Tadango

Good to see it running again EGT's look good. You made a flight with the 2 piece cone? I only get 4.62 kg's of thrust at 167k with the 2 piece. Egt's about the same as yours. A single piece cone from a 1200 (a bit wider then a 1400 cone) gave me 5.6kg's at 167. Egt rose 40-50.


Is it possible for you to measure the thrust?

Xairflyer

My Feedback: (1)

Yes flying has been done with two piece cone, I think the thrust is now the same as before with the single piece just going by the Push felt on the ground and the vertical performance. I believe I never had all injectors working properly from the start and the single piece cone then was poor, much different now. Single piece may be tried again at a later stage but not needed on this model anyway.

Xairflyer

My Feedback: (1)

Thanks maybe I have not worded it clear enough so I might take apart an old bearing today and take a pic showing the correct orientation of the inner cone to bearing outer case. Pictures do say much more, I will edit it in to that post.

chrigui

ok...no problem...

BJ64

Seamus, you've done an excellent job here in showing us n00bs how to go about stripping and rebuilding a Turbine.

Well done mate.

Is there any chance that you might be putting it all together in, say, a Word document that we could download somewhere and print off to use as a handy Manual in the garage?

Regards,

BJ

BJ64

...or, alternatively, if you wouldn't mind, I could cut & paste your work and collate it...

BJ

Xairflyer

My Feedback: (1)

I have planned to put it, plus other turbine related stuff, in a word doc for my own use (I forget easily ) and when I do I will probably put it on my website.

Jetbono

Yeah welldone Xairflyer , you done a great job and its good for all jj owners or at list most of them ..

Jetbono

Hey Pips

Im currently building a KJ66 style combustion chamber , does anybody know where I can get Inconel vaporizer tubes ?

Also WhichGrade inconel is best to use, 718 or 625 ??

frema

you can buy it at wren.
Its 600, enough for the sticks.

Jetbono

What is the best way to make the combustor ends such as in picture bellow ?

Press or Spinning ?

Whats best ?

chrigui

the part in the picture with pressing

Jetbono

Do you think I will get better finish by spining ?

Ok , how much pressur do you think I would need to press that ?

Xairflyer

My Feedback: (1)

I would suggest going onto the GTBA site for information like this, the guys there have been building KJ66 and other turbines for years and know the process inside out

Molnar142

My Feedback: (38)

Any chance I could get clarification on the orientation? One post says to put the tapered inner race towards the wheels (compressor and turbine) another post I interpret to mean one or both (not sure) should point towards the mid point of the shaft.
Which is it for both bearings?

Xairflyer

My Feedback: (1)

Again maybe the wording is not clear, the inner race is tapered and the narrowest part of the taper points IN away from both wheels.
The arrow on the bearing case is the best to follow it should always point out (towards the wheels). see pictures in posts 8,9 &13

text from post 8
After cleaning and inspecting the shaft/wheel a new ceramic D688/602976 GRW bearing can be fitted. The bearings have an arrow stamped on the outer case, (see pic) this is for fitting the correct way around, the arrow points out towards each wheel. The reason for this is the bearing inner race is tapered.

Molnar142

My Feedback: (38)

Got it. Thanks.
Was cleaning and reinstalling bearings in a used RAM750. No arrows on outer case. Wanted to make sure they were in the correct orientation.

Mike

chrigui

look this

jetrichie

I know this is an old thread but found it very useful recently for rebuilding my old wren 54

ledd4u

My Feedback: (23)

Very informative but man these bearings are extremely expensive. Don’t know how the manufacturers charge $300 for maintenance etc. The bearings are like $300 new.

jetrichie

dont know where you are buying them but last set cost me 120euro

ledd4u

My Feedback: (23)

I haven’t bought any, that’s what they seem to
be going for here in the USA. 120 is very reasonable. Where would that be obtained? Thank you in advance.