Friday, December 26, 2014

Erroneous Values!

So, after pulling my hair out trying to find this separate piece, I gave up and decided to reduce the thickness of the "finished floor" by 1mm just to see how much money this would knock off the total price. It turns out 1mm translates out to about an $18 savings. More importantly, though, the product no longer registered as having "thin walls" or multiple parts! The loose piece didn't exist (thank goodness) and, as designed, all of the walls were reading as having acceptable dimensions. The problem was just some mathematical artifact in the file's coding picked up from somewhere. The new, thinner, file didn't have such errors. Success!

But wait. Not so fast. I knocked off a few more millimeters here and there (things I decided weren't essential and probably wouldn't actually help much) just to see how much more I could get the price to drop, uploaded the new file to Shapeways, and suddenly two of my old friends reappeared. Now knowing what to look for, I was able to find them much more quickly. For some reason, part of one of the seats was not registering and this was causing the stanchion connected to that seat to be attached to nothing. (This is where the multiple parts issue came from.) The other problem, it turns out, is being caused by a shape emanating from one of the windbreaks. This shape is too thin for the printing constraints.

Here's the kicker: none of these issues are representative of the 3D model I've created. I can't just fix them on my end, because they're non-existent. This means that there's either an error in the exporting process from Google Sketchup's native file format (.skp) to Collada (.dae) which is one of the acceptable file types for Shapeways, or the problem is with Shapeways and they way their computers are reading such files.

Either way, I have no solution at present.

Wednesday, December 24, 2014

Virtually Completed

No pun intended.

Work on the interior of the 3200s has progressed and I have, at last, acquired all the necessary measurements to build the center section of the car to my satisfaction. Once again, to assure proper alignment in the car (and to make sure they don't fall over in the process) I've designed the seats to be affixed to a thin "finished floor" which will be mounted on top of the real car floor. The car is then divided into three sections: front, middle, and rear. My efforts have been focused on the middle section and it's almost ready to be sent off to the printer.

Shapeways digital preview of the middle section

This seating configuration is for an odd numbered car. The even numbered cars have a box next to the single seat by the windbreak.

The view down the aisle toward the front of the car.

There are holes or reductions through the floor and behind the door pockets. These serve not only to reduce the material needed (and thus the cost) but also to allow multiple points to hide wires to and from the roof.

The thickness of the floor here is not final. It will be reduced sometime in the (hopefully near) future once I determine what material I'll be using for the car floor and how thick that material is. I also have to figure out how wide the floor grooves are in the aisle of the car so that the proportions will look right. Some will say, "But you won't see the floor grooves in the model!" My response to that is simply that I don't care. (It will satisfy my brain to know that they're present.)

Lest things turn out to be too easy, there, of course, have to be some problems. In this case there are three. The first problem is that while all of the components individually check out for printing, the combined object somehow fails the wall thickness checks. (Don't ask me to figure out how that makes sense. As far as I am aware, my 3D models are not on any kind of exercise/diet regimen.) This is easily overcome by the "print it anyway" option.

The second problem is that whenever I upload or modify the file, it keeps registering as being a two part object by Shapeways. At first it registered as a four part object, then I discovered that two of the seats were actually hovering about 1/20 of a millimeter above the finished floor. I have looked and looked, but for the life of me, I cannot find the remaining "separate" piece and I'd really rather not print this thing off, only to have it come back with something integral rattling around in the box.

The third, and most predictable, problem is cost. As of right now I'm looking at about $108 to have this thing printed. (And this is only the middle section. For one car.) Yes, the price will drop once I reduce the thickness of the floor, but not by that much. This price pretty much killed what little hope I had for selling these to other people interested in making their 3200s look better.

A cage will eventually be added to protect the poles from snapping off in shipping.

Friday, December 12, 2014

Initial System of Subways entrance

This is one of those other projects I mentioned. This is a full scale model of an original entrance to an Initial System of Subways (State and Milwaukee-Dearborn subways) station, excluding North/Clybourn. Obviously, this model has not yet been finished.

I got the idea after seeing a number of subway entrances available in multiple scales for the New York City Subway, but being immediately aware of any subway entrances for Chicago. The other motivation is CTA's "Your New Blue" program which promises, as part of station renovations, to obliterate the last remaining original style entrances. Creating 3D models (and scale models) is my small bit for historical preservation.

Sunday, December 7, 2014

Time to Focus

In the past two months I've continued working in Sketchup on a number of the projects outlined previously. None of them are, as of yet, finished. I was trying to take care of a few other things at the same time, but that cannot completely account for the lack of progress. After some consideration I've come to the conclusion that I've been trying to work on too many things at once. A distinct lack of focus has been a chronic problem of mine and this jumping from project to project has not helped the situation at all.

In order to get back on track, I'm going to work on one project at a time. The first order of business is getting back to the interior of the 3200-series cars. The last time I discussed this, I had recently gotten the prototype seat back from Shapeways and was relatively pleased with the result. That didn't last. As I discussed in that post, I left the possibility open that I might try my hand at making the scoop in the seats. Lo and belold! I did just that. (This is the hazard of never being satisfied with your own work.)

They aren't "perfect," but I am satisfied with how they look. (For now.) I haven't printed this design yet, although it did pass Shapeways' file initial and wall thickness checks when uploaded. That's good enough for me and I've gone ahead and begun designing the different types of seats found in the 3200-series. These are (from memory) as follows:

  • Single seat with handhold (pole on left)
  • Single seat with handhold (pole on right)
  • Single seat without handhold
  • Double seat with handhold
  • Double seat with handhold and ventilation box
  • Double seat without handhold
  • Wheelchair position double seat (flips up)
  • Longitudinal double seat with windbreak on left
  • Longitudinal double seat with windbreak on right

Shapeways digital preview of some of the pieces to be made. The scoops are more evident in this rendering than they would be in a screenshot from Google Sketchup.

The problem with simply printing the chairs is that a fair number of them are not self-supporting. They are (naturally) small and somewhat fragile. Trying to accurately mount something of this type to the floor of a model sounds like a chore and a half. I've thought about this for some time and eventually came up with something I'm willing to try.

The obvious answer is to print them as part of the car floor and be done with it. Unfortunately, this would be expensive to do (still earning vet tech wages) and the product is too large to be produced by the Frosted Ultra Detail printers. (The details are too fine to be printed in anything else.) My solution is a sort of compromise on this idea. I plan on dividing the car into three sections (front, middle rear) and designing the interiors in these sets. Each set will have all of its "furniture" (chairs, windbreaks, door pockets, etc.) created together and mounted onto a thin "surface floor." The three sections would then be placed end to end and mounted onto the real car floor (made of an inexpensive, but durable, material) and slid into the car body as one piece. Doing it this way solves the problem of mounting the chairs properly (without damaging them!), positioning them correctly, and also will allow me to make the grooves in the floor fairly easily. The grooves can also help to hide the separation lines between the three segments. We'll have to see how well this works and how expensive it turns out to be...

There has been a definite success with the printing. I sent off the updated version of the snowplow frames and received the finished product days later. These are a resounding success. I just have to fit them with the blades (to be made from index cards) and paint them.

These are remarkably crappy photos, but they do illustrate the point. This is a pair of snowplow frames, held back to back by sprues. They have a good amount of detail (which probably won't even be seen) and are decently strong. They're also reasonably flexible so they shouldn't break too easily.

I also have some new acquisitions to report: CA&E car 500 and a section of the Lake Street "L" structure. Both of these come to the Dunsel Line via the Chicago, Wheaton & Western (my father). He's beginning to focus on some other things and has come to the conclusion that he won't be doing anything with either of these, so he gave them to me.

The 500 (which could also be built into a North Shore Line 350-series streetcar—yeah right) is from a kit produced by Greg King. Currently it is completely unassembled, although it did come with a Q car power and trailer truck set. The downside is that the power truck is only set up for overhead operation. This will pose a slight problem as my (eventual) layout will be two rail, but for the time being it doesn't matter. (I'll probably also change out the power truck later.)

The Lake Street "L" structure is from a portion of the line with provision for only two tracks and the majority of support columns in the street and not anchored at the curb. The structure is somewhat old and slightly brittle. When removing it from my father's basement, I accidentally slightly tapped one of the columns against a wall and it broke off. (Apparently this has happened before.) I believe it is still structurally sound, so I'll fix it and post photos of it at a later date.