Dumas L-19: Walnut scale!

[Joker 53150]

Looking good! For your elevator modification, are you using balsa at the seam that will be hinged? If so, you may want to use a harder wood that won't twist easily as you'll be putting some force on it during flight. Forces won't be huge, so maybe something as simple as a popsicle stick shaved down to size would work fine.

 

[DarkFire]

Soldering together an extension would be pretty simple

I have equipment from my brother, only problem is I don't think I'll learn soldering for this project at least.

you may want to use a harder wood that won't twist easily as you'll be putting some force on it during flight.

Good idea, I'll do that when I get home.

 

[rockyboy]

I have equipment from my brother, only problem is I don't think I'll learn soldering for this project at least.

When you're ready to step into that, here's an excellent guide from Adafruit on that, including equipment selection and techniques https://learn.adafruit.com/adafruit-guide-excellent-soldering/tools

 

[Joker 53150]

Certainly put "Learn to solder" on your to-do list! From soldering your own connections to making custom landing gear, it's knowledge you'll use a lot in this hobby.

 

[TexMechsRobot]

Certainly put "Learn to solder" on your to-do list! From soldering your own connections to making custom landing gear, it's knowledge you'll use a lot in this hobby.

I've always been "ok" at soldering and only enough to get two wires to join together. I wouldn't trust my skills or knowledge to building custom landing gear.

I am about to embark on a journey of creating custom landing gear for a DC-3 model for the Balsa Fall Build Along. What resources are out there that could help me with soldering metal components together. What type of solder? Should a flux be used? How to apply flux? How to get maximum strength in a soldered joint? What iron tips are best for which applications?

In an effort not to hijack this thread, I've started another one here so please go there to answer.

 

[DarkFire]

In an effort not to hijack this thread, I've started another one here

Lol

Also how do you quote other's posts?

 

[rockyboy]

The "Reply With Quote" button on the bottom right of each post - you can also copy and paste that text multiple times to get fancy "multi-quote" replies going

 

[DarkFire]

Oooh fancy quotes!

 

[agentkbl]

how much was this kit? I've been looking to get into stick and tissue and this seems like a simple/small enough kit that I could actually build/store it!

 

[DarkFire]

I got this kit (Dumas #236) from Tower Hobbies (great service from them so far) while it was on sale. I think it costs about $17 normally, and so far it's been an absolute joy to put together. This is my first balsa plane ever and the only problems I've had at all are due to my own modifications when converting it to RC.

 

[agentkbl]

yeah, I'd be sticking to ff as I don't want to buy a brick for it, but I think I know what I'm putting on my Christmas list.

 

[DarkFire]

I don't want to buy a brick for it, but I think I know what I'm putting on my Christmas list.

Heh heh
I had some UMX Spacewalker elecs laying around begging to be in a project, and i can't just ignore them can I?

 

[DarkFire]

Update #3 I Think

Alright so I've made some progress last night on the plane, mostly covering and weight estimations. I took all the parts along with the covering and various other little bits and put them on my *innacurate* kitchen scale :black_eyed:. The end result was about 32 grams AUW from three different weighings. I did account for glue by including a small amount of covering that I figured out would be left over after it's all said and done. I also covered one side of the vertical stabilizer. I used a 50-50 blend of Elmer glue and water to 'paint' the outer edges of the piece then put the rough cut covering on then left it to dry for 2 hours before spraying it to shrink overnight. This morning it looked really good and it was nicely taut with no twist to the piece. I put glue and covering on the elevator and horizontal stabilizer this morning, I'll see how it's doing when I get home.

I'll post pictures and other stuff when I get home

 

[DarkFire]

Everything on the scale, just tipping 30 grams. Over three weighings the average weight was just under 32 grams



I stole the tail wheel from the mini Champ I took my push rods from and made a steerable tail wheel (I plan to taxi test in one of my school's buildings. Nice big linoleum floors! )

 

[DarkFire]

So I maayyyy have screwed up. I was covering the bottom of the wing and this happened



How do I fix this? I have enough covering to take the section of tissue off (i covered the wing in 3 sections). That option seems a bit extreme though, so would a sort of patch work?

 

[roversgonemad]

You can probably just replace the section between the ribs. That would give good places to apply the adhesive, and make the seam a little less obvious.

 

[DarkFire]

Long Overdue Update #4

Fear not brave citizens! This thread may have died for a little while, but the project and I did not meet the same fate!

A couple of things lately got in the way of building *cough* *cough* school *cough* and progress has been steady but slow. Most of this work was covering, which I didn't really take pictures of. I followed along with TexMechRobot's excellent series of videos to help me with the covering aspect https://www.youtube.com/playlist?list=PLjRklP7odcIjhDefSlU_M_CjkCeKdMMLD. Other than that, I put the stringers on, completed the tail surfaces, and installed the pushrods. I am now on a time crunch, because my science teacher agreed to supervise taxi tests on Tuesday. One of my school's buildings has a largely open area with linoleum floors, perfect for my tests.

Anyway, here's some pictures! (I tried to keep them in cronological order, but eh )



The tail feathers completely covered and glued together.



I stole the control horns from a Parkzone Champ and retrofitted them the the control surfaces before gluing the vertical and horizontal stabilizers together.



All the stringers attached to the fuselage. The kit included more than enough to cover two fuselages just in case you screwed up a whole bunch :black_eyed:



I stuck two pieces of 3/32 balsa between the stringers just behind the 3rd former. I sanded the pieces smooth with the stringers.



The wing fully covered.



Thanks to rovers' suggestion, the patching on the wing went off with out a hitch.



This side of the wing is the side that I attempted the top covering first. I painted glue (50/50 elmers and water) on the trailing edge spar then put the covering on. This lead to the covering kind of 'sucking' down to the balsa.



As with most of my projects, i used the mistakes from one side to make the other side better. The only bad thing is one side is better now . This time I painted the glue on through the covering and it did not suck down to the balsa.


I think I will be making a review of this kit (Dumas FF L-19 kit #236) with both an article here on Flite Test and on RC Groups, as info about this plane is virtually non-existent . Feel free to make suggestions on what to put in the article or how to write it, because I don't know :black_eyed:.

Thanks!
Dark

 

[DarkFire]

I covered the bottom half of the fuselage. I've been using a 50-50 elmers glue and water solution to stick down the covering, and for the fuselage I switched to a glue stick. MUCH easier. Also, since this fuselage has a lot of curves and tricky corners, it probably isn't the best first plane covering wise :black_eyed:. It took a few relief cuts and some trimming, but I think it looks relatively good. I cut out a piece of the covering where the battery will be mounted via velcro.

 

[jsknockoff]

Looks way better than my early attempts at stick and tissue. The covering job so far is fantastic.

 

[DarkFire]

Thanks! It doesn't look quite as good in real life, because you can see the wrinkles and little dents . I still have no idea how to do the rest of the fuse. It's going to take at least multiple sections of covering and probably some patching. I've been thinking about how the weight is almost certainly creeping up, but it's almost 5 grams under my original AUW estimate