Tag Archives: 1:4 scale

Keep moving forward!

As you may have guessed, the day job got in the way of my preferred interests making it hard to get anything done on the airplane. But, now I’m back in the shop going over the construction plans trying to decide where to begin. Most builders seemed to start with the empennage. Building the vertical stabilizer and the horizontal stabilizer first. Because of my shop’s space limitations, I’m thinking about starting with the bulkheads; building the firewall bulkhead, forward spar bulkhead, aft spar bulkhead, and lastly the stern post.

VP-2After the bulkheads are built I can do a temporary fit of the cabin, building the seat components and cabin floor structure without permanently affixing them to short, temporary longerons. I can’t build the completed fuselage just yet, there is just nowhere to put it. Next I can move on to wing ribs, horizontal stabilator ribs, and vertical stabilizer ribs. With all of the ribs cut I can go ahead and start building larger assemblies. I should have enough room to easily store the completed vertical stabilizer. Then I can move on to the horizontal stabilator spar and the stabilator itself.

With the empennage components completed I can move on to other assemblies, forwards spars, aft spars, fuel tank, control stick, landing gear and such. By the time I get to this point, I should have access to a larger space for fuselage construction then I can put it all together. At least that is the plan for now.

As I’m sure you figured out by now, because of my space limitations I am looking to build flat components first, then flat and/or small assemblies. This should keep my space requirements to a minimum until absolutely necessary for the fuselage. The longer I can keep the build in a small space the better.

On another subject, I have been reconsidering the model this last week. The paper laminates that I planned on using as plywood substitutes for the 1:4 scale model just don’t provide enough structural support or hold shape well enough for me to consider them viable, especially the two-ply and four-ply laminates. I had thought about purchasing some balsa materials in the proper size but I almost fell over when I saw how expensive balsa wood has gotten. Another problem is the mechanics of milling small pieces of material from Douglas fir. That being said, I have decided to go with the VP-2 rather than the VP-1 and build it as a single place instead of a two-seater. Because I don’t need to compare the airframes, I don’t really need to do the model. If I run into a problem I can always model the assemblies involved if I need a solid reference.

Following the plan outlined above and building the bulkheads first all I should need to put together right now is a materials list for the bulkheads, source it out and figure what my cost are going to be. I already have some of the Douglas fir and I know where to get everything else I need, so this should be little more than an academic exercise, until I start making saw dust anyway. Oooo… sawdust… I am really looking forward to building.

Until next time, blue skies and tailwinds.
~Jon

Back on track

Greetings Intrepid Aviators,

The last few days have been plagued with zombies; no seriously, take a look . Now that the zombie menace has been put down for the year, they will be back next year, it’s time to get back on track with the matter at hand, building an airplane.

Nothing new has been done on the 1:4 scale since last week, but I have had some thoughts on the matter. I think making the paper laminates in smaller sections rather than the 24” x 12” pieces I planned on, using thinned glue, and pressing the material with more weight should help make the resulting material a high quality substitute for very thin plywood. This week I am going to focus on the laminate first and then if all is going well I will get started milling the lumber materials from the Dough Fur I purchased last week.

VP-2Another task for this, and the next few weeks is to dive into the plans in much more detail. I have looked over both the VP-1 and VP-2 plans but I have not really focused on them in detail or thought about what assemblies to begin with. I am considering picking up a large drawing pad and redrawing the plans so that all of the details for a sub assembly will be presented on a single sheet. I like to study the details of drawings and plans by reproducing them by hand. The process helps create 3D models of each piece and assembly and how they interrelate with other parts. It gives me a clearer vision of the entire plane and all of its component parts. By redrawing the plans I will also be able to come up with a complete parts list, assembly parts lists, work operations list by assemblies, and other useful administrative minutia that should make the build go smoothly for me. A side benefit is taking the time to include the 1:4 scale dimensions in parenthesis alongside the full scale dimensions.

All of this may sound like it is complete over-kill, and it may be, but it’s how I work. I like to plot out all of the details and have contingencies for problematic areas. It comes from decades of working with non-profit groups and producing events. Even though I have been harassed mercilessly for taking so much time in planning to the smallest detail, everything works out smoothly even in the face of adversities most of the time. It is an attitude thing, too. When running an event, it is easy for panic and frustration to kick in when something starts to turn south, particularly during the event. It’s all about focusing on solving the problem at hand, removing the cause, and smoothing out the bumps. Oh, and doing it all behind the scenes without the general public knowing it happened at all. All in a day’s work as they say.

Blue skies and tailwinds,
~Jon

Starting the 1:4

1:4 MaterialsWell, to start things off this post is a bit late. As I mentioned in a previous post, this time of year is very busy for my wife and I. I did manage to get out and pick up some supplies. A trip to Home Depot yielded some Gorilla Glue for the frame and some Titebond III to make the laminate that I will use as a plywood substitute and thinned a little it should work well as a sealer to replace varnish on the 1:4.

After looking over the wood at HD and finding all of their lumber riddled with knots, I decided to head over to Southern Lumber. Since I was planning to use clear vertical grain Douglas fir for the aircraft build I decided to use DF for the 1:4 as well. I have heard that DF is more difficult to work with so it makes sense to experiment a little with it before buying a bunch for the full size aircraft.

WorkspaceAfter I got home I set up a little workspace at my desk and set up an area for testing the ply material layup. I cleared the space and prepared the surface, laying out some 6 mil sheeting and taping it down to the desk top. After the work surface was ready I started the first piece of the paper laminate by covering a 1′ x 2′ sheet with Titebond III. Once the glue was brushed over the entire sheet I let it set until slightly tacky to the touch, once it was ready I added the second sheet and smoothed it out, making sure any air bubbles had been worked out, you can see these steps in the pictures below.

Later in the day I checked out how things looked. I was not pleased with the results.

let it dry under a little weightmake sure glue is spread out evenly spread the glueAfter all was said and done, the end product was wrinkled, warped and in general undesirable. Thinking back to my days doing some bookbinding I remembered that glued paper products need considerable compression and dry time. I am going to experiment a little more with the laminating process. I still have hope for the it working well as a stand-in for plywood.

Next week I should have time to start the milling. I know what size pieces are included in the spruce kit so I can start with those. Once I have the lumber milled I can get started with the bulkheads. Hopefully I will have figured out the ply stock issue by then.

Till next time, blue skies and tailwinds,
~Jon

Materials

Got out this morning and did another material sourcing run. It didn’t go as well as I had hopped, but that’s okay. I have made some solid decisions on materials and can now start buying what I need for the 1:4 scale project, as well as buying materials for the full scale airplane. Full steam ahead!

Full Scale

First and foremost, I’ve been able to source a majority of wood products locally. However, it looks as though I will have to run with one of the regular aviation suppliers for the 1/16″ plywood. I can find 1/4″ and 1/8″ but that’s as thin as local suppliers carry. 1/4″ AA marine is relatively easy to find, 1/8″ is tougher, 1/16″ is nearly impossible in any grade.

I found a local source for aircraft cables of the mechanical control variety; not electrical, which I suppose would be obvious to anyone who has been reading this blog since I don’t plan on installing an electrical system in the airplane. It looks like Orchard Supply carries aircraft cable as a regular item.

A local supplier for composite materials is TAP Plastics. I had a feeling it wouldn’t be particularly difficult getting some of the composite supplies locally. They don’t have all of the right fabrics, but they do have some. I am not sure about the resin and epoxy they stock, but for the basic materials to work with them, well those they have in spades. I will check out the chemical stuff later when I get to a point that I actually need to think about composites.

1:4 scale

I am rapidly coming to the conclusion that I will need to manufacture the ply products I need. The lumber is readily available, ply products on the other hand… With the full scale ply sizes being 1/4″, 1/8″, and 1/16″ the 1:4 sizes are 1/16″, 1/32″, and 1/64″ respectively. As I said earlier in this post, it is tough if not impossible to find ply this thin anywhere locally. So, I have resigned myself to the arduous task of manufacturing a replacement material.

At this point I think it will be a laminated paper product. Layers of a a heavy water-color paper should do nicely, maybe a 25 sheet pad. With any luck the end product will be moderately stiff ply-board in the appropriate thicknesses. In 1:4 scale a 4’x8′ sheet of plywood is only 1’x2′ so it shouldn’t be difficult to find the paper stock large enough. I was thinking of using Gorilla Glue as the laminating adhesive mainly because it is very strong and you can use water to thin it for spreading a very thin layer evenly across the surfaces of the laminates. I was hoping to avoid this but ya gotta do, what ya gotta do.

Composites

In truth the only composite parts that I would need to build are the engine cowling and the turtle-deck faring which isn’t even a required part, though, I must admit, I am definitely warming up to the idea.

The EAA Chapter 62 meeting I mentioned in the last post got me thinking about composite materials and processes. I haven’t done any fiberglass work in a long time but that is going to change with a day-job project that I recently started. It has some fiberglass work that needs to be done, so I figured I could brush up on those skills and maybe put some of the new techniques into action.

I purchased a book on fiberglass repair and construction to refresh the old gray matter on the subject. It has nothing to do with aviation but it is all about the basic skills for fabrication and repair in the medium. The book was published in 1988 so some things might be a little different or out of date material-wise, but the skills should transfer reasonably well.

Till next time, blue skies and tail winds,
~FlyBoyJon

VP-1 or VP-2?

Decisions decisions… I purchased the VP-1 plans set last week and acquired a set of VP-2 plans this weekend, now I have to make a decision between the designs. Which one should I build? I am estimating the VP-2 would cost between 5% and 7% more for the materials. I don’t think there would be much of a difference in the build time. The gross-weight bump and the extra seat are certainly good reasons to lean in the direction of the VP-2, but ultimately the decision needs to be a combination of practicality, mission, and my own comprehension of the plans. If one set of plans proves to be significantly more difficult than the other for some reason, that will affect the decision as well.

Evans Volksplane VP-1The idea of building a scale model before starting construction of the full scale plane had come up in a previous post. Now it looks like that might be the best way to decide between the two designs. If I build both of the aircraft as scale models first, that should give me a better parts list and I could evaluate the difference in material costs more accurately. It will also give me more insight in the build process for both airplanes.

Cost estimates for a 1:4 scale model of the VP-1 came out to about $45. Building two 1:4 scale models should come in less that $60. A question more important than cost is 1:4 or 1:8 scale. The 1:8 scale becomes problematic as the smaller plywood sizes in that scale would have to be balsa wood, which would increase the cost significantly, or be laminated paper stock, adding a lot of time in material fabrication. The idea with doing the models is to decrease the overall time and address problems with fabrication, not create materials and a whole new set of issues. Another problem with the 1:8 scale is hardware. In 1:4 scale I shouldn’t have a problem locating scale hardware.

Evans Volksplane VP-2With 1:4 scale the only real problem is that the product is on the large side. For the VP-1 we are talking about a 6′ wingspan, 4’6″ long, and a 1’3″ wide tail. The tail being the widest part of the structure with the wings detached. The VP-2 has a 6’9″ wingspan, is 4’9¾” long, with a 2′ wide tail. These are some big model airplanes and the only thing they are missing is the engine and maybe the rigging.

In the end I know that building the scale models is going to help save me a lot of time in the long run. I also know that the 1:4 scale makes more sense for dealing with potential build problems. With the models I don’t have to worry about Aircraft Grade materials and I can devote my time to building rather than sourcing. I also think that the models will give me a better estimate of the build process, and allow me to modify my build order and schedule.

It’s hard to say what direction things will take. I have my own ideas about the build process, when things will happen, how they will happen and all of that. No matter how much I plan, since I haven’t done this before, I just don’t know the path things will take.

Till next time, blue skies and tail winds,
~FlyBoyJon