quickly decided .. uhhhh … no. (on an aside that is 160 threads per inch. If we reduce that to 1:48 that is something like 3.3 threads per inch)

I had fair success in taking a single-cut file and rolling it across a piece of 0.020″ solder. Holding the file at an angle (“Single-cut files have rows of teeth cut parallel to each other at an angle of about 65 degrees from the centerline.“) the teeth empressed grooves into the solder that looked very much like threads. The problem with this method is that you are restricted by the tooth-spacing of the file you are using – this of course relates directly to the ‘threads-per-inch’ of the pesudo-threaded rod we are trying to create. A ‘Smooth Cut’ has the greatest number of threads per inch – and a 6-inch file has more teeth per inch then a 12-inch file.

This running around in circles brought me finally to Acme threads. This is what would be used on a valve stem. The Acme thread was a development of the square thread. It has a 29° thread angle with a thread height half of the pitch; the apex and valley are flat. A 1, 1-1/4″ dia rod would have a Pitch of 1/5 (5 threads per inch or .200″).

Now .. at 1:48 – one inch is 0.021″ (rounded). Dividing that by 5 we find that the pitch would be 0.004″ .. woziers!

The 12′ x 12′ Shed that never was
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Once upon a time .. long, long ago, Shortline Modelers Lounge held a contest for construction of a small building – 12′ x 12′. In the end, my submission was a shed that was mostly falling down …

A 12′ x 12′ Scratchbuilt shed

Prior to doing the ‘falling down’ shed I had intended to do a super-detailed building with all of the framing exactly as the full size building would have been. Never happened but thought I would share a couple photos of the structure that “never was”

Clinic Prep
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I’m prepping for a clinic at a local TCA meet next Saturday. This is one of three similar pieces. One will just be a stack .. carved and distressed .. one divided up into about four stages .. paint, AI stain, shadows, highlights and pigment wash and then this one which will be complete. I’m just at the stage with highlighting the rock with white. The ‘rock’ .. is a stack of two different kinds of foam, couple layers of 3/8″ sheetrock, cork (squares) and cork (shelf liner). Letting dry tonight .. tomorrow do a pigment wash (brown tempera washed with water into crevices etc.) .. then when that dries (prob next day or late tomorrow) .. rubble, rock, sand, dirt secured with white glue & water. The day after that paint and final staining .. should be ‘good nuff’ for a clinic.