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Jetlegend L39 build

Started by STORM, September 03, 2010, 21:49:32 pm

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STORM

If this system shows any sign of play I will of course have to cut into the wing and use the more conventional system.

A plate was made from 3mm standard British ply as I would not trust Chinese liteply for this job.

Space is tight so I chose to use two countersunk bolts so the plate would fit flush to the fin inner skin, this will be epoxied in place so I can simply undo two nuts and retrieve the servo if need be. The rudder must be finally hinged and attached before the servo plate is glued in place.

Final job this evening was to glue the ailerons to the wings, at last it is starting to assemble and look a little like an aircraft.

STORM

Managed a bit more work over the last couple of evenings, pics of elevators and ailerons now finally glued.
Tailplane is now complete, wings still need flap hinge slots cutting.

STORM

All retracts and brakes have now been tested using my airgun, all seem very smooth in operation, think I'll take a chance on not dismantling and air leak testing, probably regret it later!
Whipped the main wheels off to lubricate drum brake o rings with silicon, nice to note that axle wheel retaining bolt was loctited.
Nice new wheel well covers fitting system now being factory fitted, very rigid, looks good.
I noticed the first lack of glue in the wheel wells which I have just rectified.

STORM

I have just glued the servo plate into the fin for rudder actuation.

I decided to temp join the two huge fuse assemblies together to have a ponder.

This thing is huuuuuuuuuuuuuge!

Standing on it's nose I can't get it vertical without clouting the ceiling, my partner went ballistic when she saw it on our bed!

I measured up for the two main extension leads for rudder and elevator, these will be made up to an accurate length using Ashlock supplied cable and plug/sockets.


STORM

I just made the extensions up and placed them in some spiral wrap the cack half of which will be wrapped in some form of heat protection material, open to suggestions on this one.
I will also measure up the airlines for main gear and brakes before I take the fuse apart again, getting close to the good bit now, installation of goodies, can't rush though, haven't got the turbine and associated bits and bobs yet, time to bite the bullet and order methinks, this job is going together quite quickly now.

Vinceyboy

Quote from: STORM on September 25, 2010, 21:15:38 pm
This thing is huuuuuuuuuuuuuge!
Standing on it's nose I can't get it vertical without clouting the ceiling, my partner went ballistic when she saw it on our bed!


Too much information Gary ;D

You can buy the heat shield tubing for your cables from most hobby stores, Al will have it :af
"Jet flying is strictly on a shoestring"

STORM

Sorry for not much activity, been busy building though so it's catch up time.
A trip to see Uncle Al this week to procure some heat resistant tubing for the main loom plus a few extra bits needed for completion.

I have always found Al to be willing and able to pass on some of his extensive knowledge gained over the years, on the few occasions I have been to his Jet Centre in Wolverton I have always returned home that bit more knowledgable.

Wren 160 k/start ordered from the ever helpful Jeff Sewell of JetLegend fame, I have until now always been a JetCat fan but the price of a larger turbine forces me to try a Wren, a decision I pondered for some time as I like to keep everything as standard as possible with my installations for obvious reasons.

So, a pic attached of the spiralwrap loom now encased in the heat tubing and installed. Bitch of a job, next time I'll fit the plugs and sockets last!

STORM

Back to the wing, the flaps have now been painstakingly installed, quite a bit of thought invoved here to dry fit and get all the hinges correctly aligned before finally epoxying in place, before and after pics.

STORM

I was feeling quite pleased with the way the flap job turned out until checking for free movement I discovered that the flaps bind on large deflection due to the tapered wing geometry, they tend to move off to one side so I will probably have to grind some material off them later to give more gap clearance, depends on final throws which I am not sure of yet.

STORM

With the tailplane and fin completed all that now remains on the wings is to fit the control surface fairings (f/size scale) to the top surfaces and also the l/edge mounts for the two huge pitot tubes to eventually screw into.
Btw on the flap control arm the original 3mm clevis's supplied in the kit had to be replaced with rose fittings due to the twisting movement of the flap/horn.

STORM

So it's back to the fuselage bits again.
First a rough trial fit of the bypass, can't do much here until the lump arrives.

STORM

October 09, 2010, 12:14:17 pm #131 Last Edit: October 09, 2010, 12:18:41 pm by STORM
I have now installed the air lines and servo extensions from wings taking care to route them so they do not interfere with the gear when it closes, the majority of which sits in the fuselage.
All this will have to be tidied up later, experience has taught me to leave this job until last as when you do a nice neat tiewrap job you invariably find the need to add something else later and have to redo the whole lot, for instance the fuel feeds and electrics for the turbine still have to be routed.

STORM

A pic of just how much space this thing takes up in my small workshop, this remember is just the rear half!

STORM

October 09, 2010, 12:30:52 pm #133 Last Edit: October 09, 2010, 12:35:43 pm by STORM
Next job to start installing the front section airlines, needs a bit of thought here, the main headache being sure to be able to remove the finished radio tray far enough to work on it later (air leak checks etc) and allow for future maintenance.
I marked the tray at the point where upon sliding the tray back it could be angled to allow access underneath. This mark also allows me to check that nothing overhangs the board and fouls the former when sliding back.

The resulting rats nest of air tubing looks horrifying at this stage but it is so important to have more material to play with than not enough!
A period of sparking in the past taught me to leave long tails!

This of course will be tidied later although it will never be perfectly neat as excess tubing has to be left to allow main board access as previously mentioned.

I cannot think of an easier way to do this without installing extra joints on all airlines for future detachment, we all know that the more joints the more likelyhood of a failure or leak. The main thing is to make sure the airlines cannot get trapped or kinked!

STORM

Thank goodness for colour coded air tubing!
Before laying out the r/c tray I decided to do something about the damn air tanks which were flopping about as they are only supported by one former, as work progressed and the tray was in and out like a yoyo marking and cutting, drilling etc. they were becoming a nuicance.
I have added an extra tank to add to the two kit supplied 350cc jobs as it's obvious the large retract cylinders will require a lot of air capacity. This tank is intended to be used for brakes and gear doors, although much smaller the door cylinders are quite small and brake usage hopefully not excessive.
I had been thinking about some sort of bodge but in the end I decided to fabricate an extra former for proper support and do the job properly.
Not too difficult as JL supply 1:1 drawings so it was just a case of tracing from the main installed former and modding a bit to compensate for the slight fuse taper.
This was then epoxied in and left to dry.

STORM

Yet more air tubing was added!

STORM

A few bits and bobs were then added to the tray, got to be careful here as I still do not have the ECU and pump to hand.
This model apparently comes out tail heavy and requires copious amounts of noseweight to balance which is why the uat and eventually pump will be placed as far forwards as possible.

STORM

Next the dreaded air valves, I say this because I always find them akward to install to get the inlets and outlets orientated neatly.
This is where they will finish up.

STORM

A view of the tray in position, a couple of fuel fittings now added.

That's about up to date, enough time spent on here, back to the workshop!

martin lees


   Looking good Gary, keep chipping away.

    Rgds    Martin.

STORM

Thanks for the encouragement Martin, no vid I'm afraid, but then I'm not the builder Alex is!

STORM

Decided to tackle a nasty job today, one cock up here can catch the trained eye and ruin everything.
Wing top fairings and pitot tubes need epoxying to the wings, bit of corse wet & dry to rub everything down to key the glue to.

I decided to use some of the small screws supplied, one on each leading edge a) to secure them well in flight and b) to aid line up and cut down movement when fitting thereby splurging epoxy everywhere.


STORM

One thing I do like is JL painting in the mold leaving join lines, these are handy for lining uo the pitot's by eye.

I just hate this job, one false move or a little too much glue can leave a real eyesore, pics of job loose taped and left to set with checks every half hour to make sure nothings shifted!

One wing done, second to follow hopefully today if I can stay in the mood.

Vinceyboy

"Jet flying is strictly on a shoestring"

Alex48

Looks good Gary.  :af

I like what you did with the airtanks, I'll admit to being lazy when it comes to those and just silicone them in.

Are those pitot's removable?  With the best will in the world they wont last if they're not.  Even if you don't knock them there's always a helpful onlooker that will do the job nicely  :banghead:  I cut them down and glued some studding and tapped the wing fairing after making it a little more solid,

Cheers, Alex

The Little Jet Company
www.facebook.com/TheLittleJetCompany

selleri

Sverrir  - Icelandic Volcano Yeti - RCMF Tech Team

STORM

Thanks guys, gives me hope!
The tubes are screwed in Alex, I have just assembled them so I get the final line up correct, as soon as glue has set they will be off pronto!

I am aware of the vulnerability, I have made sure they are not fixed too well so they do no damage when knocked off!

Looking forward to getting some air under the wheels tomorrow!

Gary.

Alex48

Ahhh good the one I did was a bit different....
The Little Jet Company
www.facebook.com/TheLittleJetCompany

STORM

Yes Alex,

JetLegend appear to be quite up to scratch with some of their design idea's, quite impressed.

I have just checked the fairings and all have set beautifully, so all my worry was unjustified, the turned out fine.

A little epoxy seeped out under the tape but because I was using Devcon two ton overnight stuff after about four hours I removed the tape and could peel the partially set seeped glue with a scalpel, good tip there!

STORM

Onwards and upwards as they say, more progress this week.
I have cut the plugs off the flap/ail extensions and soldered multiplex plugs which should make a quick, safe connection with the wings eliminating the need for safety locks.

STORM

Then, disaster.
I decided to silicone oil the second drum brake o ring, I had already done one previously, I suddenly noticed a cap head screw protruding from the wheel hub.
On close inspection all the screws were loose so these were tightened. Rather than carrying on with the build I decided to check all the main undercarriage system for other loose stuff. The other wheel was the same.
First I checked the main gear axle clamps which were fine, then the centre wheel holding small c/sunk bolt. As mentioned earlier the first one I checked in the past had threadlock on it and so did this one.
When I went to replace the screw with very little pressure the head of the screw parted company with the thread! Turns out the preformed allan key hex was very deep and left virtually no wall thickness. I was left with a written off axle as it will be very difficult to remove the remains of the screw, a job to tackle later.
After speaking to Jeff Sewell he pointed out that I should have undone the axle clamp and disassembled that way. Doh!

STORM

Whist speaking to Jeff he told me that the turbine was on it's way, happy birthday coming up!
I also noticed that the brake air lines were scuffing against the tyre, these must be rerouted.
Also, a very empty hole waiting to be filled!

STORM

October 15, 2010, 14:54:46 pm #152 Last Edit: October 15, 2010, 14:59:06 pm by STORM
I then fitted the m/plex plugs to the wing extensions.
Whilst the soldering iron was out I made up the main flight battery leads up to the powerbox again using m/plex.
These were then cut off about 150mm at the box end and yet more plugs fitted so when charging the plugs did not have to be constantly disturbed from the box and the leads could be easily accessed.
I don't like to put any more connections in than neccessary but rather that than keep messing the box about.
My soldering is not the best in the world but I inspected the joints under a magnifying glass before heat shrinking was applied and used all three plug pins for attachment.
Care must be taken to get the polarity correct and when soldering I had the male and females connected to act as a bit of a heat sink, also important to remember to thread the h/s on to the cables before final assembly.

STORM

I then laid the fuse next to the wings and connected all the cables to test at the same time setting up the radio, temporary sub trims and end points.
When doing this most folk disconnect the linkages so a servo cannot overdrive and stall but I simply set the original throws to zero so this cannot in theory happen.
At the same time I set up the flap multibox to save a channel, I am only using a DSX9 system.

STORM

I don't beleive this forum sometimes!
I just typed out a load of stuff and when uploading got the attachment file too large warning which deletes all the text!!!
Is this really the 21st century???

STORM

I'll try again.
Back to the r/c board to set up the sequencer for the air valves using servo's to physically monitor movement and delays etc.
I cannot finally position the odd bits yet until I get the pump, ecu and valves together.

STORM

The only drawback I've found using the Spektrum powerbox with three remote recievers is that you have to plug in all three to get it to work and those tiny plugs are fragile.
Please note the 4mm fuel tubimg to protect the fragile antenna's from snapping off, easily done.
I was going to say that I need to keep the powerbox and ecu as far from each other as possible but this will not be a problem of course as the remotes will not be on the board, just scattered around the airframe.

STORM

Attention now turned to the rats nest of airlines, these have been tie wrapped together, split into feed and supply and 3mm festo's connected to the tails supplying the main rear lines installed in the fuselage.
These will all be connected to the valves, tanks, fillers etc. last when the r/c board is fully equipped.
Enough tails have been left so the board can be pulled back and tilted for future maintenance.

STORM

The festo's are being used so that I can split the fuselage in the future if need be. Servo leads are connected with safety clips for the same reason.
I am hoping they will be airtight, if not I will change them to some other sort of connector.
Anyone have any comments on this?

The rear cables have been spiral wrapped and attached to a bulkhead along with the airlines for support and it is consequently starting to look neater.

selleri

I've used Festo on some of my airlines and seen other use them so I'd think you'd be alright.

It's the suction side that can cause trouble if the tubing isn't stiffer than a viagra popping old fart!  No offense ment...    :nananana:
Sverrir  - Icelandic Volcano Yeti - RCMF Tech Team