ArdWrknTrk Posted January 20, 2018 Share Posted January 20, 2018 Jim - It is lazer sintered nylon, so Acetone wouldn't smooth it. But, maybe the polishing or burnishing would work. I'll ask. As for the HP nylon, that's a good point about the size. So, maybe the HD Acrylate? My father was director of engineering for a number of acrylic companies (Polycast, Ever Kleer (?), and Cast Optics) Acrylic has good hardness and takes a good polish. (can be solvent, flame, or mechanical polish) It is also brittle, subject to notch sensitivity, UV, ozone and chemical attack. Link to comment Share on other sites More sharing options...
Gary Lewis Posted January 20, 2018 Share Posted January 20, 2018 It is hard for me to see that on my phone. Although zoomed way in it does look like the letters are not distinct from one another. I wonder what would happen if you attempted to wet sand the raised area with fine paper stuck down to a slightly resilient surface? This might polish up the flats while not leaving sharp corners. No, the letters are not distinct from each other. I could put spaces between the letters, but then the overall string would be too long unless I scrunch it up some. As for sanding and polishing, how 'bout I try to sand it on sandpaper held on a hard surface, and then put the whole thing in my vibrating polisher? The only issue is what media to put in the polisher. Thoughts? Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted January 20, 2018 Share Posted January 20, 2018 No, the letters are not distinct from each other. I could put spaces between the letters, but then the overall string would be too long unless I scrunch it up some. As for sanding and polishing, how 'bout I try to sand it on sandpaper held on a hard surface, and then put the whole thing in my vibrating polisher? The only issue is what media to put in the polisher. Thoughts? I guess the question is how aggressive a media, and what size? How do you feel about the background texture? How 'soft' a corner do you want on the letters and border? I use carbide paper on my surface plate for sharpening chisels and plane blades but for cleaning a surface (where I don't want razor sharp edges) I will put down one of those sheets of orange gasket rubber you can find in the plumbing supply. It seems to have just enough give that I don't cut myself. Link to comment Share on other sites More sharing options...
Gary Lewis Posted January 20, 2018 Share Posted January 20, 2018 My father was director of engineering for a number of acrylic companies (Polycast, Ever Kleer (?), and Cast Optics) Acrylic has good hardness and takes a good polish. (can be solvent, flame, or mechanical polish) It is also brittle, subject to notch sensitivity, UV, ozone and chemical attack. What is notch sensitivity? Does that mean it is easily broken at a notch? Concentration of forces? There's a discussion of how the acrylate parts are made here. And one statement looks encouraging: High Definition Acrylate is made of a photo-reactive resin. It is printed using Direct Light Projection (DLP) technology which provides excellent resolution and accuracy. It is capable of fine details and is therefore ideal for miniatures and models trains. Additionally, the DLP process produces a smooth surface, making it well suited for painting. The material is heat resistant up to 120°C and is printed at 50 micron layer thickness. The color ranges from matte black to a dark grey charcoal. Further, here's a comparison of plastic materials, and the one I used was Strong & Flexible: Link to comment Share on other sites More sharing options...
Gary Lewis Posted January 20, 2018 Share Posted January 20, 2018 I guess the question is how aggressive a media, and what size? How do you feel about the background texture? How 'soft' a corner do you want on the letters and border? I use carbide paper on my surface plate for sharpening chisels and plane blades but for cleaning a surface (where I don't want razor sharp edges) I will put down one of those sheets of orange gasket rubber you can find in the plumbing supply. It seems to have just enough give that I don't cut myself. For the polisher I only have the plastic pyramids, which are much too large and aggressive, and a nut hull media with polishing compound embedded. I'm afraid the polishing compound would embed in the plastic and be impossible to wash or scrub out. I wonder about using walnut hulls from the blast cabinet? Or, glass bead? Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted January 20, 2018 Share Posted January 20, 2018 What is notch sensitivity? Does that mean it is easily broken at a notch? Concentration of forces? There's a discussion of how the acrylate parts are made here. And one statement looks encouraging: High Definition Acrylate is made of a photo-reactive resin. It is printed using Direct Light Projection (DLP) technology which provides excellent resolution and accuracy. It is capable of fine details and is therefore ideal for miniatures and models trains. Additionally, the DLP process produces a smooth surface, making it well suited for painting. The material is heat resistant up to 120°C and is printed at 50 micron layer thickness. The color ranges from matte black to a dark grey charcoal. Further, here's a comparison of plastic materials, and the one I used was Strong & Flexible: If acrylic is scratched or exposed to some chemicals (like anerobic thread lockers) these tiny fissures are places for cracks to start. And acrylic does like to crack! Link to comment Share on other sites More sharing options...
Ford F834 Posted January 20, 2018 Share Posted January 20, 2018 Jonathan - I'll contact Shapeways to see how to get a better finish. Maybe they offer finishing, via acetone or whatever, but I don't see it when looking at their site. However, I think the best solution is to go with another material instead of the "Strong & Flexible" that was used. A couple that look promising are shown below in comparison to Strong & Flexible:: Strong & Flexible: This nylon plastic is our most versatile material suggested for both functional and decorative products. HP Nylon: This nylon plastic has excellent material properties and is recommended for mechanical and functional products. High Definition Acrylate: This black acrylic plastic is suitable for intricate details and some handling. Having said that, the one I have doesn't look that bad. As said, I put it in the worst possible lighting conditions to take the pics, and when holding it in my hand in normal conditions it looks much better. However, there is one thing that I've noticed that no one has mentioned - the letters "AMP" of FOG LAMPS appear to be smaller than the rest. Does anyone else see that? By their own definitions and descriptions it would seem that the high definition acrylate would be the highest resolution material and give the best resolution on the lettering. Plus acetone smoothing would at least be an option. It also sounds to be the most fragile choice, but this bezel is cosmetic and does not need strength except to hold itself on by the mounting posts. I would think it would be worth trying to see if the overall resolution and surface detail is cleaner or if it would at least clean up easier/nicer... Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted January 20, 2018 Share Posted January 20, 2018 For the polisher I only have the plastic pyramids, which are much too large and aggressive, and a nut hull media with polishing compound embedded. I'm afraid the polishing compound would embed in the plastic and be impossible to wash or scrub out. I wonder about using walnut hulls from the blast cabinet? Or, glass bead? Yeah, I would stay away from media with compound mixed in. If you just want to burnish it maybe BB's or steel shot would be an inexpensive solution Link to comment Share on other sites More sharing options...
reamer Posted January 20, 2018 Author Share Posted January 20, 2018 It is hard for me to see that on my phone. Although zoomed way in it does look like the letters are not distinct from one another. I wonder what would happen if you attempted to wet sand the raised area with fine paper stuck down to a slightly resilient surface? This might polish up the flats while not leaving sharp corners. Actually the Shapways lettering is Horrible. The letters seemed to "melt together" and the lettering from the one I got was "altered" to get them to resolve... Link to comment Share on other sites More sharing options...
PetesPonies Posted January 20, 2018 Share Posted January 20, 2018 Actually the Shapways lettering is Horrible. The letters seemed to "melt together" and the lettering from the one I got was "altered" to get them to resolve... You're going to come back and paint the silver right? Polishing isn't needed. You only need to sand with some 600 wet, on a flat surface like glass, then paint the surfaces that your smoothed. If you find the surfaces too flat after sanding, then a buffer will soften the edges. Some white or blue buffing compound on a pedestal buffer would do it. Link to comment Share on other sites More sharing options...
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