Nitroplanes 87.5" 50cc SU-26 E-Build

[Z06kal]

So I've finally started building this plane. I bought it right when Nitroplanes first started carrying it. I had a repeat customer coupon and I got it for about $310 SHIPPED. Can't beat it for the price as normally just shipping on a 50cc bird is around $75.

When I bought the plane last september I weighed it roughly:

Cowl and Wheel Pants - 13oz
Wings - 3lbs 14oz
Fusalage + Horizontal + Elevator + Rudder - 5lbs 10oz
Landing Gear + Wing Tube + Tail Tube - 1lb 11oz

Total Empty Weight: 12 pounds not including firewall plate or any linkages or linkage hardware.

Here is the gear I will be running:

Hyperion HP-Z5045-B18 149kv for a Motor
Turnigy 100HV ESC
3 x 4S Zippy Flightmax 5000mah (For 12S)
Fasst 7 channel receiver
4 x HS-5625MG (Ailerons/Elev half)
1 x HS-5985MG (Rudder)
Airwild 1.5" and 3" arms
3 x CCBEC (1 on Rudder/Receiver), (1 on Left Elev half + Left ail), (1 on Right Elev half + right ail)

CCBEC's will be run off one of the 4S flight packs and set for 6.8v operation.

Anticipated output based on "Geoff Dryer"'s motor test results
Xoar 24x10 prop
27 lb 10 oz thrust
71.5 Amps
3134 Watts

According to the long thread on this plane on RCuniverse, people with DA-50's up front are having to move their receiver and ignition batteries up over the motor box AND add around a pound of lead. Apparently the nose is too stubby. This is the first e-build on this model that I am aware of. The plan is to cut a hinged access hatch into the massive cowl and mount the batteries into a tray that goes directly under the motor its self so the batteries are actually at the very tip of the nose. This will put about 5.5 pounds in the nose which should allow me to get to CG without addding any weight.

If this works out as planned this will ironically make the plane lighter than any of the gas setups. People are ending up with 19-21 pound AUW's DRY with a gas setup and complaining about performance. I'm hoping for a sub 19lb AUW ready to go. We'll have to wait and see were the final numbers come in at.

[tai626]

Subscribed.
I do have a Nitroplanes Katana 80" waiting for e conversion. The first thing I would do is to get another wing tube. I have heard it folded in the air in two airplanes.

[Z06kal]

That wing tube is fairly thick AL. I don't see how it could "Fold." I can see people landing and finding a few degrees of dihedral added but I can't see how it would "fold." Guys are replacing it with carbon to save the weight as the tube is pretty heavy having a fairly thick wall I'll measure the wall with calipers later on and post the data for reference.

[tai626]

Yeap. Adding few degrees of dihedral is what i've heard, one managed to land and another wasn't that lucky. Another guy even reinforced the tube with wood dowel rod. Not the lightest option, obviously.

[Z06kal]

Wings are done. Using all the supplied hardware minus the airwild servo arms. The supplied hardware actually looks really decent quality. Put locktight on all the screws. Roughend up the carbon guide tubes and CA'd them in. I had to solder about 6" of extra length into the servo wire.

I had epoxied in the hinges on the ailerons a few weeks ago. The included hinges also look really decent. I exerted some hard forces on one to test it out before I glued them in and it seemed to be solid and well constructed.

[Z06kal]

Coming along... Hinged the tail and installed all servos and linkages. Began work on the firewall... Next will come the CF reinforcement and mounting of the firewall. Home depot made motor mount :).

[staggerwing]

That wing tube is fairly thick AL. I don't see how it could "Fold." I can see people landing and finding a few degrees of dihedral added but I can't see how it would "fold." Guys are replacing it with carbon to save the weight as the tube is pretty heavy having a fairly thick wall I'll measure the wall with calipers later on and post the data for reference.

Some off shore suppliers definitely lack in availablility & understanding of metalurgy so don't gauge stength by thickness in thier tubing or for that matter many other vital metal parts such as clevises, etc..
In this country, most general aircraft as well as giant scale planes use 6061 T6 aluminium tubing & a fairly thin wall (.050) will do the job for most models. There is no comparison between this & the soft "who knows what" alloy you may be getting off shore.

[Z06kal]

Moving along.. Due to the heavy loads that will be imposed on the firewall and motor box with all that weight up front I went ahead and reinforced the firewall and the whole motorbox with carbon fiber.

I then cut out a hatch from the cowl, hinged it using CA hinges and boxed it in with ply. Mounted up the motor and made the battery tray. With a 2 pound motor and 3.3 pounds of lipos in the nose the plane still seems like it will be tail heavy...go figure.... May end up having to put lead in the nose (I SURE HOPE NOT!!).

[MarkF]

I had the same problem with my magic hand yak. Even with the cells in the cowl I still had to add lead. I fixed this by getting rid of the 2 servos in the stab and moving one of them up into the fuse and doing a double pull pull system. It took a couple of nights to get the geometry right but was well worth it. Now my cells go were the gas tank use to go. Much better and I lost over a half of a pound in extra weight.

Mark

[Z06kal]

Well she's ready to fly. AUW 20.5 lbs :mad: She does look nice however :o

[mpope1]

Checking in on the maiden, I am doing a similar conversion. Hope it went well!

[chalmrast]

Have you done any run-ups on your wattmeter? I see that motor is on sale for $191.50 at Allerc. I am doing a similar conversion but have not purchased the motor yet.... wondering how well these Hyperion's perform....