RCU Forums - Jetcat Titan NGV

RCU Forums (https://www.rcuniverse.com/forum/)

- RC Jets (https://www.rcuniverse.com/forum/rc-jets-120/)

- - Jetcat Titan NGV (https://www.rcuniverse.com/forum/rc-jets-120/11555873-jetcat-titan-ngv.html)

mitchilito

06-28-2013 10:38 AM

Jetcat Titan NGV

1 Attachment(s)

I was replacing my bearings when I noticed a crack in my NGV. Since Jetcat will not sell parts I'm wondering if anyone out there may have a P160 NGV kicking around that I could get? Sure would help me out.

ddennison

06-28-2013 11:19 AM

RE: Jetcat Titan NGV

yikes. Glad you found it before something happened. How many hours on that turbine?

Good luck,
Dave

mitchilito

06-28-2013 01:28 PM

RE: Jetcat Titan NGV

Not really sure about the total history. But I'd guess more than 50 hours. The NGV on these big turbines is really stressed - more than any other component.

bcovish

06-28-2013 01:58 PM

RE: Jetcat Titan NGV

Well, we gave it our best shot[:o]

mitchilito

06-28-2013 02:36 PM

RE: Jetcat Titan NGV

Yeah Bob, turns out the P120 NGV is too small to work. Thanks for loaning it to me!

Still hoping someone out there might have a 160 ngv for me. . . . .

Henke Torphammar

06-28-2013 02:53 PM

RE: Jetcat Titan NGV

If it did turn up in the first hour of run it's no problem if it did in the 49'th hour it is a problem... Never fun to run with broken parts even though they might be perfectly fine in terms of performance.

AlW	06-28-2013 05:19 PM

RE: Jetcat Titan NGV

I sent a P120 to Jetcat last winter for service. This was the first service and the total run time was just under (50) hours. It was performing well with no issues but I figured that a bearing change would probably be in order. When it was disassembled the NGV was also cracked. I guess I got lucky!
Al

Turbotronic

06-29-2013 12:57 AM

RE: Jetcat Titan NGV

The casting in this case is actually holding up well in the sense that the stress caused by the welded on SS ring places extreme stress under temperature gradients. It would have been bad if the vanes itself were cracking.
The issue is ill conceived engineering by welding onto a casting using dissimilar metals. Another issue as a result would be turbine rubbing when running small tip clearances.
Andre

SJN	06-29-2013 01:15 AM

RE: Jetcat Titan NGV

Cant it just be stop drilled ?
Still lots of bits holding it together.

mitchilito

06-29-2013 02:39 AM

RE: Jetcat Titan NGV

It doesn't show up well in the pictures but the crack is propagating in several different directions. Stop drilling won't help. I'm going to try to TIG weld it but that's going to be iffy at best.

Anybody got a useable one out there for me (please!)?

josecilurzo

06-29-2013 08:58 AM

RE: Jetcat Titan NGV

Dont do it, very dangerous, high : temp, rpm, stress of exposure.

Jose

LN-JET

06-29-2013 09:37 AM

RE: Jetcat Titan NGV

I don't know how well it would match the turbine wheel, but maybe an unmachined ngv from D.Albisser can be adapted to your engine?
http://jetmax.ch/leitsysteme.htm

Lars

mitchilito

06-29-2013 01:49 PM

RE: Jetcat Titan NGV

1 Attachment(s)

Quote:

ORIGINAL: josecilurzo

Dont do it, very dangerous, high : temp, rpm, stress of exposure.

Jose

That's one perspective. Another is that after this TIG weld repair/anneal job we did today the NGV will be fine for at least 5 or 10 more hours.

You know what's funny is that all this would be unnecessary if Jetcat USA would just sell me an NGV!

Jackjet

06-29-2013 09:16 PM

RE: Jetcat Titan NGV

Quote:

ORIGINAL: mitchilito

Quote:

ORIGINAL: josecilurzo

Dont do it, very dangerous, high : temp, rpm, stress of exposure.

Jose

full size turbine parts are repaired by tig welding then heatreated - if you know what your doing.........that ngv should made out of inconel or hastalloy

jackjet

spaceman 01

06-30-2013 08:38 AM

RE: Jetcat Titan NGV

Hi there,
I have one with all the insides.
If you want call me at 312 375-6188, Nick.

GhostRider 1

07-01-2013 03:52 PM

RE: Jetcat Titan NGV

You can take apart your Jet Cat, change the bearings, change the NGV,put it back together and run it without balancing the rotor assembly? Isn't that a bit risky?

josecilurzo

07-01-2013 04:46 PM

RE: Jetcat Titan NGV

You have reason at this point, but JC, doesnt have some parts available...

Jose

mitchilito

07-02-2013 06:46 AM

RE: Jetcat Titan NGV

Quote:

ORIGINAL: GhostRider 1

You can take apart your Jet Cat, change the bearings, change the NGV, put it back together and run it without balancing the rotor assembly? Isn't that a bit risky?

I don't think I would recommend this course of action for everyone. However, since I have an A&P license and have spent a large part of my career overhauling and testing jet engines it just seems like business as usual.

As for not balancing, if the engine is reassembled EXACTLY like it came apart, with all the same parts (except bearings of course) it will not require rebalancing. After my rebuild it runs as smooth as ever.

basimpsn

07-02-2013 09:12 AM

RE: Jetcat Titan NGV

Quote:

ORIGINAL: mitchilito

Quote:

ORIGINAL: GhostRider 1

You can take apart your Jet Cat, change the bearings, change the NGV, put it back together and run it without balancing the rotor assembly? Isn't that a bit risky?

;)+
This youtube video show a full tear down and reassemble without balancing and its still running today.

http://www.youtube.com/watch?v=yeOt4z3rtio

http://www.youtube.com/watch?v=YjPL_The0Xc

All times are GMT -8. The time now is 11:56 PM.