surface box multiple knockouts align with trunking advise

[Telecoms_man]

Hi Guys,

I have to fit an MK 3 way grid surface mount box below 3" metal trunking and require the use of all three knockouts on the top of the MK surface box. This needs to be repeated for a number of surface boxes.

Cutting one hole in the trunking for a 20mm coupler and bushes is easy, but any tips how I can cut all three so they align?

MK have no details (that I can find) on their web site as to the hole spacing or have any templates.

My initial thoughts are either to measure carefully the surface box knockouts to find the centre & spacing of each knockout & make my own template on a piece of cardboard,

or,

offer the surface box up to eyeball & mark the centre of each hole and drill a pilot hole. Offer the surface box up again and use the knockout to align a Qmax cutter, to punch out the first hole. Fix the box to the first hole with bush& back-nut, then punch out the remaining holes.

or,

similar to the above, but cut the bottom of a surface box to use as a template & use a hole saw without the pilot drill.

Thoughts, help tips appreciated.

 

[James]

Hi,

It is three 20mm holes that have to align exactly with the three 20mm knockout holes in one surface box.

Just drilling three 20mm holes is easy, but each one has to line up exactly with the pre-made holes in the surface box. Then I have to repeat it multiple times.

Just wondered how other people do it, what tips they have or what experience they have with doing this. Are there any 'tricks of the trade'?.

Think I will measure very carefully, then make a jig, to give the centre point of each hole.
Can then test it first on a bit of scrap, if it works, then will be easy to mark each set of three holes, pilot drill & pop out with a Qmax.

I'm certainly not panicking, instead, I'm sitting back, not rushing and taking time to think of the best way to achieve a neat professional looking job. I have posted in the sh** work section some of the stuff left by the 'professional' NICEIC registered electricians who just f***ed everything in as quickly and shoddily as humanly possible. I have been asked to de-cak some of their work and want to ensure it is super-neat.

nice to see people who take pride in the appearance of there installs.
anyone can make it work
most can make it safe
some can make it look good
many can do it in the time required

A true professional,
MANAGES ALL THE ABOVE AND THROWS IN SOME GOOD CUSTOMER SERVICE.