Arduino Forum

Using Arduino => Project Guidance => Topic started by: lost_and_confused on Jul 19, 2012, 11:01 pm

Title: Drilling a hole - need help.
Post by: lost_and_confused on Jul 19, 2012, 11:01 pm
Sorry if this is the wrong area, but I couldn't see any better ones.

My project is in a somewhat larg PLATIC box.

3 mm thick.

For the sake of not having to take the box appart and all the stuff like that, I am wanting to put a USB socket on the side.

Alas the socket is 23mm diamater!  Maybe 24!!

I have asked and a couple of options have been mentioned:
Big drill
A lot of small holes around the edge of the big hole area and knock it out when complete.  Ofcourse this would then mean having to smooth the edges of the hole to make it round rather than "star" edged.
Anyone?
Title: Re: Drilling a hole - need help.
Post by: dannable on Jul 19, 2012, 11:06 pm
Hole saw? Mine go up to 75mm.
Title: Re: Drilling a hole - need help.
Post by: lost_and_confused on Jul 19, 2012, 11:09 pm
Yeah, but the teeth are more for wood cutting than plasttic.

The last thing I want to do is break the plastic box.
Title: Re: Drilling a hole - need help.
Post by: dannable on Jul 19, 2012, 11:12 pm
If you have any worries use it in a hand drill and take your time.
Title: Re: Drilling a hole - need help.
Post by: jackrae on Jul 19, 2012, 11:37 pm
Coping saw then a dremel drill with a round emery wheel installed to clean it up
Title: Re: Drilling a hole - need help.
Post by: wildbill on Jul 19, 2012, 11:40 pm
Jigsaw?
Title: Re: Drilling a hole - need help.
Post by: florinc on Jul 19, 2012, 11:53 pm
Start with a smaller hole, then use a tapered reamer to enlarge it.
Title: Re: Drilling a hole - need help.
Post by: justjed on Jul 20, 2012, 12:03 am
I agree completely with starting small and then using a tapered reamer. You'll get a much cleaner hole that way.

However, if such is not available to you, then use a spade bit, but be sure to get one with cutting spurs at the edges, such as this (http://www.drillspot.com/products/78050/speedbor_88820_wood_boring_spade_bit). In a non-metric size, you'll want either 7/8 or 15/16. Go slowly, and use a piece of scrap wood as a backing block when drilling your hole.
Title: Re: Drilling a hole - need help.
Post by: graynomad on Jul 20, 2012, 12:23 am
A hole saw will work just fine.

_____
Rob
Title: Re: Drilling a hole - need help.
Post by: WillR on Jul 20, 2012, 12:31 am
Look for a hole saw of some type...

Much easier...
e.g.
http://www.wattmaster.com.au/toolsandinstrumentsdetails.asp?PGID=147

http://www.josco.com.au/newsite/jia/products/cuttingtools/cuttingtools_hsm.htm

hth


Title: Re: Drilling a hole - need help.
Post by: wanderson on Jul 20, 2012, 12:34 am
These are very useful for drilling round holes in plastic, http://www.amazon.com/Neiko-Titanium-Step-Drill-Bit/dp/B000FZ2UOY/ref=sr_1_1?ie=UTF8&qid=1342737118&sr=8-1&keywords=unibit

When the hole is not round (ie. square) I drill a round hole and then use a file to square it up.  Doesn't take long and given a little practice produces nice results. 

Both tools work with plastic as well as sheet metal.
Title: Re: Drilling a hole - need help.
Post by: macegr on Jul 20, 2012, 01:19 am
Surprised how many people don't know about nibblers.

I would carefully mark the cutout I need, drill a hole somewhere inside the area, then nibble out to the edge and around the perimeter. Very minimal filing or sanding after that, if any. You can make a nice square hole this way if you need it.

http://www.youtube.com/watch?v=1q3w2GsovJ4
Title: Re: Drilling a hole - need help.
Post by: graynomad on Jul 20, 2012, 01:28 am
I love nibblers, been using them for years, but the ones I know about can't to 3mm.

______
Rob
Title: Re: Drilling a hole - need help.
Post by: wanderson on Jul 20, 2012, 02:07 am
I haven't had much success with nibblers on plastic.  Everytime I have tried I end up with cracks.  Filing doesn't take very long.  A good range of files should be in everyone's toolbox.
Title: Re: Drilling a hole - need help.
Post by: PeterH on Jul 20, 2012, 02:21 am
I'd agree with the suggestions to drill/hole saw undersize and then file to the exact fit.
Title: Re: Drilling a hole - need help.
Post by: abrookfield on Jul 20, 2012, 02:43 am
there's always good old fashioned routers