rsxse240 Posted February 27, 2015 Share Posted February 27, 2015 (edited) So I was looking at someone's build where the underhood looked really out of scale in the inner fenders and chassis details. So it got me thinking that the real cars don't have 3 inch thick fenders, why should our models? I don't yet have the ability or means to build a vacuum forming machine, but building some bucks (molds) isn't out of my ability. Maybe later this idea could come into a realized dream. How much more detail could actually be built in with accurately scaled sheet "metal"? I wanted to possibly plant a seed in some of your minds to possibly see what you all may come up with. Please Discuss... Edited February 27, 2015 by rsxse240 Quote Link to comment Share on other sites More sharing options...
blunc Posted February 27, 2015 Share Posted February 27, 2015 (going to get my popcorn and flame resistant pants...) Quote Link to comment Share on other sites More sharing options...
Ace-Garageguy Posted February 27, 2015 Share Posted February 27, 2015 (edited) Vacuum forming has been a staple technique of the modeling community for many years. Though it has some advantages in allowing the fabrication of close-to-scale-thickness parts, it also has several disadvantages. The fact that details don't form crisply with most vacuum-forming processes (which usually form the part over a "positive" mold) is one major drawback. I've been experimenting with making close-to-scale-thickness fiberglass parts since 2005, and have the process pretty well worked out. It has several advantages over vacuum forming, chief being that it requires no heat, and as the parts are formed in "negative" molds, sharp details reproduce perfectly. My fiberglass parts that are .020" thick are at least as "strong" as injection-molded styrene parts, are of consistent thickness (if you do it right) and will take a great deal of handling and abuse during finishing. These early parts are about .030" thick, and will take very rough handling. In the mold... Edited February 27, 2015 by Ace-Garageguy Quote Link to comment Share on other sites More sharing options...
62rebel Posted February 27, 2015 Share Posted February 27, 2015 vacuum forming works great for rounded contours but can't recreate crisp edges, and the parts are fragile compared to injection molding. they also require a lot of planning to eliminate undercuts, as they're also extremely difficult to recreate with the technology. the parts often vary greatly in thickness due to the variance in temperature and "sag" of the stock used, and small details are virtually unrecognizable. if scale edges are the issue, then thin the edges of your fenders, hoods, etc. making parts that can handle the process of building, painting, sanding and polishing almost precludes "scale thickness" in most cases. the process has been used for decades by aircraft modelers, though, and provides options that often simply are not available any other way. those builders have a tried and true system of reinforcing the inner structure so that they can complete their models without the risk of crushing it, usually by adding cyano glue and baking soda filler or similar methods to back up and thereby thicken the form. still, they're very susceptible to solvent damage from cement, primer, and paint, and can be short-lived in comparison to resin or styrene molded kits. i do think, however, that certain types of parts might be done well in vac form, mainly inner door shells, trunks, inner structures for hoods and decklids, especially where a builder might want full opening doors, etc. cementing these parts to thicker kit parts would impart added strength greatly needed. Quote Link to comment Share on other sites More sharing options...
62rebel Posted February 27, 2015 Share Posted February 27, 2015 the basic design of a vacuum forming machine is a box with a lid that has lots of holes in it, and a hole in the side for sticking the nozzle of a vacuum cleaner into. bingo. vacuum forming machine. nothing Harry Potter about it. Quote Link to comment Share on other sites More sharing options...
Ace-Garageguy Posted February 27, 2015 Share Posted February 27, 2015 the basic design of a vacuum forming machine is a box with a lid that has lots of holes in it, and a hole in the side for sticking the nozzle of a vacuum cleaner into. bingo. vacuum forming machine. nothing Harry Potter about it. Not magic, for sure. But it definitely takes skill, paying attention to detail. precise temperature control, and some applied intelligence on an ongoing basis. Well, if you want consistently good results, anyway. Quote Link to comment Share on other sites More sharing options...
Belugawrx Posted February 27, 2015 Share Posted February 27, 2015 I've been looking at Kijiji(ebay) used dental vacuforming machines for only $90. - $100. The ones they use to mold dental implants. Work surface ...about 5" X 5" Could get some windshields and smaller parts formed Quote Link to comment Share on other sites More sharing options...
rsxse240 Posted February 27, 2015 Author Share Posted February 27, 2015 I was thinking of items like windshields, inner fenders, radiator core supports, inner door panels and other blobby looking shapes that are either pressed or formed in a mold in 1:1. I realise the lack of detail that is inherent in vacuum forming, but if you remove all the wires, hoses, bottles, clips and the sorts from a real car, you're left with blobby looking shapes therefore vacuum forming would be great. However the fiberglass thing is way friendlier to the average do-it-yourselfer. Quote Link to comment Share on other sites More sharing options...
LDO Posted February 27, 2015 Share Posted February 27, 2015 You can build a vacuum former. It doesn't have to be big enough to make 1/48 scale bombers. I built this one a few years ago The brown "platform' is Perf Board from Radio Shack. It's super-glued to a Project Box, also from Radio Shack. The white pipe on the left of it is PVC pipe and fittings, put together with "blue glue" (very strong PVC cement). Get PVC that is as close as possible to a vacuum cleaner hose. Make up the difference with duct tape. Quote Link to comment Share on other sites More sharing options...
southpier Posted February 27, 2015 Share Posted February 27, 2015 Quote Link to comment Share on other sites More sharing options...
southpier Posted February 27, 2015 Share Posted February 27, 2015 from micromark Quote Link to comment Share on other sites More sharing options...
Belugawrx Posted February 27, 2015 Share Posted February 27, 2015 Yep that's the one Joe Now I gotta get one!! Quote Link to comment Share on other sites More sharing options...
rsxse240 Posted February 27, 2015 Author Share Posted February 27, 2015 OK,so I can see all kinds of uses for vacuum forming. I'm going to build one. My wife's been wanting a new vacuum for a while and that 12 year old dyson will be perfect for my project. Plus there's lots of parts for other projects. Quote Link to comment Share on other sites More sharing options...
Ace-Garageguy Posted February 27, 2015 Share Posted February 27, 2015 LDO (Lee)...using perf board for the stage is sheer genius. Great idea. Quote Link to comment Share on other sites More sharing options...
chunkypeanutbutter Posted February 27, 2015 Share Posted February 27, 2015 We have one here at school that's just a box of Masonite with holes in the top. Make something out of clay. Clamp some milkjug plastic between two wooden frames and heat it with a heat gun. Attach the vacuum to the pipe in the box, and put your clay thing on top of the box, slowly lower the frame over it, and there! Quote Link to comment Share on other sites More sharing options...
LDO Posted February 27, 2015 Share Posted February 27, 2015 (edited) LDO (Lee)...using perf board for the stage is sheer genius. Great idea. I can't claim credit for it. I read it somewhere, possibly Fine Scale Modeler. I don't remember. It's been years. Darn sure works, though. The frame to hold the plastic was just two pieces of corrugated cardboard with thumbtacks holding the plastic. good for one or two uses, but that's all. Wood is a much better choice. It does show that you can buy a few parts in an afternoon and be making model parts that evening, with the most complex tool being a hole saw. Edited February 27, 2015 by LDO Quote Link to comment Share on other sites More sharing options...
rsxse240 Posted February 27, 2015 Author Share Posted February 27, 2015 I have seen all of these being positive bucks in the vacuum forming process. If one were to make a negative buck, with the right kind of plastic, would you not be able to get finer details? Or possibly couple vacuum forming with Bill's fiberglass process to yield highly detailed very thin, rigid forms? When making fiberglass and carbon fiber auto, aircraft, or other type of panels, they use a vacuum bag or similar (depending on the part) processes to squeeze the air from the multiple layers and to press the resin into the details of the molds. Could this process be beneficial to yielding finer details with the fiberglass method? you could get some really nice details on a body, such as trim and body lines built on to your wooden buck, so as to cut down on detailing time on the working panel. Plus you could change the details on the buck and make several molds with varying details such as louvers, different grills, door panel shapes, etc. Ok, I'm getting lost in my imagination here. I know this topic has me thinking and new (to me) ideas are popping up. I hope you guys are getting as much out of this as I am. Quote Link to comment Share on other sites More sharing options...
southpier Posted February 27, 2015 Share Posted February 27, 2015 http://www.automodeler.com/modules.php?op=modload&name=Sections&file=index&req=viewarticle&artid=1243 http://automodeler.kitmaker.net/modules.php?op=modload&name=features&file=view&artid=705 http://public.fotki.com/notlezah/vacuformercollector/ http://www.starshipmodeler.com/tech/jw_vac.htm http://www.clubhyper.com/reference/vacformbg_1.htm http://www.finescalerr.com/smf/index.php?topic=2184.0 http://www.7-8ths.info/index.php?topic=16680998.0 http://www.gaugepods.com/vacuform/index.htm http://www.freerails.com/view_topic.php?id=5665&forum_id=6 i have more; let me know when your pain threshold is reached. Quote Link to comment Share on other sites More sharing options...
LDO Posted February 27, 2015 Share Posted February 27, 2015 OK,so I can see all kinds of uses for vacuum forming. I'm going to build one. My wife's been wanting a new vacuum for a while and that 12 year old dyson will be perfect for my project. Plus there's lots of parts for other projects. I've only used mine once, for that belly tank project. If you want to work out a trade, we can talk. Quote Link to comment Share on other sites More sharing options...
Ace-Garageguy Posted February 27, 2015 Share Posted February 27, 2015 When making fiberglass and carbon fiber auto, aircraft, or other type of panels, they use a vacuum bag or similar (depending on the part) processes to squeeze the air from the multiple layers and to press the resin into the details of the molds. Could this process be beneficial to yielding finer details with the fiberglass method? you could get some really nice details on a body, such as trim and body lines built on to your wooden buck, so as to cut down on detailing time on the working panel. Plus you could change the details on the buck and make several molds with varying details such as louvers, different grills, door panel shapes, etc. Ok, I'm getting lost in my imagination here. Your thinking is right on the money. I've been building vac-bagged glass and carbon parts for years (for 1:1 aircraft and surface vehicles). Carbon HAS to be bagged, as it is so rigid it simply will not follow any tight curves otherwise. Vacuum-bagging COULD be used to advantage on model glass parts, but adds a level of complexity that's not necessary for scale parts with the techniques I've developed. My parts have gone from .030" down to .010", and are still tough and can be finished using conventional processes. Surface details are reproduced perfectly, every time. Notice the surface details present on these parts and molds. Quote Link to comment Share on other sites More sharing options...
Tom Geiger Posted February 27, 2015 Share Posted February 27, 2015 fin Everyone forget about our favorite tool for burning houses down as kids? You can find original Mattel Vac-u-Forms on the 'bay for under $50. As others had said, vacuforming is limited to items with limited detail. Also, your new part will be once size larger than the original since the process wraps your plastic around the original piece. As such I found that I was best using it to form windshields. Here's a freshly formed windshield. I have found that I may have to make three to get one good one. Other times I get lucky. And the perforated sheets are still available through the source in this photo. Quote Link to comment Share on other sites More sharing options...
Ace-Garageguy Posted February 27, 2015 Share Posted February 27, 2015 Everyone forget about our favorite tool for burning houses down as kids? You can find original Mattel Vac-u-Forms on the 'bay for under $50 Bought one several years back, and it takes some hot-rodding (in my opinion) to get consistent results. Upgrades for these are available as kits, and common-sense mods will make it hotter and suck better. The size is a limiting factor too. Experimentation is critical to get a good part every time...for me, anyway. I don't have the patience to make 3 parts just to get one good one. I have both of these books, and recommend them to anyone who's serious about doing this stuff. Quote Link to comment Share on other sites More sharing options...
rsxse240 Posted February 27, 2015 Author Share Posted February 27, 2015 Thanks for those books, I'll see if I can get them on kindle Quote Link to comment Share on other sites More sharing options...
kruleworld Posted March 1, 2015 Share Posted March 1, 2015 (edited) So I was looking at someone's build where the underhood looked really out of scale in the inner fenders and chassis details. So it got me thinking that the real cars don't have 3 inch thick fenders, why should our models? I've built a couple of PETG vacformed shells that were intended to be used as slot cars. they are horribly flexible (lots of twist) and are difficult to glue or modify. They also lack detail and look kind of smoothed over. stick with styrene . the red one Edited March 1, 2015 by kruleworld Quote Link to comment Share on other sites More sharing options...
southpier Posted March 1, 2015 Share Posted March 1, 2015 (edited) i think the manufacturing process needs to be tailored to the subject. Edited March 1, 2015 by southpier Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.