10x10mm Woven Carbon fiber arm [Second-rate]

    (10 customer reviews)

    $ 2.50

    Out of stock

    SKU: N2CFArm Categories: ,

    Description

    These arms are of second-rate quality!

    Please note that these arms have not passed our quality control in regards to aesthetic qualities. They may be severely scratched, have a very uneven finish, be clogged on the inside, have sharp edges and/or other faults. The edges may be square or of the more rounded variety. They are, however, mechanically sound. The price is set taking this into account.

    Please note that this is a legacy product. This means that once the current stock has run out, it’s unlikely that this product will be re-stocked. Product information will then act as a reference.

    These woven carbon fiber square tube arms are incredibly stiff, strong and lightweight. The torsion (twisting) strength is unparalleled which results in a crisp and precise flying experience, even with high power setups. Unlike extruded carbon fiber arms, these arms can take abuse without cracking. They are also lighter, have more room inside to run wires (if they are not clogged) and are stiffer in all aspects.

    Specifications:

    • Material: 3K Carbon Fiber twill weave
    • Length: 325mm (approximately)
    • Outside dimensions: 10x10mm
    • Inside dimensions: 8x8mm (may vary, or be clogged)
    • Wall thickness: 1 mm (may vary)
    • Weight: ~16.5 grams

    Price includes one arm.

    Most other carbon fiber square tubes on the market are made using a process called extrusion. Basically at one end there is a huge container of carbon fiber. These fibers are mixed with resin and then gets pushed through a die that has the shape of the tube you want to produce. This process is quick and inexpensive. However as the carbon fibers only run along the length of the tube and are not interwoven. This means that torsion strength and durability is low. These tubes can’t withstand compression nor twisting motion without cracking. Once cracked the tubes lose most of their torsion strength and get so soft that they twist during flight, often causing catastrophic in air failures (don’t ask me how I know). They are also difficult to drill as the force required to cut the carbon strands using a normal drill bit is really close to the compression strength of the tube. More often than not you end up with a cracked tube. Tired of changing arms after a small crash, or even a hard landing, I set out on a quest to find a better alternative. Square aluminium profiles worked but they were heavy and tended to bend in a crash. Would work great on less powerful setups and during the learning stages of flying, but it lacks the fine control and precision achieved with stiff and high torsion strenght booms. It’s also difficult to hide the wiring.

    So I decided to find a manufacturer and make my own woven carbon fiber square tubes. These arms are made using a technique called bladder molding. This means that you start out with a woven carbon fiber cloth, which you wet with epoxy and then place into the bottom part of a two part mould. Multiple layers are laid down at a 45° offset. A balloon is placed in the middle and the carbon fiber cloth wrapped around the balloon. Then the top part of the mould is placed on top and screwed down. The balloon is then inflated at very high pressure pressing the carbon fiber out against the mould. The mould is then placed in a heated chamber to activate the epoxy resin. The pressure in the balloon is maintained for the whole curing time. This process creates incredible strong and nice looking parts. The carbon fiber cloth has fibers woven together at 90° angles and the different layers are placed at a 45° offset to achieve the highest possible torsion, compression and tensile strength.

    The wall thickness is 1mm, which leaves 8x8mm of space inside the tube. This makes running wires inside a breeze. Since these arms uses less material than its extruded counterpart, they are 33% lighter. That is 8 grams lighter on a 325mm long arm.

    These arms also comes with a 3mm hole pre drilled at 18mm from one end, to fit the tricopter.

    Since each boom is hand laid the wall thickness may vary a bit, meaning that the inside dimensions might differ a bit. The outside dimensions however are always the same. Also being hand made there might be small imperfections in the finish of the part.

    Use the “circle motor mount” for mounting the motors straight to the arm.

    Additional information

    Weight 18 g

    10 reviews for 10x10mm Woven Carbon fiber arm [Second-rate]

    1. SimONtron (verified owner)

      Great tube’s if you need strength. Enough light. But …
      In fact, they are not quite square. In the section corners are rounded and the sides is not quite straight. This can cause a lot of problems with the installation of the engine in the same plane. Just enough width tubes varies from instance to instance and can be up to 0.5mm.
      Just tubes are poorly suited for use with Rotorbits elements and do not sit snugly.
      But anyway it’s very good tube at a great price and almost unique. Honest winding carbon fabric.
      I recommend!

    2. Terje (verified owner)

      Ordered 6 tubes as I have previously broken quite a few hobbyking booms.

      The booms have a very nice finish and none of them have warping issues. Perfect for spare booms, or as booms for a DIY version of the RCExplorer Tricopter V3.I don’t know what it takes to break these, I haven’t been able to yet!

      I can highly recommend these booms.

    3. Rotorblade (verified owner)

      Very High Quality! No flex or torsion. Great arms to experiment with scratch building due to their properties!

    4. Christian (verified owner)

      I’ve ordered 8 tubes, they seem to be really good. Will buy more if needed 🙂

    5. Andy

      Can I make The arm longer ? I want to increase its stabilization.

    6. Sasha

      Is it possible to get the uncut and undrilled version? I’d really like to use it for my DIY quads, but the length is a little bit too large for that, and cutting away small pieces from each one is counterproductive.

    7. Finn (verified owner)

      These booms are works of art! I ordered 4 for my large scratch built quad project, and they shipped from Sweden to Hong Kong in 5 days!!! 5 DAYS!!! David said it would take 2-4 weeks, but I’m glad he was wrong! It beat my HobbyKing order! Came very well packaged. I planned to run my motor wires through these things but NOTE: 3x 3.5mm bullets will not fit down the inside of these things. Other than that, I am very happy with them. I will soon drill more holes into them, and will find out then how they fare, but for now, I am ver impressed! Best booms I have used on any of my quads thus far; there is no compromise for the best!

      • RCExplorer – David

        Wow that was fast 😀 Glad you got them so quickly! Good luck with the build!

    8. Terje (verified owner)

      Just received two arms from the new batch. Compared them with three spares I still have (since they are near indestructible). The “old” arms weigh 16.69/18.07/18.65g and have tolerances between 9.70mm to 10.14mm. The new batch arms weigh 16.8/17.05g and have tolerances between 9.74 and 9.90mm. The new booms are really square and slightly more shiny than the “old” ones.

    9. Daniel (verified owner)

      Excellent product. I bought these before the new shorter versions came out (which I will buy if these ever break). Super easy to cut and drill but strong as hell. I put mine on an electrohub, which for some reason really likes to taste grass at least once a session. I previously had the hobby King extruded carbon arms, which are strong but due to the uniform grain, still break like timber. These new ones are excellent, I bought enough to make 2 1/2 sets of arms and several heavy hits later, have not had to replace a single arm. Also only took about 10 days to get to Australia – very happy camper.

    10. Bojan (verified owner)

      Hello! What is the best way to drill into this tube, because my baseplate is little bit modified, so my holes must be 2cm from the edge, not 1.5. Must I watch to something when drilling into the carbon?

      Thanks, Bojan

      • RCExplorer – David

        Use a very high speed drill and drill with very little pressure. Do not breathe the carbon fiber dust. Wear eye and breathing protection. A very sharp drill is also recommended.

    Add a review

    You may also like…