Advice on using the downlighter hole cutter sold by TLC

[Jonny7]

I've about 12 new holes to drill so I would think that either of these would be a good investment:

http://www.tlc-direct.co.uk/Main_Index/Ventilation_Index/Core_Drills_100mm/index.html

I'd prefer the 29.99 one mainly on cost of course but my question is to those that have experience of using one.

I also have about 8 holes that exist but the ceilings have been skimmed so the holes are now reduced to a lot less than they were (I left the fittings dangling down on their cables - not exactly safe but it seemed a good idea at the time) so they want opening up to the correct diameter.

Now this cutter, I take it that the bowl doesn't rotate and that it might be possible to hold the bowl hard against the ceiling with one hand whilst carefully (i.e. minimum pressure) cutting a new hole but of course without the pilot drill biting into anything. I reckon if I could even just get a circular score around the ragged edged hole, I might be able to finish it off with a plasterboard padsaw. I'd remove the lights and cable first of course.

Or would a stepped cone cutter be better if used very gingerly? Or is there another way anyone can suggest? Or should i just simply draw a circle and get a few plasterboard padsaws?

any advice gratefully received,
Jon.

 

[nstreet]

I've always used a 50p kiddies compass set to the diameter of the fitting, mark the hole and cut with a plasterboard saw. The rim of the fitting should cover an inaccuracies.

http://www.diytools.co.uk/diy/Main/Product.asp?iProductID=35813

To be honest it's probably just as quick if not quicker than a powered device, plus theres less chance of cutting through Mr Bodgits the elctricians' bad cabling.

 

[andy]

normal holesaw will do the job

 

[Thermo]

do it by hand. most of the holesaws are designed to cut a new hole with the pilot bit keeping the whole thing central and stable. Use that and theres every chance it will go all over the place, as your basically putting a very fast spinning piece of metal into a hole with no guidance.