Centrally-holed mounting boxes

[davewb]

Can you get metal socket/light-switch flush mounting boxes with the cable push-out bits centrally positioned?

We have some quite old wooden "mounting boxes" where the cable access comes down the middle: I do not want to hack the wall to either slightly reposition the new box so its off-centre, or re-route the cable down the wall....

Thanks Dave

 

[Lectrician]

16mm deep single boxes have a central hole. 25mm single ones will not.

25mm double usually have 4 holes on one side, and 3 on the other. But it does alter from make to make.

 

[securespark]

If you are clever with a 20mm hole cutter, you can cut a hole in the centre, but you have to take GREAT care that you don't send the drill skidding off the workpiece and into your body!

 

[plugwash]

you would probbably also want to put a block of something inside the box to avoid the holwsaw pushing out the two knockouts

 

[ban-all-sheds]

If you are clever with a 20mm hole cutter, you can cut a hole in the centre, but you have to take GREAT care that you don't send the drill skidding off the workpiece and into your body!

No more care than drilling or cutting anything. Surely you're not in the habit of holding things you're drilling, are you?

you would probbably also want to put a block of something inside the box to avoid the holwsaw pushing out the two knockouts

And whilst you might get away without grommets on ko holes, ones you've cut with a saw will definitely need them...

 

[davewb]

Thanks folks. I got some ideas now to get on with it!

Dave

 

[crystal ball]

Instead of using a holesaw try a 20mm sheet metal punch, sometimes called a chassis punch, safer than a holesaw and leaves a nice clean edge all you need is a pilot hole about 8mm. A good hardware shop (not a shed) should be able to help, CPC also have them

 

[securespark]

No more care than drilling or cutting anything.

Of course. It goes without saying that great care should be taken with all aspects of DIY, but especially with power tools.

Surely you're not in the habit of holding things you're drilling, are you?

No, I'm not in the habit of holding things while I'm drilling...Even if you mount the piece in a vice or workmate, you can still slip and (eg) catch your hand.

While we're being picky, surely you're not in the habit of not fitting grommets to factory punched knockouts?

Miaow!

For reference, please fit grommets to your metal boxes regardless of how the hole was made. It is good practice and better safe than sorry.

If you ever think of getting complacent with power tools, look out for a programme on telly (been on twice over the last few years) telling the story of two geezers who came to grief at the hands of power tools.

One guy completely severed his forearm with a chopsaw (he was hacked off!), and the other had some kind of woodworking power tool (forgotten which) embedded in his (tool that is). Actually, it wound up in his groin and I think it missed you know what, but nevertheless he was in a bad way!

 

[ban-all-sheds]

While we're being picky, surely you're not in the habit of not fitting grommets to factory punched knockouts?

Wouldn't dream of it - but some people don't fit them, I believe. I was just trying to point out that while this might be OK with factory punched ones (c'mon - be honest), it would genuinely be a bad idea for a hole you'd sawed yourself.

If you ever think of getting complacent with power tools, look out for a programme on telly (been on twice over the last few years) telling the story of two geezers who came to grief at the hands of power tools.

One guy completely severed his forearm with a chopsaw (he was hacked off!), and the other had some kind of woodworking power tool (forgotten which) embedded in his (tool that is). Actually, it wound up in his groin and I think it missed you know what, but nevertheless he was in a bad way!

You should look at this: http://www.sawstop.com/home.htm it's quite astounding..

 

[pipme]

Amazed at the 'Saw Stop' !!

Quote :-
The system's brake is housed in a cartridge that is easily replaced should the system ever be triggered. These replaceable cartridges enable the system to be quickly adapted for use with different sizes and types of saw blades.
Sounds like the cartridge is a 'one shot' safety device, be even better if user resettable ... Nothing like a sausage test for confidence in the safety device.
Greatest danger ... over confidence !!

P

 

[fubar]

You should look at this: http://www.sawstop.com/home.htm it's quite astounding..

That is pretty cool!

Greatest danger ... over confidence !!

I guess that is the advantage of it not being totally safe - you still get quite a nick, just no lost pingies.

The brake is pretty low tech. I thought they were going to use electric braking (back EMF) before I saw the demo. I guess the motors in table saws and the like are optimized for running in one direction only.

--
Michael

 

[ban-all-sheds]

If you brake it that way, isn't there a danger that the arbor nut will unscrew?

 

[fubar]

If you brake it that way, isn't there a danger that the arbor nut will unscrew?

No, there is masses of torque on those nuts when they are done up - and they tend to tighten up even more when in use.

The two things that are most likely to happen are that the saw blade shatters because it had a hairline fracture before the brake was activated or the fuse blows, but I assume that the electronics disconnect the power to the saw when the brake is applied.

I'm guessing that the blade has to be thrown away once it has been embedded in a lump of plastic like that.

--
Michael