Coach 64

Discussion in 'My Work In Progress' started by rkapuaala, Jan 17, 2016.

  1. rkapuaala
    rkapuaala Well-Known Member
    printing front end wall.jpg
    This is my most ambitious print job ever. It takes up almost my whole build platform and will take an estimated 20 hours to complete. It is the front end of my coach 64 with windows and door casment as well as bead board and trim.
    I've already had to abort this print job three times. Once the machine stopped printing and I discovered that the ribbon cable to the extruder head had popped off. The next time I discovered the extruder got impacted when the job shut down. The last time, I started the project only to discover that the bed needed leveling. Luckily the last two times I aborted I only lost a total of 3 hours. I started the project early this morning and it seems to be moving along much better than the previous three attempts.
    westinghouse brake cylinder.jpg
    While I wait for the front wall to print, I work on the air brakes. I have another pair of 1:20.32 scale brakes, but this is a 7/8ths scale project so I decided to build a 3D model of the brakes in 7/8ths scale. Not bad for some sketchy dimensions and blurry photos being the only resources I have at my disposal.
    I also printed out all the windows and window casements for the lower part of the coach along with 3 out of 8 siding panels. I'm getting closer to assembly.
  2. rkapuaala
    rkapuaala Well-Known Member
    front of coach 64.jpg
    Well, it took a total of 14 hours to print not including the windows which I already printed. Now, I have to print the rear end.
  3. rkapuaala
    rkapuaala Well-Known Member
    rear end wall.jpg
    After printing out the front end wall, I went back into the model and redesigned both the rear and front end walls. The improvements reduced the print times by four hours. I didn't realize till I owned my own printer just how hard it is to slice and print an model built by combining several shapes instead of a single mesh.
    westing house brake assembly.jpg
    As I waited for the print to finish, I worked on the brakes for the coach. Coach 64 has an interesting brake configuration.
    64s Brake Cylinder.jpg
    As you can see the triple valve is connected right to the brake cylinder instead of the resevoir which requires a mounting plate I could not find in any plans online. I did my best to copy the dimensions then,
    westing house brake meshmixer.jpg
    Then I converted the 6 parts I wanted to print to solid meshes in meshmixer and added the lettering. The lettering didn't slice well so, I doubt it will print, but it is worth a try. I will run it at 20 micron layers with 20 microns being the minimum detail and see if that get's close.
  4. rkapuaala
    rkapuaala Well-Known Member
    revision 1 assembled brake cylinder.jpg
    The lettering printed out just fine (both times). I had to rescale the first print after I discovered
    it was too small for 7/8ths. The image above is of the revised print.
    comparing first revision to original brake.jpg
    Here is an image of both sizes. I switched back to hatbox filament. The monoprice filament had issues with flowing. Of course, after switching reels, there were still tiny bits of the monoprice stuff at the beginning layers, luckily it disappeared by the time the lettering was printed.
  5. rkapuaala
    rkapuaala Well-Known Member
    progress on rafters.jpg
    So I printed out most of the major parts. At first I was just going to print out templates to fabricate the roof parts from wood, but I thought, 'why not make as much of this with my 3D printer?' It is a big coach in 7/8ths, and I feared that PLA would not be strong enough for the roof and the roof was too big to print out in one piece so I'd have to glue it. I came up with the idea to buy a 3D pen and join the parts with PLA and it worked. The roof was more than ridgid.
    Dry Fitting all parts.jpg
    I decided that it would be even beefier if I just made the signboard out of one 9 mm thick piece of cedar. I dry fitted all the parts together to make sure my dimensions hadn't drifted.
    working on the roof.jpg
    I did have to fabricate a few parts over again, but the siding and everything seems to work out fine, so I can busy myself with redesigning those parts and printing out more of the others before I finish assembly and paint this giant.
  6. rkapuaala
    rkapuaala Well-Known Member
    scroll work brackets.jpg
    I fastened my shapeways scrolled knee braces for the deck. I could never print these on my printer. These were printed in FUD and, like the ornate railing, they are perfect.
    progress on paint job.jpg
    I'm starting to paint the parts now and apply the decals.
    I'm etching the plates beneath the side windows (shown in the photo above) and the plate over the front window (just above the lady's hat). One I attach those and paint the inside, I will permanently attach the walls to the deck. Right now they are just held into place by the pressure of the fit.
  7. rkapuaala
    rkapuaala Well-Known Member
    checking fit for sides.jpg
    It took me forever to etch the 3 plates I needed before I coudl assemble. I did two builder plates for Kauila and the number plate for the front of the smoke box. Unfortunately I left the number plate in for too long and I'll have to machine and etch a new one :(
    laying out undercarriage.jpg
    I'll do that later though. I fitted the sides to platform and tested the fit on all the other parts so now, I'm laying out the undercarriage. I'need to fabricate a few more parts like the linkage and air tank and the bolster buffers (which I will print) as well as the mounting plates for the bolsters but I am just laying them out for now.
  8. rkapuaala
    rkapuaala Well-Known Member
    blue tape disaster.jpg
    I've been drying my prints in the sun for almost 7 months now and I've never had them distort or show any sign of getting softer till now. I have 32 pieces of sash to paint and move a little faster I decided to tape one side of the sash to a strip of 3M blue painter's tape; that way I could line them up and paint them without them moving. So I painted the first four pieces very quickly and laid them out in the sun to dry (still on the tape). Thirty minutes later, this is what they looked like!!!!
    That day was rife with mistakes. The nozzle on my printer was starting to clog so I bought some cleaning filament hoping to resolve the issue only to make it worse. I had to remove the nozzle and scour out the inside of it and change the tube. I got the PLA flowing again, but the bead was erratic and weak. So I had to buy some new nozzles from Amazon. Ten U.S. dollars got me five nozzles and now I'm printing again.
    progress shot jun 4 2018.jpg
    I managed to finish painting the sash and test fitting it and painting some parts that I printed up after the new nozzle.
    inside panel.jpg
    panel over door obs deck.jpg
    front deck ceiling.jpg
    I have decided to redo the front threshold plate after receiving some better images. I think I'll have it printed at Shapeways in FXD.