Steven S Posted December 3, 2019 Share Posted December 3, 2019 Any local craft store that sells vinyl cutters should have some. The "Michaels" here sell 84 different colours, including a couple of golds. Quote Link to comment Share on other sites More sharing options...
David Hayward. Posted December 3, 2019 Author Share Posted December 3, 2019 Thank you all for your suggestions; much appreciated. Quote Link to comment Share on other sites More sharing options...
David Hayward. Posted February 9, 2020 Author Share Posted February 9, 2020 My Chorus Gull is finally finished so here are a few photo's taken along the way. I based this on the David Beale Mew Gull replica, and also scaled the plan up 20% to give the model a wingspan of 6ft. Scaling up meant I had to make my own canopy, so I will add another post with a video showing production of the canopy... Quote Link to comment Share on other sites More sharing options...
David Hayward. Posted February 9, 2020 Author Share Posted February 9, 2020 Here is the video showing production of the canopy... Edited By David Hayward. on 09/02/2020 12:16:11 Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted February 9, 2020 Share Posted February 9, 2020 Why do you not get creases from the plug to the corners of the vac former? My last few attempts have been useless because of this problem. Quote Link to comment Share on other sites More sharing options...
David Hayward. Posted February 9, 2020 Author Share Posted February 9, 2020 Posted by Martin McIntosh on 09/02/2020 19:24:30: Why do you not get creases from the plug to the corners of the vac former? My last few attempts have been useless because of this problem. Well, probably more luck than design as I am no expert at vacuum forming, this being my first attempt. What you see in the video is actually my second attempt as I did not heat the PETG enough first time and ended up with a perfectly formed 3/4 depth canopy. I watched as many YouTube video's as I could find of people making all sorts of vacuum formed components and noticed the problem of creases forming at the corners. To try and counter this I made the plug about 1/2" deeper than it needed to be and then later also spaced the plug up from the vacuum form box by another 1/4" because I felt the 1/2" already added might not be enough. After the second successful attempt I did in fact have a couple of small creases but these were lost when the surplus depth was removed. If I do this again I would just make the plug a good 3/4" deeper than needed. Other than that I guess it's down to heating the PETG to a high enough temperature and having good suction. Hope this helps. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted February 10, 2020 Share Posted February 10, 2020 I have probably watched the same videos as you and quite a few people had the same creasing problem. Have tried the usual oven heating, a heat gun and a combination of the two. I even modified my frame to have rounded corners, same result. Tried propping up the plug too; the vacuum and seal are strong. I got through most of an 8x4ft sheet of PETG making the five needed for my Lancaster. I had more success the first time I tried vac forming, it must have been beginner`s luck also. Thanks for the info. Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted February 10, 2020 Share Posted February 10, 2020 The sheet needs to be so hot that it will sag under its own weight Then transferred to the vac forming machine quickly as David demonstrated It's a good idea to have a look at bespoke machines You see the heater above the sheet, and the sheet starts to sag Then is pulled down onto the plug to be drawn down Quote Link to comment Share on other sites More sharing options...
Piers Bowlan Posted February 10, 2020 Share Posted February 10, 2020 Beautiful work David, love the video too, you make it look so easy (it's not!). Looking forward to the flight reports. Quote Link to comment Share on other sites More sharing options...
Steve Jones 2 Posted February 10, 2020 Share Posted February 10, 2020 Looks great , What thickness of material do you use and what temp for the oven and how long would you say.. I know its trial and error for the part you are trying to form but some pointers would be useful please Steve Quote Link to comment Share on other sites More sharing options...
David Hayward. Posted February 10, 2020 Author Share Posted February 10, 2020 Posted by Steve Jones 2 on 10/02/2020 12:18:39: Looks great , What thickness of material do you use and what temp for the oven and how long would you say.. I know its trial and error for the part you are trying to form but some pointers would be useful please Steve Hi Steve, I used 1mm PETG bought from Trent Plastics, oven temperature was set to 230 degrees C and pre-heated for about 5 minutes. PETG was in the oven for about 3 minutes and I had to turn it half way as it was sagging quite a lot more on one side. I waited until the PETG was sagging by about 3" before attempting the 'pull'. Quote Link to comment Share on other sites More sharing options...
Nigel R Posted February 10, 2020 Share Posted February 10, 2020 Very nice work David Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted February 10, 2020 Share Posted February 10, 2020 Exactly as I have been doing David, only the gods were not smiling on me. What size is your frame, A3? I shall have a look at Trent Plastics. Lucky with my 1/4 scale Gull. I picked up a perfectly sized canopy from a box of bits at a show. I still have the female moulds for the grp u/c pants but mine are the long version which I prefer. Quote Link to comment Share on other sites More sharing options...
David Hayward. Posted February 10, 2020 Author Share Posted February 10, 2020 Posted by Martin McIntosh on 10/02/2020 15:10:38: Exactly as I have been doing David, only the gods were not smiling on me. What size is your frame, A3? I shall have a look at Trent Plastics. Lucky with my 1/4 scale Gull. I picked up a perfectly sized canopy from a box of bits at a show. I still have the female moulds for the grp u/c pants but mine are the long version which I prefer. Martin, the frame is 460mm X 260mm Quote Link to comment Share on other sites More sharing options...
David Hayward. Posted October 19, 2020 Author Share Posted October 19, 2020 I finished the Chorus Gull in February 2020 but it has taken till now for the maiden flight for which I engaged the services of Derek one of our resident test pilots; I just managed the camera... Quote Link to comment Share on other sites More sharing options...
Trevor Posted October 19, 2020 Share Posted October 19, 2020 Brilliant - congratulations David! Always good to hear of a successful conclusion to a project. Trevor Quote Link to comment Share on other sites More sharing options...
Geoff S Posted October 19, 2020 Share Posted October 19, 2020 That looks really good, David. One of my favourite aircraft. I'm pleased to see that you also chose to represent a different Mew Gull than the usual G-AEXF of Alex Henshaw even though it's a copy - so a model of a 1:1 scale model Here's mine I built 3 years ago. It flies really well on 6S but landing is a nightmare because it has a tendency to nose over. I've angled the u/c forward which helps but now the spats don't fit. I may use your spats as inspiration. Not a Chorus Gull but but from a part kit (Complete-a- Pak? - can't remember). Geoff Edited By Geoff S on 19/10/2020 17:07:44 Quote Link to comment Share on other sites More sharing options...
David Hayward. Posted October 19, 2020 Author Share Posted October 19, 2020 Looks great Geoff, see you have the proper spats and indeed mine will nose over as well with not too much provacation; sharpening up my landing skills! Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted October 19, 2020 Share Posted October 19, 2020 Very nicely flown, you should be pleased with your effort. Your test pilot made a faultless landing. Quote Link to comment Share on other sites More sharing options...
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