SR117

Hi Izzy

Cool idea with the magnets.

I had managed to get the nut back in the top but still could not get at it wit the bolt.

Issue I had was that the screw that drives into the clamp that holds it (the clamp) to the wing root was physically extending into the bolts path so I could not get the bolt all the way in...ie bolt hit screw end. (which was protruding into the bolt cavity ).... nut was sitting losely on top of screw end just above where it should have been sitting.

Magnets to get it in there is a much better idea if the nut has come out...and you dont have the added bonus of the screw in the way..

nice one.

sillyness

My Feedback: (25)

Anyone?

Also... any tips for aligning the engine to ensure no side-thrust?

Is everyone using the self-tapping screws into the wood as per the manual?

Dansy

My Feedback: (53)

I did a bunch of measurements from the back end to make sure it was center.....for the 2 fillers I used 3mm bolts and blind nuts, so I can change them if ever require, also blind nuts for the engine all using light blue locktite.

i3dm

My Feedback: (51)

So i managed to squeeze in a P-80 to the Xcalibur. definitely took some hacking!

Once inside, it does sit nicely. Kero plug sticks out of the top cover a bit - no big deal, this aint a beauty queen jet

Fly Mower

Sorry missed that question! Wet and raining in the UK today so I have just popped into the workshop to measure for you.........

Fly Mower

I used a 300mm (12") metal rule across the back of the turbine nozzle and then eyeballed against the rear of the fuselage.....



For actual turbine mounting, I used M3 bolts into T-nuts. The T-Nuts are mounted under the engine mountings and needed 4mm clearance holes. To avoid any play in the 4mm hole vs. 3mm bolt I sleeved the hole with brass tube.





Cheers,

Lee.

Fly Mower

Nice job! You have obviously put a lot of thought and work into that conversion.

I have no idea how heavy the P-80 is but it will be interesting to see how much (if any) weight you need up front to balance at the CG?

i3dm

My Feedback: (51)

im building everything i can close to the nose cone, and we'll see soon
while we are on the topic, whats the recommended CG point? point listed in the manual, or something different?

Dave Wilshere

P-80 is 300g more, so even with everything forward I expect weight (or BIG batteries) to be needed.
Manual figure is safe, so you can go 170mm

Dave

i3dm

My Feedback: (51)

did you try it more backwards than 170mm? would probably help with my fat turbine
P-80 center of mass is about 21cm behind the CG, while nose weight (if added inside nose cone) is about 80cm in front of the CG.
with that being said, when comparing to the lighter engines, additional 300g of P-80 should require an additional 75g of lead at the nose cone. not too bad considering i wanted to use the engine i had at home.
Ill build a;; the turbine gear on the nose trays above the front LG, so we'll see when i get to the CG stage...

Dave Wilshere

Maybe another 5mm, so 175mm, but you are already heavier than 'norm' so I would add weight first and see, then remove.
Yes, the moments do help, but most people end up with weight in the nose anyway, so its additional. If you have electric gear, that's probably heavier too, tail servo weight. It all affects things.

Dave

i3dm

My Feedback: (51)

agreed 100%, but wasnt going to buy another turbine for this model, P-80 was just laying here, and while heavy - its a work horse of a turbine!

g_boxwood

I've been struggling with this for a while... it should be simple and I approached it the same way I see it in your pics. I ended up with something more elaborated which IMHO should not be the case. So... what is the trick? What is the distance from the servo shaft and the hole you picked? From the last picture you posted I guess you are able to get the 75 mm deflection stated in the manual... I couldn't. I have to change my setup as I discovered tonight it interferes with the wing tube but again, it was not supposed to get that far away from the original intention.

Thank you,
Giacomo

g_boxwood

I've been struggling with this for a while... it should be simple and I approached it the same way I see it in your pics. I ended up with something more elaborated which IMHO should not be the case. So... what is the trick? What is the distance from the servo shaft and the hole you picked? From the last picture you posted I guess you are able to get the 75 mm deflection stated in the manual... I couldn't. I have to change my setup as I discovered tonight it interferes with the wing tube but again, it was not supposed to get that far away from the original intention.

Thank you,
Giacomo

Dave Wilshere

What arm radius? 20mm is all that is needed. Set the flap channel 100-100% with the servo arm forward flap up and back flap down =. I have more that 75mm...which to me is a minimum!

g_boxwood

HI Dave, yes, that I get it but I couldn't achieve the required throw. I was asking the arm length, which is what you mentioned, 20 mm. Thank you, I'll try again.

sillyness

My Feedback: (25)

Thanks man!!!

My Jet is finally shipping! Will be here Wednesday... just in time for me to go out of town for two weeks

Couple more questions...

1) How are you securing the air tanks?

2) UAT? I have the BVM UAT, and in front of the nose gear well seems like the ideal place... just don't know what's holding it up there.

3) Im using Interco (SP?) wheels and brakes... do I grease the brakes? With what?

Thanks again!

viggkri

My Feedback: (1)

I wanted too try some lights on my Exalibur, ordered the 4-channel controller, two "landing" lights and one red strobe from Unilight, wow, they are really really bright, tested today in sunny weather, and they are clearly visible at all times, i am only on 2S, would be even brighter at 3S.
The install and programming was very easy, i have a big light-package for my Nijhuis Vulcan, looking forward too install them.

Viggo

Fly Mower

When you have the Flap Channel at 100-100 how many degrees of rotation from you get from the Flap Servo?

With a 20mm servo arm I needed approx 95 deg of rotation to get the required throws and I had to increase the ATV's up from 100. From memory I ended up at about 125-125 to get the necessary range.

Fly Mower

1) In terms of location for the air tanks you pretty much have two options; Under the equipment trays each side of the nose wheel molding or on top of the fuel tank. From studying the 60 odd pages in this thread I would say the majority go on top of the fuel tank.

Assuming you go for the top of the fuel tank, the 'arrangements' range from just using velcro straps on the fuel tank to more elaborate mounting frameworks.

I decided to go elaborate....




2) UAT

Again from the 60 odd pages of this thread; over the nose wheel or recessed into the right-hand equipement tray (next to the nose wheel molding). Cable ties seem to be a common element in both locations. If you go on top on the nose wheel molding, I would fabricate and Hysol a couple of 'brackets' each side of the molding to secure (cable tie against).



3) Im using Interco (SP?) wheels and brakes... do I grease the brakes? With what?

I have no knowledge of those but on the standard Xcalibur units (which are just great by the way), I simply used a thin smear of Vaseline on the brake face (as advised by Dave), and it's working perfectly (slows quickly without locking).

Cheers,

Lee.

g_boxwood

That's one hell of an installation Fly Mower! Well done!

I'll try the flap linkage again today and let you know but I already went through all these steps the first time I tried it. I have the ATV set to 150% at both ends. I don't know I'm struggling with it.

Thank you,

Giacomo

Fly Mower

At 150 end points how many degrees of rotation do you get from your servo?

Dave Wilshere

Went to test fly/set up a couple of models for a club member Musafa, seen smiling after I had finished tweaking the set up to suit him. This Xcalibur BA is powered by a Wren 100, JR DSX-12 radio. Other than removing 150g!! of nose weight it flew just like all of them.

g_boxwood

That's my whole problem, don't ask me why but with ATV set at +/-150% I only get maximum 80 degrees of rotation of the servo. So I had to stick to my crazy linkage and re-tweak it so that it doesn't interfere with the wing tube. I have plenty of travel now, well beyond the 75 mm and I'll flight-test it like this. If it works I'll keep it, otherwise I'll swap the servo.

DAVE: when you mention 75 mm as a minimum, what is your preferred landing setup then? 90 degress or a little less?

Thank you,

Giacomo

Dave Wilshere

Giacomo

Does not need 90 degrees, but 80 is about what I have.

You don't have a travel limit on your radio that ignores the ATV?

Dave