X-34 Concept Scale Build

Since NARAM 56 is just around the corner I decided to stop looking for the perfect project to build as my concept scale model and proceed to construct an X-34 which is still a way cool looking design.

I’m using typical model airplane construction on this model just like my Navaho. It took about two and half hours of work tonight to assemble the parts shown. This should be a really quick build and should be framed up hopefully in less then a week.

The rear three formers containing the hole for the 29mm motor mount tube are 1/8” light plywood. Everything else in the images is either 3/32” sheet balsa or 3/16” square balsa stock. In the bottom front of the model you will see a BT-5 body tube. This is where I will place any nose weight to balance the model with. Once the model is all covered up it would be hard to get weight up front but now I can simply poor some lead shot down the tube and back it up with a balsa plug. Still left on the fuselage are the application of the top rear sheeting which is 3/32” sheet balsa, the top center will get some 1/16” sheet balsa and the top front will be planked with 3/32” by 1/8” balsa sticks.

And yes this model will be Radio Controlled, since who doesn’t like extra mission points.

John Boren

Should be a great build!

NICE,NICE,NICE, Love your builds, watching as always. I like the fact that we can learn so much from your builds.

I spent about 5-1/2 hours this evening pretty much framing up the rest of the fuselage.

The X-34 fuselage is 33-1/2” long and weights 5.2 ounces. I still need to add some balsa fairings to blend in the box shaped rear top of the fuselage to the rounded top front fuselage. Once this is completed I will then remove the bottom of the fuselage where the wings goes, so I’m thinking I will actually loose a little weight.

The images show the center top being sheeted with 1/16” balsa. The rear top of the fuselage got some stiffer 1/16” sheeting with the grain going across the fuselage. The top front is planked with 3/32” x 1/8” balsa sticks. It doesn’t look very pretty when completed but the shape is designed so a whole 1/32” needs to be sanded off to get to the final contour. If you need a little light weight spackle here and there to get it to be perfect, so be it.

The nose section is just a couple of blocks of balsa glued in place and sanded to shape. It all goes well I show have the wing done by the weekend and then there’s just the vertical fin after that, so the framing on this build is going really fast.


John Boren

Once again your work is peerless. I cannot wait to see the rest of this build.

Wow great work so far

op: This will be interesting ! op:

I got quite a bit more done of the X-34 and I took bunches of pictures, but unfortunately I forgot to install the memory card in my camera so I really didn’t take any photos of each step.

Those tapered pieces on the top of the fuselage started out as one large block of balsa. I first cut the top round contour of the fuselage into the block then proceeded to cut the top and side views of the needed part out and you end up with two tapered sections. A little spackle and you’re done.

For the rudder I simply sandwiched two pieces of 1/4” balsa over a center piece of 1/16”, drew the airfoil sections on the root and tip and cut and sanded away everything that didn’t belong.

My original wing was going to be built up, I then figured why not cut a foam core and sheet it and I then said no lets just stack some 1/8” and ¼” sheets of balsa together until I have a block thick enough for the wing. I again simply drew the root and tip airfoil on the balsa and cut and sanded everything that wasn’t supposed to be there. Next the bottom of the fuselage was cut away and sure enough the fuselage is lighter now then before I added those two tapered balsa blocks. As seen in the image the entire model weighs in at 8.4 ounces. This bird should be less than 16 ounces ready to fly minus the motor.


John Boren

Tonight I added a 3/32” balsa sheet wing saddle doublers to the fuselage. If I ever have to make another one of these I’ll incorporate it into the fuselage sides before assemble. Basically I just added a sheet of balsa to the inside of the fuselage were the wing goes and trimmed it to clear the wing. I also added some plywood inside the fuselage to accept the two 4-40 socket head screws that hold the wing in place. The last thing done was to add the leading edge wing extensions. Without these that wing sure looked small but now it looks like it has all kinds of wing area. It’s starting to get heavy now and weighs in at 9.5 ounces. The last thing I am gong to do tonight is to add a bunch of epoxy resin and micro balloon filler to blend the wing and fuselage into the leading edge extensions.

John Boren


I wish you guys would ask me some question about this project. I hate posting images and not getting questions.

Your work is documented and illustrated well. Hence, the shortage of questions. It looks like you did your planking method, again, on the forward fuselage. Your nose cone looks good. Did it take a long time to sand? Do you have any sanding shortcuts or tips? Can something this light withstand a 29 mm motor? Since your fin surfaces have a projection on only 180 degrees, are their any special stability issues on lift-off?

I can't remember did we see a final finished photo of your Navajo?

Yes, I planked the forward top fuselage area. It took about 10 minutes to plan and sand the nose blocks. I use a David Combi Plan for all my shapping and then sanding blocks for the final finish. I intend to use low impulse F motors but just because thhis thing is light doesn't mean it's not really strong. Won't know about stability issues until about a half second into the first flight. The Navaho still isn't done buy I'm getting closer to getting it ready for a test flight and then if it flies ok will I apply the final finish to it.

John Boren

JumpJet said:

... I wish you guys would ask me some question about this project. I hate posting images and not getting questions.

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I don't usually ask questions since I look at your work and am pretty much dumbstruck, as in "that's just an incredible level of craftsmanship". A lot of "Wow" factor, so there's not much to say.

That said John, I do have a question (if it's been asked before, just the link would be fine). What CAD system you are using and what your work process is to go from design to cut parts.

Greg

I use AutoCAD to design all my personal and Estes Stuff. I did a little solid model work on this subject just to visualize it but 99% of this model was done in 2D cad so ANY free basic cad package out there can be used to design this model and just about anything else out there. At Estes I create Solid Models on everything I do so I can then get line drawings off them to create all those images in the instruction manuals. But for personal use you simply don't need Solid Models. Solid models are needed if you plan to use a rapid prototype machine to create your parts with. Every thing plastic that Estes has come out with in the past four years is first created on a rapid prototype machine, including the Huge Mega Der Red Max Nose Cone which was made in two large pieces over a two day period.

Once a part is drawn, I simply cut it on a laser cutter if one is available or I mist a coat of contact spray glue on a sheet of balsa, place a printed template over the wood and start cutting with an Exacto knife or band saw if the part is plywood. Inside cuts in plywood are done with a scroll saw. The very first air intake for part test fit on the QCC explorer was cut by hand. Luckily soon after, I had a laser available to cut all other parts.

John Boren

The wing has been shaped and the leading esge extensions have been cut so now the wing contains a portion of them and the fuselage contains the rest. Sorry no pictures of this tonight. I decided to add a little scale detail to the wing so I cut away a 1/64" deep area along the trailing edge of the wing where the Elevons will be hinge to. This was done to both wings, top and bottom. When dry I then rounded out the trailing edge of this hinge line so the elevons can be recess into this area. This hides the hinges used to connect the surfaces together and looks more real and cool.


John Boren

Over the last few days I've made some progress on the model. I installed the elevon torque rods, mounted the wing and started the finishing process even though I still have a little more work to do on the rear of the model. Those black lines on the bottom of the wing where the panels join together is were the carbon fiber tow was inserted into the wing to act as dihedral braces. The first time I joined the panels I didn't add enough dihedral in the panels so I needed to cut the wing apart and reconnected it with the proper dihedral.

I went ahead and applied a layer of ¾ ounce fiberglass cloth and West System Epoxy resin. The images show the bottom of the model being covered. The next day I turned it over and covered the top. Today I gave the entire model a sanding applied my favorite Primer and then smeared ¾ of a tube of Bondo Spot Putty over the entire model. I bet 99% of the putty will be sanded off so I’m not worried about the weight it will add. I’ve never been able to get this specific brand of Krylon Primer locally and since I’m on my last can I just ordered another case of 12 online. The stuff to buy is Krylon Tough Coat 341 Light Grey Sandable Primer. With shipping the cans come out to $5.04 each and it’s worth every penny compared to the standard Krylon Primer you can buy at your local WalMart. It dries in minutes and sands so easy and it doesn’t build up in your sandpaper. You really need to try this stuff.

John Boren

JumpJet said:

The wing has been shaped and the leading esge extensions have been cut so now the wing contains a portion of them and the fuselage contains the rest. Sorry no pictures of this tonight. I decided to add a little scale detail to the wing so I cut away a 1/64" deep area along the trailing edge of the wing where the Elevons will be hinge to. This was done to both wings, top and bottom. When dry I then rounded out the trailing edge of this hinge line so the elevons can be recess into this area. This hides the hinges used to connect the surfaces together and looks more real and cool.


John Boren

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Very nice ! I'm glad your doing this project now. I'm learning a ton from this. ---H

Who's your Krylon vendor? Grainger carried it for a while but last time I checked they only could find a case in IL and weren't allowed to ship it to PA for some reason. That sounds like the old stuff and I'm starting to run low on it, especially since I started painting again recently

Who's your Krylon vendor?

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This is the cheapest place on the web I have found. Just select which color primer you want on this page.

https://www.fullsource.com/krylon-tcp-16oz/



John Boren

You are a brave man.

I would have approached it the "chicken" way, and built a simple round-BT-with-OTS-NC, spliced on some slab wings and tails, just to see if it can even be balanced/trimmed for glide. If that was successful, I would have tried installing the RC gear and launching.

But noooooo. You just dive in to create another Rembrandt/Michelangelo masterpiece, paying no heed to those frivolous real-world concerns that scare the beans out of us mere mortals. My hat is off to you.....if I wore a hat.

NICE WORK!!

thanks, their prices are pretty good, and the 6 can cases of regular are reasonable too.
Fantastic work by they way can't wait to see flight pics of this and the Navaho

Old World wood planking meets New World light glass and bondo.

Fantastic work by they way can't wait to see flight pics of this and the Navaho

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I've been thinking about this. I may have to wait until after NARAM 56 to let everyone know how both of these models fly. I need to keep a little information from the competition.


John Boren

I’m still chugging away at this build. I started working on the rear portion of the model and it’s almost completed. The motor tube, screw retainer and bell nozzle are just test fitted at the moment. The most expensive thing on this model is the 29mm aluminum motor retainer. Notice the different shape of the left and right portion where the bell nozzle attaches. My case of primer arrived so I can now proceed in getting the surface of the model nice and smooth.


John Boren

This is coming out fantastic!! I have a question and a request. What kind of wing loading are you looking at when your finished?? Please keep the pictures coming. I'm particularly intrested in your control surface hinge areas. Your designs and techniques are very clean.

Wow it's really looking great!! Cant wait to see more!

What kind of wing loading are you looking at when your finished??

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If it comes in at 16 ounces, the wing loading will be 10 ounces a square foot. have a feeling I may hit 18 ounces with a spent motor installed. I'm not looking for a glider out of this bird, just something I can control and land close by to get mission points.

John Boren

Thanks for the response JumpJet. I'm falling somewhere near that with the JQ build. Using your numbers as a sort of base line. Bill

I haven’t had a lot of time these last couple of days to work on the model but three days ago I tapped off areas of the model so I could apply a coat of Phenolic Micro Balloons and epoxy finishing resin to blend the main rear wing into the forward leading edge that blends into the fuselage. I also applied it to the lower wing where it meets the fuselage. After sanding you see what you have and then continue with other areas until the wing and fuselage appear to blend into each other with perfect joints between the parts. This does add weight but it will turn this model into a real show model. Bondo Spot Putty will finish off the blending but you really don’t want the Bondo along any corners where it can be easily chipped away.

John Boren

I’m just about to the point where I’m going to stick this bird together; install a radio and test fly it. If all goes well, I’ll then start applying the finishing details and paint. I carved out the last piece to this bird today and applied a coat of Epoxy Resin to it. This is the Rear Trim Flap that mounts to the bottom rear of the fuselage.

John Boren

Just keeps getting better and better !!!!