GunnarO

Hehe... I just love TLA's (Three Letter Abbrevation) The SLA printer is a stereolithography printer. It uses an UV laser to cure a liquid photopolymer resin into a solid part layer by layer. It can produce highly detailed parts, but are often quite expensive and has a small build volume. (at least for the consumer market) The FFF (Fused Filament Fabrication) or FDM (Fused Deposition Modeling) printers uses a plastic filament as an additive material and melts the plastic in a heated extruder head to build the model layer by layer. The parts have often more structure in the surface and less detail, but build volume is usually larger. Mostly aimed towards the consumer market. Models are made in a 3D modeling software and exported as STL (stereolithography) file format. Both printer types use the STL model to produce G-code through a slicer software and use the generated code to control the position of the laser or extruder head. (G-code is also used for CNC mills and lathes to make parts by removing material from a blank) 3D printing is very popular these days, but it's actually a quite old technology. It was started in the late 70's and the term Stereolithography was patented in 1984, over 30 years ago. Enough history, back to the workbench... Cheers

Thanks! I kind of knew about part orientation, but had forgotten it all. I used to have a form1 SLA printer, but found it too messy and didn't use it that much. The resin got old and didn't work so well. It was messy and time consuming to clean the parts and needed sun or UV light to be properly cured. That said, it created parts with great detail. In the end, I sold it. I found the FFF printers to be more suitable for me, easier to print parts and more economical to buy filament instead of resin. I've printed a lot more with my Prusa i3 in the last 6 months than I ever did in 4 years with the Form1. I've seen the Form2 printers are much easier to work with though, that's the drawback of buying the first model of a new technology, it gets quite fast outdated. On the price point, I could buy 4-5 FFF printers for the price of 1 SLA printer and 9 (6,75kg) rolls of filament for a cassette with 1 liter of resin. It is important to think about what you want to use the printer for. For large scale models or rc models, I think the FFF printer is a better choice. For small scale and intricate detailed parts, the SLA printer is probably better, but you can buy a lot of models from online printing services for the price of owning one. What many people don't think of, is the time it takes to make the 3D models to be printed and the extent of CAD knowledge to possess to make them. You have no use of a 3D printer if you can't make the parts you want to print. Anyway, I've already started to increase the wall thickness. They got too flexible for printing correctly. I'll try to keep the 0,8 mm for the cockpit walls. At the moment I'm not planning on opening any panels or hatches, so increasing wall thickness shouldn't pose any problem. I'll probably get some details made by Shapeways, like a brass undercarriage and some flaps detail. They need to be stronger to carry some weight. Litho plates and tin pewter foil are on their way. Riveting- and other tools are ordered, there's a lot gone missing in 20 odd years... Feels good to be back at the workbench Cheers

Thanks! I stopped it before it was complete due to flexing of the nose/tail (mostly tail), but I think it was around 11-12 hours for 80-85% of the print. I didn't take any pictures of the printer display and it was to early for me to remember accurately. It was a detail print with 0,1 mm layer thickness, so quite slow. I'll put on a coat of spray filler to these parts this evening to see if that's enough for a good surface finish while the next print is running. I guess this process is more time consuming than building one from scratch with polystyrene sheets, but at least I can make another one much faster. (not saying I'm going to make more than one Whirlwind in 1/24 scale... although a prototype is tempting...) Cheers

So... I'm back. After several tests and failures, I've come up with something that seems to works quite well. And it was right in front of me the whole time. I'm using SolidWorks for my 3D models, and it's got some nice tools for checking the models. (I'd just forgotten it...) 3D printers don't like too much overhang on the models, that's usually when they start making spaghetti. So, by utilizing the right tools, I can check what angles are best suited for printing the parts. As wunwinglow said, odd angles tend to work best. I used a draft check to find the best angles that gives the least overhang in the geometry to set the base plate. I try not to make any angle larger than 45 degrees, less than that seems to work fine. This worked out nicely, the parts are just a little too long/tall to print without support. I have to add a support for the next, and hopefully final print of the fuselage sides. Cheers

You might want to check out abebooks for the Firefly from the Cockpit, I often find used books at a good price there. https://www.abebooks.co.uk/servlet/BookDetailsPL?bi=22524989231&searchurl=tn%3DFirefly%2Bfrom%2Bthe%2BCockpit%26sortby%3D17 Amazing and impressive work you are doing with your models Peter, You have inspired me to start building again after being away for 20 years. Thanks! Cheers

I am interested as well, if you're planing another sheet. Thanks.

You're absolutely right, I just had to try the other way. I guess it's the thin walls that make it difficult to print it properly. I'll try one more print with reduced speed to see how it works out before I make it a little thicker. Cheers

Wow, what a response ! Thanks @ Cap'n Wannabe: I'm using PLA for now. It's easy to work with, no warping and very little shrinkage. I do have a roll of colorFabb NGEN on order, it's supposed to have very similar printing properties to PLA and stronger than ABS. Looks like an "ideal" material, but not sure I need the strength though. So, how did the print turn out? Well, this test was not so successful. Some small pieces came loose and the thin walls did not work out well in this orientation. Comparing surface finish with the previous print, it's no doubt that vertical prints is better. Back to the drawing board... Cheers

Thanks a lot guys! You sure make newbies feel welcome here Cees: Thanks, I couldn't wait for HK Models to get started with their 1/32 scale version One of the downside to 3D printing is waiting for the next print to finish... looks like it's going to be a long night... Cheers

Hi all Have an idea that starting a thread here will help me get this done, but it's going to be a long lasting experience I'm afraid. Sooo.... This is my first build in years, (20 years in fact, kids have now grown and are starting to move out ) so I'm a bit rusty on building. At the same time I want to find out how I can use my 3D printer for this hobby as well. It will be a scratch building project and a lot of experimenting with 3D printing for model kits. The intention is to print larger parts as a "kit" and detail it with plastic card and whatever suits when building. I've seen some of the marvelous metal work done by Peter (Airscale), and plan to do something similar for the skin. (after a LOT of practice) The subject was a natural choice, I've been involved with the http://whirlwindfighterproject.org/ for some years. Doing all the CAD work for the project gives access to all available documentation there is on the Whirlwind, and that's what this model is based on. The Whirlwind is not a particularly large plane, in 1/24 scale it has a wingspan of 571,5 mm and a total length of 411,7 mm. That's why I chose this scale. Since the 1/32 scale model from Special Hobby has been announced, it would be silly to start a scratch build in that scale when a kit is soon to be released. Bigger is better... On to the experiments... I've chosen a wall thickness of 0,8 mm, and doing panel line details with a gap of 0,2 mm. Panel lines is just for placing metal panels at a later stage. Surface structure is present since I'm using an FDM printer, and I have to test if I need to do much filling and sanding before putting on metal panels. I'm using a Prusa i3 printer for printing, and I'm very satisfied with the detail level of the prints. I just have to figure out how to print thin wall parts most efficiently. First test was no success, they need a firmer base to stay put on the table... Next one... was ok I guess... (I have removed some details to have a clean and simple model to start with) I'll experiment some more and do another print before selecting what works best. Cheers