Just to inform you all on the way of doing business with Wren and David Owens:

yesterday I received a part of the conversion kit by Dave Owens; yesterday evening, Melanie, David's wife, called me for informing me on the rest of the stuff !!

This is the way I like to do business !!

I had already the same positive experiences with Wren !!

Keep up doing the good work you all !!

Thanks for your advice Bell, especially that third point :-)

Started the build last night, I'm doing it over a number of nights. A few things I had problems figuring out from the pictures, but it worked out!

I must say, it's a really nice engine. Well made! The craftsmanship is just incredible! You don't appreciate how well something is made until you have to build it from scratch. I'm a definite BIG fan of Wren!

Cheers,
Deron

ddragon (Quote)'The craftsmanship is just incredible! You don't appreciate how well something is made until you have to build it from scratch.'

You know that's exactly what I thought when I first built mine!
And the best bit is you will fly it more because you will feel that you have a total understanding of it and are no longer afraid to have fun and use it............
I do think that some people must worry about the hours they clock on their turbine engines, even the non home build Wren owners. But when you've built it yourself, I promise you that you can't wait for that 60 hours to be up, just because you will be burning to see whats inside after 2 years or more. That's how I felt anyway.
I think that it's great also that even the factory assembled owners may find that they are owerwhelmed with an intrest to see what's inside their Wren and so may dedcide to do the first service themselves. It's this choice that I like the most, we are model makers after all, so why shouldn't we have a knowlegde of every aspect of our machines. I don't want any no go areas on my model, I want to understand and feel total confidence with everything, and when you've done it yourself and seen it work!!!.........that's the best bit because you can say to yourself......
I DID THAT!
And what's more,
you will be a man my son!

I always did like Mr Kipling, and he does make exceedingly good poems.

Bell Bloke et al,,

the manual for the new 2nd stage gearbox says to put in 15ml of 90 wt gear oil before you use it..

Regards,

Doug C

here is the quote from the manual

Gearbox as supplied. Please note that it is supplied
EMPTY, 15ml of ‘Hypoid 90’ gear oil should be added
before use, preferably after fitting to helicopter. It is fitted
with an extended elbow to facilitate lubrication to tunnel
bearings. A dummy spacer is also fitted in place of the
power turbine wheel. The two tapped holes in the rear face
of the gearbox are for mounting the gearbox support, and
are through holes. Oil may therefore leak out if the screws
are removed.

Excellent post this - I eagerly await the next installment!

THE OLD STYLE GEARBOX......
If you have the older style (SUMP) gearbox where the oil is fed from the gas generator to the GEARBOX BEARING ONLY, then you need to put in 15ml of oil as you stated. Note that the old style gearbox oil feed from the gas generator feeds only the gearbox bearing not the gearbox itself. The feed pipe enters the gearbox at the bottom, and only 10mm from the exhaust.
This is only a bearing oil feed it is not gearbox lubrication.
With the old type of gearbox the oil is changed every 5-7 hours no more! The oil is best drained not from the drain plug but from the 2 bolts in mount 654 at the rear of the gearbox, while the engine is still warm.

THE NEW STYLE GEARBOX..........
If you have the new style gearbox you don't put any oil in at all.
There is an oil feed from the gas generator just the same as the old style box BUT......The new style feed goes into the gearbox itself from the side. So at first glance they may look similar but they are not. The new style needs no oil at all ever...

Good practice....
It's a good idea when running your engine for the first time, to check that the oil from the Gas Generator (jet engine) is running through the clear pipe. Remember that the oil is mixed with air from the compressor so it comes through in a kind of mist and is hard to see, BUT you can see it if you look hard so make sure that it is.
If it is not after 2 mins then shut down the engine and speak to Wren, or us here on the forum.
Note that this oil feed is needed for both types of gearbox, so it must be working. The only reason for it not to be working that I can think of is that the pipework in the fromt of the engine is either kinked or the restricter in the pipe is blocked. This can happen at anytime if you don't filter your fuel properly!
I have a 3 filters in my fuel can, then a filter on the filler pipe going into the helicopter, the helicopter tank has a filter clunk in the bottom, and finally there is a filter on the engine after the fuel pump. THIS LAST FILTER MUST BE AFTER THE FUEL PUMP!

There you go chaps! Did I miss anything.

Bell,

That last post was perfect. I don't think you missed anything. I will add my comment that the new style gear box requires a 5% mix of oil to fuel. In my older engine I mixed about a 3% to 3.5% mix.

Lou

Twin Bergen 44Magnums FBL Wren NW44s - Kero start

Second delivery of Dave Owens Conversion kit; some small parts

Last delivery of parts should be comming next week(s)

Restrictors and T connector.

I have a question for Bell, or DMR or anyone that build the Wren 54 before. I asked Sara this question and haven't received a reply yet.

But I'm attaching the restrictor tubes to the Y connector for the Air/Fuel lube. And according to the instructions I cut off the access tubing at the short end of the tube so that the brass restrictors went into the Y connector (see photo). Did I do this right?

Next question... I received the "Updated" T connector that the Lube Tube goes into. Instead of the nipples with the lock/screw ring... I got the nipple only connector. Problem is it looks like it's for a 4mm tube and not a 3mm tube. I don't want to force it on and split the tube. (See photo) What should I do?

I was thinking of ordering 3mm straight festo connectors that screw into the brass connector. Is there any reason I can't so this.

Thanks for your help!

Cheers,
Deron

New member of the Wren family.

That is different from both of my engines, the fitting looks better than a festo. The pipe does look a little tight but then it should be. What I would do is either put the end of the pipe in boiling water, ie boil the kettle and plunge the end in strait away or, wait for it.....chew the end of the pipe to make it soft and then push it on. The later idea sounds a bit stupid but it's what I do and it's never failed. If the pipe just will not go on while you are doing this then maybe the next size up is the answer BUT, it should be tight, so give it your best and it should go on! As for the restricters, I left mine 1cm from the festo, not in it. Not sure if the festo is going to disturb the restricter..... Thing is you have cut the pipe now so there is no easy way of moving the restricter down the pipe without damageing it, so I would leave it as it is...

Thanks Bell. I was able to heat up the tubing a little and push the restrictor down a cm. Should be fine. I'll try the same with some scrap tubing on the nipple.

Cheers

sorry ddragon but I didn't built the engine myself

hi d dragon
i had the same problem , when doing the T niple, i would say it is for 4mm and not 3mm because when you put the thredded bit on right tight it is not doing any thing,

so i done what bell said, good way of doing it,

but before i put the pipe on the niple i slid a 2/3mm approx
of tygon over the 3mm pipe, then when you get the 3mm pipe on the niple slide the tygon over the niple and do the thread bit up,
job done that holds the 3mm pipe to the niple nice and tight,

cheers kim

hi d dragon
just now looked at your photo see your type as no thead bit
so all you have to do is slide the short bit of tygon over,
cheers kim

Thanks Kim.
Cheers,
Deron

Kim,

great trick ! I will secure all my lines like that

still continuing this story...

I'm receiving bit by bit all the piece from David Owens.
When I noticed they mention a part in the manual that was not present in the delivery, I sent him an email.
Within one day the whole issue was solved and as I type, the stuff is coming to me.
This is how I like to do business, especially if you're new in the whole stuff, great service makes it all a lot easier.

If only every business man was doing business like David and Mel, the world would be a lot nicer !!

soon the building will start but first some family holiday....

Finished Product

Hi DMR - glad to hear that all is going well with the David Owens (Remove Before Flight) conversion kit and with Wren.
I've attached a couple of photos of my recently completed Wren / Cuatro / RBF machine.

I converted to 12 oz Sullivan oval aux tanks - same size as the MSR drinks bottles supplied by RBF - I like to physically see the fuel levels - also I was having syphoning issues with my MSR set up. Comments anyone please?

I'd also recommend Paul Heckles School of Flying near Swindon in Wiltshire UK. He can actually offer buddy boxed tuition with a school Wren / Cuatro. He did the fine tuning of the set up with mine - super bloke too.

Cheers
John B

I've got the last delivery of RBF and a nice RBF
cap too.
The battery plate and boom holders are really nice parts (like all the others)
I've ordered also some extra's at Wren (some festo couplers, an extra gas canister (RBF adds two clamps for the gas bottles, so lets use them ;-)) and some spare festo line (3mm); kind of having some spares in stock at home, not having to look for an inch of fuel line less or more.
The project can really start now (after the holiday period which is more of a family thing)