Cutting holes in plastic DIY boxes.

[PaulCa]

This is a very newbie (to DIY) question, but when you have a plastic enclosure box for electronics, how do you cut the holes for cable glands and displays etc.

I currently only have a dremel and while I can drill holes with the drill bit I don't believe I can round that whole out to 25mm and keep it .. well.. round.

Anyone know if you can get 25mm hole saws for rotary tools?

Is it time to invest in a proper hand held wireless drill?

I'm also wary that plastic might catch fire while drilling, this is probably paranoid.

For cutting square holes, can I just use a cutting disc or is this likely to seize and shatter in plastic?

 

[winelight]

I just use a drill and then needle files to enlarge / shape. It's very easy to work these boxes. They don't catch fire.

 

[Maldon john]

Hi Paul. B&Q sell a range of hole saws around that size that fit rotary drills. I used one to drill a hole in my plastic fermenter to install a tap

 

[evanvine]

As above, B&Q or Screwfix.
If you get the "plumbers" set, then you have the most useful sizes.

 

[Jeltz]

https://www.aldi.co.uk/en/specialbuys/t ... -saw-sets/

also spade bits are useful to have and you should be able to get a 25mm one

 

[PaulCa]

Thanks guys, I'll try HomeBase first tomorrow night on the way home. I think I'll need to "see" and buy, I can't trust the online descriptions as they don't tell me much about the adapter and whether it will fit the dremel chuck. I don't have the normal chuke adapter for it.

Marking it with a scorer and then drilling lots of holes, cutting out the middle with snips and knife and then filing/sanding is an option too if I get stuck finding a hole saw.

Hot knife was another one I spotted on my web travels today, apparently a stanley (or craft) knife heated in a flame to over 150C will cut through it.

The hard part will be the cable glands as they have a large 25mm thread to go through, but the fixing nut only extends 1mm, so if I don't want a gap it has to be that accurate. I get the feeling I'll end up with a mess.

 

[winelight]

Well goodness me you lads have it easy these days. I used to fit valves to steel chassis, drilling holes in a circle and then filing out (by hand and by eye) the most beautiful perfect round holes. Now all you have to contend with is a bit of plastic!

 

[billybacardi]

those were the days eh..... GW1CXT

 

[evanvine]

I agree G4NXB

 

[winelight]

Indeed yes but this was for audio, actually. I owned a valve 2m Storno rig but never made any valve radio equipment myself. G8KGG

 

[PaulCa]

I'll bite, whats with the 5 digit codes starting with G?

 

[evanvine]

Amateur Radio call signs!
(Radio ham)

 

[hairybiker]

Funny how so many of us are hams? GM1JLP (just renewed my licence :shock: )
How ever never drilled for any valves other than plumbing ones :lol:

 

[PaulCa]

I "should" get my HAM license as I own a 435Mhz transmitter and I shouldn't. Though I think I've used it about 3 times, for 15 minutes each time. It's just that the non-HAM bands available at the time were 35Mhz and 2.4Ghz. I was already using 2.4Ghz to down link video, and I found 35Mhz terribly unreliable with drop outs and brown outs, so I bought an chinese 435Mhz long range transmitter instead. Suppose to have a HAM license to use it.

(I think it's 435Mhz, or 433Mhz, can never remember which). Same frequency used by car fobs and garage door keys etc.

My use was for PPM control for a video drone.

 

[PaulCa]

Well I decided to just buy a drill. Got the 25mm holesaw, job done. Cutting the square hole was a little more difficult, the clutch has gone in my dremel again, it won't cut the disc just stops. So I drilled a few holes and cut the rest out with a hacksaw blade.

 

[rpt]

I don't think I've been on the air for twenty years or more. G4TGJ

 

[evanvine]

I don't think I've been on the air for twenty years or more. G4TGJ

Yes, the internet and mobile phones kind of knocked its duck off!

 

[PaulCa]

You guys will come in very useful if the Internet goes to pot in any way. HAM-Packet switched networks. Or TCP/IP over HAM radio. You certainly won't be delivering NetFlix videos but basic communications such as bulletin boards and email is very possible and useful.

There have even been real world tests of TCP/IP over avian carrier with homing pigeons. The "ping" round trip time was not measured in milliseconds and the timeouts had to be extended to days, not seconds :) Still it worked.

 

[Fil]

You guys will come in very useful if the Internet goes to pot in any way. HAM-Packet switched networks. Or TCP/IP over HAM radio. You certainly won't be delivering NetFlix videos but basic communications such as bulletin boards and email is very possible and useful.

There have even been real world tests of TCP/IP over avian carrier with homing pigeons. The "ping" round trip time was not measured in milliseconds and the timeouts had to be extended to days, not seconds :) Still it worked.

iirc 'Aloha' one of the first packet switching networks was braodcast by FM radio over the hawian islands..

http://en.wikipedia.org/wiki/ALOHAnet

ill get me sad lil coat..