cteno4 Posted December 25, 2017 Share Posted December 25, 2017 Gavin, yep that is a good idea on how to form your tunnel with filer. Not sure how easy/hard it will be to do the arm with your tunnel profile paddle, but in Theory that should work. I do think it will I’ll be very hard to get your lights in there well. if you are going to cast it why cast it in foam? Why not something sturdy like the cast plaster cloth? Foam is going to be easy to ding and break and it’s a lot more difficult to do your lighting in. i realize you are good at working in tight places, but I still think the casting path is going to get you so much more if yo are trying to shoot for the moon to get lots of detailing,lighting and the perfect curves. I also fear that you get 75% innand somethin happens to really mess something up it’s a long path to start over or major hack and whack. Wirh casting just make a couple of extras and you can then just replace a section. Toughest thing on casting will be the seams, especially the vault seam if you split it. If you were to mount like a 3/4” wide arc of like 3/16”ply to the tip of your casting and epoxy it on well, you could take the tunnel on a band saw or scroll saw and easily split it along the crown of the vault. Then the pieces would mate perfectly and just a tiny smear of filler would fill any remaining crack or leave it as the top detail seam. Or hide it with a piece of conduiting running along the peak of the vault (just glue it to one side of the tunnel before assembling). The ply would then give you a top that you can just lay another identical ply arc over and screw down to firmly attach the two tunnel sides firmly together. Similarly, identical mated plates out of ply (cut mates together at the same time to be indentical profile) cut in the profile of the tunnel can be epoxied to the ends so the sections can be screwed together. Finishing and sanding the ends of the insides of the tunnel sections flat and clean up to these joint plates edges would give you really clean vertical section joints that could be filled a little if needed. The. Just bolt or screw these end plates together. again I think it wiser if this can come apart to both build, detail, and light but also fiddle with, repair, etc later as if it’s all one big mono Block foam construction and assembly then Murphy will come in and zap you. Doing scenery shells to drop over your tunnel is pretty easy and done a number of traditional ways. Foam core frame and hot glued cardboard strips and plaster cloth or paper mache is a tried and true way of making removable shells. You can even cover your tunnel with a cardboard frame and then either glue in chunks of extruded foam to make an outer shell or pour/spray your own foam shell to carve if you want carved foam scenery. Also if you decide to ever change the external scenery you don’t have to muck with your tunnel and it’s workings, just make a new scenery shell to pop on top. Also doing the messy external scenery work away from your very elaborate tunnel would be advisable as scenery work has a way of mucking up everything around it! Even a ship in a bottle is built 98% outside the bottle! I think casting is more like building the ship outside the bottle and slipping it in whereas carving it out and working inside that is more like building the ship inside the bottle, which yes it can be done, but it will be a lot more painful to do and may not let you do all the stuff you may want to do... for the investment I think the former gets you a lot more bang for the buck than the latter. Plus you learn some casting which is very handy to know. Cheers, jeff Link to comment
inobu Posted December 25, 2017 Share Posted December 25, 2017 Its all about geometry. The squares are straight cuts. Cut them in half will double the number them. Glue them in place Print up the wall detail on paper and glue them to the foam support. Inobu Link to comment
kvp Posted December 25, 2017 Share Posted December 25, 2017 6 minutes ago, inobu said: Its all about geometry. The squares are straight cuts. Cut them in half will double the number them. Glue them in place. Print up the wall detail on paper and glue them to the foam support. That pretty much sums up how the bent sheet tunnel liner techique works. The old TT premade tunnels used thick cardboard for both the tunnel prortals and the inner bracing. Then glued the inner lining to these cross sections and the portal brick/stone patterns printed on paper to the outside portals. This could be built from thick cardboard, styrene sheets and even wood for the blocks. All these materials could be cut with a scissor, a knife or a band saw using straight shallow cuts only. For curved tunnels, the lining material could have cuts and/or overlaps on the curve inner side to make it curve easier. One nice thing about this structure is that the other side of the tunnel wall remains accessible for installation of lighting or anything, just make holes into the lining material and glue on the parts from the outside. Then cover the whole tunnel assembly with the mountain surface. It's like flex tracks for tunnels where these cross sections are the sleepers. For foam supports, it's possible to cut/sand them to wedge shape after cutting, so they match up flush against each other, like on the linked video. ps: one word about expanding foam: it's really strong and could push a weaker structure or mold apart 1 Link to comment
gavino200 Posted December 26, 2017 Author Share Posted December 26, 2017 1 hour ago, inobu said: Its all about geometry. The squares are straight cuts. Cut them in half will double the number them. Glue them in place Print up the wall detail on paper and glue them to the foam support. Inobu Thanks Inobu. I would do it this way if it were'n going to be an open tunnel. For a visible tunnel I think the flat surfaces and angles would be to obvious. Link to comment
inobu Posted December 26, 2017 Share Posted December 26, 2017 9 minutes ago, gavino200 said: Thanks Inobu. I would do it this way if it were'n going to be an open tunnel. For a visible tunnel I think the flat surfaces and angles would be to obvious. You cut the section in half. Inobu 1 Link to comment
gavino200 Posted December 26, 2017 Author Share Posted December 26, 2017 6 minutes ago, inobu said: You cut the section in half. Inobu I'll use this method if I can't make a continuous curve. As always, I appreciate your ideas. Link to comment
gavino200 Posted December 26, 2017 Author Share Posted December 26, 2017 2 hours ago, cteno4 said: Gavin, yep that is a good idea on how to form your tunnel with filer. Not sure how easy/hard it will be to do the arm with your tunnel profile paddle, but in Theory that should work. I do think it will I’ll be very hard to get your lights in there well. if you are going to cast it why cast it in foam? Why not something sturdy like the cast plaster cloth? Foam is going to be easy to ding and break and it’s a lot more difficult to do your lighting in. i realize you are good at working in tight places, but I still think the casting path is going to get you so much more if yo are trying to shoot for the moon to get lots of detailing,lighting and the perfect curves. I also fear that you get 75% innand somethin happens to really mess something up it’s a long path to start over or major hack and whack. Wirh casting just make a couple of extras and you can then just replace a section. Toughest thing on casting will be the seams, especially the vault seam if you split it. If you were to mount like a 3/4” wide arc of like 3/16”ply to the tip of your casting and epoxy it on well, you could take the tunnel on a band saw or scroll saw and easily split it along the crown of the vault. Then the pieces would mate perfectly and just a tiny smear of filler would fill any remaining crack or leave it as the top detail seam. Or hide it with a piece of conduiting running along the peak of the vault (just glue it to one side of the tunnel before assembling). The ply would then give you a top that you can just lay another identical ply arc over and screw down to firmly attach the two tunnel sides firmly together. Similarly, identical mated plates out of ply (cut mates together at the same time to be indentical profile) cut in the profile of the tunnel can be epoxied to the ends so the sections can be screwed together. Finishing and sanding the ends of the insides of the tunnel sections flat and clean up to these joint plates edges would give you really clean vertical section joints that could be filled a little if needed. The. Just bolt or screw these end plates together. again I think it wiser if this can come apart to both build, detail, and light but also fiddle with, repair, etc later as if it’s all one big mono Block foam construction and assembly then Murphy will come in and zap you. Doing scenery shells to drop over your tunnel is pretty easy and done a number of traditional ways. Foam core frame and hot glued cardboard strips and plaster cloth or paper mache is a tried and true way of making removable shells. You can even cover your tunnel with a cardboard frame and then either glue in chunks of extruded foam to make an outer shell or pour/spray your own foam shell to carve if you want carved foam scenery. Also if you decide to ever change the external scenery you don’t have to muck with your tunnel and it’s workings, just make a new scenery shell to pop on top. Also doing the messy external scenery work away from your very elaborate tunnel would be advisable as scenery work has a way of mucking up everything around it! Even a ship in a bottle is built 98% outside the bottle! I think casting is more like building the ship outside the bottle and slipping it in whereas carving it out and working inside that is more like building the ship inside the bottle, which yes it can be done, but it will be a lot more painful to do and may not let you do all the stuff you may want to do... for the investment I think the former gets you a lot more bang for the buck than the latter. Plus you learn some casting which is very handy to know. Cheers, jeff Jeff, I definately see the wisdom of this. Making the scenery framing will be a whole learning curve in itself. But it seems like it could be fun. I think I'll start by making a 45 degree negative and go step by step from there. Link to comment
gavino200 Posted December 26, 2017 Author Share Posted December 26, 2017 10 minutes ago, inobu said: Inobu The beauty of this system is that each one of those pieces would be extremely easy to cut with a foam cutter. I'm using the method of clamping a card template on either side of the foam and riding the foam wire along the templates like a train on tracks. (as opposed to free-hand technique, I guess). I think this method would be a quick and suitable way to do the far side of the tunnel. But I think filling the gaps without creating a 'polygon' effect would be tough. How do you mock these 3D sketches up so quickly btw? Link to comment
cteno4 Posted December 26, 2017 Share Posted December 26, 2017 yep that would be a great way to do it if you could put up with the faceted curve. then maybe a mould with the angled ends and half sections and then do them in foam. interiors would be easy then with printed paper on the walls to get your form lines in easily. seams are still going to be the trick to get flush as this is the place that will catch your eye on a camera. easy to mock up a few of these with a hand scroll saw and then try to skin them to see how they will look. still have a bit of foam to work on sticking your lighting thru. get a cheap spy camera to play looking at it as the camera would see it as well. i guess the big thing to think about as well is how are you going to see the tunnel (ie cutaways and camera car) and make sure you look at them thru that "lens" to see what you can get away with as well. you may find that facets dont look so bad as with the not so clear camera, lights, and motion some things may just not really be noticeable. that is unless you just knowing its perfect is there in your head--and thats cool, if thats important to you! could also easily do all the chunks cut out on a band saw, cut the tunnel cross section then the angled ends. then glue together and then sand smooth, but still issue of trying to sand in the concave, not so hard on the inside wall but the outside wall will be harder to get scooped out of the concave cleanly. making a scenery shell is really not hard at all. number of different paths to it and thats the easiest part of this proposal! But i do think doing them separately will help loads if you want to do all that lighting and detail in the tunnel as things are gunna break at some point and other issues and changes will come along later. cheers, jeff 1 Link to comment
inobu Posted December 26, 2017 Share Posted December 26, 2017 47 minutes ago, gavino200 said: The beauty of this system is that each one of those pieces would be extremely easy to cut with a foam cutter. I'm using the method of clamping a card template on either side of the foam and riding the foam wire along the templates like a train on tracks. (as opposed to free-hand technique, I guess). I think this method would be a quick and suitable way to do the far side of the tunnel. But I think filling the gaps without creating a 'polygon' effect would be tough. How do you mock these 3D sketches up so quickly btw? Yes, That's the way to do it. Just imagine tacking long strips of card stock longways. You will not have the polygon effect. Once you paste the printed walls you won't see anything. I pretty verses in Rhino 3D. I've been using it for years. Inobu 1 Link to comment
tossedman Posted December 26, 2017 Share Posted December 26, 2017 (edited) 21 hours ago, gavino200 said: How do you mock these 3D sketches up so quickly btw? You can do that in SketchUp too. Same thing I'm drawing my Moruoka Castle with. Great program. You can download a free version. Cheers eh, Todd Edited December 26, 2017 by tossedman 1 Link to comment
gavino200 Posted February 10, 2018 Author Share Posted February 10, 2018 Finally got around to working on this again. I wanted to do the foam cutting outside, which meant waiting for the snow to clear. Which it did....for a few days. First iteration of the 45 degree curved sausage. Next I'll give it a coat of drywall filler and sand it a bit smoother. 2 Link to comment
cteno4 Posted February 11, 2018 Share Posted February 11, 2018 Sausage for lunch! Or making French bread? jeff 1 Link to comment
gavino200 Posted February 19, 2018 Author Share Posted February 19, 2018 (edited) This isn't perfect, but it's about as good as I can make it. I'm going to do one more round of plaster and sanding, but just at the edges of each end to I can get the edges sharp and make sure each end is exactly the same. I'll have to read back through the thread and prepare for the next step. I think that's applying a hardening coat. I also, smoothed out one of the straight segment trials and opened the front to see how it looks. I think I'll use this to experiment with lighting and detailing techniques. I've been collecting some "tunnel interior looking" do-dads to add. I'll probably just hand paint this one. I'm planning to air brush the final version. Edited February 19, 2018 by gavino200 3 1 Link to comment
gavino200 Posted February 22, 2018 Author Share Posted February 22, 2018 On 12/2/2017 at 5:19 PM, Kiha66 said: Since it would be a dedicated line, you could use tomix track and use a tomix tcs unit to easily automate it. For three trams you could have two Double tracked stations at each end, and it your save you the expense of adding DCC to each tram. http://www.1999.co.jp/eng/10040736 Wow! That's a much cheaper Tomix controller set than the one I've been looking at. It's something to consider. (I'm reading back through the thread, sifting for ideas I missed btw) Link to comment
gavino200 Posted February 22, 2018 Author Share Posted February 22, 2018 On 12/3/2017 at 11:26 PM, cteno4 said: For final you can paint layer and sand smooth then coat in mould release and plaster. The sausage is almost ready. I'm getting ready to cast. Are you talking about this stuff - mold release? https://www.amazon.com/Smooth-Universal-Mold-Release-fl/dp/B004BNHLOK/ref=sr_1_1?ie=UTF8&qid=1519258150&sr=8-1&keywords=mould+release Do you recommend any kind of coating of the sausage before this stage? Clear coat? Hardener? The surface is part foam, part dry wall filler. Link to comment
gavino200 Posted February 22, 2018 Author Share Posted February 22, 2018 On 12/25/2017 at 4:52 PM, cteno4 said: Toughest thing on casting will be the seams, especially the vault seam if you split it. If you were to mount like a 3/4” wide arc of like 3/16”ply to the tip of your casting and epoxy it on well, you could take the tunnel on a band saw or scroll saw and easily split it along the crown of the vault. I don't fully understand this idea. You mean an 3/4 inch arc in cross sections. That runs the length of the tunnel. Right over where the "keystone" of the arc would be? You mean "plywood". I can see this working for a straight tunnel but how would you shape plywood like this for a curved tunnel. I think i could cut a seam using a dremel type tool. But, I agree, it would make a gap. I'd need something to fill the gap. However, as my tunnel is open at the front, access for detailing will probably not be a problem. If I use fiberglass casting material, I could probably get the cast off the mold without breaking it. Then I could cut out the front window before detailing it. What do you think? 1 Link to comment
gavino200 Posted February 22, 2018 Author Share Posted February 22, 2018 On 12/25/2017 at 12:56 PM, inobu said: The hot wire is better. Cutting them in sections is easier. Once glues together you can hot wire the shape of the mountain. Inobu Inobu, were you ever able to see if you had an extra one of these portals to sell? 1 Link to comment
Pauljag900 Posted February 22, 2018 Share Posted February 22, 2018 17 minutes ago, gavino200 said: I don't fully understand this idea. You mean an 3/4 inch arc in cross sections. That runs the length of the tunnel. Right over where the "keystone" of the arc would be? You mean "plywood". I can see this working for a straight tunnel but how would you shape plywood like this for a curved tunnel. I think i could cut a seam using a dremel type tool. But, I agree, it would make a gap. I'd need something to fill the gap. However, as my tunnel is open at the front, access for detailing will probably not be a problem. If I use fiberglass casting material, I could probably get the cast off the mold without breaking it. Then I could cut out the front window before detailing it. What do you think? Wow,that’s a lot of work for a tunnel,but it shows,that s gonna look superb,good effort buddy👍👍😀 Link to comment
gavino200 Posted February 22, 2018 Author Share Posted February 22, 2018 Just now, Pauljag900 said: Wow,that’s a lot of work for a tunnel,but it shows,that s gonna look superb,good effort buddy👍👍😀 Thanks. It's a bit nuts. I agree. I'm learning a lot from the process that I'm sure I'll be able to apply to multiple projects in future. If it looks good that'll be great. If not we'll keep it 'closed up' and apply what we've learned on the next attempt. :) 1 Link to comment
inobu Posted February 22, 2018 Share Posted February 22, 2018 27 minutes ago, gavino200 said: Inobu, were you ever able to see if you had an extra one of these portals to sell? I think I have 1 or 2. I just have to find it. I will let you know. Inobu 1 Link to comment
gavino200 Posted February 25, 2018 Author Share Posted February 25, 2018 First experiment with homemade light guides, and a tiny bit of "detailing" - a catenary. This isn't the practice tunnel pictured above. This is an earlier effort that I kept to use as a "pre-practice" piece. This isn't how I'm planning to paint the final tunnel. It's just grey latex paint, to flesh it out a bit. The purpose here was only to test the light tube idea, and decide on a length and thickness. This thickness is the winner. It seems about right and can be easily sourced. It's plastic from one of those little Kato decoder boxes, sawed, filed and sand papered. It's powered by a single led from behind. The LED is turned almost fully down, as the brightness doesn't scale well on my phone camera. But when turned up it creates a nice illumination effect. 4 1 Link to comment
Kiha66 Posted February 25, 2018 Share Posted February 25, 2018 Wow, nice work gavino! The "concrete" and light both look very realistic! Don't forget to run some thin wire between the lights to model all the cabling that is hung along the tunnel walls. 1 Link to comment
gavino200 Posted February 25, 2018 Author Share Posted February 25, 2018 4 minutes ago, Kiha66 said: Wow, nice work gavino! The "concrete" and light both look very realistic! Don't forget to run some thin wire between the lights to model all the cabling that is hung along the tunnel walls. Yes, wires are the next step. I also want pipes. And maybe a walkway. Link to comment
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