Multiplex 100" span Flamingo Glider build and conversion to electric (cont'd)

[Frank v B]

Started this in the midst of Covid and am now handling the conversion to electric.  The original post was https://temac.ca/smf/index.php?topic=7929.0
The fuse is fibreglass.  The wings are balsa covered foam.

Conversion:
- picked a motor- A Turnigy  3536-1100 kv.  A 400 watt motor (2 or 3S).  This plane will weigh about 4 pounds so need about 280 watts (70 watts per pound).
- picked a prop.  Found a 10 x 6 folder with a 1 5/8" metal spinner.

How to:
- held the spinner at the nose and moved it back until the spinner diameter approached to fuse diameter.  Drew a line with a pencil.
- Cut the nose off with a razor saw.
- sanded the nose with a block sander until the diameters matched.
- will make a firewall using scrap balsa until it fits, then use this template to cut out the proper plywood firewall.

F.

[Frank v B]

How to make the firewall and fit the motor.

1) Make a template:  made a 3/32" thick balsa form and drilled a hole for a skewer which split the piece.  Glued it back together and braced it on the back.  Filed and sanded it until it fit.  Photo 92 and 94
2) transfer the shape to 3/16" plywood.  Cut it out.  Photo 96.  To figure out the mounting holes,  I put toothpicks in the mounting holes, trimmed them short, applied a drop of dark paint to the toothpick end and pushed the new firewall onto the coloured toothpicks. Photos 97,98.  The paint spots on the back located the holes.  Drilled them through.  Attached the motor.  Photo 01.
3) Glue the firewall in place.  Applied 5 minute epoxy to the edge of the firewall and inside the front edge of the fuse.  Pushed the motor in from the back, attached the spinner and applied two 1/16" spacers between the fuse and spinner.  Letting it cure. Photo 03

Frank

ps: had to figure this out.  A practice run.  Have to do the same with my newer purchase- a 12' span 9 pound glider that will have the same nose-ectomy to install a Power 32.

[Frank v B]

Finished!!

Note the nose is elongated (egg-shaped) with the top being higher than the diameter of the spinner. Drilled two holes for air circulation.  Small enough not to weaken the firewall...I hope.

Queue the next project, a .46 sized Mustang.

Frank

[Frank v B]

It has been a while but the plane is ready to maiden:
- installed the radio/motor/esc.
- made all the servo connections (spoilers, ailerons).  One spoiler servo needed a servo reverser because of the awkward servo location (2 servos connected into one channel via a Y connector).
- programmed the radio...as much as I program (reverse and throw).  I do not use dual rates or exponential.  I program with enough throws to safely fly the airplane and return it to earth in one piece....based on my guess.  I never program to throws in the instructions.
- tested the motor.  Will do the maiden on 3 cells.

Hopefully maiden it next weekend.  Have to channel Glenn for the maiden.

Frank

[Andy Hoffer]

Hey @Frank v B ,

Beautiful build and superb build thread.  See my post about reversing a servo (https://temac.ca/smf/index.php?topic=9105.0); you don't need a servo reverser.  You just need to reverse the leads on the servo motor and servo potentiometer inside the servo.  Glad to help out if needed. 

Cheers!

Andy

[Frank v B]

Andy,

That sounded like a compliment.  Are you OK?

I had two options:
1) Follow Andy's advice.  From your post: "some simple but delicate soldering to reverse the electrical connections of the motor and potentiometer inside the servo". I don't open servos and change things..for the same reason I don't do open heart surgery even though it is only plumbing.
2) Buy a $10 servo reverser. Plug in one end.  Plug in the other end and it works.

The $10 servo reverser is the insurance premium on a $300 glider.
Such a deal.

Frank

[Frank v B]

Maiden flight attempt will be tomorrow- Saturday, November 9 at about 1 pm. 
Wish me luck.

Frank

[GuyOReilly]

Have fun with the Maiden flight.
Hopefully, @Andy Hoffer will be there to document this momentous event.
Perhaps a video?

[Frank v B]

The best maiden flight ever.  It flew like a homesick angel.
Especially pleasing because there were no instructions.  Everything was a guess (CG, throws, motor, prop, motor thrust line, etc.).
Thank you to Peter for the perfect launch.  Launched horizontally and it flew straight and level from the release point.  At every point my "what could possibly go wrong now" was answered by nothing!  I was ready for a nose dive or a tail stand.  Never happened.

This is the first glider that acted like a glider.  With the motor turned off it only appeared to lose 20' of altitude per circuit.  When the motor was turned on there was absolutely no change in attitude.  Never had that happen before.

Andy launched for the second flight and the same great result.  On this second flight I used the spoilers for the first time once it was on final.  No change in attitude.  It just lost attitude faster.  Beautiful.

A beautiful day with a bit of a chill, very light wind but beautiful sunshine.

This plane was 100" span.  The new quarter scale one is 145" and from the same manufacturer. 
Can't wait to fly it in the spring. Build post https://temac.ca/smf/index.php?topic=8941.0

Life is great!

Frank

ps: thanks to Jeff Fisher for sending the photo.  I am (was?) 6'2" for size perspective.  Andy will have something to say about the windsock growing out of my head.

[Frank v B]

The importance of a post maiden inspection:

Both aileron servos were very loose.  The previous owner attached them with double-sided tape.  I had not made plywood covers in case I needed to make adjustments.
Took out the double-sided tape and glued the servos in place with 5 minute epoxy.  Also made cover hatches out of 1/32 plywood and screwed them in place.

No other problems noted.

Frank