Spitfire Update: Pretty much done!

I've had to redo a few things, some a couple of times, but she's running and ready to maiden with a few adjustments.

Ready to start!

First run (Though Joe Nelson at RCGF-USA test started it before sending it to me). I had a lot of trouble finding the right settings for her. She runs great, but finding her tune spot was tough. To get a nice balance between high RPM and sufficiently slow RPM at idle took hours, of trial and error and I'm still not sure its right. Her high needle pretty much stays where it is, around one turn. The low needle which is tuned to get a clean advance from idle to high, changes everything including high RPM. It is the only needle I adjust, for the most part. That's odd. 

I used a Master Airscrew Scimitar 14x8 and a Master Airscrew 13x8x3, and with both get around 8100 RPM at full sometimes as much as 8400, idle around 280. The servo limits are at the stops for the throttle t about 115% high and 20% low. With the 14x8 I get about 6.8 lbs of thrust, and with the 3-blade, about 7.7. The plane weighs 7 lbs, so I am going with the 3-blade. She gives me over 20 minutes a tank at mid-throttle. I had to dial in a throttle curve to get a true 50% throttle, and a transition at low and high approximating 25% and 75%. All this spinning dishes... changing one thing changed another. I do think I have found her sweet spot. I suspect as she breaks in more, and when I get the cowl on she will need more tuning. I decided I need to create a hatch in the cowl to get to the needles. More on that later.

The left mount cracked during the break-in runs, so I had to replace it. I didn't want to re-grind one, since that's why it broke. So I decided to do it the way I should have, and cut out the triangle wedge that prevented me from putting it there. Later I noticed that the engine was pointing a bit left... so I replaced the right one, also grinding down the wedge, and now its straight and not MacGyvered.

The QuikFire was a tight fit, added weight, and I wasn't sure if the little engine could pull fuel through it making the tuning more difficult. It has taken a lot of time to tune her... She still idles a bit high. 

Cowl on!

I had to go through a couple versions of the choke arm.  Straight out works best. That's the cylinder on the plane's right side next to the cylinder. Works great!

Next will be seeing how things change with the cowl on, then maiden. I am thinking of doing the maiden at the SNHRCC field in Hudson, where there is more open space. 

In fact, I am hoping to head out there again soon. I rode my motorcycle out there the other day, and I like the field, first time I had been back in a year. I love the openness. Its a little further out, and it doesn't have the geo-tex runway, but the grass is short, even if it is a bit of a hill. Lots of room to fly, close in, and nice un-obstructed approaches.

Spitfire is ready for engine testing!

Yes, the letters are black, not white. Decided I liked the black better. Also, different on either side. It's not meant to be historically accurare.

I decided also to try the 3 blade 13x8 prop, for break in and flight testing. I do have a 14x8 MA Scimitar if I don't like how she flies. As a gasser I think she is heavier than a glow or electric.

It will be a couple of days (work) before I get a chance to fire her up.

Oh! Oh! Oh! Its finally available!!

Phoenix Models PH152 Waco F5C

OMG! I have been waiting for this to become available for a couple of months now. JUST TAKE MY MONEY!!!

I want to pair this up with an RCGF 15cc gasser. This is going to have to wait, though, as it is going to be the most expensive project I have ever built or flown. It will have Hitec MG servos, and a Spektrum receiver.

Maybe for Christmas?

It was a good day.

One day off yesterday, had to fly AND ride the motorcycle, did both. I flew well and everybody came home as they left!

My Skyline MXS-R Breitling 30cc DLE. Love that sound!

I wanted to shake off the jitters, so I brought out the Alpha 450 and flew the crap out of her. I twisted her so hard her horizontal stab came loose. She still had a jiggy nosewheel (likes to peel off to the right) and I wasn't able to field adjust it fully, solved it when I got home by re-doing the entire rudder/nose wheel/rudder servo assembly. I think I have straightened her out. 

I also had an event on the ground that was odd. While she was on the bench all of the sudden her rudder went hard right and stuck there. Remember that this has happened in flight. The first time I flew in Merrimack I had a rudder issue and had to land despite it. Well when this happened I found nothing wrong, and the control horn didn't strip. I checked my DX8 transmitter and the subtrim on the rudder was all the way 150 right. That's not were I put it. Also all my DR/Expo went to 100/0!  This is a transmitter problem... I had sent my DX8 in after the first incident and it checked out. Spooky. The transmitter is only about 4 years old. I think I will index all the models on the SD, and reinstall the firmware. Curiously it only happens on this plane and I think one other (which one... was it the Pulse?).

Well, despite that I flew 6 packs and did landing after landing, yanked her around a few feet off the ground, take off, immediate 180, downwind landing, takeoff, 180, upwind landing, occasional crosswinds as the increasing winds shifted. I remembered I am a good pilot.

Then I took the 30cc up, less nervous, and flew several tanks, multiple landings and takeoffs, some simple aerobatics. I tried downwind approaches from the south over the Southern Ents, and could get her down but had to work it to drop hard without increasing airspeed or stalling, and with the tailwind ate up a lot of runway. From the north on the Runway 18 approach easy peasy, can easily get her in. I think I can reliably land this big one from the south if I have to, as there will be a nice headwind in that case.

Flew for a couple of hours, one flight after another, and enjoyed it! Left and worked briefly on the Alpha, then got on my Triumph Tiger 800 and spent a couple of hours taking the long way around.

All in all, I am a happy man.

Skyline Corvus 540 or PA Ultimate Project

So...

I really would like to build the Precision Aerobatics Ultimate, to replace my Eflite Ultimate, representing quite the upgrade in the process, but that's gonna be an expensive build. In the meantime, I want something aerobatic, not too expensive to lose, and fast, to replace the Ultimate and the Pulse XT 25e.  I REALLY want that PA Ultimate... and in the end may just wait and get it. But I REALLY want that powerful Corvus. I spec'd out a Skyline Corvus 540 build, electric with some oomph. At $140, she isn't so painful to replace, and I have the most expensive parts already on hand.

PA Ultimate

Skyline Corvus

But the PA Ultimate... "she so fine..."  and I love the way Ultimates fly. The parts I am getting for the Corvus could easily be used in the Ultimate, and I have the motor and ESC on hand for both planes. The Corvus would require investment in new 6S batteries, the Ultimate would fly 3S with what I already have on hand. The Corvus would be wicked powerful with a 1400 watt motor (she is rated for 1000-1200 watts, but who's got time for that?).

To build either plane I have on hand the motors, ESCs, and receiver, likely the prop. I would need to get the servos, and a BEC,

I spec'd and priced out Spektrum A5040 metal gear mini digital servos, a quite affordable, excellent performer, and Spektrum/Horizon Hobby quality. I love Horizon Hobby, but they use bicycles to deliver parts from Champaign, IL (8 days to get to NH, please...). May buy them from someone else (probably Hobby King... But I think they use cats with ADHD to ship and deliver from their US warehouses and their times have been so hit and miss lately).

I can pick up a 6V BEC anywhere for less than $10.

In the end, there is a $100 difference between the prices of the aircraft, with the PA coming in at $250 for the ARF. That's quite a chunk of change, not just in initial investment, but in "cost of crash" and the agita it induces.

When I finish the Spitfire, I will need to think about what I want to do... I am leaning to the Corvus, and sometime later I can do the PA.

I met a wonderful man some of you may know, James Tyrie. He LOVES to build. I didn't get a chance to talk much to him, but would love to chat and learn from him, see his work!

Not much happened...

In between rain and under cloudy skies, the winds were calm with breezes from the south, and I had been itching to fly, so I took the two gassers out.

The 10CC decided to be a pain in the ass and didn't like the change from 40-50 degrees with no humidity, to 70 and Mississippi muggy. She would run, but didn't actually run right, bogged down and quit time and again in idle. So I abandoned her, and set up the DLE 30 cc Breitling MXS-R. She ran fine, so I warmed her up and since she hadn't been flown in a couple of months, I ran a half a tank through her, refueled and took her up.

Perfect takeoff, tootled around and realized I was scared to death. I have had such a bad run of luck lately that I had no confidence. A couple of simple loops and I brought her in and landed perfectly, trying not to hyperventilate. I calmed down and put her in the bench. Since I hadn't tuned her up since the cold weather and wondered if she ran a bit under powered (still with unlimited vertical) I de-cowled her and tweaked her a bit. In the middle of that my teenager texted that he was back from Boston and needed to be picked up, so I had to pack up. Next time I take her out I will likely finish tuning her.

I got home and tweaked the 10cc, and she is running better than ever. Noticed that with the cowl on I picked up another 200 rpm.  I am glad RCGF abandoned the pressurized pump and single needle carb as it's a bit touchy and needy. I expect that the new edition with the Walboro style carb  I have on the Spitfire will run fine.

Bummed I didn't get more time to shake off the jitters...

Phoenix Models 10cc Spitfire Build Update

I've been working on the Spitfire, installing the electronics including the servos for the throttle, rudder and elevators, installed the fuel and ignition systems, and today installed the landing gear, flap and aileron Y-harnesses and passed them into the upper compartment.

I had it in my head that with al these Y's a 6 channel receiver would be enough. Of course I need 7... in no particular order:

1. Throttle
2. Flaps
3. Ailerons
4. Rudder
5. Elevator
6. Remote Ignition Kill Switch
7. Receiver Battery-Bind

Last night I ordered a Spektrum 7 channel reciever from Horizon Hobby. Right after I clicked SUBMIT I realized that I could have picked one up at ABC RC & Hobbies on my rounds today... dammit.

UPDATE:  OMG... The receiver is going to take 8 days to get here! Who knew FedEx uses bicycles for deliver from IL to NH?

Put a bigger wheel on the tail.

Under-side electronics bay. empty.

Upper-side electronics bay, empty.

Bringing the wing together, the vertical and horizontal stabs being hinged.

Upper bay FILLED literally to the brim. The receiver itself will go on the left next to the switches. At least that's the plan.  In this view you can see the fuel dot and intake line. It runs down the port side, crosses in front of the tank to the starboard and goes out of the motor box to the lower nipple on the QuikFire.

The bay is filled. The Remote Ignition Kill Switch, the underside of the switches, the throttle servo, and aft, the elevator and rudder servos. You can see the fuel vent; the only place it could go. There is a spar in the centerline, and I did not want it sitting on the side of the fuse with fuel dribbling down the cote. I chose to let it collect in the airscoop of the cowl and dry/drain from there.

I installed the QuikFire fuel filter. The RCGF ignition is in orange under the box.  I had to trim the exhaust pipe to get this through the cowl. I may need to put a coupler on it to extend it...

In these views the fuel line from the  fuel dot, into the lower of the paired QuikFire nipples is not yet connected.

The Y-harnesses for the landing gear, flaps and ailerons coming out of the wing. I will be making these as short as possible and run permanent leads down from the receiver. I want to be able to remove the wing for transport.  Yes, I did tear the cote... and I have since fixed it.

 

This is the form fitting cut-out. In the end, to get it to slide on easily and get the spark plug wire though and out, I had to enlarge and expand the openings. When things are done I'll post a new pic of the final.

Wings on! Awaiting the Spektrum 7 channel receiver!  Once that's in I will program it and start working on getting the engine started.  One thing I had to compromise on was the fuel vent... it had to come out under the section just behind the motor box, which puts it INSIDE the air scoop of the cowl. The inside of the fuse is almost entirely taken up by the fuel tank. I coated the inside of the fiberglass  air scoop with epoxy, and will use thinned fuel proofing in the adjacent fiberglass to protect it. I will need to be conscious, more than usual, of the fuel overflow on filling the tank. I vented the bottom of the scoop with two holes, and opened the back a little to allow airflow to dry any gas that drains out. I am not happy with this, but there really is no where else for it to go. On a glow there would be no ignition battery, so it could go there. We'll see if she goes up in flames one day.

Once I have the cowl on and secured I'll start the decal application.