[Kelly W]

The transmitter issue is a possibility, but very unlikely. Glenn said he did that already. So long as the top position was truly trim up and stick up, there's not much else to discuss there. This is 99% likely to be an EGT probe issue. Sounds exactly like the cases I've seen in the past.

Not to knock down cliff's last post, but I'm afraid that's not correct with respect to teaching the ECU how to run on a new set of batteries. That may be true for Jetcat, RAM, any turbine using a FADEC ECU, etc. but don't assume this for every case. Every ECU manufacturer does this differently, some similar to others but the PST ECU does not do this...

Here's the short story... With the engine off, the user can adjust the 'target' idle and full throttle RPM levels. In the start-up sequence, the motor will reset the idle pump voltage, but it may need to be fine tuned after a throttle cycle I've found. Then with the engine running, the user needs to enter the full speed calibration functions and do this on their own. There's an automatic full speed option, but I recommend sticking to the manual version if you're changing altitudes between calibrations, just to limit the potential for an overshoot at the top end. The voltages (pump output pulse widths) at each end of the throttle curve will not change unless the user enters these functions again later. The ECU does not self calibrate in flight or with throttle cycles, so its largely running open loop and just watching the RPM and EGT for shut down limits if it happens to go out of bounds.

Kelly

[Pepperpete]

Thanks for the info guys. I will pull that probe out a bit and see if that helps. Because I tried again and it's still in the 750 and up range.

[Pepperpete]

Ok now I'm starting to get downright cranky. I bought this plane for hassle free flying and I'm still having turbine issues.

Now the new thing is when I'm running the turbine and I go full speed, it does settle at 160,000 (pulled out the probe) which is good but now the turbine will randomly start to slow spool down (a very slow shut down) and when it does it starts throwing flames out the back. They are not violent flames or anything. Not like a true wet start but it's enough to scare me. I always know it's going to happen because the turbine starts to get very loud in a rumbly way and not in a high pitched way and I lose thrust control and thrust. It's now done it three times to me.

What the heck is wrong with this thing? There is no way I would fly this plane with these problems. Its easy enough on the ground to turn off the fuel flow to get rid of the flames but if this happens in the air I'm completely screwed.

At this point I'm almost ready to call this turbine a lemon. Can anyone help?

[Kelly W]

What you're hearing is the combustion moving outside of the chamber. its suppose to happen well ahead of the NGV and wheel. If it goes over rich the combustion will move rearward. Once it starts to make it through the turbine wheel, you loose the differential pressure across the wheel. With no differential pressure, you loose torque and thus the compressor wheel will drag the motor slower. Meanwhile the fuel is still trying to ramp the engine up faster (on a PST ECU...), which makes it more rich, and the cycle goes further unstable to the point where the flames are visible. Its normally accompanied by a shut down due to EGT over the 800C limit, or rarely RPM below the minimum sustainable RPM (can't remember what that is at the moment.). Normally the temp will rise way faster than the RPM will drop.

The solution usually involves adjusting the ramp up settings in your data terminal. It can be attributed to a partially clogged / uneven injector ring, but that can clear with run time. It can also be aggravated with altitude.

Try running the following settings:

ramp up lo - 12
ramp up mid - 8
ramp up hi - 6

It may seem noticeably slower ramping up. If this isn't much different than your settings are today, please reply and let me know what they're set to right now.

see if that helps... :neutral:

Kelly

[Guest]

Originally Posted by Pepperpete

At this point I'm almost ready to call this turbine a lemon. Can anyone help?

Glen,
There are many things in RC modeling that can be very frustrating indeed. However, I know this engine is not a lemon. This engine was mine originally, I flew it in Reaction 54 (ironically, the R54 that Cliff has now).
I ran into a small issue with the engine doing basically what you are saying it is now doing, some flame out the back and then shut down. I slowed down the ramp settings under Dean Wichmann's advisement and I never had another issue. I used a Nicad pack on that engine though. Since Cliff has had it, I don't know if the ramp settings have been changed, though using a different type of battery may have affected the ramping at full charge (I don't know, just throwing that out there).
It is a turbine and this is a low hours turbine, it obviously needs some setup, but take it slow, put on your patience cap, and things will work out. Take Kelly's advice, he knows these engines better than anyone. The PST600R's have been good engines historically.
It will work out, but don't let yourself get frustrated, that's when bigger problems start to occur.
Jeremy

[Pepperpete]

My patience is very thin right now to be honest. I suppose I got spoiled with the "Just press go" Jetcat that I had although I know it was newer than this one by a huge margin.

Thanks for the settings Kelly. I will give that a try tomorrow. I've got to admit that if the ramp-up gets any slower I could make coffee before it gets to full throttle. I think I should have picked up something a bit newer but I'll try tomorrow to see if it will stay running.

[Cliff]

Hi glen , it could just need a few runs in her to get her cleaned out then change the settings to run a little faster. Go with kelly's advise as he knows this turbine well.

[Pepperpete]

Thanks for all the help and words of encouragement! Ok I've made the changes but it's a bit late to run her up. I'll give it a go tomorrow. The settings that were in the terminal are vastly different than what Kelly recommended so I am very hopeful that I will have success tomorrow.

[Guest]

So, did you run the engine again today?

[Guest]

hmmm, does no news equal good news?