reedy
Veteran Member
Joined: January 2017
Posts: 111
|
Post by reedy on Jan 21, 2018 8:14:33 GMT -5
Hi Jeff I agree with John about the metal thickness 0.016 (I used 20 thou 304 spot welded)is getting too thin unless you have gone with something more heat resistant than stainless,only saving grace is the burn in the FD3 is not as intense as a KJ. I try not to fully weld up a combustor until I am happy with it,I weld the inner to the front combustor and the outer to the back then use 0.020 stainless welding wire and wire it together at the front outer corner drilling 1mm holes in about 4 to 6 places. The 10 large holes near the front are going to blow deep into the flame and with 8 sticks will cause uneven stick temp on some sticks unless your sticks don't go in that far ? My standard size FD3 used 8 sticks. I tried changing the flaps to 6mm holes, seemed to work better,I would not do louvers as it needs to stop the flame coming out louvers will make the cooling air more of a skin cooling . Link to kingtech k-80 F sticks lot of work and welding, good design medium size holes on outer can to blow across ends of sticks ,can't find a picture of inner hole pattern. No skin cooling holes on outer can at the back in fact not many small holes on outer can. shulmanaviation.com/product_info.php?cPath=56_73&products_id=2571Chris
|
|
|
Post by jetjeff on Jan 21, 2018 13:34:53 GMT -5
Hi Chris, The U shaped tubes go down about 2" or so. The burner can is welded up,,,just have to cut the flaps in the outer can. Regards Jeff
|
|
|
Post by jetjeff on Jan 24, 2018 11:06:13 GMT -5
Hi Guys, Here is the finished burner can. Regards Jeff
|
|
ripp
Veteran Member
I'm sorry, I don't speak english, so I torment you (and myself) with a translation program,Sorry
Joined: January 2013
Posts: 231
|
Post by ripp on Jan 24, 2018 15:52:59 GMT -5
Hi Jeff, You are doing an excellent job, but I can not understand why you're holding onto an old combustion chamber design. This shape of combustion chamber has worked reasonably well with an evaporator coil. But you use bent sticks and these are also blown by cool air from the tertiary holes (very bad !!!). You want a well-functioning turbine so build a modern combustion chamber, or at least adapt the hole design. www.gtba.co.uk/engine_designs/schreckling.htmwww.modelbouwforum.nl/threads/ik-ga-ook-een-turbine-bouwen.72354/This combustion chamber ran without hot spots (1996). good luck Ralph translate.google.com
|
|
|
Post by jetjeff on Jan 24, 2018 16:47:26 GMT -5
Hi Ralph,
Thanks for the reply and your input. I'm basically copying the design of the Swede that built the 2:1 Schreckling engine.
Also, from my experimenting with old designs, I found my Schreckling engine showed the most promise in trying to run, although my Kamps build actually runs.
Respectfully
Jeff
|
|
reedy
Veteran Member
Joined: January 2017
Posts: 111
|
Post by reedy on Jan 25, 2018 9:04:53 GMT -5
Hi Jeff
Excellent work as usual,you said you are basically copying the x2 engine just that you have deviated slightly and it has caused problems,if you look at your combustor and his the inner cone is more tapered on his as per the book then he has added finger flaps on the NGV to seal the cone at the back.
Looks like you opened the cone (less of a taper) to fit the kamps style NGV that does only make it tighter at the front but not by much but it is already very tight.
X2 engine build thread say's he reduced the size of the big main holes and also some of the smaller holes at the very front to offset the extra air from the u tubes.
On a lot of combustors the orientation of the inner and outer raps must be so and the stick straight or u shaped must align/avoid holes.
The 8 sticks cause problems as they align /block some of the 10 large holes,you can see in the middle picture of three (jan 21)
If you could have put 10 shorter u sticks and 10 holes as per x2 jet engine and aligned the cross over v shape in the sticks to the 10 holes . 10 Straight sticks from the back would have been my option or the updated design PT35 combustor design.
Kurt fitted 3 u sticks to the original combustor just to try them knowing it was not enough he then redesigned the combustor with a straight inner and outer at 95mm and six u sticks at the front this is the first combustor I made to fit the fd3/64 but later fitted the hobbyjets 631/ PT35 combustor which was better.
Kurt did not put any holes in the outer combuster (99mm dia) but found out at one of the GTBA meetings ( think it was Mick Murphy wren turbines or Mark Drake 631 hobbyjets) that you need a certain distance between the outer combuster and the casing or the air is restricted and does it go through the holes,Kurt mentions this in his book on the TK50 made from a thermos flask he used the inner part to make the outer combustor gave him the right air gap.
Basically the outer combustor 99mm dia on the FD3/64 is too big a diameter to have holes that would work.
Hey-ho, it is what it is now, suck it and see at least you are moving forward with the build not sat on your arse typing these words of wisdom /tripe ( delete whichever you think is appropriate] the combustor can easily be modded or replaced later when you have the engine running.
ATB Chris.
|
|
ripp
Veteran Member
I'm sorry, I don't speak english, so I torment you (and myself) with a translation program,Sorry
Joined: January 2013
Posts: 231
|
Post by ripp on Feb 14, 2018 1:16:51 GMT -5
Hi Jeff, what's new with you?
Ralph
translate.google.com
|
|
|
Post by jetjeff on Feb 14, 2018 8:16:12 GMT -5
Hi Ralph,
Just getting over some kind of bug that had me off my feet for about two weeks.
Working on the last main part of this build, the fuel manifold.
I still need to order the bearings for it.
Regards
Jeff
|
|
|
Post by jetjeff on Feb 14, 2018 13:53:35 GMT -5
Hi Guys,
Here is the finished fuel manifold. I got lucky silver soldering and didn't have to redo any plugged needles.
Hmmm,,,I can't seem to upload a picture at this time.
I used 16 gauge needles, .065" diameter, I get them from TSC (Tractor Supply Co.), they are for giving livestock vaccines and other meds.
Regards
Jeff
|
|
|
Post by racket on Feb 14, 2018 15:43:17 GMT -5
Hi Jeff
Its always good to have that fiddly job done .
Yep , I've been having problems with uploading pics as well
Cheers John
|
|
reedy
Veteran Member
Joined: January 2017
Posts: 111
|
Post by reedy on Feb 20, 2018 10:19:59 GMT -5
Hi Jeff Glad to hear your well again. I got off my Arse and got my KJ66 going again on the test stand made about 3.1kg at 0.8 bar at 300c check it out on my YouTube channel reedy93. Not easy filming and running an engine had to keep resetting the scales every time they froze.
Regards Chris
P.s also been working on electric starter using a trigger(£2.50 off eBay from china) for a 24v electric drill so i can start it slow.
|
|
|
Post by jetjeff on Feb 24, 2018 9:09:12 GMT -5
postimg.org/image/kpu7jschn/Hopefully this link takes you to my picture of the finished fuel manifold. If not I've run out of ideas to try to upload pictures, I think other JATO members are having issues as well. Chris, thanks. It's good to see you dusting off your builds and running them again!! And posting new YouTube vids. This summer I'd like to see the Heinkel flying. Regards Jeff
|
|
|
Post by jetjeff on Apr 15, 2018 10:23:34 GMT -5
Hi Guys, Sorry its been so long since my last post. I've taken a job as a machinist after getting surplused by AT&T. Kind of interesting as the company I work for helped manufacture a small (model sized) turbine. The company was absorbed by a lager company and further work on the small turbine was halted. See the cutaway pic,,,it used a radial turbine. It took a stupid long time for me fitting the main fuel manifold and starting gas injector to the outer case, on Heineken II. Starting to fit the components together for Heineken part II. s7.postimg.cc/iuirvwx97/DSC00098_39.jpgs7.postimg.cc/d6ch4yvgr/IMG_0719_1.jpgRegards Jeff
|
|
|
Post by jetjeff on Mar 16, 2019 13:53:43 GMT -5
Hi Guys, It's been a while since I started Heineken part II, but it's finally ready to test. A job loss, a career path change (at 57 years old!!!) and life's typical interruptions, delayed my project, but it's ready to run now. Working as a machinist for the last year has greatly improved my machining abilities at home. I had to remake the shaft for this engine out of solid chrome moly, my tube shafts were simply not accurate enough. Regards Jeff
|
|
|
Post by racket on Mar 16, 2019 16:15:43 GMT -5
Hi Jeff
Pretty :-)
All the best with the first spoolup.
Cheers John
|
|