rbrown7713 Posted December 16, 2017 Author Share Posted December 16, 2017 Here is the first half of the window frame mold, hope I can keep everything in alignment. Bob. Quote Link to comment Share on other sites More sharing options...
enginear joe Posted December 16, 2017 Share Posted December 16, 2017 YES! Your making me want to build these sooner. I have walked away from scratch building for awhile. I spent some time adding an inner mainline to my indoor G scale layout. I still have many things to maintain and then there's a growing list of new problems to fix. So at least someone I know is moving forward! Quote Link to comment Share on other sites More sharing options...
rbrown7713 Posted December 16, 2017 Author Share Posted December 16, 2017 Here is one half of the mold for the window frames and I clayed up the shape to see what it will look like, much better than just flat plastic, if I can get the other side of the mold to match up with this one. I have an old mill and the tolerances are not so good, but maybe it will be ok. Bob. Quote Link to comment Share on other sites More sharing options...
rbrown7713 Posted December 17, 2017 Author Share Posted December 17, 2017 I bought this brass 0 gauge diner for modeling mine. The detail is fantastic. Bob. Quote Link to comment Share on other sites More sharing options...
nscaler711 Posted December 18, 2017 Share Posted December 18, 2017 That's so pretty! Just need to find the lounge car to save you some work! Oh I thought of another car, Transition Sleeper! Quote Link to comment Share on other sites More sharing options...
rbrown7713 Posted December 18, 2017 Author Share Posted December 18, 2017 Thanks, I do have an HO model of the lounge car, but would like to have an O gauge to copy, that would be nice, but probably too expensive. This brass O gauge care that I bought was only 225., I thought that it was cheap for brass. It is an Overland models model. Bob. Quote Link to comment Share on other sites More sharing options...
rbrown7713 Posted December 18, 2017 Author Share Posted December 18, 2017 The window frame molds are done and I have no idea yet if this will work given that these were made on an old worn out mill. All of the numbers were correct, but with an old mill, even if the numbers are correct, the tolerances of the mill might be different than the numbers, so we shall see. I plan to make some parts tomorrow, Bob. Quote Link to comment Share on other sites More sharing options...
rbrown7713 Posted December 19, 2017 Author Share Posted December 19, 2017 Today I made a mount for the molds to hold it while I tighten the bolts and pour the plastic which I just poured, so we shall see how my mold making abilities are in the morning when I remove the window frames, so says me. Bob. Quote Link to comment Share on other sites More sharing options...
rbrown7713 Posted December 20, 2017 Author Share Posted December 20, 2017 The alignment of the two halves of the mold is perfect and will make some good parts with a minor adjustment, adding more bolts to squeeze a little more. You can see in the pictures that there is some more flashing to remove and will be easier when the plastic gets a little harder. I pulled the molds apart a little early, like I always do, to see how the parts came out, they came out very good. When I add some more bolts and machine some more channels in the molds, it will relieve some pressure on the excess plastic when squeezing together and make the flashing thinner and easier to remove. All in all, I am very happy with the mold. There is not much room for error for the size of the glass for the frames and for the openings in the sides for this type of installation, but I think it will look good as the windows will be flush with the sides and look more prototypical. I used urethane for the frames, but I am also going to try epoxy to see if it will work out better and also I will be adding some pigment to the mixture to simulate rubber. Bob. Quote Link to comment Share on other sites More sharing options...
rbrown7713 Posted December 21, 2017 Author Share Posted December 21, 2017 Here they are painted flat black. These things are delicate and very hard to work with, but after reworking the mold a little bit, they should be a little bit better to handle. Bob. Quote Link to comment Share on other sites More sharing options...
Sean Posted December 21, 2017 Share Posted December 21, 2017 Could you make them with black plastic ? Quote Link to comment Share on other sites More sharing options...
rbrown7713 Posted December 21, 2017 Author Share Posted December 21, 2017 Yes, but I have not found black urethane so I add black pigment to the white urethane, which I will be trying, but I am afraid that it will not be black enough, because you can only add 1% black pigment to the mixture. In the end, just painting them with flat black will work, but I am also going to try black pigment in epoxy mix as I have done with my E8 number boards and it comes out black enough. I am also experimenting with some JB weld type stuff, but don't know how that will turn out. The problem is getting them out of the mold without breaking them as they are fragile, so I am looking for some stronger stuff. I am also reworking the mold to make it easier for the parts to be removed, that should work out OK. Bob. Quote Link to comment Share on other sites More sharing options...
Sean Posted December 21, 2017 Share Posted December 21, 2017 Have you thought of 3d printing them ? Quote Link to comment Share on other sites More sharing options...
rbrown7713 Posted December 21, 2017 Author Share Posted December 21, 2017 I don't know for sure, but as small as these are, I doubt if it would have a high enough resolution. I am guessing that the layers would be seen and not be acceptable. Besides, when I get done with reworking my molds, they will be good. Bob. Quote Link to comment Share on other sites More sharing options...
enginear joe Posted December 22, 2017 Share Posted December 22, 2017 any good? maybe you could just try the mold rubber you have??? Quote Link to comment Share on other sites More sharing options...
rbrown7713 Posted December 22, 2017 Author Share Posted December 22, 2017 Yes, that is good for flexible parts, but the window frames have to be very rigid. But thanks anyway. Bob. Quote Link to comment Share on other sites More sharing options...
rbrown7713 Posted December 22, 2017 Author Share Posted December 22, 2017 Sean, I figured the layers that would be needed for my frames and at .05mm per layer, it would take about 20 layers for the thickness of my frames which are roughly .040. And I am pretty sure that the layers could be seen, even with an SLA type 3d printer, so I think my mold will do the job just fine, and also with no layer marks, so one could say that they have an infinite resolution. Bob. Quote Link to comment Share on other sites More sharing options...
Chuck Posted December 22, 2017 Share Posted December 22, 2017 3D print at .02mm and watch those layers disappear. Lots of folks print in a low resolution like .05mm just to move the job along. Quote Link to comment Share on other sites More sharing options...
rbrown7713 Posted December 22, 2017 Author Share Posted December 22, 2017 How much does that 3d printer cost that prints at .02mm thickness?, and how long does it take to print? I can make a mold and continue to make parts quickly, without lines. Also, tell me and show me that it has no visible lines, even at .02 mm. My frames, from a mold, for sure has no lines, as it is smooth right out of the mold, no body work needed. A larger print, and not so delicate is OK, because one can do some body work on it, primer etc. and make the lines disappear. When they come up with a 3d printer, that I can afford, and you can't tell whether the part has been printed with a 3d printer, than I will buy one. Bob. Quote Link to comment Share on other sites More sharing options...
rbrown7713 Posted December 23, 2017 Author Share Posted December 23, 2017 The first batch of frames had flashing, in some spots that were too thick. One reason for that is that I didn't have enough bolts spread about the mold. The other reason was that the flashing was too thick in some spots is that the excess plastic had no where to go, so I added some bolts and channels for the escaping plastic, so now, I believe that I will get more uniform parts without thick flashing, so says me. This mold is sort of a poor man's plastic injection mold, just slower. Now for the polishing. My next batch will tell the story, Bob. Quote Link to comment Share on other sites More sharing options...
Chuck Posted December 23, 2017 Share Posted December 23, 2017 22 hours ago, rbrown7713 said: How much does that 3d printer cost that prints at .02mm thickness?, and how long does it take to print? I can make a mold and continue to make parts quickly, without lines. Also, tell me and show me that it has no visible lines, even at .02 mm. My frames, from a mold, for sure has no lines, as it is smooth right out of the mold, no body work needed. A larger print, and not so delicate is OK, because one can do some body work on it, primer etc. and make the lines disappear. When they come up with a 3d printer, that I can afford, and you can't tell whether the part has been printed with a 3d printer, than I will buy one. Bob. Well the CR10 that's been getting rave reviews all year. This model can print down to .015mm resolution and that's because of the code. Cost is like $379 as model is being replaced with the CR10s. Those window frames would take like maybe 10 minutes each to print...or less. Quote Link to comment Share on other sites More sharing options...
rbrown7713 Posted December 23, 2017 Author Share Posted December 23, 2017 Let's back up a little bit. One of the primary uses of a 3d printer is to build a prototype in a 3d form. It is better than a 3 view drawing because it combines the front, the side, and the top all in the same place, which is useful for prototyping and correcting the design of an item, so far, so good. The final part will usually be made from a plastic injection mold, and by the way, no visible lines, hence no body work, or smoothing to get rid of the lines, usually, priming and painting. Try priming and painting a part, such as my frames, even at .015mm. Making my window frames at the resolution of .015mm would only add about another 30 lines for a total of 50 lines, and still visible. Can you imagine trying to prime and sand my fragile frames for final paint? Half of them would break, in fact sometimes removing from the mold come out broken. BTW, even the highest resolution printer manufactures state that there is a finishing process for smoothing. Making a large part or locomotive makes it possible for the finishing process, so not a big deal, but not for small parts such as this. Still a .015mm resolution does not compare in any way to an infinite resolution, and that is what you get with a mold.--- One layer. I challenge you to make my window frames with the .015mm reso. printer and see how they come out, would be interesting, don't you think? I looked up a high end printer yesterday, prints on regular typing paper in any color and not any visible lines, that I could see, but it was a $30,000 printer, no, I will continue to make my infinite resolution molds, thank you, Bob. Quote Link to comment Share on other sites More sharing options...
rbrown7713 Posted December 23, 2017 Author Share Posted December 23, 2017 I went on YouTube and looked at some reviews of the CR10 and almost without exception, they used a term, new to me, overextrusion. That is where a bulge is visible when layering a part. They are very visible. Just one of those over extrusions on my window frames would ruin the part. If one was making a larger part and that happened, no big deal, one would just sand it out. No thanks, I will continue to make a pattern and then a mold, remember, infinite resolution, no over extrusions in my molds. Bob. Quote Link to comment Share on other sites More sharing options...
Chuck Posted December 23, 2017 Share Posted December 23, 2017 Now you're being an butt head and going off on a technology that you know nothing about..so you shoot it down. I don't need to make your window frames because I know the results...you don't. But don't worry as your windows frames would print out very sturdy in either PLA or ABS plastic. Could they be broken?? Yes but they'd be very tough...not delicate or brittle. Over extrusion..you're kidding me right??!! A simple setting change will eliminate that. If you do have an over extrusion just take an Exacto knife and slice it off. Like using your milling machine...if you don't stop soon enough on your x axis what happens?? C'mon as I've watched plenty of injection molding videos and that process isn't foolproof. Someone inspects each part for imperfections then the spot glazing putty comes out. Then the sanding down of parting lines etc. You make big deal about infinite resolution but your own models show you using bondo & glazing compound to cover your perfect moulds imperfections...like this... Quote Link to comment Share on other sites More sharing options...
rbrown7713 Posted December 24, 2017 Author Share Posted December 24, 2017 OK, let's assume that I don't what I am talking about, and I doubt that, but never the less, why don't you show the world, not only me, how good a 3d print of my window frames would be. I will send you a drawing of the measurements and you can make a 3d drawing in an .stl format and run some off of a 3d printer and we will all see just how good it would turn out,compared to mine. How about that? As far as your calling me a butthead, come on Chuck, you can do better than that. My ex wife called me worse than that. Quote Link to comment Share on other sites More sharing options...
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