3d printing process

[thibaultron]

For those of you (like me) who use the free 2017 version of SketchUp (the last one that let you do all the work on your computer, not online through them), they have disabled the Extension Warehouse feature, due to "Security Concerns".  This even though 90% of the offered extensions still worked with that version.

 

I'll have to back up my operating system onto another drive in case mine dies, My files are far to large to do them over the net, even if I wanted to allow SketchUp, or someone hacking them, access to them.

 

 

[thibaultron]

Well after a couple years I finally finished mostly) the 3D body for my Santa Fe Superintendent’s Car! The drafting would not have taken so long, but I kept finding better references, to correct detail mistakes in the original drawing I used. The drawing was well done, but was hand drafted by a modeler over 50 years ago, and the hundreds of rivets laid out on it were not always correctly placed. Also many details were not clear, without the photographs I found from various internet sources. Next will be the underframe, roof, and interior. For now I have a donor car for the underframe and roof to make a mockup.

 

Here are a few views of the CAD file.

 

First a perspective view from the front of the car. Note that the front wall/vestibule is and angled surface, making placing the rivets interesting. The window glass is filled in here as support during printing. I am rethinking the way that the final window glass/ frames will be designed. They may be a separate assembly that pushes in from the rear.

 

 

Next is a similar view from the back of the car. If you look closely, you will notice that it has a main door and a screen door. The main door is a separate piece, and will not be printed in place, as shown here. This lets me install both the main door windows and the screening on the screen door. This wall is set into groves in the side walls to locate it.

 

 

Next is a view of the observation end of the car. There will be an observation platform/porch floor, designed into the underframe. The roof line shown will likely change after the prototype roof is drafted. The roof line shown on the wall marches the interior lines of the donor car.

 

 

This is the front/vestibule wall. This wall fits into matching ledges in the side walls. You can see the inside observation main door at the other end of the car. The inside of the observation wall also has the interior trim.

 

 

This is a top view of the body. You can see the angling of the outside of the vestibule wall, as well as the locating ledges between the four walls.

 

 

I also redesigned the tender oil bunker I drew several years ago. Most of it was correct, but when I placed the rivets I spaced them too closely. I used 1 1/2 inch spacing as I had to guess, having found no info on this. I found out late last year it should have been 3” spacing. I bought reprints of 10 years of the old “Santa Fe Modeler” magazines, and found the new (too me) information in them.

 

 

I’ve gotten a 3D print of this latest version from Shapeways and will be fitting it to my 2-8-0 tender in the next week, or so. I was planning on 3D printing it at home, but I still haven’t got the supports right, it keeps distorting during printing. Once I verify the fit, I’ll offer it through Shapeways, as it will be more readily available to the public.

 

The next Oil Bunker project is to convert a Bachmann 2-10-0’s tender to oil. This is much more of a SWAG, as there are only a handful of under exposed photos of these. Santa Fe acquired the locomotives from a smaller railroad it purchased, and did not use them for very long. They were too small for most of their operations, and in poor repair. Hence the lack of pictures.

 

The old 2-10-0 bunker is on the left, and the new 2-8-0 version on the right. You can see the difference between the old and new rivet spacing.

 

[CDR_Ret]

Looks like you are using Sketchup. Nicely done!

 

Terry

[thibaultron]

Yes. SketchUp 2017. For future projects, I may have to switch to another software package, as I recently found out that I can no longer install addons (extensions) due to security concerns and lack of available ones that work with my version! Even though in December, most of them were compatible and were offered by 3rd party vendors!

 

[thibaultron]

I spent the last few days drafting the frame for the Superintendent’s Car. The frame is finished as far as the major assemblies. I’ll add the various levers, equipment boxes, tanks, etc. as separate pieces, and as I get more information on items like the brake system. The pictures of the frame show two strap assemblies. These also are separate parts, and will be printed as such. I had to draw them in place, though, to get the proper angles, so I’m showing them as if installed. I still have to place the blocks for mounting the couplers, but will do that after I’ve printed and assembled a car. I have a set of the correct type trucks for another car, so I can make the proper measurements using them.

 

I initially drew the frame members overlong, and the floor overlong and too wide. Then I placed the frame in place under the sides and ends, and marked the areas that needed to be cut. This saved a lot of detailed measuring, and gives me a perfect fit.

 

This is the frame from the side, with the straps.

 

And two others showing some close-up details. Lots of rivets.

 

 

 

This picture shows the frame in place, with a close-up of the observation platform. The various bosses at the end of the platform are mounts for the railings. This platform area sits a few inches lower than the interior floor.

 

The last picture shows the assembly from the underside.

 

 

I volunteered to draft some of the cannons for the NRG Cannon project, and will turn my efforts to them for a while, then start on the complex roof for this car, and any other Pullman Heavyweight passenger cars I may tackle in the future.

[Srenner]

Hi... I've taken the plunge today and pressed the purchase button on below. In terms of software will be Inkscape and blender before taking it to a slicer... hoping my software skills will improve alot as I plan to 3d print all the decorations for the 1720 royal navy ship, ships windows etc, figure heads that sort of thing. Exciting but also quite daunting 

[JGR]

22 hours ago, Srenner said:

Hi... I've taken the plunge today and pressed the purchase button on below. In terms of software will be Inkscape and blender before taking it to a slicer... hoping my software skills will improve alot as I plan to 3d print all the decorations for the 1720 royal navy ship, ships windows etc, figure heads that sort of thing. Exciting but also quite daunting 

Great choice in both hardware and software. I'm sure you will be happy with it.

[thibaultron]

I've been CADing several early 17th century British cannons for a project, and I just finished printing out the first test set of the 6 and 9 pounders (long and short barrel) in 1/24th scale. It took almost 24 hours at 35um layer heights, but the files checked out! Presently the 18 and 24 pounders are printing. I will have to reprint the first set, as I did not have the supports all correctly set up, but the cannons printed OK, so the original STL files are good. I just need to add a few more supports for the final printed set. These prints are for my use, to go on display along with my 1/24th Model Expo Naval Cannon displays. The barrels and cypher emblem came out well, but the trunions are warped. I also have to figure a way to better clean the bore and touch hole out as some resin was still in them, and caused blemishes when I cured them. That is the great thing about resin printers, I can just make another set.

 

The lighting is poor on the picture, as I had to go with ambient lighting. The flash washed out all the detailing, at such a close distance. The longest cannon is a little less than 5" long, in this scale.

 

[thibaultron]

I finished a print of my Santa Fe Oil Bunker Insert, for a Bachmann 2-8-0 steam locomotive. The Santa Fe bought another railroad, and inherited several locomotives. The Bachmann model is close to some of the 2-8-0 locomotives they acquired. The biggest differences, are that the sand dome was different, and they were converted from being coal fired to oil fired. The Santa Fe had oil bunkers that would sit into the coal bunker, for this type of conversion, and a drawing of one is the basis for the model. I originally drew the oil bunker and printed it out using Shapeways. It took a few revisions but I had a good model. Then I found new information showing that my guess as to rivet spacing was wrong. I had spaced the rivets along the tank seems about half the correct spacing (i.e. 1.5” instead of the correct 3”). So, I redrew it with these rivets at the correct spacing.

 

By now I had purchased a 3D printer of my own, and tried out the new drawing in it. It came out only fair, but proved that the printer could do the job. The main fault was that the rear wall of the bunker was distorting as the weight of the cantilevered model and forces from pulling the model from the film after each layer was printed had started to pull the model out of shape. Some of the other lower parts also suffered from this.

 

I redrew the model with support platforms that were attached via thin walls to these areas, and reprinted the bunker.

 

This print just finished, and is a vast improvement! There is still a little bowing at the very top of the rear wall, not along the whole wall. And there is a slight distortion at the cutouts that give clearance over the model’s coal bunker rear lip. There was some damage to the rear wall when I removed the platforms, so I will have to thin the attachment walls to help with the problem. I also need to make those attachment walls a little taller, to give me more room to use the razor saw to cut them off. This version, of the model is useable though.

 

Since I have the printer, I’ll make final corrections and print out a new model, to actually put on the loco tender.

 

Here are a couple of graphics showing the present model.

 

 

 

The smaller pieces are at a 45-degree angle as the model will be printed at this angle to increase the resolution of the fine details. The model was printed at a 35um layer height, to match the 35um pixel size of my printer screen. If I printed it flat, my printer leaves some visible lines between some layers, and doing it at 45 eliminates this problem. In addition, printing it flat may rip the model off the build plate when it starts printing the top of the tank. It would also probably bow the top from the forces of detaching that large area from the film, after each layer is created.

 

This picture shows the attachment walls of the platforms.

 

 

 

The long overhang of the platforms is so any distortion in them will be stabilized when the printing of the bunker itself is started.

 

Here are a couple of graphics of the supported model.

 

In the first one you can see the small parts attached to the main body by small sprues. This works for the Shapeways prints (in fact it is required as otherwise each part would be a separate print, with each one incurring its own setup fee!). With the finished print these broke off while I was removing the supports. In the next print I’ll just let them sit level and not attached to the bunker itself.

 

 

This shows a side view of the supported model. The leftmost “Tower” has the two oil fill covers and the crew’s drinking water tank. The next part over, is the new sand dome. The next two are the tool boxes that sit on either side of the bunker at the front of the tender. At the far right, attached to the front of the bunker, is a sandbox used by the fireman to occasionally throw a little sand in the firebox to help clean out the boiler tubes. The attachments under the sandbox are supports, not part of the finished model.

 

 

Here are two pictures of the finished print. Each rivet is only a 1.5” hemisphere, full scale. In 1/87.1 scale they are 0.017” or 0.44mm in diameter and 0.22mm in height. So, the new resin printers give you fine detail!

 

 

 

After I removed the supports the next two photos show the attached rear platform. You can see the slight bow in the top of the rear bunker wall in the second photo.

 

 

 

The last set of pictures are with the bunker and toolboxes installed on the tender. The only modification that is needed to the tender, is to remove the separate coal load casting, which is attached with a screw.

 

This picture shows the front of the tender. The color of the printed part, in this shot, is close to the actual color. The next photos are under shop lighting, not flash, like this one. The shop lighting shows the rivets a bit better. I have to check, I think I have the tool boxes on the correct sides, but they may be reversed. The hole just to the left of the sand box, is where the Crew Water Bottle goes. I did not install the water tank and oil fill covers for these shots, they need a little sanding, and I will do that later.

 

 

The next two pictures are of either side of the installed bunker. You can see a divot at the rear of the bunker, where one of part supports broke off. This problem will not affect the next version, as all the small parts will be printed, unattached to the bunker. After taking these pictures, I noticed that the cutouts for clearing the tender coal bunker rear wall are a little too tall. I’ll have to fix this. The little spots you see running along the center length of the bunker top, are stanchion bases for the handrails. I’ll make these out of brass rod, for the final model. I also plan to design and print a bending jig for the rails.

 

 

 

The last photo is the rear wall of the bunker. You can see the section that broke off, while I was removing the platform.

 

 

It has taken me a long long time to draw up this bunker model, and I could have probably hand built one in the time I spent on this, but I can now use the drawing as a basis for other types of locomotive models that need the same conversion. I have another Bachmann 2-10-0 that will need a variant of this tank, and at least one brass locomotive.

[Kevin-the-lubber]

Ron, that bowed edge is the same issue that I had when printing cabins for my Cutty sark. Similar objects I.e. straight edges. The issue occurs almost regardless of object size - it was even happening on 1} square hatch covers, which was quite frustrating. My solution was to tilt the object on two axes rather than just one, which works. (But for smaller things like hatches I actually just print them flat).

 

Regarding supports, I usually put a few thick ones on the underside, supplemented by loads of very thin ones. The latter are just to mitigate the convexity you get with widely spaced supports. The main difference I notice between our approaches is that I usually make my shortest supports at least 15mm long, but longer still if they are thick. It’s wasteful, but here’s why I do it: when it comes to removal time, I first snip the supports where they attach to the raft. I then snip them as close as possible to the object. This means all the stress of snipping happens down at the raft end, and the extra support length allows the support to bow a bit, which it wants to do, since I’m basically forcing the side cutter blades into the material. When I’m strict with myself about this process, there is rarely any damage to the object. I find it especially important when I’m printing ultra-thin and delicate parts which are sometimes thinner than the actual supports themselves. I also almost always get rid of the cross supports, as they make cleanup more difficult and I don’t find they add anything. They are probably more useful with large war gaming miniatures.

[thibaultron]

Next Step In The Oil Bunker Project

 

While I’m waiting for a print to finish, I continued working on the oil bunker.

 

I made the changes to the print file I mentioned earlier, and added some features. The bunker has 3 grab irons and a handle for the sandbox lid. In the prototype the grabs and the handle are formed from steel rod, with the ends hammer flat, so that they can be riveted on. The 3D prints are too fragile to print these, so they most be formed from wire. To make this easier, I drew up a forming jig for the grabs, the hand rails, and a U-Shaped bracket that supports the rear fill hatch, when it is open. Why the detailed jig? Well, I will be making more bunkers in the future for other locos, and having the info on the jig, will help there. Also, I do have hopes of selling kits, in the future, so the better designed, the better kit.

 

 

 

On the oil bunker, I added pilot holes for drilling the attachment holes, and flat pads to simulate the flattened ends of the grabs. I also made the holes for the handrail pilot holes a little larger, to aid drilling.

 

I generated a file of a completed bunker, with all the railings, grabs, the support bracket, the steps, and the tool boxes all mounted.

 

Here are pictures of a completed bunker, with all the bells and whistles.

 

 

 

I have another print to do, after the present one finishes, then I’ll print the, hopefully, final design model.

[Hank]

Glad to see that others are finding Anycubic as being a good printer for both detailed and large parts. I've been 3D printing now for 4 years beginning with a Phrozen Mini and now into the 2nd year with an Anycubic Mono X 6K printer. What could be bought on Shapeways I now make for myself and use the freeware software Design Spark Mechanical for my 3D CAD designs and Chitubox (free version) for my slicing software.

 

I will advise other modelers to make sure they do maintenance on their printers on a regular basis - this includes greasing and lubricating the sliders and vertical rails on their SLA printer with the proper grease, etc. Some AC models (mine included) have mini grease fittings on the underside of the sliders and finding a tip for a grease gun to fit is rather difficult. But, those fittings need to be greased or you will suddenly come to a screeching halt when the sliders freeze up. Proper grease needs also to be applied to the vertical (Lead Z) threaded shaft. The owner's manual and instructions generally don't mention these little tidbits - but are VERY important in the printing operation.

 

Here is one of my latest large scale (1/48) projects - a 6"/47 D.P. 2-Gun Turret which was designed for the WORCHESTER class CA's in late WWII -

I designed/printed all the parts for this display model using Phrozen Rapid Black Resin on my Anycubic printer. 

Edited August 5 by Hank

[Egilman]

On 8/5/2024 at 9:54 AM, Hank said:

I designed/printed all the parts for this display model using Phrozen Rapid Black Resin on my Anycubic printer. 

There is is brothers, the future of modeling is here...