The machine is amazing for sure!  The pained engine house looks great!  Yes, I heard it was really hot in Kentucky yesterday.  I do like that rivet section also!

Thanks! It sure is! One nice thing about "The Machine" is it can work on weekends. My deal is "I don't do modeling on the weekend", but the machine is humming away downstairs and I'm upstairs not modeling. 

I successfully printed the air conditioner legs and am ready to glue the entire project together and paint it. The support network was SO much more involved than the actual part it's almost comical. The part only used about $0.40 worth of resin, but the support network probably tripled that. The slicer doesn't give you the network estimate.

I'm learning how to carefully cut away the supports without damaging the part. You have to remove it in layers watching for the interconnecting angular ribs. Then you can reach the interior supports. 

EC Legs Supports

Here's the finished leg assembly. I added all the cross bracing in the modified drawing so it had more structural integrity. It worked!

EH AC Legs Fin

Immediately after this came off the printer I printed the entire Hoist Structure in one go. The print was actually successful, but it's not going to work. In true 1:48, it's really a bit small. I would be almost invisible in the engine house. Also, as I'm still a student, not a master, I learned that if a free-standing wall in a 1:1 thickness is much less than an inch, will print too thin to be practical. The wall thickness for the outside of the wheel assembly was 3/8" in 1:1. That printed at .008" thick in 1:48. As I was cutting away the supports—carefully—it was breaking away. This resin at .008" is too thin to handle. Otherwise, it really resolved pretty well. The wheels, motors, bumpers all printed. The bumpers too were too fine to withstand the cutting pressure.

EH Gantry Hoist Trial 1

\EH Gantry Hoist Print Trial

So I went back to the drawing board (figuratively) and enlarged the entire unit by 30%, then I thickened the floor place and the outer wheel housing plate to over 1" true inch. It's now printing again, and I believe it will be successful. All the motor and gear box ribs showed up. They're thin too, but they're not unsupported or attached to support rods.

One the original download from SketchUp, there were a lot of objects that were not solids or had their faces reversed. If the faces are reversed the STL file converted doesn't recognize them and leaves the shape unclosed, not solid and missing walls. You can review the STL file visually to see where these errors are. I just learned that today! I am literally learning new stuff every day with this technology. Alanrail has been doing this for a number of years and he and I communicated via eMail and he gave me some other pointers. I'm still printing at 40 micron layer sizes. I may start experimenting with finer resolution (and therefore even longer print times) on these kind of complex structures. Because layer thickness plays such an important role in print time, you need to understand what resolution will do for print quality and optimize it by the job.

I'm making steady progress building the complex front-end of the 567. I check each part by exporting them as an STL and if they check out, put them into the rest of the assembly. I'm using ALL of my SketchUp skills on this job. The rectangle with the angled bottom is the mount for the Woodward Governor.

Screen Shot 2019-07-21 at 8.41.30 PM

The new print came off the machine and all the changes I made were successful. I enlarged it and strengthened the week areas. I used the "Heavy" support setting, but that was overkill. I'll not be making any more of these so I'm not refining it further. Here's the top view. Notice how all the bumpers are now there.

Hoist Final 1

Here's the bottom. Motor and gear box flutes came out perfect.

Hoist Final 2

And here's the comparison of the trial piece at 1:48 and the fixed one 30% larger. Imagine doing that if you had to scratch-build them. It took me just a couple of minutes to make the changes. You can't see it in the pics, but the machinery is all sitting above the platform on their legs. Tomorrow I'll prime and paint it. I'm thinking of printing the main wheel trucks also. I'll make the wheels to conform to the Atlas gantry track profile. The rest of the gantry will be scratch-built from styrene. This thing is really going to pop when it's painted!

Hoist Comparison 2

This application is exactly how I've envisioned it. I'll continue to scratch-build sensible assemblies and use the printer to handle the nitty gritty details that would be a pain to build or I'd simply ignore. It just ups the ante. Onward and upward.




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Last edited by Trainman2001

Myles, that support structure for the air conditioner stand is complex, but I get the concept of why it is necessary.

I don't see the last three photographs, the ones after the drawing.  The first four photographs are visible.

Look again! I find that OGRR's forum site times out if you interrupt the writing process. The pictures appear in the text, but disappear from the attachment list. So I went and edited it and then pictures appeared as doubles so they I edited it again and now all the images are where they should be. The last three pics are the best part.

The pieces that I had done at Shapeways were way too big. I think I enlarged it 150%. It was $40 down the drain, but I'll mark it up as experience building. "Good judgement is the result of experience which is the result of bad judgement!" The 30% enlargement looks pretty good when I held it up in the engine house. Painting tomorrow and putting in the windows. I'm also going to put the "Pennsylvania & Pacific RR Main Shops" lettering on the building front. The printer will print anything, but that doesn't mean it will work. It's all in the design.

The printed items look amazing. Thanks for sharing, Myles. The leg assembly with all the support looks like it might be easier to make from structural styrene.

Thanks Pat and Mark! 

I printed this Marx patch for Marty Schwendau, who's the plastics dept manager at my favorite hobby shop. He had a picture of this 1950s Marx Toys patch and asked me if I could make it on the printer. Of course I said yes. I had to download another couple of extensions to handle wrapping the 3D text inside the medallion, and I used Fredo6's "Round Edges" extension to round the edges around the dino without wasting hours doing it by hand.

Marx Badge Fin

I cleaned up. It's up to Marty to paint it.

I assembled the ac unit, primed it and sprayed in Tamiya Bare Metal rattle can. It came out pretty well. The next one will be better since I've added some internal bracing to prevent some of the warpage I found. To mount the fan, I drilled a .162" hole for the stub on fan. In the next round, I'm going to modify the drawing and have the printer build that hole in it.

EH AC Primed

EH AC Paint

Up next will be to work on the fan and housing a bit more. I want to paint the area behind the fan flat black so it looks like it's open below and then paint the fan a different silver than the body. I may paint the doors a different shade of silver to show some contrast. Notice, that I broke off those tiny free-standing door handles. Like I've said, the printer can reproduce ridiculous level of detail, but will it stand up in the real world.

I primed the hoist and put it next to the huge pieces I had done at Shapeways. I don't know what I was thinking getting it done so big. I think the size I've made it now is just about right. When you see the Shapeways parts next to the main, those motors are way oversized. I had reduced the details on the parts I sent to them thinking that they couldn't be reproduced. For example: I didn't flute the motors or detail their tail housings. But I did do this on my printer's version and it replicated all of it. On the original drawing, the end bells were hollow and had cooling fans inside them. I'll bet that the printer would have tried to reproduce that too, but it would have been very fragile.

EH My Print Versus Shapeways

I then went on errands and bought some wood strips to reinforce the roof truss system and provide a place for the lighting system. I also bought some new epoxy. Marty and I problem-solved the roof stiffness problem. Instead of adding more layers to the roof deck, I'm going to added longhorns to the base of the trusses. That will stiffen it like crazy and will provide a perfect place for all the lighting.

When I got back I airbrushed the yellow coat on the hoist, and proceeded to wreck my Badger 200 fine line brush by not cleaning it thoroughly after I used it last time. The needle froze in the assembly and I bent it overpowering it to remove it. I've ordered a new needle and front nozzle assembly directly from Badger.

I also need a cheaper source of high-concentration alcohol to wash resin off the printed parts. Using 190 proof grain alcohol is not the cheap way at $30 per large bottle. It's liquor and must be purchased at a liquor store and has a hefty alcohol tax. I found 16 oz bottles of 99% isopropyl alcohol for $10 at Amazon. I bought two bottles.

EH Hoist First Coat

I'm going to paint the rest as it was on my original drawings with the hoist engine being medium blue, and the traction drive below the platform bright red. I'll pick out other details like the bumpers in black. There's a trolley system on these machines that carries the power feed cables to the moving hoist body from a cable system hanging over the edge. Chose not to print this… yet… because I don't know how much clearance I'll need over top of the gantry walkway railing.



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Thank you all. The Tamiya spray paint is basically a lacquer and dries very fast. 

The printer is now almost finished printing the second AC main body. This time I've included the hole for the fan and added interior X-bracing to see if I can control the slight warp. 

I painted the hoist today and it looks pretty much like the SketchUp drawing. When I look at this image, there's a couple of slight spots that need addressing and I'm going to give it a light coat of aging liquid so it doesn't look so "shiny new". It just cries out for some electrical wiring, don't you think?

EH Hoist Paint

I masked and painted the fan area black so when I paint the fans chrome or aluminum it will look like it's open below. I could also have the print actually open up the areas below the fan on the fan housing and the main box (if I wanted to). Again, the printing gives you so many options it's overwhelming at times. I thought the bottle contained flat black, but after it dried it was semi-gloss black (picture was when it was just painted), so when it dried I shot it with some Dullcoat.

EH AC Fan Black

As I mentioned, I will strengthen the roof system and provide a good surface to mount the LED array using some bass wood strips glued solidly to the truss bottoms. 

The basswood comes in 24" lengths and I have 40" engine house so I had to splice them. I made a pseudo scarf joint by mitering the ends and sanding to a true 45, and then putting on 1/32" ply splice plates to reinforce the joint. I did this on both sides, and then realized that the glue side had to fit between the trusses. I went back and marked them, cut through the ply and removed the excess piece. Of course the Aleen's glue (plus CA reinforcement) dried and I needed to pry it apart with that trusty plane iron blade. I make their ends and cut the strips to length and then took them outside to paint them the same turquoise I used on the trusses. I had exactly the amount to paint one side of the four pieces and actually ran completely out with one tiny space unpainted that's going to face the wall. Two strips go onto the truss ends and the remainder I spaced evenly between them. It measured at 860mm from each end. I glued them in place with Aleen's and clamped them with my faithful gravity clamps. After dinner I removed all the weight and the is dead straight at very strong. The idea worked perfectly. Tomorrow I'll start installing the lighting.

EH Truss Spanners Scarf Joint

EH Truss Spanners Joint Trim

EH Truss Spanners Fit up

EH Truss Spanners Paint

EH Truss Spanners Gravity Clamps

These strips are overkill. Real roof systems don't have that much mass, but I needed a broad flat surface for the LEDs. These are the kind that I got from eBay that are designed for lighting outdoor signage. They're in series and already wired up with proper drivers. All you do is provide 12 VDC. I'm not sure how many I'll need in each row. They're already equipped with mounting tape on their backs which accounts for the strip width.

EH Truss Spanners Done

All the handling of the massive building broke some glue joints loose on the floor so I regaled them. There's not much gluing surface area especially since some of my thick buttresses are just a bit high and aren't contributing to the glue joint.

EH Fixing Cracked Joints

Should be all better tomorrow. I also trimmed some more foam from the building site so the side pilasters site below the ground line. I want to be able to landscape up to the structure. Now I have to go into the shop and look at the next part that the machine just gave me.

So the second AC box came out good, but none of the X-bracing printed. Apparently, they weren't solids. The longitudinal brace was disconnected each place there should have been an X-brace. The box still works, but a little warp is still there. I'm going to fix the drawing and see if #3 solves the problem. At least the engine house requires four complete AC units. It's not often that you get the chance to do it over and still need all the parts. And of course I broke off the two delicate door handles.

EH 2nd AC Box

An interesting thing happened today. You recall that I did that soldering clinic at our local modeling club. A new member in attendance is also a member of the Bowman  Airfield Heritage Group. They're tasked with restoring this airfield that's going to celebrate its 100th anniversary. They have a metal model of a Sikorsky S-38 that was part of a commemorative sculpture that had fallen over some years ago wrecking the plane. They tried fixing it four years ago with hot glue and, of course, it was a fiasco. Then he saw what I do and realized I was the person, if anyone, who could salvage the model. It will be for a commission to be determined once I examine the wreckage and see what, if anything, I can do about it. I was very pleased to have his reaction from my clinic. I haven't lost my edge… As they said in "Dory", "Just keep swimming!" Life is definitely cool sometimes.



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Last edited by Trainman2001

The hoist does look good!  It is amazing what paint can do to bring out the details!!

I like the blue you painted the trusses!

I agree, you are the man for the Sikorsky project.

You have undying faith in me. I hope I can live up to it.

Built the second HVAC unit today and found something out about post-print-processing. After the pieces printed last night I didn't want to fuss with them so I just dropped them in the alcohol soak and planned on trimming all the supports today. If I'm not trimming I can pull off a complete print and start another in just a couple of minutes. As soon as you remove the print from the platen, it's ready to go again. But… it isn't fully cured yet and sitting in the alcohol caused the part to soften and swell a bit. It was spongy and the fan blades had expanded until they started to buckle. I put it under the UV hardening lights and stabilized it. I was able to press the bottom flat when I CA's the fan to the housing and put it in my woodworking vise. I also found out why none of the cross-bracing printed. The faces were reversed in the SketchUp drawing. The STL file does not recognize the opposite side face. Depending on how the shape was created the inside surface can be expressed on its outside. That fixed shape is now downstairs being printed.

Here are two units. The 3rd fan is done and I'll have it all printed tomorrow. That means the fourth unit will be done probably on Monday. You can see the misshapen fan blades. I'm not going to scrap it. It's not going to be that obvious on the building.

EH AC Now there are two

But the 3rd fan came out fine since I didn't leave it in the solvent too long. My 99% isopropyl came from Amazon today. I mixed it with the remaining 91% I had so it's running about 95% which is good.

While all these parts were printing I got the lighting installed in the main building. Here's how it looks when it's all on. 

EH Light Test Interior

And here it is in a darkened room. Plenty of light!

EH Lighting Test in the Dark

Now let's talk about how I did it.

I was mistaken in thinking that the lights didn't need current limiters. I tested two set in series and they turned green and went "Poof!". Plan B. I made a series of four, 3 LED unit strings each with its own CL3N2 LED driver. I tried using six sets in series, but my voltage source was petering out and they were dimming. The LEDs units are already in a string array, but the lead spacing was much too narrow. All of the work was cutting the leads and splicing in some red/black power cord. I like the red/black since all of this is DC and needs to be polarized.

EH LED w Driver Chip

This was a test. I tested each array before I pulled off the backing strip and sticking them down. I use shrink tubing at every joint and wire are tied to the cross strips with electrical tape. I may rethink that and use zip ties. I saw some tape already unwrapping.

These four parallel circuits had to be joined to one, so I used ferrules and Euro-style junction blocks. These are disconnect blocks and can be separated. It's overkill, I know, but it's what I have in the parts boxes left over from layout construction. I'm still using junction blocks that I got when building layout #1 in Germany. I wanted the last connector to definitely be a disconnect type so I could remove the roof fully if I had to. I had entertained the thought to run the wires underneath the strips through holes in the strips, but it would greatly complicate the soldering job. As it is there were lots of joints to be made.

EH Parallel Light Wiring w Disconnects

Then I went to put the roof on which is the first time I did since all the stuff was in there. The roof wouldn't go on. The cross strips were impinging on that big 3/4" cross-member. It worked with just the trusses, but not with the strip in place. I broke its glue joints and fastened it lower just under the upper roof support blocks. I used a screw instead of glue because I had to pull the sides in forcibly. The previous glue job wasn't all that good anyway since it slipped while drying and one wall was 1/8" further out so there was a gap when the roof was one. In this image you can see that far strips with lighting right on top of the cross brace.

EH Cross Brace Interference

Moving it straight down didn't quite work either since the light units sat right on top of it and it was still pushing up the roof. I then move it two bays to the left and re-screwed it. I have filler drying on the errant screw holes. It now works and still pulls the walls together. I didn't want to go any lower since it would get into the gantry area. I may spackle the screws so they'll disappear. That brace really doesn't ever have to come off.

EH Cross Brace Solution

If I didn't put the trusses on the roof, they would have held the walls tight, and that's how I originally designed it. But with the trusses in the roof (which make it much stronger) those long flex walls needed some help.

I then tested the entire array and it all worked correctly. The wiring is very conspicuous, but the lights are so bright they're not so obvious when it's in the building. I may paint those wires the same color as the trusses to make them disappear.

EH Light Array Comp

I'm going to run the leads from roof to the basement using a tube that will simulate roof drain piping. I'm going to maybe print some roof water collectors and have some pipes leading down inside like is done with most big buildings. Next week I'm putting the building back on the layout and starting to put in the windows. I don't want to do them in the shop since carrying the beast is not easy and the windows would suffer.



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Nice job, Myles. The lighting looks great. The AC units look fantastic. You can't tell the fan blade is malformed unless you are looking for it and it will be even harder when the grating is added.


Have you thought about using hot glue to hold the wires in place?  It would be faster and easier to conceal than the tape.


Pat! You are too kind!

Jan, That's a good idea! I have hot glue! Not used to thinking about it except for making stuff out of cardboard. The 3rd HVAC box printed last night and this time all my internal bracing worked. Absolutely no warpage! I'll post pictures later today.

Myles, The interior lights look like long fluorescent light fixtures in the first photograph of the engine house.  Yes I see how the wires stand out, but painting them would make them hard to notice. I take it the paint won’t attack the insulation.  Good idea to put in the windows on the layout! Besides weight, I would think the building is a bit unwieldy to carry.

Thanks. It does look cool.

I replaced the electrical tape with cable ties. I thought of hot glue and had the gun warmed up and ready to go, but I have a ton of these small cable ties and they do make the wiring a bit less visible.

I ran a couple of Plastruct ABS tubes in the corner that will be conduits for the wiring to get in the "basement" and did use hot glue to hold them into the corner. I prepared the wiring and did run it through them. I needed to prepare the site some more to remove any remaining ballast from the between-rails ties so the new strips from Rail Scale will fit properly. 

I resolved the warping problem completely with the X-bracing. The walls are dead straight.

EH AC Box 3

The X-bracing is a bit of overkill, but they worked, especially since I reversed those faces so the STL translator could identify them as surfaces. Reversed surfaces in SketchUp are recognized as nothing. All the garbage inside is the remnants of ton of support rods that had to be cut way. They out of sight and therefore out of mind.

EH AC Warp Control

I also got the vent stacks printed and the legs are on the machine now. They'll be done in less than an hour and that will give me three complete HVAC units, with one more to go. By printing all night I'm able to finish a complete unit in a 24 hour period. Machine doesn't care.

I put the engine house back on the site and ran the leads down a large hole drill in the platform. I also drilled a hole for the wire from the Machine Shop's lighting which I haven't built yet. I have two more modules LEDs and that should be bright enough.

I began installing windows and found that my clearances were very, very tight. Some windows needed trimming. I probably was too optimistic in the spacing accuracy. If I was off no more than a 1/16" in gluing in the buttresses it interfered with the back window flange. I'll just trim them as I go… annoying, but not much else.

The cable ties… now if I was a really smart man, I would have preplanned better and left just a little more slack in the interconnecting cables and they could have wrapped around the stringers and been fastened on the bottom effectively out of sight. Instead, I cut them to fit perfectly on top. Live and learn. The next engine house I build, I'll do it differently.

EH Cable Ties

The tracks are now completely clear of ballast where the fillers will go. The fillers arrived today. I will have to shim up the running rail sides a bit since on the power rail side the fillers sit up on the rail spikes. Probably some paper strips should be sufficient to build up the other side so they sit level.

EH Cleaning Ties for filler strips

The power conduits...

EH Power Feed Trunks

The big hole to capture both wires which are no longer together.

EH Power feed hole

And the windows. This inside view shows how tight the flange sits with the pilasters. If I would have made the flanges just a little less robust they would have slipped in.

EH Windows tight fits

They look spiffy on the outside.

EH Window install begin

Now for something completely different...

I'm taking the contract to restore that S-38. I visited Bowman Field today and took some pictures. It probably is pot metal or it could even be lead. It was made in the 30s. It sits atop this large hemisphere extolling the virtues of an aviator that was lost in a plane crash in 1937. The hot glue repairs are gross, and even though they painted it over with gold, it still looks like… There's an old aphorism about painting s… and this proves it. It's about 7 feet in the air.

S-38 Gast Display

Here's some closeups...

S-38 Strut damageS-38 Nacelle Damage 2S-38 Nacelle damage

This is the one existing prop. I now have a machine that can produce another if I can make a decent drawing of it. There may even be an STL file out there of a classic two-blade prop.

S-38 Prop DesignS-38 Strut mess

Don't know what this was.

S-38 Wha


This is a commission job that will cost plus materials, but I have absolutely no idea about what the costs should be. I don't have a clue about their budget or what they were considering worth fixing this historical thing. I will be meeting with the historical society next Wednesday and we'll iron out the details. It definitely is built of castings and my guess is their either pot metal or even possibly lead and soldering might be difficult. Of course I will try it, but my fall back is drilling, brass pins and epoxy (J-B Weld). Wish me luck. I know it's not model trains, but you have to admit, it's interesting.



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It may be pewter.  Pewter is mainly tin with other non-lead metals and is malleable.  Pewter is used in decorative objects, mainly collectible statuettes, models, and jewelry.


Last edited by Jan

The conduits look great as does the wiring.  I do like all those windows!!  It is shaping up nicely!

That is a neat looking airplane!  Another nice project refurbishing it, just like when they came back from a wartime mission!!

The basic building is approaching completion and looks great. Now for the detailing. For me, that is the real interesting part. Good luck on the restoration.

I agree. The devil is definitely in the details.

Today was productive. Windows are all in and I crafted the personnel doors. I continued manufacturing HVAC parts assembling the 3rd unit and having all the but the legs for the 4th and final one. The legs are being grown by elves in the basement right now. 

EH Windows in Lft SideEH Windows in Rt Side

Entry doors are 0.040" thick styrene with 0.100" Evergreen angle framing. When I'm cutting miters I get a least 3 of them wrong until I final get the 4th one right.

EH Back Door

I have to figure out what kind of door handles I need and then decide how to make them (3D printed perhaps?).

EH Front door

I masked, adding a tad more filler and re-sprayed just a bit of that wrongly placed hole.

EH Touch Up masking

A neat thing about the printer is once you have a drawing that is working, it keeps working exactly the same each time. Unlike a silicone mold with resin casting, the software driving the machine doesn't vary, nor does the chemistry in the vat that's producing the parts. Repeatability is very good. You get a good idea of the massive amount of resin supports that have to be cut away to release the parts. I've been using the medium weight setting and am getting no parts breaking away. At least I figured that out. I'm now a member of the Elegoo affinity group on Facebook and was given a tip by another user that with the Elegoo's 40 watt LED array, I may be able to successfully print using 6 second layer exposures instead of 8 that I'm now using. That's a 25% increase in printing speed. It's worth checking out. I haven't been experimenting with either layer thickness or exposure times since I want to get these parts built to finish the project, but I will be doing it in the future.

EH HVAC almost done

When the day ended I was just about to add the lighting to the machine shop roof. I also have some touch up painting in the machine shop. I didn't paint the corner reinforcements white to match the walls. The end is in sight...

Here is a status shot showing this imposing structure sitting exactly where is should.

EH Status

Happy weekend!


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That is looking sharp on the layout!  Your layout is big enough to support a building of that size. 

Myles, Between the laser cut building parts and your new 3D printer you seem to be  turning out models in record time. The engine house will be definitely be the center piece of your maintenance facility.  Great model. Like that air conditioning unit, the details complete the picture.

I have been looking at 3D printers, is your printer a ELGOO model US-EL-3D -016?         Also have you noticed any odor associated when printing? So other printers caution users about need to operate in well ventilated area to avoid odors.


Great work.

Maybe a nail grinded down or a piece of brass with a blob of solder could also be ground down to look like a door knob?

Just a quick thought.

It's Sunday, but the machine is still working, so I have something to write about.

First of all, here's the exact machine… Here's a direct link:

Screen Shot 2019-07-28 at 10.51.08 AM

The resin has an odor. I don't find it objectionable. I wear a lab coat, nitirle gloves and avoid splashing as much as I can. With the plexiglass cover on the machine, it really produces no odor at all. All the smells come from the alcohol baths needed to clean off the uncured resin. I started using 190 proof grain (ethanol) alcohol, but at $30 a pop, decided to go to 99% isopropyl alcohol. It requires 95% or better. I chose to buy two pints of 99 and mix with 91% available for cheap at CVS giving me the correct concentration. The smell is not coming through the HVAC like it does when I'm spraying rattle can enamels and have had no complaints from the boss.

BTW: I buy nitrile gloves at Costco for half the price of the building supply stores. You get two packs of 200 gloves for less than $20. You go through a lot of gloves with this process.

Re: door knobs. Good suggestions! For a number of my buildings, I've actually turned brass doorknobs on the lathe. What I'm really asking is what kind of knob is used on an industrial door? I may see if I can print them.

Speaking of printing… I found a design for a Pennsy style concrete end-of-track bumper and drew one up in about 1/2 hour. One printed yesterday afternoon, and the second overnight. The third is now on the machine, so by day's end I'll have the three parts. 

I first measured the space on the engine house floor and the proper coupler height for the bumper. This set my overall parameter.

Here are views of the drawing. Notice that I drew the nut, bolt and washer right in the drawing and they reproduced perfectly. I first did it as a full solid and experimented to let the Slicer hollow out the insides. It hollowed okay, but I was having trouble putting in the drain holes to let the uncured resin out. Didn't nee a bumper with a liquid filled center.

I made a series of progressively smaller rectangles which I pushed up inside. What took the longest was insuring that the rectangles didn't pierce the outside envelop. For the bolts, I first counterbored the surface by drawing a simple cylinder positioning it through the sloped surface and then "Intersect Faces" with the model. After removing the unwanted parts of the cylinder, you're left with the properly shaped hole. All that's left to do it reverse the faces of the bore's sidewalls, since they are the remnants of the inside of the cylinder. The software needs only outside facing surfaces thus the reversing procedure. I then made the NBW set outside of the model, made them into a component and copy, paste and positioned them where I wanted. The curved edges are created with an extension called Fredo6 Round Corners. It created some extra faces that needed to be removed and some surface corrections to create a singular solid. That took some time too.

Pennsy Track Bumper Frt

Pennsy Track Bumper rear

Pennsy Track Bumper Bottom

When I first loaded the drawing in the slicer and watched the animation of how it would layer, I noticed that the very back edge was forming before any support was there. That edge would disappear and cease to exist. I tried adding additional supports which may have work, but instead, I repositioned the angle it was sitting at so that edge would form after the surface below was forming. I also checked the NBWs for the same problem and they were okay. This was the biggest learning in doing this process: pay strict attention to the animation, especially from the bottom up view which is how it grows during production. The software's animation starts top-down, which is harder to follow.

EH Pennsy Bumper

The translucent plastic makes it very hard to visualize what's on the surface vs. what's below the surface. In the above you can see through and see the hollowing of the model.

In the below, you can see the NBWs, but you really can't see how clean they modeled. When painted it will stand out nicely.

EH Pennsy Bumper NBWs

Now there are two and in 4 hours, three. I won't do any cleanup and painting until my official basement work day on Monday. I gave these parts a 15 minute hardening time in the UV chamber. The longer you harden, the darker the resin becomes.

EH Pensy Bumper Now there are two

I may use contact cement dots or hot glue to fasten these bumpers down to the engine house floor. I don't want a brittle connection. I'm also thinking of putting either a rubber face or a silicone drawer bumper on the bumping face to reduce shocks to the equipment.

Not a bad deal… 1/2 hour of drawing and finished parts.


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Thanks Mark! The last one printed as good as the other two.

Then I decided to try pushing the envelope. I'm aggressively working to finish detailing out the diesel. Little by little I'm adding details to the front and started working on the massive blower end just for a change of view. I'm trying to decide just how to print it. I wanted to try to see just how small I could practically print. 

I separated out the throttle mechanism including the Woodward Governor to print as a subassembly that I'd glue on separately.

Screen Shot 2019-07-28 at 7.49.14 PM

I copied this mechanism to a separate file so I could work on it more easily. I added some diagonal bracing that I would remove after printing. 

Screen Shot 2019-07-28 at 7.51.27 PM

I almost doubled the thickness of the linking rods. Even with that, although the print was effectively perfect, those little extensions that connect to the heads (and ultimately the fuel rack) broke off when I attempted to snip off the supports. They're just too fragile.  Not having anything in the image for scale, I measured the rods and their .021". That's okay if you're using brass or piano wire, but not resin. I imagine they might work if I added about 50% to the rods and cranks. The governor printed nicely and could work as is. Even contemplating using real wire, the cranks are so minuscule that you couldn't drill them to accept the metal. If all metal, I could solder it.

567 Failed Throttle Linkage

There are two choices. I could enlarge the very fragile parts so they'd function, or make the fragile parts as a relief on a flat background that would hold it all together. With 3D printing the rods could be free of the surface and the cranks attached perfecting the illusion. 

This was printed at 30 microns per layer and 7 second exposure. The detail was awesome and the print did work perfectly. It's all in the design now.


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Happy Monday!

I had my first print failure in a long run of success. I was printing the engine house vent stacks 2-up since they would both fit. The lip on the first part of the cone on both pieces failed to print. 

Smoke Jack other Failed Print

The reason: When I had printed that little throttle linkage, I had changed the settings from "Heavy Support" to "Light" and this was the result. the long skinny support that was suppose to contain that lower lip, didn't form properly and the print failed. I have redesigned the supports and will be ready to print again when my next experiment finishes.

I assembled the last HVAC unit and painted the bumpers. I made a mistake. I wrote down the track width, but neglected to record the width I wanted the bumpers to be. As a result, I made them track width. It looks fine, but reduces the surface area for fastening it to the building. Ingenuity will rule the day. I'm going drive a couple of long screws into the inter-track space that will retain the bumper from moving backwards. Then I'll use the contact adhesive patches to hold the back portion. It will be okay.

EH Bumper Test

EH Bumper Position

After painting, those NBWs really popped as predicted.

EH Printed Bolt Details

I'm waiting for the Tamiya Bare Metal spray to return to the hobby shop so I can paint the other three units.

EH Lots of Printing

I'm trying to print the entire 567 gear end as one part. I added some extra supports to the throttle rods which I may or may not remove after printing if I can do it without breaking them. They'll be okay if they're supported properly.

567 Gear End showing supports

There's some more pieces to add. There's the fuel pump, oil pump and oil scavenging pump that go on the three remaining blank spots. It's should be printed later tonight and then I'll know if this idea works. Notice also the extra support under the power-take-off shaft that would go to the air compressors and traction blower drives. I'll cut that away after printing. I watched the print forming and saw that lower flange edge hanging out there. This is the part of 3D printing that they don't tell you about, but when mastered, leads to successful prints.


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Monday addendum.

It's 11.29 p.m. and I just pulled the 567 gear front test off the machine and gave it a coat of primer to bring out the details. I'm quite pleased. I lost the starter lever almost immediately. Both it and the throttle links need to be beefed up. But the rest was terrific. Notice that the bolt holes in the output shaft actually formed as holes. And those things are tiny. By additional supports worked. The cranks on the throttles formed as I drew them. The water pumps and piping are terrific including their flanges and bolts. I'm confident that I can finish drawing all this stuff and it will print. To the right of the right water pump is the starter push buttons and they're visible too. I can crank up the resolution too, which will reduce those layer lines. But this picture is almost 4X its real size, and they're not that visible in normal size.

567 Gear End Test


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Most people would be happy with a generic engine sitting in the corner of their shop. You are going to have a scale model. Fantastic work, Myles.

Morning update. After the mods I made to the smoke jack scaffolding, the prints overnight were a success. I've now got the machine working on the next set of two. By tomorrow, the six will be produced. The bottom bells will print as threes, and I want to draw up a mounting ring to positively fastened them to the roof and I think I'll get six of them in one go. Today's my birthday, but instead of model work, I'll be cleaning the house because old friends are arriving from Pennsy on Thursday. Tomorrow I'm tied up with a meeting about the plane restoration so it had to be done today. Bummer. But on the bright side, the Machine doesn't care and it will be making parts for me throughout. After hardening you can see how the resin darkens.  You can't make it out in this image, but I also had three pad eyes grown on the tubes for guy wires. It was easier than drilling and gluing in wire eyes. Why fabricate it when you can grow it. This whole process is eerily organic.

EH Smoke Jack Success

I may report from time to time over this weekend, but with guests probably not.


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Pat, other than the extensive drawing and testing time, building the model will consist of maybe 10 parts: block, 2 heads, front gear case, back plate, 2 blowers (although both blowers could be part of back eliminating these two parts), 2 exhaust headers and mufflers (also could be a single part), and 1 open valve cover. In other words, it would be no more difficult to make a dead-on scale model than it would be to cobble together a generic engine. Once the drawings are tested, the machine does the rest. If I were to sell them, the price would be to cover development time, the resin and something to amortize the Machine. How much would be willing to pay for such a thing as a kit,  or a fully assembled unpainted, or painted model? 

Trainman2001 posted:

Pat, other than the extensive drawing and testing time, building the model will consist of maybe 10 parts: block, 2 heads, front gear case, back plate, 2 blowers (although both blowers could be part of back eliminating these two parts), 2 exhaust headers and mufflers (also could be a single part), and 1 open valve cover. In other words, it would be no more difficult to make a dead-on scale model than it would be to cobble together a generic engine. Once the drawings are tested, the machine does the rest. If I were to sell them, the price would be to cover development time, the resin and something to amortize the Machine. How much would be willing to pay for such a thing as a kit,  or a fully assembled unpainted, or painted model? 

Glad all my diesels are ALCOs or my wallet would be about to take a hit.

Trainman2001 posted:

 it would be no more difficult to make a dead-on scale model than it would be to cobble together a generic engine. 

That's what I think is so fantastic about this process. 

Happy Birthday, Myles. Enjoy your day.

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