Re: [Aus-soaring] JS3/production techniques
At 06:49 PM 12/14/2016, you wrote: Poland is also becoming a threat Indeed. The GP 14 wing weighs 31Kg and broke at over 10g. Anyone know how they are building that? I had a chance to have a really good look at a Diana 1 a few years ago. When they say monocoque they mean it. Just about nothing in the fuselage besides the carbon shell apart from the main bulkhead and there isn't much to that. The cockpit appears to have one molded part that drops in to form the seat. I don't know if the fin and tailplane have any foam sandwich but they are small enough that just carbon monocoque skin would probably do as would the same on the outer parts of wings. The control system with the side stick is also a model of simplicity. I was impressed by all that and the small size. When I look at most gliders now I think that I'm looking at altogether too much glider. The Russia AC4 eliminated the pins on the end of the spar stubs. They fit into molded recesses in the opposite root rib. Means the pins aren't there to concentrate stresses and fatigue or corrode. Design is the key. Eliminate parts. Anybody can build something complex. Good design and engineering is making it as simple as possible. I don't think the bottle neck to glider production is actually making the wing and fuselage shells or time in the molds. Putting in dozens of small parts, all of which had to be made in molds or the metal shop or cut out of plywood and covered in glass (Schleicher) plus the finishing shop seems to be the problem. Shaping the glider isn't a problem if the molds are accurate and parts fit properly and Schempp obviously solved that problem for wings 30 years ago. I can see why gel coat is used but there are other ways of protecting molds and using highly toxic two pack paints would also seem to be overkill given that gliders generally don't sit outside in all weathers. A good quality single pack acrylic lacquer over a UV barrier undercoat would be as useful and very much easier to touch up and saves around 20 + Kg on a glider. The ongoing use of vorgelat (T 35 or not) is a disgrace. Certification is a problem and I suspect the established manufacturers love it as it is a steep barrier to entry for new manufacturers. Witness the drawn out process for the JS 1 to get certified in Europe. There was a bitter joke going around a while back that CS22 Amendment 3 read something like "all non German gliders must perform worse" meaning if it was better it wasn't going to get certified. Germany Inc. at work. Now if gliders were produced as kits and the designs were simplified as suggested above maybe using automated layup and pre pregs would be economical. At least certification would go away and owners would have a much better understanding of their gliders. The design however must be for the highest performance. In the past kit gliders have failed because they are only OK performance but not for contests. The world is awash with very cheap used gliders right now which offer 80% + the performance of new ones so a kit of that performance is going to fail. Mike Borgelt Instruments - design & manufacture of quality soaring instrumentation since 1978 www.borgeltinstruments.com tel: 07 4635 5784 overseas: int+61-7-4635 5784 mob: 042835 5784: int+61-42835 5784 P O Box 4607, Toowoomba East, QLD 4350, Australia ___ Aus-soaring mailing list Aus-soaring@lists.base64.com.au http://lists.base64.com.au/listinfo/aus-soaring
Re: [Aus-soaring] JS3/production techniques
The major German manufactures are cooperating with government help to investigate means of producing gliders more economically. They are concerned about South Africa’s lower labour costs. As Jonkers have produced 100 high performance gliders that otherwise might have been produced in Germany, pretty understandable. The German manufacturers have until now steadfastly refused to incorporate ideas proven successful by other manufacturers. Just think about Hotelier fittings and self connecting devices to connect wing functions to the fuselage. Harry Medlicott From: Mike Borgelt Sent: Wednesday, December 14, 2016 7:23 PM To: Discussion of issues relating to Soaring in Australia. Subject: Re: [Aus-soaring] JS3/production techniques It all comes down to money. Gliding isn't large enough to support the large capital expenditures to automate the manufacturing processes and I'm not sure making gliders a fair bit cheaper would actually increase sales by all that much as the sport appeals to a limited number of people, including a limited number of people who are already pilots. Mike At 12:58 PM 12/14/2016, you wrote: >>I do believe though that for the wings at least most have gone to CNC aluminium moulds. The German ones I saw were resin and about 7 years ago. However, two years in Dubai, I saw keels being machined out of solid steel billets inside machines which were large enough to fit a truck and other even larger CNC machines being used to machine one piece moulds for one-off 60' boats. There were also autoclaves as large as factories for cooking the parts. D ___ Aus-soaring mailing list Aus-soaring@lists.base64.com.au http://lists.base64.com.au/listinfo/aus-soaring Borgelt Instruments - design & manufacture of quality soaring instrumentation since 1978 www.borgeltinstruments.com tel: 07 4635 5784 overseas: int+61-7-4635 5784 mob: 042835 5784 : int+61-42835 5784 P O Box 4607, Toowoomba East, QLD 4350, Australia ___ Aus-soaring mailing list Aus-soaring@lists.base64.com.au http://lists.base64.com.au/listinfo/aus-soaring ___ Aus-soaring mailing list Aus-soaring@lists.base64.com.au http://lists.base64.com.au/listinfo/aus-soaring
Re: [Aus-soaring] JS3/production techniques
It all comes down to money. Gliding isn't large enough to support the large capital expenditures to automate the manufacturing processes and I'm not sure making gliders a fair bit cheaper would actually increase sales by all that much as the sport appeals to a limited number of people, including a limited number of people who are already pilots. Mike At 12:58 PM 12/14/2016, you wrote: >>I do believe though that for the wings at least most have gone to CNC aluminium moulds. The German ones I saw were resin and about 7 years ago. However, two years in Dubai, I saw keels being machined out of solid steel billets inside machines which were large enough to fit a truck and other even larger CNC machines being used to machine one piece moulds for one-off 60' boats. There were also autoclaves as large as factories for cooking the parts. D ___ Aus-soaring mailing list Aus-soaring@lists.base64.com.au http://lists.base64.com.au/listinfo/aus-soaring Borgelt Instruments - design & manufacture of quality soaring instrumentation since 1978 www.borgeltinstruments.com tel: 07 4635 5784 overseas: int+61-7-4635 5784 mob: 042835 5784: int+61-42835 5784 P O Box 4607, Toowoomba East, QLD 4350, Australia ___ Aus-soaring mailing list Aus-soaring@lists.base64.com.au http://lists.base64.com.au/listinfo/aus-soaring
Re: [Aus-soaring] JS3/production techniques
>>I do believe though that for the wings at least most have gone to CNC >>aluminium moulds. The German ones I saw were resin and about 7 years ago. However, two years in Dubai, I saw keels being machined out of solid steel billets inside machines which were large enough to fit a truck and other even larger CNC machines being used to machine one piece moulds for one-off 60' boats. There were also autoclaves as large as factories for cooking the parts. D ___ Aus-soaring mailing list Aus-soaring@lists.base64.com.au http://lists.base64.com.au/listinfo/aus-soaring
Re: [Aus-soaring] JS3/production techniques
When Carol and I visited Schleichers in 1988 they assigned a friendly bloke who gave us the tour of the what appeared to be a Bismarckian era building of unknown original purpose. One passageway had the molds for the ASH25 inner panel spars in it and I fully expected to see some folks working on wooden tailplanes for the Messerschmitt 109 on a Third Reich contract that someone forgot was no longer in force. Seeing them lay up the kevlar wing skins for an ASW 24 while the fog rolled in the open windows was interesting too. What was that about less than 50% RH? I'm not surprised about the manual typewriter. Somewhere on the Schleicher website they have a bit about how proud they are of their handbuilt gliders. Hand building is what every manufacturer on the planet is trying to avoid except in the German glider industry it seems. I do believe though that for the wings at least most have gone to CNC aluminium molds. The Discus 1 used concrete I think. We weren't allowed to see the molds for that in 1988 although Eberhard Schott was very proud of the accuracy and stability. Apparently there was only a 1mm line of un gel coated skin there. He said it would be better to just paint that line than put heaps of gel coat and sand smooth as you would lose the contour. Mike At 06:25 AM 12/14/2016, you wrote: >>Not only save weight but the wings wouldn't shrink, warp or develop waviness. Using pre pregs in the fuselage would save non lifting parts weight and save even more wing weight. Agreed. The German certified glider industry is not innovative these days. All the fuss about electric gliders is only possible because most glider pilots don't look to anywhere other than 3 factories in Germany. Their construction methods have not changed in 50 years. It's staggering to see a worker with a jam jar fully of poxy bog and a pop stick about to join a wing. The last place I saw a working manual typewriter in use was Schleichers, about 6 years ago. Of course, a little investment in ATL machines and proper moulds would help. I can't understand why yacht mast makers and boat builders can mill a mould from solid alu for a single boat while glider manufacturers stay with low-temp resin moulds which are reused for a decade or more. Maybe we're not paying enough? Though I believe the problem is almost entirely certification. D ___ Aus-soaring mailing list Aus-soaring@lists.base64.com.au http://lists.base64.com.au/listinfo/aus-soaring Borgelt Instruments - design & manufacture of quality soaring instrumentation since 1978 www.borgeltinstruments.com tel: 07 4635 5784 overseas: int+61-7-4635 5784 mob: 042835 5784: int+61-42835 5784 P O Box 4607, Toowoomba East, QLD 4350, Australia ___ Aus-soaring mailing list Aus-soaring@lists.base64.com.au http://lists.base64.com.au/listinfo/aus-soaring
