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Building Tips and technical articles. => Building techniques => Topic started by: Motorman on January 27, 2021, 04:27:46 PM
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I've used the stuff for control horns on RC planes with great success.
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You will be our guinea pig.
I suspect that it'll be OK, but if you're worried you could bush the holes with aluminum tubing, then put the brass through that.
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I haven't used G10, but I've used bushed carbon sheet for 1/2A bellcranks
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I've made several bellcranks from 1/8" phenolic (epoxy and linen). This time I ordered something different G10 epoxy and fiberglass. I think it's stronger but will it cut the brass tubing on the lead outs? I know one thing, it wiped out 3 jigsaw blades in 2 inches. Had to go to the dremel tool cut off wheel to finish the job. Anyone ever use this stuff for a bellcrank?
It.s either phenolic or epoxy - in the case of G10 I think it is epoxy and fiberglass. Phenolic and linen is micarta. They are similar materials, G10 is much more suitable for our purposes.
Either way, .020 G10 would be excellent for making the face sheets on a "forked" bellcrank, without the bonding issues associated with aluminum or titanium, although it is heavier. ACP has a wide array of suitable materials including honeycomb sheets that *also* makes a good bellcrank.
Brett
p.s. then there is this:
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G-10 is ( ... ) is created by stacking multiple layers of glass cloth, soaked in epoxy resin, and by compressing the resulting material under heat until the epoxy cures.
https://en.wikipedia.org/wiki/G-10_(material)
I only wonder if it is brittle as thin sheets.
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I see, phenolic is a type of glue. LOL, I guess I shouldn't get my info from Mcmaster Carr.
It's the first resin commonly used, thermosetting, and a wide variety of different things were made out of it, like circuit boards (phenolic resin with paper), anything made of bakelite (phenolic resin and sawdust), Micarta (phenolic resin and linen), and a bunch of similar products like catalin. It is highly resistant to heat, an excellent insulator for both electricity and heat, doesn't melt (burns or breaks down instead), but tends to be brittle on its own, which is why it is almost always used with fibers to toughen it. Micarta (tufnol to foreigners) is extremely tough, bakelite is extremely brittle and just shatters on shock. All early printed wiring boards (PWBs, AKA "PC Boards") were made with phenolic sheet, but any good ones are made of G10 or something similar now.
Brett
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Yes, G10 is abrasive to metal parts that come into contact with the cut edges.
However, the glass fibers are fully contained along the molded faces, so you would only be rubbing up against a fairly hard resin material if that was to be your contact surface. If you keep the contact force and relative velocity low, the resin will not heat excessively and get soft and change the friction.
Cutting G10 with saw blades eats saw blades because it is tough--and abrasive.
The next question should be "how abrasive, and therefore how much life can I expect from such a combination?" Now you will need to test. Most engineers would not design edge contact with G10 sheet for aerospace parts. That does not mean it wouldn't work for certain model applications. Personally, I would not run cable leadouts thru a drilled hole in G10 bellcrank due to a likely short lifespan and suspect reliability. It is easy to do something much better.
But if you were using glass-reinforced solid stock (FRP) to make things, then any cut edge, or any wear on a molded edge will also be more abrasive than you might otherwise expect.
Here's some light reading. Knock yourself out:
https://www.slideshare.net/iaeme/two-body-abrasive-wear-behavior-of-short-glass-fiber-and-particulate-filled-polymethyl
The Divot
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... and a bunch of similar products like catalin.
I knew a guy who had a Catalin brand guitar amp. He pried the nameplate off a Pontiac.