New big Ripmax Xcalibur (Xcalibur+)
#502
Last weeks I could fly a lot because of calm weather and good vis. With every flight I like it better! Good handling, I now make many close to full stall landings with the tail boom skid (own mod) scraping the concrete. Most jets I fly with a little itch in my belly but this one is getting close like when I am flying my tow planes, with which I have thousands of flights.
My last mod was reducing the rudder deflection on the "opposite" rudder:
Eg, when You give full left rudder to make a knife edge: I reduced the max left deflection of the RIGHT tail boom's rudder. Of course same with right rudder, I reduced the left boom's right rudder deflection. (like the front wheels of any car do a different deflection when turning.)
Those magnificent computer transmitters came 50 years too late!!! My first impressions are that the tendency to roll INTO the turn like it did before during knife edge, almost disappeared. (Normal fuse planes tend to roll OUT of the turn during knife edge when not countered with aileron).
The mod with toe-out rudders with full flap(air brake) is recommendable, there is enough aerodynamic braking to make a short circuit with an idle descent possible with a steeper descent as normal. I like those better as sneaking in with a flat angle. The deflection is about 20 degrees.
Just a little downward elev mix is needed but I also have the ailerons moving during flaps usage.
I am progressing with more in flight manouvres, like outside loops, flick rolls and improving my stall turns. Like with prop A/C I did the stall turn with idle power, but with a jet it is better to leave some 1/3 power on, and it works! A friend advised me on this.
So here is a summary of the mixers:
Aileron: No differential. (edited)
Rudders full left: right boom less deflection (about 80% of the left one), rudders full right, Left boom 80% deflection.
Nose wheel on a separate channel, so that You can trim it with another trim wheel (most modern transmitters this can be directed to another wheel) and it does not influence the rudder(s) itself.
Nose wheel mixer from rudder commands, but reduced angle and at reduced speed.
The rudder/nosewheel mixer ITSELF is activated by the gear switch: gear up: the nose gear automatically centers and remains there during flight, no matter what You are "ruddering".
Neutral flap, controls centered: all normal.
Half flap, both ailerons DROOP some 10-15 degrees, plus a few degrees ELEV down. This allows for a high lift grass T/O
Full Flap: both ailerons move back to some 15 degrees UP, rudders go toe-out some 20 degrees, slightly more ELEV down. So there is some "crow mixing" here, plus the toe-out. Great for high drag finals.
(ELEV compensation is just a general statement, they have to be flown in with test flights to find the fitting value with each flap setting for Yr plane.)
ELEV/Wheel brake mix, starts to brake with about 25% into elev DOWN. MAX with full down. The mixer ITSELF is activated by the gear switch, Gear DOWN activates the mixer so I don't have brake commands in flight during acro, casing to loose air pressure.
If You are not accustomed to more complex mixing: program and testfly one by one, not all the same time. Try the next only after the first one is working fine.
Good luck!
My last mod was reducing the rudder deflection on the "opposite" rudder:
Eg, when You give full left rudder to make a knife edge: I reduced the max left deflection of the RIGHT tail boom's rudder. Of course same with right rudder, I reduced the left boom's right rudder deflection. (like the front wheels of any car do a different deflection when turning.)
Those magnificent computer transmitters came 50 years too late!!! My first impressions are that the tendency to roll INTO the turn like it did before during knife edge, almost disappeared. (Normal fuse planes tend to roll OUT of the turn during knife edge when not countered with aileron).
The mod with toe-out rudders with full flap(air brake) is recommendable, there is enough aerodynamic braking to make a short circuit with an idle descent possible with a steeper descent as normal. I like those better as sneaking in with a flat angle. The deflection is about 20 degrees.
Just a little downward elev mix is needed but I also have the ailerons moving during flaps usage.
I am progressing with more in flight manouvres, like outside loops, flick rolls and improving my stall turns. Like with prop A/C I did the stall turn with idle power, but with a jet it is better to leave some 1/3 power on, and it works! A friend advised me on this.
So here is a summary of the mixers:
Aileron: No differential. (edited)
Rudders full left: right boom less deflection (about 80% of the left one), rudders full right, Left boom 80% deflection.
Nose wheel on a separate channel, so that You can trim it with another trim wheel (most modern transmitters this can be directed to another wheel) and it does not influence the rudder(s) itself.
Nose wheel mixer from rudder commands, but reduced angle and at reduced speed.
The rudder/nosewheel mixer ITSELF is activated by the gear switch: gear up: the nose gear automatically centers and remains there during flight, no matter what You are "ruddering".
Neutral flap, controls centered: all normal.
Half flap, both ailerons DROOP some 10-15 degrees, plus a few degrees ELEV down. This allows for a high lift grass T/O
Full Flap: both ailerons move back to some 15 degrees UP, rudders go toe-out some 20 degrees, slightly more ELEV down. So there is some "crow mixing" here, plus the toe-out. Great for high drag finals.
(ELEV compensation is just a general statement, they have to be flown in with test flights to find the fitting value with each flap setting for Yr plane.)
ELEV/Wheel brake mix, starts to brake with about 25% into elev DOWN. MAX with full down. The mixer ITSELF is activated by the gear switch, Gear DOWN activates the mixer so I don't have brake commands in flight during acro, casing to loose air pressure.
If You are not accustomed to more complex mixing: program and testfly one by one, not all the same time. Try the next only after the first one is working fine.
Good luck!
Last edited by richbran; 04-02-2017 at 11:39 PM. Reason: Aileron differential corrected
#505
Thread Starter
195mm is my balance point, it is with hopper tank full and 1" in main tank (always balance as I expect to land) You could shift it back a bit, but 215 sounds too far
#507
Thread Starter
You need to balance with some fuel in the main tank or it will be nose heavy. Unless you like really long flights you will never land with an empty tank!
https://youtu.be/7CdcYxxV1Io
One 12 minute flight and 1.5" fuel left on landing.
https://youtu.be/7CdcYxxV1Io
One 12 minute flight and 1.5" fuel left on landing.
#508
Thread Starter
Got to do a maiden on AP (JP-1) Xcalibur Plus I built back at Xmas. JetCat P-140Rxi and JR XG14E radio, this is the first Plus I have flown with an iGyro 3e, even in really rough conditions it was smooth!
#510
Hello Dave!
I am also planning to use the iGyro 3e in my Plus. Howe did you handle the rudders in the iGyro 3e? There is only one connection for rudder. Did you use an Y-lead?
Jannica
Sweden
I am also planning to use the iGyro 3e in my Plus. Howe did you handle the rudders in the iGyro 3e? There is only one connection for rudder. Did you use an Y-lead?
Jannica
Sweden
#515
I corrected post nr 501 with all them mixer settings regarding aileron differential.
During vertical rolling (a manoeuvre best to check if it rolls axially) I still saw the nose describing a circle. So eventually I completely discarded the differential setting. It rolls much nicer now, but I might do more testing to fine tune. In one delta jet a while ago (Graupner Hotspot) I even needed "negative differential" to get it rolling axially...
The Xcal has become my favorite jet to fly, easy to take with me (tail booms and stab fitted to the fuse) and very forgiving to fly, spins, even flickrolls (but close to the stall speed region for not overstressing it) are in its envelope. Touch and goes are my favorite!
During vertical rolling (a manoeuvre best to check if it rolls axially) I still saw the nose describing a circle. So eventually I completely discarded the differential setting. It rolls much nicer now, but I might do more testing to fine tune. In one delta jet a while ago (Graupner Hotspot) I even needed "negative differential" to get it rolling axially...
The Xcal has become my favorite jet to fly, easy to take with me (tail booms and stab fitted to the fuse) and very forgiving to fly, spins, even flickrolls (but close to the stall speed region for not overstressing it) are in its envelope. Touch and goes are my favorite!
#516
Join Date: Sep 2013
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I have been a fan of the Pro-link series of electric retracts for years. The one for the + uses a larger motor than the regular X-Calibur and that makes since. I also had an issue with the Pro-links slightly to long for the +. I was advised by DreamWorks that my wheel wells must of been slightly off as another airframe they had the Pro Links fit just fine. It's odd that no other builder has had issues with there "off" wells using the JSM gear and now 3 others have had issues with the Pro Links in the + but that is what I was told. The solution I was advised was to grind the back side of the well off 1/8 inch. This pretty well ruins the sealed concept of the wells we all like very much. I ended up putting in a lathe and taking off 1/8 on the shoulder and shortening 1/8 inch. Fit fine now. If anyone wants an easy way to remove the spring or put back on take aluminum siding and make up shims to go on the spring. 5 shims lengthens the spring very nicely.
#518
Thread Starter
We had a bit of an Xcalibur day at my local club Andy Roshier's new Xcalibur Plus RAF replaces a KingCat. Model has JR servos throughout, iGyro 3e and a JetCat P-140Rxi turbine. JR 28X
One flight to fine tune the set up and Andy was happily flying it.
One flight to fine tune the set up and Andy was happily flying it.
#520
Well done and that Xcalibur+ colour scheme looks nice in the air too!
#522
Join Date: Sep 2013
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Have been flying (and working) the mid size X-Calibur so not a lot of time to work on the +. Spent the last few days fitting some parts. The Pro-Link Hercules retracts seem to provide more than enough pull. I even tried to stop the retract each way from retracting and coming back into the wells and could not stop them. The new Hercules retracts are the way to go if you want to use electrics. Only issue as mentioned before is the main wing tube is very tight. Spent some time sanding and fit well except the last inch that would not seat in the clamping mechanism. Kept hitting the clamp and not go into it on the left wing. The only solution was to sand the clamp and then using pressure from into the servo well push the tube into position. I'll keep the tube in this wing from now on and work the wing tube through the fuselage into the other wing. Anti rotation pins needed some sanding to place Inside the wing. All in all it's a nice design. I'm using a Wren 180 as this is the only airframe where I can stand a turbine loss and able to bring it back home. Nice work from Dave and the team that designed and built this.
#523
Today I maiden my Xcalibur +. It flew just as well as I had come to expect. It is powered by a Jetcat P-80 with only 80 N of thrust and the take of was from a grass strip. Of course I could have used a few extra newton’s but it was airborne after about a 100 meters run and the power was quite sufficient to peacefully fly around the circuit. I noticed more pronounced trim changes in pitch than I had expected when I selected flaps and when I executed the landing gear, but nothing dramatic. On the second flight I had a flame out and had to make a dead stick landing witch also was rather undramatic due to this very stable airframe. However, I decides not to fly any more today before I can look through the fuel system for possible air leaks. The Xcalibur + is a great aeroplane and I think that I will have a lot of fun with it. An 80 N power plant is a little bit on the tame side and I think that a 120 N turbine would be much more appropriate. Maybe I’ll try to change to that in the futur
#524
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Has anyone flown the plus with 100 size turbine ? I just got my plus and have a jetmunts 100 and see that the plusbstates 80 to 140. Anyone know is a 100 will be fine ?
I know she won't have vertical performance but that's not something I want right now as I leave that for my mid xculibur
Thanks all
I know she won't have vertical performance but that's not something I want right now as I leave that for my mid xculibur
Thanks all
#525
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Has anyone flown the plus with 100 size turbine ? I just got my plus and have a jetmunts 100 and see that the plusbstates 80 to 140. Anyone know is a 100 will be fine ?
I know she won't have vertical performance but that's not something I want right now as I leave that for my mid xculibur
Thanks all
I know she won't have vertical performance but that's not something I want right now as I leave that for my mid xculibur
Thanks all