Dave Wilshere

CARF Mephisto production is now in full swing, there have been three prototypes doing the test flying. I have one of the pre production kits to assemble, so this is the start (timing is bad as I have a jet meeting this weekend and then 3 days with my family so progress won't really start for another week.

The model has so many design features it needs a brief intro.
CARF decided that this design needed a fully ducted install, which is much more expensive to produce, but gives a better flying aeroplane at this size (less drag when you power off) It also needed enough fuel for the expected 220-300 turbines, though it would fly on a 180 no problem.
The overall fuselage length at 3.1m 122" wouldn't fit many cars and most vans easily, so the fuselage splits at the wing trailing edge with just three cap head screws.
The really neat thing is the three piece wing and gear all mounted in the front section. This is 86" long and 30" wide.
The gear is designed to have all three wheels below the fuselage when retracted so you can roll the section around on a flat bed. Gear is specially designed by Electron for CARF.
I have the green scheme and its going to have a JetCat P-220Rxi-B. JR 8911, 8931NX servos on the main controls and 3 x JR 579/ST126 on the gear doors.Support will be Powerbox, a MAP Hi-Flow bubble trap and a JR 28X.

Few pics to start with.

skymaster68

My Feedback: (4)

Great Dave, I also have one coming this way !!!

felker14

My Feedback: (50)

Thank you Dave for doing this build thread. Your threads on Comp-ARF models are great source of information.

Dave Wilshere

Thank you, this is a surprisingly straight forward build on production models, all the fiddly parts will be done, even the screen will be factory fitted.
The guys in Germany, put one together in 3 days with a couple of guys working on it.

im looking forward to getting back from this trip and cracking on with it.

Dave Wilshere

OK, back from family break and our National championships, so got the Mephisto out again. Looking at the wings. Put a mag on there to show you the size!

Dave Wilshere

The flaps are huge, the plug in outer wing and flap works really well. I hope to have a run at this over the next few days.

sailing1

My Feedback: (134)

Dave, do you know if there will be an option for electric gear other than Electron? I have nothing against Electron gear but already have 4 planes with Behotec Electric gear and wonder if it wouldn't make sense to stay with what I know and like just for uniformity of programing and spares.

Dave Wilshere

No, only Electron. The Behotec gear won't fit and the Electron gear is custom produced just for this aeroplane. The forward retracting gear and proud wheel requires mechanical support to avoid damage to the actuators.

Ive not been a fan of electric gear, but the operation of these units is very reassuring.

Dave

dubd

I love the thoughtfulness of the design of this plane. Dave, Looking forward to hearing your flight report.

Dave Wilshere

There is so much. The production flap set up works really well. I'm using JR 8931NX servos with a short arm. The flap just plugs in before the outer panel is fitted. Current is 100-200mAh throughout the range unloaded. Putting a flight load on the flap with it in full flap position is only reads 0.8-0.9A! The geometry Andreas had come up with takes the load off the servo.

Dave Wilshere

I’m very close to finally finishing mine, but Steve Johnson’s example was ready, so I have been up to his field and we test flew it today. Because of an oversight no one had a camera at the field so we will have to wait for flight shots. Steve’s has a KT310 for max power, low cloud stopped that being tested to the max, but what a machine. Even without a gyro it’s the most locked in model I have flown in a long time. No mixing and the knife edge tracked horizon to horizon, 10 mm of rudder!
slow flight is super solid, huge flaps slow it down. Steve stripped it at the end of the day and it’s less than 5 mins and fits in a std station wagon/estate car.

JP-1

Looks very good D, its huge isnt it?

Is that Ramsey? just looking at the mast?

Dave Wilshere

AP

Yes, huge, but pulls down to small parts, so would even fit your VW!
Yes, Ramsey club field.

skymaster68

My Feedback: (4)

Dave Wilshere

Markus has been playing with set ups and experimenting. So much seems to be

Dave Wilshere

Another scheme option.

skymaster68

My Feedback: (4)

That looks familiar, it’s coming my way 😛😛

Dave Wilshere

:-)

ZivBit

ZivBit

Dave Wilshere

Nice! really like both of those.

Andrew Bird

Yea - they are great. It's growing on me more and more as I see more great scheme choices.

Dave Wilshere

Well finally got a chance to fly my Mephisto. Not really the best conditions, low cloud, quite dark and damp-but its such a sweety. Take off roll is around 40-45m and landing today with a 10mph head wind around 25m! Touch down on each of three flights only used 60m of the whole strip.
First flight with no gyro showed it does not really need one! No couple in KE and really solid all around. Second flight was to dial in the Royal SRS iGyro and third to test and tweek expo and travel in each mode.
A club member whose kit is on the way came to watch and he was very happy. Couldn't have gone much better as far as test flying goes. With the low cloud limiting vertical stuff 7 minutes only used just over half the tanks, vector and power will reduce that, hoping for better weather next time I can fly.

JP-1

Will we see it at C.J. D?

Dave Wilshere

A
That’s the plan, hope to get a chance to do a little more setting up on it. Not played with the Vector yet and there is gyro fine tuning to get the very best from each mode.

D