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| Michigan Central Station Detroit http://www.rypn.org/forums/viewtopic.php?f=1&t=42098 |
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| Author: | PMC [ Fri Oct 23, 2020 8:23 pm ] |
| Post subject: | Re: Michigan Central Station Detroit |
https://www.freep.com/videos/money/cars ... 5lowoGCB7Y Could such laser devices someday be programmed to work with wood, for example, to duplicate intricately-carved moldings if you have an original? |
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| Author: | NYCRRson [ Sat Oct 24, 2020 8:42 pm ] |
| Post subject: | Re: Michigan Central Station Detroit |
Quote: Could such laser devices someday be programmed to work with wood, for example, to duplicate intricately-carved moldings if you have an original? Well, the 3D laser scanner shown in that video just measures the "shape" of the parts. This gets translated into a 3D computer model. Most of these computer models (AKA "Step" files and "IGES" files) comprise a whole bunch of very tiny triangular surfaces. Each triangle has all three corners defined in X/Y/Z coordinates and all the corners of the triangles must match the corners of an adjacent triangle. That process creates a computer model of any volume. Each triangle has a "vector" that points towards the exterior of the volume. How small the triangles are determines the "smoothness" of the computer model. With all the computing power available today a 3D computer model with tens of millions of triangles is common. Converting that computer model of the surface to a actual component made of a specific material is more of a production process question. Folks are 3D printing stuff out of plastic and metal today. Wood is a little different, since we can't 3D print wood (at this time), we can only remove wood that Mother Nature grew for us. But we should be able to "Laser Carve" complicated 3D surfaces from wood with the right equipment. Laser carving of 2D art work has been around for a long time (One year in the 1990's laser carved key-chain fobs with custom artwork where all the rage). All someone needs to do is program a Laser Carver to make multiple passes above a wood surface removing "stepped layers" as it goes to replicate some of those detailed wood carvings. Think of a 2D laser carver that makes "rice paddies" into a block of wood. As the carving gets deeper the "paddies" will "contract" inwards towards the center of the block of wood. If the "stepping" of the "rice paddies" is small enough (every 1/64 inch or so) then a "coarse" surface results which after some final sanding is very close to the measured surface. |
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| Author: | Termite7 [ Sat Oct 24, 2020 10:17 pm ] |
| Post subject: | Re: Michigan Central Station Detroit |
Before the advent of lasers and CNC cutting tools there were "copy carvers". Very simple tools they often use routers (or a spinning shaft) that follows a pattern to create a copy of a part. Big furniture companies like Karpen used banks of these to mass-produce the carvings on their popular furniture. Heck...even Sear and Roebuck used to sell one at their department stores. The market for these gadgets is melting away but they often show up on Craigslist and Ebay. They are fun to use and once you get the hang you can make a copy of about anything. Mass producing parts is very doable too...you just have to understand the tool and how it works. T7 |
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| Author: | jayrod [ Sun Oct 25, 2020 10:07 am ] |
| Post subject: | Re: Michigan Central Station Detroit |
Just to add a bit to what NYCRRson said, when the laser scan 3D computer model is produced, that in turn is converted into an AutoCad (or similar) file that a CNC router can understand. I’ve seen some pretty complicated pieces made from wood with a 3D router. There are some limitations on what you can route and you may have some finish work to do. Tight inside 3D corners within a relief comes to mind since you’re working with round cutting heads. An example: A lot of the ornate architectural trims and appliqués were cast from plaster back in the day. To reproduce them for a restoration, a laser scanner can map it and and a router can reproduce the mold. Costs may be an issue depending on either what is being scanned or what is being routed. An interesting story, I belong to a couple other groups that were both bemoaning the fact that there are no decent commercially available plastic models of a FM H20-44 and since drawings aren’t available, “someone” should scan one for 3D printing before they’re all gone. Out of curiosity, I requested a quote about two years ago to scan one and let’s just say that the cost to scan a full sized locomotive is not for the faint of heart. So far, a “someone” has not come forth to pony up the bucks to do it and I haven’t heard anything about it since. |
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| Author: | 70000 [ Sun Oct 25, 2020 10:18 am ] |
| Post subject: | Re: Michigan Central Station Detroit |
One of the groups I belong to, for a "new build" Edwardian 4-4-0, has recently had the wooden patterns made for the loco front bogie wheels using a CNC router... https://www.gcr567loco.co.uk/news The wheels have since been cast using them. |
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| Author: | Overmod [ Mon Oct 26, 2020 3:41 pm ] |
| Post subject: | Re: Michigan Central Station Detroit |
It occurs to me that the cost of a used TX8 or SX10 is something that could be spread across multiple projects in the historic railroad preservation field, much as 'death ray' ultrasonics were a generation ago. Even an integrated Leica pointcloud scanning setup would have a very long effective lifetime with relatively easy setup and capture in a variety of field environments, at a cost probably little more than just a few rentals or "consultant" visits. These also have value in making the equivalent of 'measured drawings' quickly and with very high precision. |
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| Author: | J3a-614 [ Wed Apr 28, 2021 7:21 pm ] |
| Post subject: | Re: Michigan Central Station Detroit |
A couple of stories out of Detroit that may be of interest here. https://www.freep.com/story/money/cars/ ... OF6vxyRklQ From 2018, but a good story with a happy ending. https://www.freep.com/story/money/cars/ ... 710459002/ |
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