My Wren 44 Turbine T-Rex 700 - Sneak peak

[Calil]

Originally Posted by KevinChiu123

Calil: Sorry for your loss. Hope the engine is not bad.......

"I don't know what's wrong, I believe who built it made some mistake in the fuel line and some bubble must have been the cause of it".......
I also suffer from the same problem. The engine quits on me twice 1 hour ago. I can see some bubbles in the fuel line...........
2 weeks ago, we found out that the hopper tank and the fuel filter have some air inside.....
We thought we solve this problem.

However, today, don't know the reason yet.......

Can anyone, such as Wren, help us?!

Thanks a lot for your help.

Originally Posted by GLimo

Pull off the data log from the ECU. This should give some clue why it shut down.

Post the .txt file here if you need some help.

/DG

How can I do that? The manual don't teach me how to.

[KevinChiu123]

Hi, dear Calil:

I got this following reply from Wren.

Because "I can see some bubbles in the fuel line..........."

Wren Turbines wrote on 07-15-2014 12:00 AM:
Hi KevinChiu123
Well if it is a fuel draw problem, I cannot help you to find the problem...it is in your fuel plumbing system. I advise that you remove the fuel system and leak check it...also ensure that your vent system is not restricted. Also check the filter.
If there is a restriction, the pump will run up to its limit and as soon as you change throttle setting, it will cause a cavitation in the delivery of the fuel.
I hope this helps!

I need to analyze my fuel system step by step......

[Calil]

Kevin thanks for sharing! I'll do the same. Change all the fuel line and filter. Then I'll make some very low flights, in IDLE1, when I got 10 or 20 tanks without fail then I'll fly again!

[KevinChiu123]

Dear Calil:

I just solve my problem.

I have 2 filters in my tanks that have too much restriction for the pump to suck fuel.

Since I changed to the ordinary one, everything is fine.

I set the engine rpm at 185,000 and test my throttle among 95-90-100%, the transition is perfect.

Hope my experience can help you.

Thanks a lot to Wren, USA.

[Coolice]

Hey.

From memory I think WREN also advise against the use of the felt type clunks in favour of the UAT type, as the felt ones can let small felt particles clog the turbine filter.

Here is a few pictures of the Trex T744 I currently have in my possession, not mine unfortunately, this belongs to a good friend who sadly passed away.
Having not been given the chance through WREN to try the MW44 heli engine, I jumped at the chance when asked to complete the build and setup of this T744 and a Bergen Magnum 44 (still sat in my loft in as new un-built condition) for my friend.
Sadly I am now tasked with selling both machines, but as you can see I enjoy(ed) every minute flying it!

Ian

[Calil]

Originally Posted by KevinChiu123

Dear Calil:

I just solve my problem.

I have 2 filters in my tanks that have too much restriction for the pump to suck fuel.

Since I changed to the ordinary one, everything is fine.

I set the engine rpm at 185,000 and test my throttle among 95-90-100%, the transition is perfect.

Hope my experience can help you.

Thanks a lot to Wren, USA.

WOW that's great news Kevin! Glad you found it! NEVER use this kind of filter on turbines! I don't use it so my problem is from other source. That I don't know yet.

I'm still waiting for new parts, it will take 1 to 2 weeks until I receive it. Till there the heli is fully disassembled, I'll redo it from zero.

I'll never let another person build a helicopter to me. Almost lost the most expensive of them, it's an error I'll never do again!!

[Calil]

Rebuilding proccess, this time with much more carefull to details and putting thread lock on the DFC head (the guy who built it before haven't done that! )

[Calil]

[Calil]

The turbine is small and, PLUS, my hand is giganteous

This turbine is a little jewell! I hope I don't destroy it.

[cbdane]

Looking good, Calil! I'm not seeing a support for the gas generator (gold turbine portion). Don't forget that; it's important!

[Calil]

Thanks cbdane!

I'm ordering the 44 engine mount from Wren, althoug I think it will not be usefull since it's for planes:

[KevinChiu123]

Wow!!! Congratulations!!!

Looks nice & great! Good to go.....

I agree with cbdane~

My personal opinion, just a thought.....

You might find some way to support the gold turbine portion because the "CG" is there.

[KevinChiu123]

The conversion kit should have "a metal strap" for holding the engine, right?

[Calil]

[Calil]

Hey guys

Reassembled the fuel line. You won't believe it, the filter was creating bubbles. I changed it, put a jet cat fuel filter, now before the solenoids, also I put some 6 mm fuel lines between the pump and solenoids.

Tomorrow I'll test everything again, I believe there won't be any problems from now on.

[KevinChiu123]

Originally Posted by Calil

Hey guys

Reassembled the fuel line. You won't believe it, the filter was creating bubbles. I changed it, put a jet cat fuel filter, now before the solenoids, also I put some 6 mm fuel lines between the pump and solenoids.

******
The filter makes some bubbles on me once, I solve the problem.

On the other hand, a new hanson UAT does not work well, but my used one works fine with me.

Tomorrow I'll test everything again, I believe there won't be any problems from now on.

The filter makes some bubbles on me once, I solve the problem.

On the other hand, a new hanson UAT does not work well, but my used one works fine with me.

Best luck.

[Calil]

Hey Kevin

Was your filter like this one?

[KevinChiu123]

Yes, I think so.

[Calil]

Did it came with your turbine? Because if so, I think we should alert WREN about a possible vicious problem.

[KevinChiu123]

Yes, mine came with the turbine.

However, this is what I did, suggested by a friend of mine.

Use a big pump (not the pump on the heli) to run fuel from your outer gas supply tank to go through all of your fuel lines/tanks on your heli.

In order to make sure the inner bag of the UAT, fuel lines, and the fuel filter..., etc. are fully dipped in fuel and make sure that any possible air/bubbles are cycled out of your fuel line.

You may need to run 2-3 liters of fuel by this procedure.

Then, test run the heli for a full tank (i.e., my tanks are 1.2 liters) without main blades.

Try the throttle transition to see if the turbine runs ok.

If it is fine, then install main blades.

Best luck.