Levanter Posted March 10, 2018 Share Posted March 10, 2018 Seeing now that a whole range of filament materials are now available, is it possible to 3D print custom shaped fuel tanks for use with glow fuel (and maybe other types of fuel)? I know absolutely nothing about 3D printing but it has been on my wish list for quite a while. Levanter Quote Link to comment Share on other sites More sharing options...
Ian Jones Posted March 21, 2018 Share Posted March 21, 2018 I'm looking into this, don't have a final answer at the moment but I can say definitely do not use PLA. I've got a photo somewhere of some testing I did by leaving the filament in some fuel for a few weeks. Nylon is looking quite promising. Quote Link to comment Share on other sites More sharing options...
Levanter Posted March 21, 2018 Author Share Posted March 21, 2018 Hello Ian Thanks for the reply. I am steeling myself to make a matching pair of soldered metal tanks for the Grumpy Tiger Cub I am building but the idea of a 3D print intrigued me. Is it possible to print polyethylene? Looking forward to hearing how you get on. Levanter Quote Link to comment Share on other sites More sharing options...
Ian Jones Posted April 5, 2018 Share Posted April 5, 2018 Hi Levanter, Polythene? tell you the truth, I don't know. Big sort out in my garage today, might be able to get in there and get some work done soon, so hopefully will be making some progress. Edited By Ian Jones on 05/04/2018 18:06:22 Quote Link to comment Share on other sites More sharing options...
Levanter Posted April 5, 2018 Author Share Posted April 5, 2018 Hi Ian I have been hedging my bets and there are a couple of local cafes that are willing to donate empty 5 litre cooking oil cans that are rectangular and should give me plenty of flat material to work with. I would like to try some soldered tanks some time, The possibilities for 3D printing though are intriguing and who knows might even develop into internal wing tanks that would have freed up space for retracts on my Grumpy Tigercub build. Providing it works, the capacity for maximising volume in any available space could be very useful. I could also foresee built-in mounting lugs, filling points separate from the clunk feed, vents in the right place, internal baffles ....... water ballast tanks for gliders with the ability to dump, fire-fighting water for the Canadair I am going to build one day..... I am getting very excited. Levanter Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted April 5, 2018 Share Posted April 5, 2018 Levanter Wing tanks? I fear you would likely end up with the need for a fuel management system, internal baffles and a minimum usable fuel quantity - just like full size! On the other hand if you could make the tanks out of aluminium they could become part of the structure - a 'wet' wing! Quote Link to comment Share on other sites More sharing options...
Bruce Collinson Posted December 11, 2018 Share Posted December 11, 2018 Did anyone ever progress this very clever idea? I have to find a tank solution for an aerobatic designed for a Yamada where the tank was over the c of g, a good 10” behind the carb. Height/Jon Harper dictates that the new tank will have to go under the undercart plate to run a Laser 100 inverted. There’s a bottom cowl to fit over it all, limiting the height of the tank. Ideally the tank would nearly fill the bottom cowl and would need to be flat on top but a flattened circle underneath. Effectively it will occupy the space designed for the pipe and exhaust of the YS. I have not a whiff of an off the shelf tank which will fit and hold more than about 2 oz. the 3D printed option is winking at me, more than the idea of a chicken hopper. I suppose there’s a possibility of adapting a standard tank with dry sand and heat but I can see a lot of wasted time and tanks developing. Plan D could be a true cylinder, max. 38mm but it could extend 7 or 8” back if it occupied the cutout under the LE of the wing which I guess was the pipe outlet. If I wasn’t technophobic I’d try to post piccies. Needless to say the airframe was second hand to me, no destructions etc. Ideas welcomed! BTC Quote Link to comment Share on other sites More sharing options...
Pete Collins Posted December 11, 2018 Share Posted December 11, 2018 Back in days of yore when I was flying free flight diesel models, I improvised a tank by fabricating it out of balsa and Perspex, and fuel proofed it by painting it with warm epoxy inside and out before adding the last panel. Worked well and lasted as long as the model! Weather it would work in the more demanding environment of an RC model I don't know, but it might be worth some experimentation. Quote Link to comment Share on other sites More sharing options...
Bruce Collinson Posted December 11, 2018 Share Posted December 11, 2018 Thanks Pete. Just found a Sullivan Flex Tank which the maker claims is mouldable with a heat gun and am waiting to hear back from them as to how far it will mould without rupturing. This might be the solution I am seeking. I wonder whether anyone has first hand experience of reshaping them? US forums have the usual diametrically opposed opinions. BTC Quote Link to comment Share on other sites More sharing options...
John Stainforth Posted December 11, 2018 Share Posted December 11, 2018 The problem is that all 3D printed objects are very porous at a macroscopic scale. To properly seal a 3D printed tank would be very difficult. There is the additional problem that all plastics and plastic fillers are permeable at a molecular level and most model fuels are very aggressive penetrants of plastics. Quote Link to comment Share on other sites More sharing options...
SR 71 Posted December 12, 2018 Share Posted December 12, 2018 Hi Bruce i make my own tanks to fit my builds, i do them in fibre glass, i first make a plug the shape i need from blue foam, i glass it with epoxy resin and cloth, i cut the tank in half and remove the foam and the fibre glass layer, fit the connectors in and join the two halves with fibre glass, never had one fail, and i use them for both glow, petrol and in my jets Tony Quote Link to comment Share on other sites More sharing options...
SR 71 Posted December 12, 2018 Share Posted December 12, 2018 I must add that i give the plug a good 6/7 coats of mould release sprayed on before i do the actual tank glassing Quote Link to comment Share on other sites More sharing options...
Levanter Posted December 12, 2018 Author Share Posted December 12, 2018 Posted by John Stainforth on 11/12/2018 22:01:33: The problem is that all 3D printed objects are very porous at a macroscopic scale. To properly seal a 3D printed tank would be very difficult. There is the additional problem that all plastics and plastic fillers are permeable at a molecular level and most model fuels are very aggressive penetrants of plastics. John All the tanks I have are from some kind of plastic. We are probably saved from the effects you mention due to the tanks being empty for most of the time. In full sized boats, diesel and petrol tanks can be made from plastic and I suppose these are made from carefully specified materials. Levanter Quote Link to comment Share on other sites More sharing options...
Levanter Posted December 12, 2018 Author Share Posted December 12, 2018 Posted by SR 71 on 12/12/2018 07:00:54: Hi Bruce i make my own tanks to fit my builds, i do them in fibre glass, i first make a plug the shape i need from blue foam, i glass it with epoxy resin and cloth, i cut the tank in half and remove the foam and the fibre glass layer, fit the connectors in and join the two halves with fibre glass, never had one fail, and i use them for both glow, petrol and in my jets Tony Tony What sort of finish do you get on the blue foam using multiple coat of release agent and what release agent do you use? I am wondering is the core could be made using a foam that dissolves (in acetone or cellulose thinners perhaps) so that the tank did not have to be cut in half. Can you explain how you make your connections. Are they mechanically fastened or do you bond them in? I am still very interested in the 3D printing possibility but have toyed with the idea of laminating the tanks for a while now. Many thanks Levanter Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted December 12, 2018 Share Posted December 12, 2018 Commercial plastic tanks are blow moulded so are not any more porous that the gallon cans that your fuel comes in. Most bottles are blow mounded.This is done by extruding a tube of softened plastic then clamping a mould round the tube and blowing it up with compressed air. 3D printed tanks are formed by laying on multiple laywers of plastic which will have thin gaps between the layers hence the porosity Metal tanks are easy.They just take a little more time. Two dodges that you might like to know. 1) If you are fitting brass tubes into the tinplate make the hole by knocking a nail into the tank. This makes a small indentation round the hole.You then get a fillet of solder which is much stronger than you get round a drilled hole. 2) To fit a normal tank bung into a metal tank, Buy a 20 mm brass conduit bush. Cut the threaded portion down to 5 mm. Solder this into the tank and you can then fit a normal rubber bung. This is the Tank for Destiny. see my build blog for more detailed photos and instructions Edited By Peter Miller on 12/12/2018 08:27:21 Edited By Peter Miller on 12/12/2018 08:30:03 Quote Link to comment Share on other sites More sharing options...
Jon H Posted December 12, 2018 Share Posted December 12, 2018 I keep meaning to have a go at some tinplate tanks. One question you might be able to answer for me Peter is how to clean its innards afterward? I was going to fill it with thinners or something and just slosh it around to try and wash the flux out. Is there a better way? Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted December 12, 2018 Share Posted December 12, 2018 Hi John I tend to just slosh a bit of fuel around in the tank. Never had problem with flux in a tank and I have been making/using them since about 1955 Edited By Peter Miller on 12/12/2018 11:44:38 Quote Link to comment Share on other sites More sharing options...
Manish Chandrayan Posted December 12, 2018 Share Posted December 12, 2018 I would suggest that one does not use the tinplate tanks with glow fuel. With diesel and petrol it should be fine. The reason being that unless the material is pure tin, the tin coated mild steel that is mostly used these days will be prone to rust especially when empty and also due to presence of methanol residue that is highly hygroscopic Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted December 12, 2018 Share Posted December 12, 2018 Posted by Manish Chandrayan on 12/12/2018 13:06:06: I would suggest that one does not use the tinplate tanks with glow fuel. With diesel and petrol it should be fine. The reason being that unless the material is pure tin, the tin coated mild steel that is mostly used these days will be prone to rust especially when empty and also due to presence of methanol residue that is highly hygroscopic Even petrol will cause corrosion in tin plate tanks these days as it has up to 5% ethanol and is Hygroscopic , not as much as glow fuel but it still absorbs water from air. The ethanol is likely to increase to 9 or 10% in the future so be aware . Most cars now have plastic fuel tanks , I believe for that reason. I recently stripped a petrol engine and was surprised to find the early signs of corrosion on the bearing ! this was unheard of a few years ago and using petrol for washing parts (not advised I know ) it soon turns milky white from water absorption. Edited By Engine Doctor on 12/12/2018 13:29:10 Quote Link to comment Share on other sites More sharing options...
Jon H Posted December 12, 2018 Share Posted December 12, 2018 Back to paraffin for parts washing i suppose? Quote Link to comment Share on other sites More sharing options...
Manish Chandrayan Posted December 12, 2018 Share Posted December 12, 2018 I used to work in full scale aviation industry, where for washing parts Naptha was used and for preserving the engines transformer oil was used Quote Link to comment Share on other sites More sharing options...
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