Shenyang FC-31 / J-31 Fighter Demonstrator

Status
Not open for further replies.

delft

Brigadier
Video on the 3D laser printing techniques used to manufacture the stress bearing parts on the J-21.

Please, Log in or Register to view URLs content!


I have a feeling that we might be overestimating the empty weight of both the J-21 and the J-20.
What is the metal being used here?
I saw on the Y-20 thread the designer cites as mentioning the use of 3D printing on his project. To what extent is this or a similar technology used in other countries?

I remember seeing a little of the F-104 Starfighter production at Fokker half a century ago where I was told some fuselage bulkheads were made from thick slabs of metal using chemical milling, very much a brute force technique and pretty expensive. We've come a long way since then.
 

Air Force Brat

Brigadier
Super Moderator
What is the metal being used here?
I saw on the Y-20 thread the designer cites as mentioning the use of 3D printing on his project. To what extent is this or a similar technology used in other countries?

I remember seeing a little of the F-104 Starfighter production at Fokker half a century ago where I was told some fuselage bulkheads were made from thick slabs of metal using chemical milling, very much a brute force technique and pretty expensive. We've come a long way since then.

Would that have been the fillets and fairings of the center fuse or center section as we used to call it Delft? Brat
 

siegecrossbow

General
Staff member
Super Moderator
What is the metal being used here?
I saw on the Y-20 thread the designer cites as mentioning the use of 3D printing on his project. To what extent is this or a similar technology used in other countries?

I remember seeing a little of the F-104 Starfighter production at Fokker half a century ago where I was told some fuselage bulkheads were made from thick slabs of metal using chemical milling, very much a brute force technique and pretty expensive. We've come a long way since then.

Titanium alloy. The United States also employed 3D laser printing for parts used on the F-22. However, they were only able to manufacturer smaller components and not the critical load bearing ones like those used on the J-31. An interesting recent development is that the U.S. also started experimenting with ion beam based 3D printing, which may be superior to 3D laser printing.
 

delft

Brigadier
Would that have been the fillets and fairings of the center fuse or center section as we used to call it Delft? Brat
Not the fillets and fairings. The wings had multiple ( seven ? ) spars that slotted into extremely massive rings where they were secured by thick bolts. The rings were very complex pieces that were produced by removing some 95% of circular forgings using strong acid. To make a heavy forging of a complex alloy and then removing so much in a very destructive way ( you can't remelt it as you might with material that you machined away ) was very wasteful.
I wonder how the wings of its contemporary, the MiG-21, were connected.
 

Air Force Brat

Brigadier
Super Moderator
Not the fillets and fairings. The wings had multiple ( seven ? ) spars that slotted into extremely massive rings where they were secured by thick bolts. The rings were very complex pieces that were produced by removing some 95% of circular forgings using strong acid. To make a heavy forging of a complex alloy and then removing so much in a very destructive way ( you can't remelt it as you might with material that you machined away ) was very wasteful.
I wonder how the wings of its contemporary, the MiG-21, were connected.

I'm sure in the usual Russian fashion with large iron fittings.......nah just joking, I did actually have an invitation to ride in a Mig 21, kinda sorta, I really didn't think I wanted to, although the outfit that had it actually has a very good soviet bloc mechanic on staff and had at least two civilian Mig 29s. Its been nearly 15 years ago or so, the Mig 29s were nearly new, but some what rough. The purchaser had them shipped by rail in a rather nefarious manner, he himself a Naval top gun alum, hid in the trunk of a Mercedes, with two suitcases full of cash to get in and out of the country. They sat on the ramp until the embargo on fuel controllers was lifted, the first one had its first flight two years ago in December. It does well to remember that the Mig 21s safety record is prolly much poorer than even the F-104, and it was not known as a good low speed airplane either????? Although it does have a very fair combat record with its cannon????? Brat
 

Air Force Brat

Brigadier
Super Moderator
Titanium alloy. The United States also employed 3D laser printing for parts used on the F-22. However, they were only able to manufacturer smaller components and not the critical load bearing ones like those used on the J-31. An interesting recent development is that the U.S. also started experimenting with ion beam based 3D printing, which may be superior to 3D laser printing.

Well guys, one flight, two flights????? whats going on with the J-31, its seems to have dissapeared from the RADAR? I've developed a pretty good gut feel for some of these projects, J-20 has been draggy lately too, but is still moving along. Did the Russians say, hey we might share T-50 data????? whas-up......???? I would hate to see the J-31 left by the wayside, I still think it is the most promising Naval project to follow the J-15.... Brat
 

Lion

Senior Member
Well guys, one flight, two flights????? whats going on with the J-31, its seems to have dissapeared from the RADAR? I've developed a pretty good gut feel for some of these projects, J-20 has been draggy lately too, but is still moving along. Did the Russians say, hey we might share T-50 data????? whas-up......???? I would hate to see the J-31 left by the wayside, I still think it is the most promising Naval project to follow the J-15.... Brat

I think J-31 testing ground is in the north China which is out of sight for wall climber unlike J-20.
 

delft

Brigadier
I'm sure in the usual Russian fashion with large iron fittings.......nah just joking, I did actually have an invitation to ride in a Mig 21, kinda sorta, I really didn't think I wanted to, although the outfit that had it actually has a very good soviet bloc mechanic on staff and had at least two civilian Mig 29s. Its been nearly 15 years ago or so, the Mig 29s were nearly new, but some what rough. The purchaser had them shipped by rail in a rather nefarious manner, he himself a Naval top gun alum, hid in the trunk of a Mercedes, with two suitcases full of cash to get in and out of the country. They sat on the ramp until the embargo on fuel controllers was lifted, the first one had its first flight two years ago in December. It does well to remember that the Mig 21s safety record is prolly much poorer than even the F-104, and it was not known as a good low speed airplane either????? Although it does have a very fair combat record with its cannon????? Brat
OT
The safety record of F-104 in Europe was horrific. The Germans lost about a quarter of the 700 or so aircraft they bought and IIRC nearly a hundred pilots. The Dutch experience was a little better.
 

Air Force Brat

Brigadier
Super Moderator
OT
The safety record of F-104 in Europe was horrific. The Germans lost about a quarter of the 700 or so aircraft they bought and IIRC nearly a hundred pilots. The Dutch experience was a little better.

I think Spain did well with the F-104, and it probably had to do with how it was employed, the point I made was that when operated with-in its rather narrow envelope, it did relatively well, but you are right and I have since done some more research although that is tougher these days. The fact remains that with an approach speed of around 200knts the 104 is a handfull and you are certainly correct in that, and once in the turning and burning the 104 does have a very unforgiving nature.
All of the 100 series aircraft were a handfull, I was very dissapointed to learn the McD F-101 Voodoo also had some very nasty low speed manners, as of course did the F-100, and even the F-105, my point was as soon as safer airplanes came along we moved away from such "fun" aircraft, the F-4 even with a very "hot" nature had some aerodynamic fixes such as the cranked wings and dog tooth, and the anhedral on the horizontal stabs that minimized "Dutch Roll", LOL, that does seem funny doesn't it. Anyway, those early birds were very hot, but very intolerant of being "horsed around", likely having a cg that moved aft, much like the old P-39, also a bad ride at low airspeeds and high angles of attack. Brat
 
Status
Not open for further replies.
Top