Guide to Custom Parts and Tools for Experimental Aircraft

Table of Contents

The world of experimental aircraft covers a wide range of machines, pilots and builders, but something they all have in common is fabrication. From businesses developing new aircraft to hobbyists building home built machines from scratch, everyone needs parts and tools to assemble them. Whether you’re working with a team developing kit parts for mass production or a lone wolf building your own machine, custom parts and tools are an important (and often significant portion) of the project, and SendCutSend can help.

This article will discuss those custom parts and tools. We’ll cover some areas of the aircraft they’re often used (spoiler, it’s basically everywhere), and why custom parts and tools are useful. And maybe while we’re at we’ll discuss where you wouldn’t want to use custom parts (and tools).

If you’re interested in learning a bit more about custom parts and tools used in experimental aircraft, read on!

Table of Contents

Components of Experimental Aircraft Parts

Let’s start with some of the major aircraft subsystems.


Lightweight, rigid and strong are the name of the game when it comes to all aircraft parts, but especially the airframe. It’s the main structure, holding the rest of the systems together. The airframe is probably one of the biggest systems where custom parts are used, very rarely is it made up from off the shelf components. In fact, if you’re building an aircraft that requires you to build the majority of it yourself to meet a specific certification (E-AB or Experimental Amateur Built for example), the airframe is a common area to put most of your fabrication effort, freeing you up to use more common parts elsewhere in the build.

The airframe is typically made up of mostly custom parts. Parts you can’t just order out of a catalog or from a website. Ribs, spars, skin panels, reinforcing braces, mounting brackets, are almost always custom designed shapes. The list is nearly endless.

Standard tools like clamps, Clecos, punches, riveting tools, dimple dies, etc are common for building your airframe, but what about custom tools? Building custom fixtures and jigs can be a huge time (and headache) saver. They can hold components in the correct relative orientations to secure them. They can be used to form parts to the correct dimensions. This is especially helpful when you need to make multiples of the same part. Having a custom built form, you can run through the process quickly to knock out as many parts as you need and they all come out the same. The same is true for parts that need to be symmetric. A jig or a custom pattern tool can make that fabrication much simpler, faster and accurate.


You may think the powerplant is more commonly a purchased part and not custom made. For the most part, that may be true, but there are plenty of builders fabricating custom engine parts. Only you can decide if fabricating parts for your powerplant is something you want to tackle or if you’d prefer to purchase most of the components. Even if your build includes a stock powerplant, you’ll still need custom parts to mate it into your custom airframe. What about connecting the controls? Again, custom parts are fairly common.

In an experimental aircraft, space can be limited when assembling your powerplant, or accessing various parts on it. Custom tools can be useful to reach fittings or fasteners that may be obstructed by nearby components.


Similar to the powerplant, the avionics are less likely to be completely custom built. They are often purchased or repurposed from other aircraft. But again, similar to the powerplant, you’ll need to mount your avionics and that’s where the custom parts show up again. You’ll want to lay out instrumentation to suit your preferences, or maybe you want to leave space for future avionics that you don’t have or need right now. You may fabricate a custom cover panel to act as a placeholder rather than look at an empty hole.

Propulsion Systems

Different aircraft use different methods for generating the required thrust. Propellers are common, used in small quadcopters all the way up to heavy duty large payload planes and helicopters. Propellers can be purchased or fabricated and come in an unlimited variety of shapes, sizes and materials. The more complex a part you’re fabricating, the more likely it is that custom tools can help make the task easier or at the very least a more precise and accurate part. You may want a template to gauge twist and symmetry as you shape a prop from wood. If you’re using composite materials (like fiberglass or carbon fiber) you may want to use a custom mold.

Maybe something more exotic propels your design, like a turbine. Performance can be tuned with different shapes for blades, shrouds and nozzles. In any case, custom tools can help form the shapes consistently and more easily than free forming.

The Need for Custom Tools in Experimental Aircraft Parts

We mentioned earlier how critical fabrication is for experimental aircraft. You can’t fabricate custom parts without tools (well, you probably could, but your fingers would get really sore). Because the level of fabrication for building experimental aircraft can be so deep, a wider range of tools are often needed, from basic hand tools, to more advanced machining equipment. Let’s explore some of these tools.

Measuring Tools

The specific measuring tools needed depend highly on the parts you’re making. At one end of the spectrum, simple measuring tapes and rulers are enough to get the job done. For parts requiring more precision (like machined parts or press fit parts) more precise measuring tools are needed. For that, having a set of calipers and even a micrometer are better. Many applications will require precisely measuring angles. Angle finders can be used to measure any angle, but don’t overlook a simple square to make sure parts are at 90 degrees when needed.

When measuring a large quantity of parts, making a custom tool for quick measurements can speed up the process. SendCutSend can help with custom fixtures with a variety of materials precision cut to your custom dimensions.

Cutting and Drilling Tools

The list of tools in the cutting category can get long. Depending on the materials you’re cutting, different cutting blades are useful. For simple holes, drills and punches do the job. For more precise holes (maybe for press fits) look into reamers. For cutting sheet metal there are plenty of options. Shears, cutoff wheels in a grinder, a bandsaw, jigsaw, plasma cutter, the list goes on. Fabric, leather and composites can all be cut with simple tools or by using specialty cutters designed for those materials. Patterns can help cut materials to the right shape. At the higher end, machine tools like mills, lathes, surface grinders can be used to make very precise parts. 

Also consider SendCutSend has materials like aluminum, carbon fiber, high strength steel and much more available and ready to cut to your specifications with free shipping in the US in 1-3 days. Have your parts cut directly, or make patterns and guides to help with the cutting.

Fixturing Tools

Often overlooked by new builders, custom built fixturing tools and jigs can be extremely useful. They don’t always have to be built from expensive materials, sometimes screwing together some scraps of 2×4 can be enough to hold your parts in the right place. They don’t necessarily need to be custom made, either. Locking pliers, c-clamps, vices and Clecos all do a great job of holding parts in place while you do what you need to do. They can help you align parts or just act like another set of hands.

Shaping Tools

Eventually flat material will need to be turned into a 3-dimensions shape. Shaping tools can be used to bend, stretch, shrink and sometimes beat into shape. A brake can bend thin metals along straight lines. A hammer and a form can pound metal into more complex shapes. Shrinking and stretching tools can be used to put convex or concave curves into straight sections of material and a bead roller can take dies of all shapes to add dimension to panels. Dimple dies (now available from SendCutSend) can be used to put stiffness back into panels that have been lightened (plus they look cool!).

Depending on the material, SendCutSend can bend parts to your specifications. Templates and  patterns can also be stacked together to make hammer forms for sheet metal.

Finishing Tools

Not the end of the list by a long shot, but we will finish this list by discussing finishing tools. Shaping parts can be a rough process and sometimes those parts need to be cleaned up before final installation. That can be as simple as filing and sanding rough edges smooth, wire brushing for a consistent surface or even spraying paint, powder coat or some other finish of your choice. A lot of builders choose to have finishing done by professionals, but it’s possible to get a professional finish at home. Finishing tools are available at all price ranges.

If you decide to have someone else finish your parts, keep in mind SendCutSend offers multiple finishing options for your parts. Tumbling, deburring, powder coat, anodizing and zinc plating are all services available from SendCutSend.

Techniques for Fabricating Custom Aircraft Parts

It goes without saying that experimental aircraft construction needs to include a certain level of precision and craftsmanship. Not just to get certified, but for safety and just plain aesthetic fit and finish. This is true whether you decide to build the parts yourself or not. There are a lot of things to consider when choosing which parts of your project to build and which parts to have made by someone else. Even if you build from a kit, there’s still plenty of work to turn it into an aircraft. 

Let’s compare your options.

Cost: It’s almost always less expensive to fabricate your own parts. Even when purchasing kits, you can often choose between multiple tiers scaling up in cost to reduce the amount of work done for you.Quality: This depends on your skills, but often outsourcing parts comes with a higher level of quality. 
Time: This can work both ways depending on your skills. Sometimes you can knock out a part yourself quickly, sometimes it’s faster to outsource.Time: Especially when batching out quantities of parts, outsourcing can save you time. Not to mention you can be working on other aspects of the project.
Learning Experience: Part of the reason people build experimental aircraft is to learn about the process. There are plenty of resources available, both paid and for free, in person and online.Professional Equipment: Outsourcing is typically the easiest path to higher end equipment. You may not have the budget or space for certain manufacturing equipment, but that doesn’t mean you can’t have parts made on them. SendCutSend is a perfect example.

It’s up to you to decide if you have the time, funds and skills to build vs outsource your parts. To be certified as an amateur-built aircraft (E-AB) you’ll need to prove you’ve done a majority of the fabrication yourself, so it makes sense to choose which (if any) aspects of the build you outsource. 

You’ve got a world of options available, both at home and as professional services. Tools available to the home fabricator become more advanced and less expensive every day. CNC routers, desktop laser cutters, 3d printers are all within reach to help you make custom parts and tools at home. 

For outsourced parts SendCutSend offers cutting, bending, finishing and a whole lot more. It’s easy to get instant pricing, and high quality parts are made fast and ship free.

There will always be a need for basic tools to fabricate custom parts for experimental aircraft, but advances in technology are constantly providing new tools and new processes to make parts faster, easier and more complex. Costs are falling for rapid prototyping equipment like 3d printers, CNC machine tools and desktop laser cutters. The same is true for more advanced fabrication equipment. Not too long ago, only large scale projects had access to CNC cut parts, injection molded plastics and elastomers and laser cut metal, but now they’re available to everyone at affordable prices even for small projects. There’s no reason to believe that trend won’t continue.

Even the internet has become a monster resource for learning new techniques and general knowledge-sharing within the experimental aviation community. The ability to connect with that community all over the world and locally is invaluable. If you haven’t already, check out the EAA website to start exploring all the resources available.

To read more about future developments in experimental aircraft check out this article.


We’re not the authority on experimental aircraft, but as it relates to custom parts and tools there are a few common questions we can address. For more detailed information check the FAA website. This is highly recommended as the rules are not necessarily consistent across all experimental aircraft nor are they the same before and after the aircraft receives its initial airworthiness certificate.

Can you do your own maintenance on experimental aircraft?

For certified amateur-built aircraft, yes. With other experimental aircraft it depends and you may be required to take a course first. That’s one of the big benefits of amateur-built aircraft. Not only can you (or anyone) do your own maintenance, but you can use your own parts which can save a significant amount of money. It also keeps you more familiar with your aircraft.

What is the difference between S-LSA and E-LSA?

Both fall under the category of Light Sport Aircraft, a certification for simple recreational aircraft. Both are designed and must be manufactured and maintained to a specific standard. The difference between S-LSA (Special Light Sport Aircraft) and E-LSA (Experimental Light Sport Aircraft) is that S-LSA aircraft are factory-built and sold in a ready-to-fly condition, where E-SLA are sold in kit form, based on an S-LSA design. Maintenance must be performed by authorized parties, but pilots may perform their own preventive maintenance after receiving the appropriate training.

Neither S-LSA or E-LSA are E-AB or Experimental Amateur-Built aircraft. Under the amateur-built certification, builders have much more freedom in the parts and build methods they use.


For aviation enthusiasts, experimental aircraft offer an affordable and fun way to own your own aircraft. With the plentiful resources available (both knowledge and manufacturing services) anyone can build an aircraft of their own. Whether you build from a kit or completely on your own, custom parts and tools are easily within reach.
SendCutSend carries over 165 materials in a variety of thicknesses with the expertise and equipment to cut, bend, tap, finish and more. If you need help fabricating a custom part or tool, we’ve got the resources to help. We even offer design services so you don’t have to create CAD files to send us to get your instant pricing.

Get our latest articles in your inbox!


Play Video
Play Video

Start your first SendCutSend project today!

Upload your CAD design or use our parts builder and get instant pricing on your custom laser cut parts, all delivered to your door in a matter of days.
No CAD File? No Problem! Send your sketch or template to our Design Services team. Starting at $49.

We proudly use hardware by PEM

Flush Standoff, 4-40, .250" Zinc plus Clear Chromate

Aluminum: 5052, 6061, 7075 Steel: Mild, G30

Thread Size4-40 x .250″
Hole size in sheet (+0.003/-.0.000).168″
Minimum sheet thickness0.040″
Maximum sheet thickness.125″
Fastener materialSteel
Minimum distance hole C/L to edge0.230″
When determining the distance between two or more fasteners, you can calculate the distance by the formula, C/L to edge + 1/2 the diameter of the second mounting hole..345″
Recommended panel materialSteel/Aluminum
Coating typeZinc
Aluminum material ranges (5052, 6061, 7075)0.040″-0.125″
Steel material ranges (CRS, HRPO, HR)0.048″-0.119″

We proudly use hardware by PEM

Flush Standoff, 4-40, .250" Passivated

Stainless Steel: 304, 316

Thread Size440
Hole size in sheet (+0.003/-.0.000).166″
Minimum sheet thickness0.04″
Maximum sheet thickness.125″
Fastener material400 Stainless Steel
Minimum distance hole C/L to edge0.230″
When determining the distance between two or more fasteners, you can calculate the distance by the formula, C/L to edge + 1/2 the diameter of the second mounting hole. Example shown with x2 of the same hardware..313″
Recommended panel materialStainless Steel
Coating typePassivated
304 Stainless Steel material ranges0.048″-0.125″
316 Stainless Steel material ranges0.060″-0.125″