UAT Installation Orientation
 

About to install a UAT in my Futura and had a general question for you guys.

I have always installed UATs at 45degrees but it's trickier to install like this. I just wondered how many people simply install them horizontally or vertically? Are there any perceived disadvantages to doing so?

Vote away above and comment away below ;)

Cheers,
Mark

RE: UAT Installation Orientation
 

it's vertical in my bobcat with no problems and 45 deg in everything else i've had. Have you seen the new baby bottle version Ali is selling?

RE: UAT Installation Orientation
 

Dunc, is it easier to see an air pocket when at 45 degrees than upright? The bubble collects nicely right in the corner that is most visible when at 45deg (if you know what I mean).

Yeah, they're the PST ones - I asked him to get hold of one for me for my Tommy Hawk to avoid the 200 potentially collapsing a non rigid UAT.

Again, this is a 160 install and I've had no issues in any of my installs in the past with this size turbine. I will err on the side of caution with the 200SX Tommy Hawk and go 3/16" bore tygon throughout and rigid UAT.

M

RE: UAT Installation Orientation
 

It's easier to see it when it's at 45 deg, the cap kind of hides them when you have it upright. Plus at 45 the bubbles are around the fill and in lines, which has got to be better than having it anywhere near the out for the fuel pump??

Dunc

RE: UAT Installation Orientation
 

Yep, agreed. Another 45deg install coming up :)

RE: UAT Installation Orientation
 

Mark,
I've use 'em 30 degrees and horizontal, no problems over 100 flights with either way,
Gary.

RE: UAT Installation Orientation
 

its doesnt matter in flight mate.
plane can turn everyway.

it matters only in fueling to take the air out so niple goes to the main tanks must the higher point.


my 2 c

RE: UAT Installation Orientation
 

Hi Mark

Heres my opinion. We all know a UAT will work in any orientation because that’s what happens when we fly. The advantage of putting it at 45 is that is purges the air when fuelling. The only other thing to consider is that a vertical half empty UAT will draw air when even a Supersport is at full power so your P-200 has no chance and I guess that restriction in the fuel system will only make this situation worse. A half empty horizontal UAT will not draw air. Of course if you have no air in the UAT there’s no problem.. The big nipple UAT I made really works well especially as none of the fittings, tube or clunk are less that 4mm I.D.

Jason

RE: UAT Installation Orientation
 

Kero start turbines are so tolerant of air in the lines, I have got rid of mine and use an Orbit clunk this has a bag and felt filter combined, had not problems with my Elan or Rookie no matter what orientation I put them into, just one opinion and on the vote looks like the only one. ;)

Mike

RE: UAT Installation Orientation
 

Mike,

Have you got a link to the clunk?

Also, what do you mean about kero start being tolerant to air in the lines? Not heard this before. I thought air was bad news to any turbine??

M

RE: UAT Installation Orientation
 

For your P200 install, get a JMP Accumulator and forget about ANY problems with a header tank failure. You'll never collapse or crack it that's for sure. AND, it has nice mounting lugs machined right into it!

RE: UAT Installation Orientation
 

Jeremy, the only thing I don't like about that is that you can't see what's going on inside it which is the first thing I want to be able to see on the ground during tests etc :(

RE: UAT Installation Orientation
 

PMSL, someone else told me that a certain make of turbine were tolerant to air in the fuel lines, right after they had crashed a model, i laughed then too :D (about the air comment, not the crash)

What difference does it make if a turbine is kero start? that would only make a difference in the start sequence surely and not in flight??

RE: UAT Installation Orientation
 

+1

Here is a pic of a simple box I made to keep mine oriented the correct way Plus its easily removable by removing the rubber band that keeps it in place. It can be glued anywhere and works really well.

RE: UAT Installation Orientation
 

I was told that Hawk turbines tolerate bubbles, they just loose a small amount of power should one be 'swallowed', they use significantly less fuel than most other turbines = less fuel per flight = less weight and do not require any form of UAT = less weight + less hassle.
Seems worthy of consideration to me.

marcs

RE: UAT Installation Orientation
 

Marc,

I was thinking more of how to mount my UAT than replace my turbine :D

The Hawk turbines do seem very interesting though as we saw at JetPower.

M

RE: UAT Installation Orientation
 

Do the Hawks have screw on tailpipes? Looks like they are threaded at the end.

RE: UAT Installation Orientation
 

Hi Marc

i wasn't refering to the Hawk turbines, i didn't know about them. It was a referance to a semi private joke with Mark
;)
Duncan

RE: UAT Installation Orientation
 

My previous supplier does not stock them anymore, will have a look around to see what I can find, I know M&R have them.

In my experience Its just that, during the start sequence if you have bubbles in the fuel feed it just seems to eat them without missing a beat, the pump then has no air to pick up as its been purged during the start, not having a UAT you don't have a bubble sitting there waiting to get into the fuel line either, it just seems to be that way, I know the editor of JI does not use a UAT as well, but uses a pleated paper filter which he makes himself.

Mike

RE: UAT Installation Orientation
 

:D Tut tut!

RE: UAT Installation Orientation
 

Duncan my post was just info, did not read anything into your post.

marcs

RE: UAT Installation Orientation
 

Andy don't think so, just the way its manufactured - interesting the fuel feeds are via Festo's mounted into the machined mounting brackets, so no feeding fuel pie through bypass cases ;)

marcs

RE: UAT Installation Orientation
 

How's that then? I thought the idea of a UAT was that it trapped the air and stopped bubbles getting to the engine??


Also I don't think them Orbit type filters are too good. I've had one or two and seen loads that although they look clean, over time become restrictive and actually cause fuel pump cavatation followed by flames outs.

Jason

RE: UAT Installation Orientation
 

Any air in the UAT has been introduced whilst filling, if you have air in your fuel lines after it has been purged and your clunk is submerged then your plumbing has a leak and is drawing in air.

Like any filter you need to clean them occasionally, if you have a filter clunk and fill from the UAT you are filling on the wrong side of the filter clunk, you should have an additional filling point on your main tank to fill from rather than through the UAT IMO.

I have used the Orbit clunk now for about two years without any problems on 120 size and under, but have heard of some problems with large turbines of 160 size and over, not having that size turbine I can't comment, but what I have tried is drawing fuel out of the tank with my fill station at max speed without any cavitation and the fuel was taken out down to the last few onz, it was very strange to watch fuel being drawn out of the tank from below the top of the Orbit clunk without any air in the line.

Mike

RE: UAT Installation Orientation
 

Respectfully, I find the "start" qualifier to be nonsensical. I don't understnd how the start plumbing matters once the engine is running (?) Further, I disagree that any of these turbines are tolerant of ingesting air. This has not been my experience at all, nor the experience of many, many particapants and various threads on the topic.

I thrilled that u are not expreiencing any issues, truly. But I don't think that your case is typical ???

RE: UAT Installation Orientation
 

When I was installing my UAT, I asked Bruce Hansen (who makes the Hansen SuperTrap) if it matters between 45 degrees and vertical. He said it makes no difference.

RE: UAT Installation Orientation
 

Mike

Using a filter clunk AND a UAT can't be a good thing and I really don't think many people would do it. Most would use normal metal clunks with an in-line filter between the pump and engine. But let’s just say some did, surely fuelling a UAT equipped plane through the main tank can't be the right way to do it, this wont purge any air trapped in the UAT from the previous run or will it??


Jason

RE: UAT Installation Orientation
 

Jase, how common were flameouts before UAT's were invented?? [&:]

RE: UAT Installation Orientation
 

Dunc

The UAT must have stopped 99.999% of air in the fuel related flame-outs so about 90% of all flame-outs in total. As time went on we all learnt what caused the other 10% and now you can go to a meet and never see one.

J

RE: UAT Installation Orientation
 

Don't forget a lot of early turbine flyers used the plasma bag, Ron

RE: UAT Installation Orientation
 

As I said in my last post, once the Kero start tubine has purged the air out of the system to get any more air into the system you have an air leak, not nonesence just logic.

Mike

RE: UAT Installation Orientation
 

OK, missed that part of ur 2nd post....BUT still....I dont accept your premise.

The air in the system might not be there from fueling OR an air leak, and there is nothing intrinsic in a kero start that somehow magically guarantees that any air in the system will be purged.

Just my opinion and pesonal experience....not trying to pick a fight, just respectfully disagreeing.



Peace.

RE: UAT Installation Orientation
 

highhorse

Thank you for your well manered post, :D unlike some, unfortunatly from my side of the pond, maners seem to be something that is lacking in a few jet modelers on here.

I respect everyone's right to an opinion no matter how diverse from mine it is, as long as it is experessed in a polite way.

I do belive that the UAT has been the saviour of many a bad installation in the past, where zip ties had been used instead of wire ties and other no no's, but if others would try using a good fabric and felt or other fine mesh filter the amount of bubbles in the air line is minimal and the turbines that are being produced now have such better burn charateristics that bubbles do not seem to effect them as much as in the past, its a simple matter to put a turbine on a test stand and just watch what happens, you may be supprised, or there again maybe not. ;)

Huskvana (spelling) make an in tank clunk that has a plastic outer cage with a fabric membrane and a hard white fine filter block inside this (unable to determine what the block is made from) and again this seems not to allow air into the fuel line from the fuel tank even if the clunk is half out of the fuel, the nice thing about this clunk is that it can be taken apart for cleaning.

Mike

RE: UAT Installation Orientation
 

The "Orbit" chainsaw clunk gave me years of perfect use, but anything over a 120 seems to run into problems. We have not sold or had stock for a few months. I tend to use the felt clunks now, de-fluff/dust them before use and have not had a problem.
UAT I prefer 45 degrees, but my Bobcat has a vertical mounted one and that has been perfect with 80 and 120 turbines installed.
The mounting is only critical for filling...as said. The reason we stocked the MAP version is it doesn't care how it's mounted, so we sell this for installs where the hopper has to be horizontal. I even have a guywith it mounted on its side! Their large nipple version for 160+ turbines is ideal for this sort of situation, so the P200SX's we have sold are including this hopper tank as std.
No turbines I've run accept bubbles...our Hawk 100R flames out with bubbles caused by a faulty pump.

Problems are caused by filling pump flow rates, some fuel station set-ups pump in bubbles at high rates, with a UAT mounted horizontal you can angle the model for the first fill and as long as you don't drain the UAT and fill too fast it will work fine.

Dave Wilshere

pix added 19-3