Large Scale Central

3D printed doors and windows

Modeling
#21

Rodney, and other folk who are 3D printing,

We have a project to build a model of the EBT’s M-1 Railcar. Unfortunately it is covered with rivets (2,000+) so the project is stalled until either someone volunteers a few years of their time, or until we find a better way.

Some months ago I enquired about using a 3D printer to print rivets on my styrene sides, and was told that you can’t print on another material - it has to be on te medium itself. [Q: can you double print? Print a flat piece and then print rivets on top of it?]

So that brings me to today’s (next) question, brought on by the comments about 12" printers. How big a piece can you print?

To give you some idea, here’s the beast:

(http://www.largescalecentral.com/public/album_photo/b9/b4/01/1b206_7dbf.jpg)

And here’s a close-up of the rivets around the baggage door:

(http://www.largescalecentral.com/public/album_photo/b7/b4/01/1b204_a97e.jpg)

Finally, the largest piece is probably between the doors, as this plan shows. The side piece with windows is just over 12" long.

(http://www.largescalecentral.com/public/album_photo/bb/b4/01/1b208_afe5.jpg)

I have a complete AutoCAD drawing, including all the rivets, but it is only 2D at present.

#22

Pete,

You are thinking in an ‘add the rivets’ mode. Where you need to be is in the ‘model the whole side including the rivets’ mode. The difficulty there is the length of the car side. Anyone with a printer large enough is most likely to be a bit pricey. Two companies that I have looked at their web sites are Shapeways and Materialise. Give them a look, and maybe get a quote.

Bob C.

PS - I could be persuaded to work with you on the 3d models required to generate the parts.

#23

If you have an AutoCAD drawing of the car then it should be pretty easy to convert it to a 3D drawing. It is time consuming and I would be willing to help, but don’t expect a quick turnaround, 2,000+ rivets take time to do.

#24

Jake - That was the ‘persuaded’ part. :slight_smile:

#25

Jake Smith said:

If you have an AutoCAD drawing of the car then it should be pretty easy to convert it to a 3D drawing. It is time consuming and I would be willing to help, but don’t expect a quick turnaround, 2,000+ rivets take time to do.

Jake, and all 3D experts,

I’m curious how it works. My drawing was done in Visio, and I was able to copy the rivets and the rivet patterns, so they are all on the drawing. Isn’t it possible to copy in a 3D model?

There are only 2 rivet sizes (fortunately.) 1.25" and 0.75" prototype.

The M-1 Railcar has a lot of rivets on strips in consistent patterns, so I imagine it would be possible to print the strip multiple times and just cut it or glue it in place.

The problem is those long sides with rivets along the bottom and the middle, where the car was fabricated. Maybe it could be made in multiple 8" long side parts?

Just to add to your info, here’s a styrene cut we tried using my drawing. It has all the rivet holes, but they are too big and don’t take rivets easily.

(http://freightsheds.largescalecentral.com/users/petert/_forumfiles/P1010017C-prototype%20build-8.jpg)

#26

Pete, with a 3D drawing of your project you could actually print the entire drawing on a 3D printer. The 3D printer would just have to be big enough. I have seen where a 3D printer created a large sphere with a smaller sphere inside of the larger one and the smaller one actually rolled around.

There is special software out there that takes the 3D drawing and slices it into thin layers. The G code to operate the machine is created by these layers and the printer head prints the layer as the machine runs.

There is a group in Canada that I’ve been watching and in contact with that has created a 3D printer head that can be attached and operated on a CNC Router. So your parts are only limited by the size of your cutting area. I’m building a 48" x 48" CNC Router and should be ready to run in the next few months. Their 3D printer head is one of my last purchases.

This is starting to look like fun!!!

Chuck

#27

Pete
I’m in the process of building a 12"X36"X12"high printer now. The problem with printing the whole car side would be the finish of the sides. I don’t know who told you that a printer couldn’t print on plastic. I’ll try to print you up a sample of rivets on .020 styrene. Then all you would need to do is apply the styrene to your shell. I should be back home by Monday and do it for you to see

#28

Archer just came out with a lot of new rivet decal sets. Might check out their site. Just got an email about it. You print off their catalog and compare it with what you want.

http://www.archertransfers.com/

#29

Jerry,

I’ve been in contact with Archer on the decals. (Although the idea of placing 2,000+ in the right place is a bit daunting.)

They are willing to make up a custom sheet to my specs - so I could get the rivets arranged in patterns and just place them on the styrene. Sounds great - unfortunately it doesn’t look too great, as Archer can’t make very tall rivets. Most of these are Archer, and they just don’t “pop”.

(http://freightsheds.largescalecentral.com/users/petert/_forumfiles/caboose%20and%20m-1%20rivets%20107crop%20enh.jpg)

(The rivets at the top are a test of the Grandt Line O scale rivets.)

Rodney,

The idea of printing on an existing medium seems foreign to most of the people I talk to.

#30

Yeah I don’t think they tech is there to print onto an existing media, but I’m not as knowledgeable as some.

As far as converting a 2D drawing into 3D it is simply adding a z axis (or depth) to the drawing and going back to every single rivet and adding depth.

#31

Jake,

I would agree partially with your evaluation. I would prefer to recreate the entire side because I would be better able to locate the key rivets and pattern them down the row, considerably reducing the time required to ‘place’ all those rivets in the model. The printer will not care either way how they are place. The only other caveat I have heard about would be that some of the plastics used in SLA MAY arch some when removed from the substrate. A thin section car side many not do that.

@Pete - Most of the 3D softwares will import an AutoCAD file, either directly or as a DXF, as a basis for a sketch, so your work will be used as a basis with the third dimension being added in the 3D software.

I would be interested in seeing the results of printing on .020 styrene. If that works, it would open up all sorts of opportunities for detailing.

Bob C.

#32

Pete Thornton said:

Rodney,

The idea of printing on an existing medium seems foreign to most of the people I talk to.

I would have to guess that a lot of them are still printing on Kapton or painters tape and don’t use heatbeds. My printers print on glass and have heated beds. I also have my nozzle almost touching the glass when it prints the first layer to press the plastic to glass so it will stick well. When the print is done I take the glass off with the print and put another piece of glass on the bed and start printing again. When the print cools off, it pops right off the glass.

#33

Pete,

OK, I just got home and this is the first try. I didn’t have any .030, but have several 4’X8’ sheets of .040 thick so I used it and it worked well for printing.

(http://imageshack.us/a/img59/1568/01wx.jpg)

There is a lot of stringing and I’ll need to play with the extruder heat and will play a little more later.

Here it is with paint. can still see the stringing.

(http://imageshack.us/a/img853/7165/h2gu.jpg)

With some work, I think I can get what you need Pete.

#34

coming back to 3d printing.
the needed files from free sources can one scale them up or down?

#35

Korm Kormsen said:

coming back to 3d printing.
the needed files from free sources can one scale them up or down?

Yes, the 2 slicing software that I use most will let you scale the original.

When I got my first printer going, I printed a lot of stuff I found on “thingiverse”

Most of the printable things on there, have the STL files so you can download them and load into the slicing software.

#36

Hey Rodney what slicing software are you using? I haven’t picked one up yet.

Chuck

#37

thanks for the explanation

#38

Hey Chuck

I use slic3r and KISS pro.

slic3r is part of the print-run (pounterface) and is opensource.

KISS is free and the pro cost about $25.

Most of the time I use slic3r and if it doesn’t print very well I reslice it with KISS.

I sent you a PM

Rodney