drilling

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hawlk2004

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ok I know it may have been posted already but whats the best way to drill a 1/2" and a 5/8" hole in G12 fiberglass tube. its for my switches
 

Tonimus

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Mark it, then use a small twist drill bit by hand to get a dimple. Then use a step-bit to open it up to the correct size.
 

flynfrog

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you want sharp bits preferably carbide and use a tight backer. higer rpm light pressure
 

markkoelsch

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For that size hole I like carbide Brad point bits.
 

Worsaer

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For holes that large, take a look at 'step drill bits'. A good one works well. It's how I drill 1/2" holes for Schurter switches.
 

djs

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I use a drill press, with a scrap piece of 2x4 under the fiberglass (if possible). Start with a smaller hole (like 1/8") and then size up from there.

I don't invest a huge amount in my drill bits, so they tend to get chewed up by FG. Nevertheless, you're only drilling two holes :)
 

OverTheTop

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+1 for using backing. Clamp them together. If you want a really clean hole put a piece over the top as well.

I could mention "backing off" the drill bit, which involves tweaking the cutting edge with a bench grinder (or an angle grinder if desperate :wink:). Most twist drills are set up with a certain angle on the cutting edge. It tends to pull it through the G10 and make for a bad job. Similar problems occur when drilling plastics (perspex etc), but cracking is the result. Backing off is the answer for that too. It makes the drill less inclined to bite in.

The easy answer is to use backing.

Never tried it, but the step-drill idea has merit.
 

TopRamen

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You want a staedy rest, meaning a "Table", and then you want something to steady the work itself called a "V-Block"
That gets mounted in the vise that gets mouted to the table of the press, and you'll do fine for rocket science without a perfect micro-measuring devise, as squaring things up with regular speed squares or store baught good squares is fine enough for our scale of rocket science.
I've built a lot of jigs recently, but have been to busy to spend time here other than to come chicken scratch for ideas, and they were all made using some basic carpentry tools I learned how to use. A tenth of a degree does not matter unless you are shooting at the moon.
Make some stuff, and you naturally get more fascinated by how precise it can be, and then keep making it, and hopefully don't get discouraged by all of the failures.
Just make it! There's youtube videos and social things now that can teach you anything if you are sociable.
I'm not, yet I still find the very best enrichment in life from things that others share with me. It means I get to learn the thing and shre it in kind, and that is my way of being social.
I've recently introduced "Old Wood Working Machines.org" to Carbon Fiber and Fiberglass Cloth. OMG! They had never even used Bondo Spot and Glazing Putty!!!" Now I get PM's from weird places asking for suggestions for repairing weird thing beyond my comprehension.
Some folks think I have some kind of grasp on the current state of composite tech, or they are purposefully "F-ing" with me.

As long as my imagination is stimulated, I don't really care the motivation of others. I am glad to offer my oppinion, no matter how UN-educated, as it usually leads me to an education.:)
I'm leaning things for free that folks go to school or apprentice for. All I have to do is look for the knowledge.

I stil can't Type worth a damn cause of my hand, so forgive typos.

Bandsaws are handy for making V-Blocks:

Progess of SAW 2016-10-28 001.jpg
 
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EeebeeE

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Fabricate a cradle for your airframe so that it is easier to hold. Use a drill press. Drill a pilot hole first with a very high speed bit, especially with filament wound. Then work your way up to the right size. DON'T use a spade bit. I made this mistake. Only made it once.
 

OverTheTop

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Forgot to mention. Filament-wound f/g leaves loose ends. Whichever way you drill it this will probably happen. Coat the inside edge of the hole with cyanoacrylate glue (I use Loctite 401) and after it is dry run the drill through again. Nice tidy edges!
 

kramer714

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we drill LOTS of holes in composites at the day job, couple of things that can help,

1) step your way up to the final size, for 1/2 inch I would drill a 3/8 to start, followed by 7/16 then 1/2inch (see note 6), high speed low force WATER!
2) ALWAYS back up the hole, pvc pipe or wood can work well
3) carbide tools
4) drill them wet, dip the drill bit in water before AND after drilling the holes, lubricates and cools
5) use a drill press or an 'egg cup' if you can to hold the drill straight
6) use a dreamer (drill reamer) or dagger drill for the final cut, not a twist drill
7) if you have to use a twist drill, use one for composite 120 or greater angle, multiple flute, don't use brad point unless you have everything held VERY rigid

For larger holes use a grit hole saw and an arbor (3/4 or bigger)

Mike K
(composite manufacturing is the day job)
 

NateLowrie

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we drill LOTS of holes in composites at the day job, couple of things that can help,

1) step your way up to the final size, for 1/2 inch I would drill a 3/8 to start, followed by 7/16 then 1/2inch (see note 6), high speed low force WATER!
2) ALWAYS back up the hole, pvc pipe or wood can work well
3) carbide tools
4) drill them wet, dip the drill bit in water before AND after drilling the holes, lubricates and cools
5) use a drill press or an 'egg cup' if you can to hold the drill straight
6) use a dreamer (drill reamer) or dagger drill for the final cut, not a twist drill
7) if you have to use a twist drill, use one for composite 120 or greater angle, multiple flute, don't use brad point unless you have everything held VERY rigid

For larger holes use a grit hole saw and an arbor (3/4 or bigger)

Mike K
(composite manufacturing is the day job)
Agree with all of this and second it. For best results it's best not to use a hand drill. The bit will cone slightly in your hands and hands and you'll find filament strands getting ripped out of the matrix. Support the material on both sides if possible and use a bushing or drill press as a guide.

And for what we do, a shot of CA on the edge of the hole is well advised. Use a thin viscosity CA.
 

rfjustin

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For holes that large, take a look at 'step drill bits'. A good one works well. It's how I drill 1/2" holes for Schurter switches.
THIS... for sure, big fan of step drill bits. They are very spendy from the typical big box stores. I got mine from Ebay for dirt cheap, very happy with them.
 

ColumbiaNX01

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ok I know it may have been posted already but whats the best way to drill a 1/2" and a 5/8" hole in G12 fiberglass tube. its for my switches
You take your drill. Unscrew the chuck on the drill. Insert a drill bit. Tighten the chuck. Then you actually drill the hole in the fiberglass tube. Not the hard or difficult. Simple really, its not rocket science lol. But seriously its not hard. Most important is to work your way up from smaller drill bits to larger one's. Start out with a tiny one then go up from there.
 
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