Material selection and sourcing for multi rotor frame

I'm researching different designs and materials for a hexacopter frame to carry a camera. It looks like the frame of the ArduCopter kits is fiberglass sheet and then aluminum for the arms. Is fiberglass a good material for this purpose? Can anyone confirm this is fiberglass?

http://diydrones.ning.com/photo/arducopter-frame-parts-5?xg_source=activity

Extren 500 seems to be a popular and reasonably priced fiberglass sheet but I'm not sure if this is meant for building structures or if it would be suitable for smaller and more precise projects like a hexacopter frame. In particular I've been looking at the .125" plates here. Probably a 24" x 24" sheet is around $65 with shipping.

http://k-mac-plastics.com/fiberglass-sheet.htm

The other material I've been looking at is carbon fiber sheet though for cost I'd rather start with something less expensive. Inevitably it will crash (or I will crash it). Like learning to ride motorcycles, you don't want to start with a nice one. I'm open to other materials and/or sources if you have suggestions. Also I will be cutting the material on a Taig CNC mill. Thank you!

After a lot of searching I think I've found the correct cutters for my mill to cut the fiberglass. They are intended for cutting out circuit boards (which are made of the same G10 FR4 fiberglass). For anyone else who is following or finds this in a search, a description of them is below.

"Chip breaker routers can cut much faster since the deep flutes that spiral around the bit allow for efficient swarf removal. Chip-breakers produce a reasonably smooth edge finish in composite materials where they are preferred for cutting internal breakaway slotting. Producing less rotational drag than diamond-cut routers, these bits are recommended for use on all mechanical etching systems from LPKF and T-Tech. Chip-breakers look like conventional end-mills with serrated edges along the flutes."

"Diamond cut routers produce a better edge finish, but cut slower than chip-breakers due to the relatively low efficiency of swarf removal. With a geometry resembling a very fine wood rasp, these bits have an abundance of cutting edges. They tend to last longer, are more rigid, and produce a finer cut than chip-breakers. Their superior rigidity make them ideal for cutting precise external contours. The large number of teeth slightly increases the rotational drag on the spindle making these tools less desirable for use in mechanical milling systems."

http://www.thinktink.com/stack/volumes/voli/store/routbits.htm

Apparently their expected life is about 3,000 linear inches in the G10 fiberglass. Not bad for $5 each. When the fiberglass and cutters arrive I'll post an update with how well it all works.

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Kubi Kara December 27, 2016 at 6:45am

How big are the molded parts? What are the max dimensions required?
captaingeek October 17, 2012 at 11:05am

what's with the carbon fiber and fiber glass obsession for simple things like frame plates?

what ever happened to using ply wood? not only is it stronger then artificial materials by weight, but its eco renewable and doesn't pump out toxins like crazy when cut with a laser or when burned. Another thing carbon will reek havoc on and 2.5ghz radio waves.
Graydon Tranquilla October 4, 2011 at 9:16pm

Commercial carbon fiber sheet is thinner than you require. You probably want carbon fiber plate. However Carbon fiber in plate or sheet form lacks significant strength on the z axis even if it is quasi-isotropic. Sandwiching a lighter material between exterior layers of cf should help or you can add kevlar or fiberglass or even a thin sheet of aluminum in between the cf sheets. These should all be made using epoxy and not polyester resins. Special etching chemicals must be used with the aluminum to make it stick to epoxy/cf plate.

Fiberglass plate is mostly available in G9 Gerrite or G10 plate but is very high density using polyester resins under extreme pressure. You will not be able to get epoxy based plate material to stick to it as it will delaminate.
Luke Olson June 20, 2011 at 10:04pm

After a lot of searching I think I've found the correct cutters for my mill to cut the fiberglass. They are intended for cutting out circuit boards (which are made of the same G10 FR4 fiberglass). For anyone else who is following or finds this in a search, a description of them is below.

"Chip breaker routers can cut much faster since the deep flutes that spiral around the bit allow for efficient swarf removal. Chip-breakers produce a reasonably smooth edge finish in composite materials where they are preferred for cutting internal breakaway slotting. Producing less rotational drag than diamond-cut routers, these bits are recommended for use on all mechanical etching systems from LPKF and T-Tech. Chip-breakers look like conventional end-mills with serrated edges along the flutes."

"Diamond cut routers produce a better edge finish, but cut slower than chip-breakers due to the relatively low efficiency of swarf removal. With a geometry resembling a very fine wood rasp, these bits have an abundance of cutting edges. They tend to last longer, are more rigid, and produce a finer cut than chip-breakers. Their superior rigidity make them ideal for cutting precise external contours. The large number of teeth slightly increases the rotational drag on the spindle making these tools less desirable for use in mechanical milling systems."

http://www.thinktink.com/stack/volumes/voli/store/routbits.htm

Apparently their expected life is about 3,000 linear inches in the G10 fiberglass. Not bad for $5 each. When the fiberglass and cutters arrive I'll post an update with how well it all works.
Russell B. Sutton June 16, 2011 at 12:11am

Can G10 be cut with a laser cutter.
Luke Olson June 15, 2011 at 7:22pm

I think I may have found a better option than the Extren 500 fiberglass. This company sells fiberglass sheets for shock towers and chassis use and they call it G10.

http://www.teamcobra.com/cobra/accessories.htm

Looking around there are other sellers that have G10 fiberglass. Since it is being marketed as a good material for shock towers and chassis use I think I'll give it a try on my hexacopter frame. Also found this on Wikipedia, an article on FR-4 which is the successor to G10 fiberglass. Similar but flame retardant.

http://en.wikipedia.org/wiki/FR-4

Hopefully this will help others who have similar questions about materials. When I get some and mill it I'll post back with how it goes.

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Material selection and sourcing for multi rotor frame

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