Shapeways FM switchers: Cleaning FUD

[Alwyn Cutmore]

Hi Folks,
If you look at the models done by mark4design http://www.mark4design.com/html/n__sd_hoods.html basically what you see is what you get. His items are made from acrylic and the striation marks on his shells are minimal. They can be used straight off the printer and as for pattern making the can be glued to-gether with MEK and then cast in a proper urethane. Eventually Shapeways will do so much damage to printed pattern no one except the desperate will go near them.
Regards

Al

[Dave Schneider]

Daniel,

I disagree that the current Shapeways model can't be used. Of course they can, especially for someone like myself who needs FM switchers. Most of the model is pretty good. The worst part by far is the rear cab of the H10-44. Thanks Matthew and others for explaining what is going on. I will take a cut at finishing these shell and show folks the results. It is a good challenge.

As for the shells by mark4design, is it possible for Matt's design to be printed by Mark if both parties are interested? I would be happy to pay more for a better shell. Matt has done a very nice job of laying out his designs, and his craftsmanship really deserves a first rate printing job.

Best wishes, Dave

[bbussey]

Has anyone ever actually encountered a FUD model that was printed from a 'stack' like shown?

For other materials it wouldn't make much (if any) quality difference but for FUD it would clearly be night and day. I've probably had +80 shells through my hands and I've never seen it (but there's a first time for everything I suppose)...

Yes.  I've repeatedly sent parts back I've designed for re-rendering where the orientation clearly was changed and resulted in a poor rendering.  Which is why I rarely use them for ProJet3000 parts (which is what "FUD" is).

[mmyers05]

Is the reason the parts warped becasue of the heat applied? If so, then we only need to find an alternative to Shapeways.

The more I think about this, the more I see a need where we can get a model oriented contractor to shoot the prototypes, and then have them resin cast.

We are so close to something totally usable, it may just take a few extra steps.

Not so much an alternative to Shapeways as an alternative to Projet (FUD). I haven't heard of another way to remove the wax (although the results might be better if the technicians were a bit more patient). That said I've received a handful of slightly 'melted' models; I requested reprints and then repaired the originals using 'old fashioned' modelling techniques (brass wire and styrene sheet). That's not always an option of course, but when it works out you end up with a free car/locomotive out of the deal...

Is there enough space between the shell and split frame to CA some brass shimstock to reinforce the long flat surfaces? Also, is it possible to add more weight to the Baldwin chassis?

Yes and yes. There is enough space in the shell to land a small plane (okay maybe not, but I'd guess that it's only about 2/3 "full")...

[mmyers05]

Yes.  I've repeatedly sent parts back I've designed for re-rendering where the orientation clearly was changed and resulted in a poor rendering.  Which is why I rarely use them for ProJet3000 parts (which is what "FUD" is).

I was specifically referring to the arrangement in the picture: where one designer's model is build beneath another. This would lead to 'fuzz shadows' that do not correspond to the design elements of the model itself (in any orientation)...

For the record, I completely understand how frustrating  the orientation issue is (it's almost become a game for me to try and guess which way they will orient a model).

[daniel_leavitt2000]

Bryan, what company do you use for prototyping parts?

[peteski]

This entire conversation is still missing one more point.

As an example I'll use ESM's White Tower building (which is not done by Shapeways but the printing technique is similar).  I don't have time to take example photos so I'll just describe it.

It is true that bottom surfaces of parts which are supported by wax will have rough surface, but it is not only the bottoms. If any part of the object protrudes beyond the surface under it, the wax will have to be built up to support that part. For example if you have a flat vertical wall of a building but in certain areas there are window sills then the wax will need to be built up during printing to support the sills. That wax will also be in contact with the vertical wall surface and will cause the solid vertical wall to have a rough texture  under each sill and smooth elsewhere.   So there are more problem areas than just the bottoms of surfaces.

The resin used is also not acrylic.  Whatever material is used is resistant to all the solvents I tried. My idea was to use a solvent to melt the surfaces of the rough areas to smooth them out).  Well I tried every solvent I have which attacks styrene, acrylic and Lexan but none of those affected the resin used on that model.  I tried lacquer thinner, acetone, MEK, Xylene, and even Methylene Chloride. All of those readily melt the plastics I mentioned earlier but the resin was not even stained.

Maybe Shapeways uses resins which can be melted by solvents - I don't know as I have not yet got my hands on any of Shapeways printed items.

[DKS]

I haven't heard of another way to remove the wax (although the results might be better if the technicians were a bit more patient)...

Speaking for myself, I'd prefer that they offered an option where they didn't remove the wax at all; I'm perfectly fine doing it myself. I'd mechanically remove as much as possible by hand, and then dissolve the rest away with heptane (Bestine).

This entire conversation is still missing one more point... If any part of the object protrudes beyond the surface under it, the wax will have to be built up to support that part. For example if you have a flat vertical wall of a building but in certain areas there are window sills then the wax will need to be built up during printing to support the sills...

Peteski, I think you missed this...

The reason that the back face is rougher than the rest of the model is the overhang of the cab roof. Since the roof needs to be supported by wax, the entire rear face of the cab is 'submerged' in wax so to speak...

[peteski]

I saw that David but I didn't think that specific example conveyed the point.  Why? Because if that model was printed nose-down then the back side of the cab would be nice and smooth. That is because it would then be on the top of the printout and the overhand would not need any wax support.

[DKS]

I saw that David but I didn't think that specific example conveyed the point.  Why? Because if that model was printed nose-down then the back side of the cab would be nice and smooth. That is because it would then be on the top of the printout and the overhand would not need any wax support.

Call me dense, but I fail to see the distinction between the two points. At any rate, I wonder if it would be any advantage to print the shell in two pieces, with the cab oriented upside-down. The top of the roof would then be rough, but that should be easy to sand smooth.

[mmyers05]

Speaking for myself, I'd prefer that they offered an option where they didn't remove the wax at all; I'm perfectly fine doing it myself. I'd mechanically remove as much as possible by hand, and then dissolve the rest away with heptane (Bestine).

Fair enough, I would certainly prefer to have that option as well...

That said, given the number of people who seem uncomfortable with the 'cleaning process,' I think we are probably in the minority.

[peteski]

Call me dense, but I fail to see the distinction between the two points. At any rate, I wonder if it would be any advantage to print the shell in two pieces, with the cab oriented upside-down. The top of the roof would then be rough, but that should be easy to sand smooth.

I guess that the point I was trying to make is that if the model has any overhangs or protrusions, there will always be areas with rough surface (not only on the bottom of pieces which are printed over wax but also on some vertical surfaces).

[Dave Schneider]

I guess that the point I was trying to make is that if the model has any overhangs or protrusions, there will always be areas with rough surface (not only on the bottom of pieces which are printed over wax but also on some vertical surfaces).

Great obsevation Pete. I was looking at the shells under magnification this evening and that is exactly what I observed. This points out some issues that could be incorporated into a design. A basic body shell with minimal details would be best. Easy to sand and fewer areas of rough texture. Doors and lovers could be added from brass etchings or Archer decals. Cab doors and windows could just be openings into which separate parts could be fitted. Any sort of body panels could be inset lines rather that standing seams.

This has been a interesting discussion. I have learned quite a bit today.

Best wishes, Dave

[Chris333]

As for the shells by mark4design, is it possible for Matt's design to be printed by Mark if both parties are interested? I would be happy to pay more for a better shell. Matt has done a very nice job of laying out his designs, and his craftsmanship really deserves a first rate printing job.

Best wishes, Dave

I'm not sure, but I think what Mark uses might require the 3D model to be broken down into small pieces. Not saying it couldn't be done, but the drawings would probably need to be re-worked.

Ever think of asking the designer to send the file to Finelines and get a quote for micro green. (I'm guessing over $200 tho)

[daniel_leavitt2000]

Ah Chris, that was the company I was looking for. If anyone would like to work with me on a project, maybe we could try Finelines out with a flat kit then I pressure cast a resin kit from the master. If we sell a few kits on eBay, we might recover the initial investment.

I don't even really care what the project would be, as long as it appealed to a few modelers. I just want to prove that flat kit to resin casting would be a cost effective and viable option. I'm willing to front half the cost and my casting expertise.