Steve N.

Hi DrV,
Yes it does help, thanks. Yeah, I've used the 5/8" in the past without the bypass, but wasn't sure if that should vary with. Great explanation on rotation of the turbine.
Thanks again,
Steve

phantom_najd

My Feedback: (2)

On the subject of thermal insulation, I recommend that you wrap a sheet of BVM ceramic heat blanket on the exhaust pipe at the section of the horizontal stab opening.



Azzam

Steve N.

That's a great tip. Thanks Azzam.
Steve

Dave Wilshere

At UK temperatures its not needed...

737Driver

Made a lot of progress the past few days. Thought I would post a few photos. I went with a heat blanket, mostly out of paranoia, for the horizontal stab area, very easy to do, Auto Zone for the blanket. The riveting method worked out sweet for bell housing, very easy and secure. Pretty much just have to install the motor, nose gear and tidy up cockpit.

Let me me know if anyone has questions.

Tom

phantom_najd

My Feedback: (2)

I don't think this method is needed for any temperature. I used it mainly to protect the elevators cables should they come close to the ducting during a high G maneuver.

Azzam

Dave Wilshere

I have a velcro tab that sticks them to the fuselage side.

Another UF for my local grass club...14 or 15 now!

P-90Rxi in this

dbsonic

My Feedback: (3)

Tom, not too heavy hopefully and not an issue for CG?

737Driver

Are you referring to the heat blanket causing CG and weight issue? That blanket is about 3-4 mm thick at most, in my mind, that weight/CG should be negligible as far as AUW. I will for sure check CG when all done.

Question???????


Those 2 half round pieces of carbon fiber that surround the motor. How are they secured in place? Are they necessary? Do some of you leave them out all together?

Thank you!!

phantom_najd

My Feedback: (2)

Tom, are you referring to the bypass? See this picture



The procedure of installing it is shown clearly in the manual.

As for why do we need them; I believe they help into ramming the cool air around the engine case making it run a bit cooler. I read on this thread that a full bypass makes the plane a tad faster. I, however, like to install it to have a little cooler engine and I love the sound of the engine when the bypass is there.

I have just completed engine, exhaust duct and fuel system install and I will take some pictures nect time I go to my work shop.

Azzam

phantom_najd

My Feedback: (2)

Here are the pictures



As you can see I installed the Jet-Tech saddle and wing tanks. I selected the modified saddle tanks that allow the install of full intake ducting and dedicate them for fuel while I dedicated the wing tank for smoke. I used MPX connectors to connect the wing servos and placed mating connectors on a plate inside the fuse (I really like the solution in my opinion much better than normal servo extensions). I used a very cool method to locate the opening for the rudder servo arm. I attached a pin to the arm and installed the servo in place then using a servo tester I moved the arm until the pin penetrated the vertical fin skin and took the servo out reversed the pin and poked the other side. Joind the two small holes and started the surgical cut it is almost perfectly centered. I also like the new nose wheel with steering servo plate although installing it required hacking the gear mount a bit but the end result was perfect. All in all, my installation is going very nice and very fast, maybe because it's my second UF. Should any of you guys want more information on any of the things you see in the pictures above, I will be more than happy to share them with you.

Azzam

737Driver

Phantom


thank you for the pictures. The engine bypass explains it, many thanks. A buddy of mine flies his Flash with a bypass and used to smoke my Classic all the time, plus his sounded awesome! I hope to have the engine mount and nose gear done tomorrow, love the direct drive for NWS!

phantom_najd

My Feedback: (2)

A question to Dave and others:

What's the best technique to grind flat spots on the pins that connect the trunion to the struts on the behotec landing gear?

Azzam

Dave Wilshere

I fix the pin in the leg with flats done using a wheel, so there are no sharp ends on the flats. The Airtech legs with 4 set screws 2 flats are enough. Use blue loctite, just a spot the same size as the thread diameter.
then I put the legs in position, nip one of the two set screws once the toe in is set. Then the other hole I screw in set screw with damp marker or paint on the end. This marks the flat line for the two set screws. Again use a round wheel, the flat does not need to be any more than 1/16" wide,
.
Loctite again and nip with a ball ended driver- but tighten with a 90 degree key from Bondus.

phantom_najd

My Feedback: (2)

Thanks Dave very clear.

Azzam

Steve N.

For Guys using Jet Tech Fuel Tank sets....

I have all four tanks,,, main and saddles with 3/16" fuel fittings for fuel, and wing with 1/8" fuel fitting for smoke. However, yesterday I just realized that all four tanks have a small threaded fitting with a 1/2" ID bore (and the main has only a 1/2" hole for clunk line in the baffle). This 1/2" bore is too small to accept CARF felt clunks, M&R Felt (and/or heavy) clunks or the heavy clunks provided by Dreamworks. (Sullivan clunks will fit, but are not heavy enough to move 3/16 Tygon).

This has not been an issue with the other Jet Tech tanks that I've had as they came with big bore threaded fittings that would accept any size clunk - specification was not required.

So I'm wondering.... Has anyone else received the Jet Tech UF set with the small bore or did they come with the large bore threaded fitting??? The JT web site says different fuel line fittings (brass) should be specified, but there is nothing about specifying which small/large threaded fitting is required. Did anyone have to specify this when ordering?

Thanks in advance,
Steve

DrV

My Feedback: (2)

I ordered mine with jet-tech clunks and told him to assemble it. So I'm not sure what the size is. His clunks are very good and heavy duty. If you are not set on a felt clunk go with his (Garry). Also you can email Garry and he is very good in answering emails quickly.

Hope everything works out.

Steve N.

Thanks DrV. I gather then that you don't have any issues with air in the UAT without the felt clunk?
Steve.

DrV

My Feedback: (2)

No problems with air in the UAT. All our Ultra flashes in our club do not use a felt clunk and I have never used one in any of my jets. I do have my main tank front elevated approximately 5mm. Whether that makes a difference or not I'm not sure but I have not had any problems with air in the UAT. In fact I just came from the field and have total of 66 flights on the UF without any issues.

Enjoy

Steve N.

That's awesome to hear DrV. I've never used felt clunks either. It's just from what I've read in this thread, I understood it was a must for the long narrow shape of this main tank. However, thank you kindly for sharing your "no air issues" experience with yours and others UFs. I'll go ahead with confidence now. Gary is sending out 4 of his heavy clunks tomorrow morning. I'm sure I'll be good to go now.

Just to clarify,,, I just measured the threaded fitting on my Elan tank. It's the exact same size as those on the JT UF tanks. I guess I've just never happend to come across any clunks as large as the felt ones, or the ones that Linda happened to send out.

LA jetguy

To add to DrV comments..... Gary from Jet-tech can custom make "High Flow" assembly to accommodate 8mm tubing.

Gary has a special center tank assembly with an 8mm clunk and connection (inside tank) with a 6mm outlet (outside tank) since most UAT have a 6mm inlet..

David

Dave Wilshere

Air in the hopper comes down to flying style, if you run a weighted clunk and have a 'vertical' flying style you will get air in the hopper late in the flight.
Its a fact that in Europe there are 100's and 100's UF flying with the stock tanks...and felt clunks and looking at the large number of UF models in my local club that never suffer fuel problems, its a good set up.
CARF tanks are light and I have seen a few that needed some attention on pin holes, but its few compared to the numbers sold.

Steve N.

Hi David,
Yeah, that's what I did get from Gary,,, the high flow assembly... 8 mm all round for the main and saddles, including two vents on the main for the saddles to feed directly rather than using a T. I'll be using an 8-6 reducer to feed the UAT.
Thanks,
Steve

Steve N.

Hi Dave,
I appreciate your comments on the Carf tanks, but my kit was already on the boat with only the main tank when I ordered it, so I ordered the full set locally.
I appreciate the tip on avoiding vertical later in flight. I hate air in the UAT.
Thanks,
Steve

737Driver

Good morning gents! Been sweating my Alpha Sierra Sierra off the past few days here in CA, but making good progress. Got the bypass and inlet joiner installed late last night. Oops, forgot FOD screen, grrrrrr!!!!

questions


1. Do I really need the FOD screen?

2. If so, the way the tabs on the sides of the starter line the up with the slots on the FOD screen, will not allow the fuel tube to pass through the plastic curves on the FOD screen, may I.....

A. Cut into metal screen to pass fuel tube through? (Yup thought about that metal mesh against tubing, maybe an O ring)

B. Cut new slots into FOD screen to line up to align holes on FOD screen to pass fuel tubing through the plastic into engine?

3. May I cut into inlet joiner to pass said fuel tubing through that? The angle isn't right to pass through bypass.


thanks for your input!!!