tahustvedt

I have uploaded all my 3D printable accessories for this kit to Thingiverse:
http://www.thingiverse.com/thing:1787126

tahustvedt

I weighed mine now with battery and everything. 7 kg / 15,4 lbs. That's with a large enough battery to fly for 20 minutes. Should fly well at that weight. It needs the big battery to balance. I balanced at 90 mm from the leading edge immediately outboard of the leading edge root exensions. The only thing that's missing before the maiden is the spring struts for the landing gear and a prop nut. I'm waiting for a 8x1mm tap and the material for the legs. I have some 20 mm material but want to wait until I get thinner stock before I turn them.

RBean

tahustvedt, great work. Mine has been down since April since we started our move. Tried to get to the field a few weeks ago, but found out one of the Wingspan electric retracts inop. Found a pinched and frayed wire. Repaired, but would only retract and not extend. Probably damaged the circuit board. Can't find a replacement retract. Finally changed over to Robart Air Up Spring Down retracts. Air pressure, "O" rings and air control valves I understand. Works on the ground. Will see how they do in use.

w1nd6urfa

My Feedback: (4)

Tahustvedt
Since you're really serious about scale details, you need to get in touch with Lazun who designed and scratch built a 92" veltro with amazing scale details

See his thread: http://www.rcuniverse.com/forum/rc-warbirds-warplanes-200/11588596-macchi-205-veltro.html

tahustvedt

Wow that is spectacular! I'm not taking it to that level though, and I don't think I'm even able to. I already printed a P-40 fuel port and stuck it to the side. I guess I should make that thingamajig on the right side of the fuselage as well.

RBean

I got the Macchi out to the field today to test the new pneumatic gear. Happy to report it works ok. My air tank is a bit small, but it is what I had on hand. Four flights without incident. So had a good days. It has been six months since it flew last.

tahustvedt

That's good. I hope my gear doesn't give me any problems. I will run a separate BEC on the gear.

Here's a video of my gear. I decided to use servos on the wheel doors instead of springs and levers like the full size. I tested the gear with the door servos disconnected and they will push open the door against the servos in case of faiilure there. I'm still waiting for the aluminum bars to make spring struts from.
https://www.youtube.com/watch?v=_Ful5CpB3wU

RBean

thaustvedt, what retracts do you have? My Wingspan retracts worked great, except lead wire got pinched between something and vibration frayed and shorted wires. Since they are out of business, could not get a replacement or repaired. Now I have one standard 90 degree Wingspan retract. Would sell this or buy one. I have some Hobby Kings electric retracts but they have the rod or bar instead of being robo strut ready. If I used them I would have to cut off about 10 mm of the strut and then put in insert to secure set screws etc, off of which would shorten the oleo travel. They are offset struts for P-51 so no extra length in the oleo. So I used some old Robart air retracts which were robo strut ready. With my flying I need all the oleo travel I can get.

tahustvedt

I got these: http://www.hobbyking.com/hobbyking/s..._10mm_Pin.html

They sell them without the pin as well: http://www.hobbyking.com/hobbyking/s..._10_12kg_.html

The 10 mm pin is removable, and they seem very strong. I will make my own struts and will probably make the end of the struts 10mm to fit in the trunnon. I tested them with something in the way to jam them and they stop and draw about 2 A for a few seconds, and then cut out. They are also able to push my inner gear doors open if the small servos fail for some reason. I tried that as well. Once the right leg didn't extend until I connected a servo tester and a 4 cell battery, but that hasn't happened after I increased the end points on the radio.

RBean

Thanks for the info on the retracts. Looks like they would work as my struts would fit into the pin mounting hole. Of course they are out of stock. I may order some and if they ever show up, change back to electric. Will use the air retracts for now.

tahustvedt

BTW, I found a good photo of the fuel port: http://walkaround.rajce.idnes.cz/Mac...#MC.205_39.JPG

Another: http://walkarounds.scalemodels.ru/v/..._0064.jpg.html

tahustvedt

I hope they get them back in stock. I could order some from the euro site and send out, but it would be very expensive because I can't avoid the high shipping cost and 25% sales tax on both shipping and part value.

Oops. They're out on the euro site as well.

These can probably be used instead. Looks like the same with a rotating sleeve instead of a pin. http://www.hobbyking.com/hobbyking/s..._10_12kg_.html

tahustvedt

I made that thing that looks like it has something to do with the pitot static system. Also, here's a video of one of my wheel wells. I reversed one of the door servos electrically so the other one is mirror image of this.

radfordc

My Feedback: (14)

The rotating nose gear would work, but the pin is only 8mm instead of 10mm like the main gear. I've used these gear in several models and they work very well. You could probably drill out the trunion for a larger pin.

tahustvedt

Me again.

I added the oxygen filling port behind the canopy (that's what I think it is). It's pronounced enough that I think it needs to be present on such a big model.

tahustvedt

Measured my wing incidence. The left side has about 1° lower incidence than the right, measured immediately inboard of the ailerons. Typical. It would have been better if the difference was opposite, as that would oppose the torque of the giant prop. Oh well. In practice it might not even be noticeable. I don't think I have measured this before on my planes. Who knows how crooked they all are.

tahustvedt

I applied tension to the wing, heated the covering and let it sit over night with tension. Left and right now seem equal. I hope it lasts and doesn't return.

tahustvedt

The inside of my fuselage looks very empty. I like it like that.

tahustvedt

Sick of waiting weeks and weeks for aluminum stock, I decided to try turning a couple of struts from some steel tubing I have and see what the weight is. Each leg weighs 50 g. Pretty heavy, but hey. The plane is actually ready for flight now, but I'm still adding more gear door parts since it's raining anyway.

tahustvedt

Undercarriage is finished and aligned. Maybe I'll cover the retract bases with a thin painted sheet of plastic. the lower doors slide up and down the outside of the upper doors, like the full size.

Provided the motor/prop test goes ok, it's finally ready for the maiden flight.

tahustvedt

I ran the motor with a half full battery. 1200 W, which is a good value. That's about 200 W more than my P-40 at the same charge state. It has slightly more power to weight than the P-40 despite being a little heavier. I'm ready for the maiden now.

tahustvedt

I made covers for the retract bases, and a protective cover for the flight controls so that wires don't rub or snag.

tahustvedt

I hope for good weather at the field. It's a 70 minute drive to get there.

tahustvedt

Here are some photos from the maiden.

tahustvedt

Here's the flight. It's quieter than I expected. I think I came close to hitting the wind sock. The landing was a bit hairy, but I'm not as close to hitting myself as it looks in the video.
https://www.youtube.com/watch?v=boh1-603kWA