32mm Holesaw in Metal Consumer Unit knock out - balls up!

[Sintra]

Bolt a metal besa box lid on and re-drill.

 

[Ryan Scott]

You could get your grinder and cut a slot out of the top of the CU and stick a bit of 3 or 4 inch trunking on top of that depending if you have many cables coming into it

 

[NDG Elecs]

Not any help now, but you could possibly drill a smaller hole and then open it up with one of those cone cutter things, designed to open metal holes up.

Not a bad idea at all. I wander whether the knock out would still hold firm though. Malcolm's idea should allow for the hole to be drilled neatly. Silly design by the manufacturers, they should have a couple of different options for the actual enclosure. Maybe they should do a bit of market research, asking sparks their views..

 

[Englishman]

May hold but may not. The horrible "knock outs" on the back of the Crabtree Starbreaker would hold though, they just refuse to ever come out.

 

[HandySparks]

For me make a new plate and pre drill this so fits nicely over balls up and your glans holds it all together !

...An interesting turn of phrase you have there ! mg_smile:

Indeed, I was about to make the same comment. :biggrin5:

A sketch of the final assembly could cause offence!

 

[Redvanman]

Doesn't help your situation but in future get the Hagar boards that have no knock outs if you are going to drill it out.
They do make both

 

[PEG]

I have had this occur,when knock-outs displace,or errors,retro-fit etc,necessitates a change of position or aperture size.

Usually,it is best to fit as large a piece of material as is possible,which matches the original cabinet. This can make any "special" shapes or slots,easier to machine,as it can be vice-work.

A few years back,i had cause to strip out several phone mast control cabins,which possessed a myriad of enclosures,cabinets and racking.

The stores area had a large pile of packaged,stainless blanks,epoxy coated on one side,and in varying size,from 50mm square,to 100 mm x 500 mm.

These have proved invaluable for such tasks,fixed suitably to maintain continuity.

When drilling around such knock-outs,you have to be ready for when they fall out...with only a "knock" :stooge_moe:

 

[overskilled]

For me make a new plate and pre drill this so fits nicely over balls up and your glans holds it all together !

don't think he or the customer will be very happy with the end of his penis holding a CU together!!

 

[Geordie Spark]

Not any help now, but you could possibly drill a smaller hole and then open it up with one of those cone cutter things, designed to open metal holes up.

This could be useful:https://www.cef.co.uk/catalogue/products/1039967-20-36mm-titanium-coated-step-drill

 

[davesparks]

This could be useful:https://www.cef.co.uk/catalogue/products/1039967-20-36mm-titanium-coated-step-drill

Apart from being made by silverline and sold by CEF it looks lovely

 

[Geordie Spark]

Apart from being made by silverline and sold by CEF it looks lovely

Yes I know! BUT it shows that they are available up to & beyond 32mm ....... I thought the biggest was 22mm.

That said, it's not something that you use all day everyday so for the occasional use it could ok PROVIDED you keep the speed (RPMs) down & use plenty of lubricant.


And there's always this:

 

[malcolmsanford]

Yes I know! BUT it shows that they are available up to & beyond 32mm ....... I thought the biggest was 22mm.

That said, it's not something that you use all day everyday so for the occasional use it could ok PROVIDED you keep the speed (RPMs) down & use plenty of lubricant.


And there's always this:

Ohhhhhhh now we are talking. Great for making holes in stainless

 

[Marvo]

I don't think you should be drilling the knock-out smaller than its intended diameter in the first place, you should either remove it entirely or not use it at all. Problem is if you drill it and fit an SWA gland there's a good chance it's going to break free anyway at some time in the future. The CU manufacturers should stop catering to DIY'ers and fit a proper gland plate that doesn't have pre-perforated knock-outs or leave the side and back walls without knock-outs assuming they're strong enough to take SWA glands without distorting.

 

[Octopus]

I don't think you should be drilling the knock-out smaller than its intended diameter in the first place, you should either remove it entirely or not use it at all. Problem is if you drill it and fit an SWA gland there's a good chance it's going to break free anyway at some time in the future. The CU manufacturers should stop catering to DIY'ers and fit a proper gland plate that doesn't have pre-perforated knock-outs or leave the side and back walls without knock-outs assuming they're strong enough to take SWA glands without distorting.

Problem is Marvo that there are countless existing installations where changing the CU is made difficult by all the DIY changes and hence why, I suspect, they have these large knock outs - quite how they expect the installer to maintain the IP rating and the "non combustibility" is questionable.

 

[Geordie Spark]

Ohhhhhhh now we are talking. Great for making holes in stainless

And the beauty of it is it's operated by hand so there's no fear of a numpty spark who has no comprehension of Speeds & Feeds (basic engineering stuff) ever burning it out!!! :laugh: