Toronto Electric Model Aviation Club Forum

Toronto Electric Model Aviation Club (TEMAC) => Building / Construction => Topic started by: Michael on December 23, 2020, 10:28:07 AM

Title: Sig Kadet - Twin Otter winter project
Post by: Michael on December 23, 2020, 10:28:07 AM
I have acquired a Sig Kadet Mark II model airplane balsa kit. It is a build-up balsa model intended as a trainer, to be powered with an glow (small internal combustion) engine.

I will try my best to finish this as an electric twin-motor model, resembling a deHavilland Twin Otter airplane.

Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on December 23, 2020, 10:30:32 AM
The first hour or so was spent examining the instructions, examining the plans, and separating the parts needed to build the wing. The wing ribs needed a lot of x-acto-knife cutting to get them loose from the die-cut balsa sheets.
Title: Re: Sig Kadet - Twin Otter winter project
Post by: GuyOReilly on December 23, 2020, 11:10:07 AM
Great project!
Title: Re: Sig Kadet - Twin Otter winter project
Post by: octagon on December 23, 2020, 12:16:53 PM
Looking forward to seeing your progress Michael. Interesting conversion for sure.
Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on December 23, 2020, 01:30:25 PM
Most lower wing sheeting and lower cap strips pinned down.

Lots of measuring, cutting, fitting, fine-sanding and gluing.

Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on December 23, 2020, 03:30:22 PM
Front and rear spars glued down (measured and fitted several times before gluing), and ribs sanded carefully.

I cut out holes/areas at the front of all ribs that go out to about 6" from the fuselage sides for wires from the motors/ESCs.

The 6" distance is to ensure propeller clearance to the sides of the fuselage. I am sure, based on experience, that I will not need 6" clearance; most likely I will use 9 inch or 10 inch propellers, requiring just over 4½ or just over 5" clearance.

I am not cutting holes for servo extension wires for aileron servos, as I will use a single servo in the mid-wing to control the ailerons. That's what this (older) kit shows on the plans, and it has worked well on other models for me in the past.
Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on December 23, 2020, 03:31:49 PM
I will scratch build nacelles and fit them to the wing before I finish the wing.
Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on December 24, 2020, 12:06:47 PM
The ribs, spars, wing-tips, and webbing are glued into the wing, and everything has been sanded smooth and to shape.

Other than the cut-outs in the ribs for wires, everything has been built exactly as per the instructions.

Before continuing with the wing, I will start making the nacelles.

Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on December 24, 2020, 06:18:55 PM
Nacelles construction underway.

There's a right and a left, to suit the dihedral (wing shallow-v-shape angle).

Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on December 24, 2020, 08:52:07 PM
Nacelles sheeted on the bottoms, and hatches made to help with access to wiring, ESCs, etc.

Wings have placement guides for the nacelles, and holes for wiring.

The nacelles are formed enough; now I'll finish the wing.

Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on December 24, 2020, 09:50:19 PM
Change of plans. (Like the pun?)

I'm not finishing the wings yet.

I read the instructions and looked at the plans, and I see that the wing is to be held onto the fuselage with elastics. I'm not doing that.

I'll build the fuselage first, and then I'll figure out a way to attach the wing to the fuselage without elastics. In order to do that, I can't glue on the upper wing sheeting yet.
Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on December 25, 2020, 10:53:42 AM
Fuselage construction started; so far as per instructions and plans.

Modifications will include a battery hatch, re-designed fuselage upper-front and nose, wing attachments, and float attachment points.

Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on December 25, 2020, 05:04:04 PM
Fuselage is completed enough to start planning and building the modifications.

Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on December 25, 2020, 05:30:29 PM
This drawing (lower image) is of a Sig Kadet, but it's close enough in shape to a Kadet Mark II.

The red marks indicate the outline I'll construct so the plane resembles a Twin Otter.

Title: Re: Sig Kadet - Twin Otter winter project
Post by: sihinch on December 25, 2020, 07:49:14 PM
Very clever Michael
Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on December 26, 2020, 10:46:38 PM
Fuselage modifications started.

Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on December 27, 2020, 11:44:14 AM
Upper front fuselage modification / battery hatch.

More progress ...

Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on December 27, 2020, 05:40:56 PM
I took a break to 'float-fly' off the snow at TEMAC. I had four flights, and a great time!

Also there was: Andy, David, Glenn, Oscar, Kenny, Loy, Felix, and Ricky

Anyway, once I got home I did a bit more work on the model.

Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on December 27, 2020, 09:24:32 PM
Okay, that's enough of the nose section/battery hatch, etc.

Tomorrow I attach the wing to the fuselage, and hopefully go back to work on the wing.

Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on December 28, 2020, 09:07:33 AM
Change of plans, again.

In order to bolt the wing to the fuselage, there will not be room for a central aileron servo and the linkage. I will install outboard servos instead, and will retro-cut holes in the ribs to accomadate servo extension wires.

I have to work this morning, so hopefully I can have fun with more model building this afternoon or evening.
Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on December 28, 2020, 07:51:55 PM
New cut-outs for the aileron servo wire extensions; wing sheeting; balsa fill (later to be drilled) for the nylon screws to mount the wing; and ready for sanding.

Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on December 29, 2020, 08:54:39 PM
More progress on the wing.

It doesn't look like a Sig Kadet Mark II.

Title: Re: Sig Kadet - Twin Otter winter project
Post by: GuyOReilly on December 29, 2020, 10:37:34 PM
Great build! 
Question: will you have asymmetric control for the right and left engine?
Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on December 30, 2020, 07:35:52 AM
Quote from: GuyOReilly on December 29, 2020, 10:37:34 PM
Great build! 
Question: will you have asymmetric control for the right and left engine?

Thanks.

No. (No differential thrust.)

As much as I want to be be innovative, I also want to keep it simple.
Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on December 30, 2020, 11:23:00 AM
Wing hold-down system done. Plywood glued into the fuselage, and holes drilled and tapped for ¼" nylon screws.

Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on December 30, 2020, 11:24:51 AM
Fin and rudder are reshaped, and built up instead of (heavier) sheet balsa.
Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on December 30, 2020, 01:59:35 PM
Elevator and stabilizer built as per instructions/plans; light and strong.

Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on December 30, 2020, 02:00:31 PM
Hinged (not yet permanently) and sanded.

Next: More work on the fuselage.

Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on December 30, 2020, 05:48:08 PM
All major construction is done. I still have to shape the fuselage front/nose, shape the nacelles, and start planning the radio/power-system installation.

(I bought skis for the plane.)

Title: Re: Sig Kadet - Twin Otter winter project
Post by: Andy Hoffer on December 30, 2020, 08:35:43 PM
Looking really good @Michael .  It's amazing how much progress you can make on a crappy flying day!

Andy
Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on January 03, 2021, 05:16:41 PM
More work on the nacelles, and aileron servos being fitted.
Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on January 05, 2021, 09:15:55 PM
Basic construction and assemble is as per the plans and instructions.

The pushrods are constructed (circa 1980-style) of ¼" square balsa and wire bound together with thick thread and glue.

Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on January 05, 2021, 09:16:29 PM
Covering started.

Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on January 06, 2021, 01:53:09 PM
More covering.

Title: Re: Sig Kadet - Twin Otter winter project
Post by: Andy Hoffer on January 06, 2021, 08:57:50 PM
Nice covering job @Michael.   Even the Pink Panther is smiling!

Andy
Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on January 07, 2021, 09:23:34 AM
More covering. I still have to complete the radio and power system installations.

Title: Re: Sig Kadet - Twin Otter winter project
Post by: GuyOReilly on January 07, 2021, 10:46:28 AM
Looking good Michael.
Was the lighting graphic a sticker or Monokote job?
Guy
Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on January 07, 2021, 10:52:51 AM
It was an old leftover graphic.
Title: Re: Sig Kadet - Twin Otter winter project
Post by: sihinch on January 07, 2021, 11:30:08 AM
Looks great. We could be Twin twins!
Title: Re: Sig Kadet - Twin Otter winter project
Post by: bfeist on January 07, 2021, 01:02:38 PM
"Winter project" - finishes Jan 7. I think we need to take away half of your tools or something to slow you down. What a great result!
Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on January 07, 2021, 03:31:42 PM
More covering, trim decoration and landing gear installation. (First flight is likely to be off skis.)

Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on January 07, 2021, 05:03:27 PM
Wing wiring.

Title: Re: Sig Kadet - Twin Otter winter project
Post by: electroflyer on January 08, 2021, 10:11:28 AM
  That looks amazing. Great kit bash!
Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on January 08, 2021, 06:42:27 PM
All finished, except throws need to be adjusted. To be maidened off snow. (More detailing after the maiden. I hope.)

Title: Re: Sig Kadet - Twin Otter winter project
Post by: Frank v B on January 08, 2021, 08:08:44 PM
Yep, a Sig Cadet alright...from another planet. 
What a great kit bash.  Good job. ;D

Frank

Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on January 09, 2021, 04:46:31 PM
Successful maiden!

Nice takeoff, about 10 circuits of the field, and a nice landing. That was my first ever takeoff and landing with skis, and that was a maiden on a built-up customized model kit.

Title: Re: Sig Kadet - Twin Otter winter project
Post by: sihinch on January 09, 2021, 05:03:29 PM
Congrats Michael, it looks awesome. You do too!  ;D

I love those props!
Title: Re: Sig Kadet - Twin Otter winter project
Post by: GuyOReilly on January 09, 2021, 06:06:47 PM
Sure looks like a Twin Otter!
Congratulations on your Maiden Flight.
Title: Re: Sig Kadet - Twin Otter winter project
Post by: Andy Hoffer on January 09, 2021, 08:59:50 PM
Beautiful job @Michael!  You had a picture-perfect day.

Now, about the maiden flight:  I have heard about it, and I've seen photos of the plane at the field on skis, but I have not seen any photos of the plane in the air.  What gives?!

I will be at the field tomorrow, camera in hand. I hope you will be there with your Twin Otter.  If you would like, I'd be happy to do some in-flight photos and portraits of you and the Otter.

Cheers!

Andy
Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on January 10, 2021, 09:26:10 AM
David made a nice video.

https://www.youtube.com/watch?v=VjqKg3_z18c&feature=youtu.be

Title: Re: Sig Kadet - Twin Otter winter project
Post by: GuyOReilly on January 10, 2021, 10:17:08 AM
@Michael your plane looks rock solid and stable.
Great video!
Title: Re: Sig Kadet - Twin Otter winter project
Post by: Andy Hoffer on January 10, 2021, 11:32:03 AM
Quote from: Michael on January 10, 2021, 09:26:10 AM
David made a nice video.

https://www.youtube.com/watch?v=VjqKg3_z18c&feature=youtu.be

Fabulous!  Love the strobing of the counter-rotating props!

Andy
Title: Re: Sig Kadet - Twin Otter winter project
Post by: Oscar on January 10, 2021, 06:59:52 PM
Thank you David for the video.  Beautiful flight.  Way to go Michael.   :D
Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on January 11, 2021, 03:59:14 PM
Photos (most from Andy). 7 flights so far, including mild aerobatics and touch-n-goes.

Title: Re: Sig Kadet - Twin Otter winter project
Post by: Michael on January 11, 2021, 05:01:42 PM
More photos from David.

Title: Re: Sig Kadet - Twin Otter winter project
Post by: msatin on January 25, 2021, 10:29:41 PM
Fantastic build Michael - congratulations!