Tag Archives: materials

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

Tool Quality

Everyone assesses the quality of tools, or anything really, based on a set of criteria only they know. My idea of quality might be very different from yours. With this in mind, I will do my best to say what it is in particular I am commenting on and why when I comment on quality. Hopefully this will give you a little more to go on when reading my posts.

To get started I thought it would be a good idea to give you some general notes about my perceptions of quality. As an example, there are several motivators that the average tool user will fall back on when buying new tools:

Brand is probably the most common. Brands hold a certain status with each tool user. Some for outstanding performance and longevity, some for cost vs. durability, some for status within groups of fellow tool users, and some just for the up-front cost. No matter how you slice it or where you sit, brand plays a part in our purchasing decisions.

Apperance has a lot more to do with the average buyers decision making process than most of us care to admit. I have to confess to this my self, there have been times when I purchased a tool because it looked similar to a higher quality brand or it just looked cool. The manufacturers know this all too well, thats why top end manufacturers go to great lengths to make there tools distinctive, and the advertising can get really fancy, not to mention the claims “So precise, NASA scientists use it.”

Reputation is very important to manufacturers. Manufacturers are always striving to get there product up to the next level and to be considered “the best” available. This can often work to the buyers advantage if your not a “professional” tool user because mid-level tools intended for the pro market can be had at lower prices than top end ones and still provide great durability. They wont be the cheapest tools in the crib but they will last a long time.

Personal Experience is a strong motivator. This is where brand loyalty comes from, and on the flip side, where negative experiences can prevent a buyer from purchasing a tool because of that experience. As a long time user of tools from the pro end all the way down to the one-time use end of the scale, I have found that tool companies have gone through a lot of changes over the last 15 years. Brands that once held high honors have been relying on reputation to get them through slumps in product quality, and other brands that farm out production have made several changes in suppliers over the years making it very possible that a tool from a particular brand that was very good 10 years ago is now being produced by some one else. The same is true in reverse for tools that you may not have liked 10 years ago.

Recommendations can be tricky in part because they are coming from some one with their own biases. For a recommendation to be useful, you have to know something about the person making it and how they evaluate tools. Sometimes, even generally held opinions, can be based on subjective information passed along by someone with media clout, or some one caught with there hand in the cookie jar so to speak, can sour the market for no legitimate reason.

There are some other things that should be involved in the decisioning process more often, and that tie together in a number of ways:

Materials that are used in manufacturing. How sturdy is the tool? Is it ergonomic to use? Does the manufacturer use materials that require hazardous processes to make parts? Will those materials be available in the future?

Duty Cycles can cover several things. First is the operating duty cycle, how long the tool can run or be used continuously and how long it needs to not be operated before using it again. Second is cycle related maintenance. Some tools say that they must be serviced after a certain number of hours. Both of these are important because they tell you to some extent how productive you can be with the tool and how much it will cost you to use it over its lifetime.

Repairability is a big one for me. I prefer to own tools that can be repaired and reconditioned. A good tool, in my opinion, is one that can last generations. This is a view that has declined over the last 20 years with the advent of inexpensive cordless tools. I like cordless tools, but batteries cost a small mint and can make a tool worthless if the battery needs to be replaced and that model has been discontinued. Fortunately manufacturers seem to be reversing this trend slowly. Another concern is with really inexpensive tools like cordless drill/drivers. Having worked at factory service centers I can tell you, they don’t repair $10 tools, or $30 tools for that matter. They replace them with new ones. A diagnostic inspection takes at least 15 minutes to be thorough, in wages and overhead that pretty much exceeds the wholesale cost of the tool. Even a tool that costs over $50 it can be a close call.

As an example, I remember a drill/driver that was brought in for repair by a customer who wanted to do the repair them self. They disassembled the tool, fixed the problem, cleaned everything up and got distracted with other things. Unfortunately before they got back to the tool they somehow lost most of the screws to reassemble the tool. After a quick inventory of the parts they had, it looked like they needed 20 something screws and nothing else. The parts alone cost about $14. The retail cost of the tool was $9.99. He bought a new drill/driver. I consoled him by reminding him that now he had an extra battery, charger, and spare parts as long as he didn’t lose any screws. After he had gone I was out front of the shop and found the old tool in the trash can, minus the battery and charger.

Availability includes parts and consumables. Even if you find a great sander that lasts forever, if it requires a special sand paper to work properly, you better hope that design isn’t discontinued and you might want to stock up on that sand paper anyway just in case. This includes batteries, bits, blades, and anything else that can be considered a consumable. Parts can also become an issue. All tools have what are called wear parts, these parts are the ones that are exposed to conditions that make them wear out more quickly than other parts, often designed to extend the overall life of the tool by absorbing forces that would otherwise damage more expensive parts. Plastic gears are often sacrificed to save an electric motor. Wear parts are usually the parts included in “tune-up” kits, things like o-rings, seals, diaphragms, plastic gears, and more. Availability is something that comes with brand names, that is part of what you are paying for in that extra cost, the ability to use the tool longer.

What all of this comes down to is set of adages:
~You get what you pay for.
~Take care of your tools, and they will take care of you.
~Tools are an investment, make it a wise investment.

Till next time,
~Dad