Building the Guillow's DC-3 (35.5" span, now 38") with RC /BL motor conversion

Andy Hoffer · January 19, 2021, 10:21:18 AM

Beautiful @Frank v B (the build, I mean)! And I fully appreciate your extra effort with complete background paper coverage to banish the supporting washing machine to the dark recesses of one's imagination.

Bravo Yousuf!

Andy

Frank v B · January 19, 2021, 11:37:15 AM

Andy,

re; your "...with complete background paper coverage to banish the supporting washing machine...."

I went out to Dollarama last week to buy two sheets of white Bristol Board as background for these photos... just to keep you quiet.

Frank

Frank v B · January 19, 2021, 11:45:34 AM

Guy,

They are 6" props so they may fit. I'll ~~take~~ buy them from you. Even if it is just for the official photograph that Andy will take before the first flight.
I'll do a reading on them. The motors max out at 7 amps.

Thanks for the offer.

Frank

ps, They are counter-rotating too.

GuyOReilly · January 19, 2021, 12:02:32 PM

Quote from: Frank v B on January 19, 2021, 11:45:34 AM
Guy,
They are 6" props so they may fit. I'll ~~take~~ buy them from you. Even if it is just for the official photograph that Andy will take before the first flight.
I'll do a reading on them. The motors max out at 7 amps.
Thanks for the offer.
Frank
ps, They are counter-rotating too.

Frank;
1- They are free. Let me know when you want to pick them up or how we can proceed wit the exchange (I might not be able to get to the field this or next week.)
2- Hopefully they will fit for flight and will look great for the official photos by @Andy Hoffer
3- The diameter is 6 inches, I measured them. I do not know the pitch.
4- One is right the other left - just make sure the prop-nut does not come loose - guess how I found out about that one...
Have a great day!

Frank v B · January 19, 2021, 08:38:03 PM

Just had to do this!!!

F.

Frank v B · January 19, 2021, 09:33:55 PM

May as well handle the wing saddle now. The kit supplies a plastic moulded fillet but it will be tough to glue flush with the fuse surface. This method will add a lot of strength to the fuselage sides.

I cut two matching pieces from 1/64" plywood and slipped it between the wing and the fuselage, then ran a bead of glue to secure it.

Photo 3320 shows one wing saddle in place. The wing saddle for the other side lies loose on top of the wing.
Photo 3321 shows the saddle clamped in place to seal the gap with the wing. Will let it cure overnight and then do the other side.

Thin plywood was used because it is paper thin and strong. I will add wedges on op of it and bend thin balsa to make the top (curved) surface of the fillet.

Frank

Andy Hoffer · January 19, 2021, 09:38:21 PM

Quote from: Frank v B on January 19, 2021, 08:38:03 PM
Just had to do this!!!

F.

Hmm.... starting to look like ....

Andy

Frank v B · January 19, 2021, 09:43:15 PM

Andy,

The old Blohm & Voss BV 141.

My DC 2.5 will have a great left turn..... until I add the other nacelle and it becomes a DC 3.

Frank

Frank v B · January 20, 2021, 08:30:38 PM

How to do a wing fillet.

This plane has a significant wing fillet. This is the curved transition from the fuselage to the wing. The other plane with a significant version is the Spitfire.

Step 1- slip a shaped piece of 1/64" plywood between the fuselage and the wing. I released the wing hold-down screw about 1 turn to create the gap, slipped it in and tightened the screw again. Ran a bead of glue on the outside to permanently glue the plywood to the fuselage. This is covered 3 posts ago (post #50).
Step 2- I glued 3 vertical triangular riblets in place. Photo 3323.
Step 3- used the orange dowel (with sandpaper glued around it) to sand a curve into the face of the 3 triangles. Photo 3325. The curved triangles show in photo 3326.
Step 4- soaked a piece of straight-grained 1/16" balsa in a wet paper towel for an hour (photo 3327) and glued it in place. Pinned and clamped it in place. Photo 3328.

Frank

Andy Hoffer · January 20, 2021, 08:44:35 PM

Quote from: Frank v B on January 20, 2021, 08:30:38 PM
How to do a wing fillet.

This plane has a significant wing fillet. This is the curved transition from the fuselage to the wing. The other plane with a significant version is the Spitfire.

Step 1- slip a shaped piece of 1/64" plywood between the fuselage and the wing. I released the wing hold-down screw about 1 turn to create the gap, slipped it in and tightened the screw again. Ran a bead of glue on the outside to permanently glue the plywood to the fuselage. This is covered 3 posts ago (post #50).
Step 2- I glued 3 vertical triangular riblets in place. Photo 3323.
Step 3- used the orange dowel (with sandpaper glued around it) to sand a curve into the face of the 3 triangles. Photo 3325. The curved triangles show in photo 3326.
Step 4- soaked a piece of straight-grained 1/16" balsa in a wet paper towel for an hour (photo 3327) and glued it in place. Pinned and clamped it in place. Photo 3328.

Frank

Hey @Frank v B ,

Isn't that the sound that a frog makes? Does this make your plane amphibious??!

Andy

Frank v B · January 20, 2021, 08:46:27 PM

Idiotlet!

Andy Hoffer · January 20, 2021, 08:48:56 PM

Quote from: Frank v B on January 20, 2021, 08:46:27 PM
Idiotlet!

Thanks @Frank v B .

Now THAT is a compliment!!

(P.S. Is that Dutch??)

Andy

Frank v B · January 21, 2021, 11:47:35 AM

Oops. Goofed again.

My knife slipped and crushed a stringer. (Photo 3331)

Now we come to the next section of our build class.... How to repair a broken stringer.

Problem: this is a bowed fuselage. If you cut out the broken stringer and replace it, you will get a flat repaired section on a curved surface.

Step 1- cut out the broken stringer at the formers. Make the cuts on an opposing angle (45-ish degrees).
Step 2- get a wider scrap of wood the same thickness and cut an angle on both ends. If one angle is correct, sand the other angle until the angle matches and the length matches. The repair piece is at the tip of the knife (#11 blade) in photo 3332. Let the extra thickness stick up above the fuse as shown in photo 3333 (the top stringer in the photo). Glue in place. Yes, I removed the excess glue after I took the picture.

Step 3- when the glue is dry, sand the contour into the top of the repaired stringer.

Now back to our regularly scheduled program.

Frank

Frank v B · January 21, 2021, 01:59:04 PM

Sanded the wing saddle and shaped the balsa to resemble the full size plane.

The white stuff is a dash of Micro-balloons mixed with a bit of epoxy to make a very light but strong filler. Just rubbed it on with a finger, then just after it set, polished it with a bit of water...and a finger. It has not been sanded yet.

The main reason for using micro-balloons was because of the compound curves in front of the high point in the wing. It tucks back in, down and around. It took only a minute to do it this way.

F.

Andy Hoffer · January 21, 2021, 03:10:34 PM

Quote from: Frank v B on January 21, 2021, 01:59:04 PM
Sanded the wing saddle and shaped the balsa to resemble the full size plane.

The white stuff is a dash of Micro-balloons mixed with a bit of epoxy to make a very light but strong filler. Just rubbed it on with a finger, then just after it set, polished it with a bit of water...and a finger. It has not been sanded yet.

The main reason for using micro-balloons was because of the compound curves in front of the high point in the wing. It tucks back in, down and around. It took only a minute to do it this way.

F.

Hi @Frank v B
Could you talk a bit about this polishing procedure. I assume no sand paper was used if the epoxy/microballoons mix had just set? How firm was it at this point?

Tx,

Andy