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Oct 21, 2018, 09:53 AM
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Lawn Dart Flyer's Avatar
That was sweet, thanks for the vid
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Oct 27, 2018, 02:13 PM
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Thread OP

Wood Prop


I finally received the wood prop I had ordered some time ago. I went ahead and put it on. I had to shorten the length of the motor shaft to get the prop adapter to sit at the right distance away from the cowl, but I think it was worth it. It looks a lot better! I did a quick run up and it seems to have less thrust than the plastic prop I removed, but that was to be expected. The old prop was a 10x8, this prop is a 9x6. I think the power will still be very adequate, and the length looks more scale.
Last edited by Plane15; Oct 27, 2018 at 02:18 PM.
Oct 27, 2018, 03:43 PM
Damage is expected
This is a magnificent model and flies wonderfully! Congratulations on a beautiful result!

Dave W.
Oct 27, 2018, 08:57 PM
Jim
Yes! The wood prop sets it off nicely. You should be very proud of this build. Beautiful plane! I so hope you build a Tiger Moth. It would be awesome!
Oct 28, 2018, 12:52 AM
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Thread OP
Thanks for the kind words guys, I'm really happy with the way that this model turned out.

Jim, I have always loved Tiger Moths! If I do start another build, I actually do think that a tiger moth would probably be my first choice

Either that or maybe an airvan.
Nov 02, 2018, 08:15 AM
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Brent Slensker's Avatar
Or....you can use your exemplary skilz for a challenge like a 60 inch twin-engine Mossy using the same Art Tech motors.
Nov 03, 2018, 07:51 AM
A Day @ a Time - Matt. 6:25-34
ruff1's Avatar
Wow, I'm so envious of your skill and attention to detail. I hope one day to get beyond the "it is ugly and flies well" to something approaching this level. Thanks for the well-balanced narrative during the build. I have learned a lot. Thank you!
Jan 02, 2019, 06:45 PM
Registered User

Specs


Plane15 , Congrats also on a wonderful build. It was important for me to find your build because I recently started on a 1/6 scale Bellanca Cruisemaster using DTF and had many questions, most of them you answered. I've included a couple pics showing a 3D model of the started fuse and the build with DTF parts just taped together.

I may have missed it but I could not find your J3's final specs for AUW or Wing Load? Could you help me out,

Thanks
Jan 26, 2019, 09:00 PM
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Since last post I made a balsa cowel then I figured I better get serious about the inside structure. The skin was derived from a Guilliam kit which was drawn into a SketchUp 3d model and then the skin was printed in 2d and built. To make the inside parts they were first designed in cad (section) then back into SU where section was extruded and then the planes intersected to derive the innards.

Finally starting assembly of skin today to the innards. Decided to do it in parts, today finished the innards and made sure they fitted together properly, then untapped the skin in the front area and made sure innard fit skin and cowel and balsa cowel. It fit, hope the remainder fits as well. The pic shows it is mostly foam, only 6 balsa parts. I went with 1/64” ply on each side of 1/8” balsa to make the bulkheads in the windowed area of the cab to open that area.

Today I also made my first guess at AUW and WL, I wrote to Plane15 and he estimated his WL was just under 11 oz/sf, my guess was about 10.5 oz/sf. I'm planning to have flaps for slower landings.
Jan 28, 2019, 05:34 PM
Always Ready!
warhead_71's Avatar
Very nice build Plane15! I just stumbled across this, can't believe I missed it -- great work!!!

I run those same DT750 motors on 3S in my Grumman Goose and DHC-2 Beaver. On the Goose (twin) I'm running 11x6x3 props. On the Beaver I am currently using an 11x7 2-blade. I get loooooong flights from both, so your 9x6 should be cool as a cucumber. These motors are ugly but so efficient, and great ballast up in the nose where you always need it.

I have a few constructive comments to add after reading the whole thread... not criticizing your work at all, just adding my 2 cents of knowledge

For your tab/slot construction method I would actually make the tabs longer than necessary instead of shorter. You can through-tenon-pin the tabs with a toothpick to hold parts together until your glue dries, then pull the toothpicks and razor the tabs flush when done.

I found that a good "scale-looking" way to secure windshields is to use flat-headed straight-pins (dressmaker pins). You can snip them shorter so you don't have sharp pins sticking inside your cockpit... they only need to be about 3/16" long. I pre-drill my windshield (hold a pin over a candle with pliers, then it pokes right through) before gluing it, then use your shortened push-pins to "rivet" the windshield in place. The pins tend to pick up a bit of glue as you push them in so they never pull back out. Looks legit.

For Cub landing gear bungees I use black elastic ponytail holders instead of rubber bands. They look more like scale bungee rope (round, not flat), keep their elasticity longer, and don't dry-rot as quickly.

For tires... I've tried the balloon-over-foam wheels and they just don't seem to last very long. Maybe I fly on too rough of a runway (dirt baseball diamond or the beach). The DTF tends to eventually crush and look lumpy under the rubber, and the balloon itself will dryrot in time. I think a better method is using EVA foam... the stuff that is used for cheap flip-flops or yoga/gym/garage mats. You can get four 20x20 black puzzle-piece squares for $9 at Harbor Freight... enough to make hundreds of tires.

Again, great build log with informative pics and attention to detail. Flies great too! Bookmarking this one!

-Warren
Jan 30, 2019, 11:08 PM
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Thread OP
JosefV, that Cruisemaster is looking good! My hat is off to you for using Sketchup, I have tried to learn it several times, but couldn't get the models to turn out like I wanted. Keep up the good work!

Warhead_71, thanks for the tips. I think I will try the ponytail holders for the bungees if I can find some that are the right size. My tires seem to be holding up fine so far, but I guess time will tell.
Feb 24, 2019, 07:02 PM
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Thread OP
** UPDATE **
I recently got a precise kitchen scale and I was finally able to get an accurate weight. So, for those of you who were wondering: the all up flying weight with a 3s 1300mah battery is 25.5 oz.
Jul 22, 2019, 10:31 PM
NewFlyer
KenChin's Avatar
First of all, great detailed build photos and a nice plane..

I've accidentally clicked 200% on the tiles on A3. Not sure what size that makes this Plan at...

Will be a slow build..
Jul 28, 2019, 12:32 AM
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Thread OP
KenChin,

Holy Moly, at 200% that thing will have a 106" wingspan! That's going to be sweet!

Half the battle is taping all of those tiles together
Also, just as heads up, at 200% in order for the parts to fit together correctly, you will need to use parts with twice the thickness specified on the plans. (for example instead of 4mm foam, you will need to use 8mm foam, or two 4mm pieces laminated together) Also, the slots for the servos, the holes for the cowl magnets, the distance of the motor mount block, etc will need to be adjusted for the specific components that you plan to use. Looking forward to seeing this come together! Best of luck friend, let me know if you have any questions.
Jul 28, 2019, 07:56 PM
NewFlyer
KenChin's Avatar
Quote:
Originally Posted by Plane15
KenChin,

Holy Moly, at 200% that thing will have a 106" wingspan! That's going to be sweet!

Half the battle is taping all of those tiles together
Also, just as heads up, at 200% in order for the parts to fit together correctly, you will need to use parts with twice the thickness specified on the plans. (for example instead of 4mm foam, you will need to use 8mm foam, or two 4mm pieces laminated together) Also, the slots for the servos, the holes for the cowl magnets, the distance of the motor mount block, etc will need to be adjusted for the specific components that you plan to use. Looking forward to seeing this come together! Best of luck friend, let me know if you have any questions.
Will be using 5mm Depron mostly for the foam areas. But will reinforce 'accordingly. Here's some of the progress, so far so good.


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