New big Ripmax Xcalibur (Xcalibur+)
09-18-2016, 05:08 AM
#476
Join Date: Aug 2010
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No problems today, had a couple of flight with no issues. I think I'm carrying a bit too much speed as she just floats in but will get the hang of it.
Flies nice, loads of grunt from the 140 turbine. Much easier to see in the air.
Simon
10-03-2016, 12:36 AM
#477
John Cooke (JEC TEK) displayed his Xcalibur + at Long Marston over the weekend, all the previously film covered components have been fibre glassed in light weight cloth, John has also fitted lighting to the under wing stores. Note the shape of the cockpit is also different.
The model is finished in a hi-vis colour scheme
Alistair Powers
The model is finished in a hi-vis colour scheme
Alistair Powers
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Dansy (07-01-2020)
10-27-2016, 01:18 PM
#481
Join Date: Jul 2004
Location: auckland, NEW ZEALAND
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Lights in Wings?
Hi Guys.
Has anyone put lights in the wings? It looks like the end of the wing is solid for a couple of inches so not sure how to mount lights and run cables back to root?
Cheers from New Zealand
Steve
Has anyone put lights in the wings? It looks like the end of the wing is solid for a couple of inches so not sure how to mount lights and run cables back to root?
Cheers from New Zealand
Steve
10-27-2016, 08:38 PM
#482
Steve, I have added a set of Unilight.at lights (somewhere in this thread), that include NAV lights in the tips. Indeed they are a block of balsa. As I have installed very powerful double LEDs (i think 2 X 8W), that require the version with a large cooling plate, I made a deep slot into the tips that was wide enough to house the cooling element plus have some air around it. The base droplet sized plate covers the hole.
Indeed You have to dig through a few centimeters balsa, but once Y're through, You can easily route wires to the root, as all ribs are open structured.
If You like I can mail You the setup I ordered with them (superb service!), but it can get costly, but even in direct sunlight they are good to be seen.
It consists of red/green tip lights, two headlights in the front of each boom (iso one in the nose), a flashing red beacon light on top mid of the stab and a white anti coll light on the bottom of the fuse.
Indeed You have to dig through a few centimeters balsa, but once Y're through, You can easily route wires to the root, as all ribs are open structured.
If You like I can mail You the setup I ordered with them (superb service!), but it can get costly, but even in direct sunlight they are good to be seen.
It consists of red/green tip lights, two headlights in the front of each boom (iso one in the nose), a flashing red beacon light on top mid of the stab and a white anti coll light on the bottom of the fuse.
10-28-2016, 12:57 AM
#483
I did it the easy way, nav's on boom sides, strobe on rear fuse below turbine, rotating red beacon under belly, two 10 mm spots in leading edge of wings just outside booms. Five minute job. Iirc the wingtips have a ply plate sandwiched inside balsa blocks.
10-28-2016, 09:03 AM
#485
Steve, here You see part of my lighting system, it really helps with confirming the actual attitude and bank with less than optimum vis or a bit far out:
http://www.rcuniverse.com/forum/rc-j...l#post12187737
http://www.rcuniverse.com/forum/rc-j...l#post12187737
12-03-2016, 08:19 AM
#487
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Hi Dave, I'm a newcomer to this forum and to the Jet world. I have quite a few decades experience in aerobatic and helis though. Since I never had to deal with a pneumatic gear. With how many PSI do I need to pressure the air tanks?
12-03-2016, 10:14 AM
#489
Thread Starter
Valve choice has a slight influence, but JP-1 is about right, with the individual valves supplied with the gear, 90 on gear and 70 on brakes is about right. On the combined Behotec valve we like to use I put 95 psi in the linked tanks.
Dave
Dave
12-03-2016, 11:00 AM
#490
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Make sure you check the pivot screws on your undercarriage. Took mine out tonight to check after 4 flights and they were very loose and one was hanging out. Undercarriage was put in by previous owner so should have checked but luckily for me it hasn't caused an issue.
Simon
Simon
12-03-2016, 02:55 PM
#493
After quite a while quiet I have absolved four flights today. The conditions were absolutely tremendous: no wind, clear skies, high (if any) cloudbase. It wasn't cold at all.
I have concentrated to get my final speed down and if finally worked. With flaps I have auto trim compensation on the elev. Works great but tends to keep the speed up. So today, after practicing at altitude I have reduced my baseleg and final speed. After selecting flaps on downwind I have reduced the speed dramatically and dialing in quite some UP elev trim to compensate for Lift loss.
That brought my speed very well down. I tried to keep that lower speed till close to the ground. It worked.
Here's a piccie that shows the high alpha. Note the toe-out rudder position to add more braking.
Yes the gear has its shortcomings and needs careful maintenance, indeed the screws and pivots
I have concentrated to get my final speed down and if finally worked. With flaps I have auto trim compensation on the elev. Works great but tends to keep the speed up. So today, after practicing at altitude I have reduced my baseleg and final speed. After selecting flaps on downwind I have reduced the speed dramatically and dialing in quite some UP elev trim to compensate for Lift loss.
That brought my speed very well down. I tried to keep that lower speed till close to the ground. It worked.
Here's a piccie that shows the high alpha. Note the toe-out rudder position to add more braking.
Yes the gear has its shortcomings and needs careful maintenance, indeed the screws and pivots
12-05-2016, 03:21 AM
#494
Sunday I did a re run of Saturday, slightly more wind but with good thermo overalls no issue. Landings are much easier with lower speeds. But there is a large UP trim change needed to accomplish a lower speed. This cannot be dialled in automatically with flaps, as the plane would climb.
Another phenomenon I noticed is the difficulty to make a stall turn. (that is, not all jet pilots want to do stall turns).
As a (model)glider pilot I know all gliders are more difficult to stall turn than (prop) powered planes, as the latter ones continue to blow air over the fin and rudder. Aerodynamically jets resemble gliders better than prop powered planes.
The mid placed engine/exhaust does not help either in my opinion.
Related is the effect in bank angle with rudder. It almost does not roll with rudder. It merely skids. Only maximum rudder will move the bank somewhat.
I reported in a former posting that knife edge flying requires same direction aileron correction, as opposed to single fuselage models that require cross control correction.
I figured out the even displacement of rudder might cause this, in my next flights I will start some testing with "differential" rudder displacement, ie, in a left turn more travel on the "inboard" rudder as the outboard, and vv with a right turn. Like the front wheels of a car do in a turn.
Gear:
Again more and more play on the lower part of the main legs around the pivot point. The pivot system is under designed, I am contemplating to replace the gear with a Behotec or likewise system. Wheels and brakes are great however.
The plane has now some 40 flights.
Everybody likes it's in-flight silhouette and low speed handling!
Another phenomenon I noticed is the difficulty to make a stall turn. (that is, not all jet pilots want to do stall turns).
As a (model)glider pilot I know all gliders are more difficult to stall turn than (prop) powered planes, as the latter ones continue to blow air over the fin and rudder. Aerodynamically jets resemble gliders better than prop powered planes.
The mid placed engine/exhaust does not help either in my opinion.
Related is the effect in bank angle with rudder. It almost does not roll with rudder. It merely skids. Only maximum rudder will move the bank somewhat.
I reported in a former posting that knife edge flying requires same direction aileron correction, as opposed to single fuselage models that require cross control correction.
I figured out the even displacement of rudder might cause this, in my next flights I will start some testing with "differential" rudder displacement, ie, in a left turn more travel on the "inboard" rudder as the outboard, and vv with a right turn. Like the front wheels of a car do in a turn.
Gear:
Again more and more play on the lower part of the main legs around the pivot point. The pivot system is under designed, I am contemplating to replace the gear with a Behotec or likewise system. Wheels and brakes are great however.
The plane has now some 40 flights.
Everybody likes it's in-flight silhouette and low speed handling!
12-28-2016, 12:55 AM
#495
Thread Starter
Just finished another Sports scheme Plus for customer and friend AP. Model uses a JetCat P-140Rxi, JR XG-14E DMSS system with JR 331, 579, 8421 and 8411 servos. MAP Hi-Flow bubble trap. AP also wanted a Powerbox iGyro3e and JetCat mini GSU installed, lastly a landing light.
Few pictures of the build.
Few pictures of the build.
12-28-2016, 01:30 AM
#496
Very nice job Dave!
...could not be different
...could not be different
01-02-2017, 07:19 AM
#500
Thread Starter
Another Xcalibur Plus sports scheme finished. This was Paul's first turbine build, two faultless flights today, I hardly needed any trim. JetCat P-140Rxi and JR radio throughout. Paul triumphant after his first flight!
