CNC machining a carbon composite lever

The video shows how a carbon composite lever arm for an aileron is CNC machined. A second lever in aluminium (AW 7075 alloy) was also made. The carbon lever weights roughly half as much as the one in aluminium. The lever is actually part of an elevon mixer of the Nurflügel mircolight #hortenmicrolight.

[@malibu188]

Very impressive build. Lighter weight and it looks fabulous.

[@foesfly3047]

You Sir, are an artisan ♠️♠️♠️

[@redbeard4979]

Sir, how did you connect aluminum with carbon? Because aluminum corrodes from contact with carbon. Did you use fiberglass between carbon and aluminum? Thank you!

[@andreschavarria1450]

I made a separate video on galvanic corrosion. I explain there how to prevent it: kzbin.info/www/bejne/eoHFhaKEl9momMk

[@divakarraju8423]

Dear Andrés Chavarría, This is very impressive to cut without delamination. What are the specifications of the CNC and Tool you used. I also looking for a machine that cuts flax fiber composite precisely and without delamination.

[@andreschavarria1450]

Flax is hard to cut cleanly. That fiber is similar to Aramid and other tough fibers, such as Vectran. Look for a tool that works well for that fibers, and you'll get a good result. Maybe not perfect, but good. Regarding the video: We used several different tools. The ball mill was a usual full carbide tool for aluminium. The other ones are composite tools by Karnasch. Speed should be chosen depending on the tool used, but in general it's not too high for composites.

[@adrianharrison5208]

what pins have you used to hold the bearring housing on with,just woundering what you haved done to combat corrosion.. Amazing looking parts..

[@andreschavarria1450]

This was just a test, and I decided to use a different approach at the end (see the other type of bellcrank). The pins would have been usual aluminium solid rivets. Corrosion can be prevented by adding a thin layer of glass fabric between aluminium and carbon. A usual mutlimeter can be used to double check that aluminium and carbon are not contacting.

[@adrianharrison5208]

Back here again watching amazing clip

[@salmastropolo1642]

When I try to cut 2mm CF sheets using my cnc, the bottom edges are burred and have strands that protrude (on the side of the CF that touches the waste board). Does anyone have any tips? What are your tips for a smooth exge after cutting? Using a carbide 3m endmill bit. Thanks

[@andreschavarria1450]

The tool should be very sharp and ideally it should have a geometry made for composites (theeths instead of blades). Do a rough cut with about 2/10 mm undersize and finish to final dimension with somewhat higher rpm at same feed rate. The wasteboard should have a level surface, so that the CF sheets have full contact. Fix well them well and avoid bridging. Machine about 1/10 to 2/10 mm deeper into the wasteboard than needed. Carbon fibers are quite tough and even carbide tools get dull soon. Tools with diamond coating stay much longer sharp. Beware, they are expensive, but they really make sense. Even so, a few fiber strands might protrude. Sand with some 120 - 240 grit sandpaper to get rid of them.

[@salmastropolo1642]

Andrés Chavarría thank you very much for your tips

[@DivyesshSivakumar]

The dust is very harmful u should be cutting the cf plate under water

[@andreschavarria1450]

Yes, the dust is harmful and precautions should be taken. If possible, it can be machined under water, or in a closed room with aspiration. Another thing to consider is using the right tool and cutting data. This efficiently prevents production of fine dust.

[@fallenlord8005]

Hi! Can I ask how long does it take a part to make? Im working on the same field, but with other cnc cutters and our product is similar.

[@techtreko]

I need similar part for my Harley Davidson XR 1200x gera lever, you can do in Carbon?

[@albatross720]

Great video. Curious why at the end you say "same strength". Isn't carbon fiber 10 or 11 times stronger than aluminum?

[@andreschavarria1450]

Carbon fiber is much stronger than aluminium, but not necessarily a carbon laminate. It depends on loading condition, orientation of the fibers and also on the expoy resin matrix. Here, for the sake of easy production, fiber orientation is not ideal. This is the reason why it has roughly the same strength than high strength aluminium 7075. By properly choosing the fiber orientation, it is possible to get more strength out of the fibers and reduce weight. This video shows how that can be achieved: kzbin.info/www/bejne/b4Sum2yilsSmrbM The expense of getting the most out of the fibers is having a much more elaborate production process.

[@marheim9361]

Did you use anything to attach the bearings, or are they just press fitted?

[@NicksStuff]

What did you use to measure or estimate the strength?

[@andreschavarria1450]

Strength was estimated over calculation and measured by a simple load test. When reliable values are needed, at least 10 pieces should be break-tested to have a good statistic of average strength and variance.

[@kangdoel1831]

Are all CNCs capable of cutting carbon fiber? What are the special CNCs?

[@andreschavarria1450]

In principle you do not need any special CNC-machine to route carbon fiber. The machine should have sufficient stiffness, though. Regarding the milling tools, you should use solid carbide tools, preferably with diamond coating. Carbon is very abrasive and blunts usual tools very fast.

[@morphey125]

это куда и на что ставится ?

[@JF32304]

Is this the same as G10?

[@andreschavarria1450]

No, G10 is made of glass cloth and will have a much lower strength and higher weight than this one. Also, the layup of the video's material is balanced and quasi-isotropic. If weight is less important, G10 with more thickness could probably be used instead.

[@ThomasShue]

What cnc machine is that?

[@andreschavarria1450]

It's a kit from Sorotec (Alu-Line)

[@NiclasGudmundsson]

What cnc are you using?

[@andreschavarria1450]

It's a Alu-Line kit sold by Sorotec

[@NiclasGudmundsson]

@@andreschavarria1450 Thank you !

[@user-nh8tc9po2l]

1:1 one to one made from aluminium to carbon what did that helps? that devinitifly not the advantages of carbon 😂

[@andreschavarria1450]

Well, though not the full advantages of carbon were take of, a carbon composite is till lighter and stronger than aluminium. Search the figures … The video shows a study on the way to a better solution. If you want to see how the advantage of carbon can be fully taken, you should rather consider the following video: kzbin.info/www/bejne/b4Sum2yilsSmrbM