Core bits

[SparkusMaximus]

Hello,

I am looking at installing a fan, however I don't want to buy a set of core bits for at least £150 so I think I shall just buy one core bit, which size would you say would be the most common, looking around I see fan diameters vary from around 170mm to 210mm so I guess just buy the one that fits the one you want to install and always install them?.

secondly, do you use a mains drill to core it out, or do you think a cordless will be fine albeit a few battery changes.

Cheers guys.

 

[malcolmsanford]

As it is the most horrendous job that you can ever do I would do it the safest way. If your doing loads of these then I would think about buying a proper core drill that as a clutch on it and a good set of diamond drills. If it's a one off then hire the kit.

Better still get someone else if possible. That's of course just MHO

 

[Mark.W]

I have a core drill for that purpose, you will only damage the gears on a cordless or normal power drill! As this is not what they're designed for!

Mark

 

[Lofty]

For a one off hire the core drill, and a decent vacumn as well !!.

Cheers,
Lofty.

 

[RODDERS80]

easy just use a 110v bosh sds drill of simular then buy a £40 diamond core bit with a hex shank(standard/cheap) and use a good sds key or keyless chuck then your sorted for £40 if you already have a good sds drill !
and i do 6 4"[107mm] cores a week ;-)

 

[Amp David]

For a 4 inch fan I use a 117mm because thats what ive got. Plus side is it gives you a bit of room for lining the duct up to the fan and outside grille or cowl.

 

[SparkusMaximus]

Hmmm thanks,

Will not used my cordless SDS then, can pick up this for £99 720W bosh 240v, do you think this would do the job? not fussed if it takes a bit longer, as long as the drill can handle it surely it can, the odd fan here and there.

 

[Amp David]

Coring out trashes SDS drills. Don't care what people say, they wern't designed for it, thats why they sell core drills.

 

[DurhamSparky]

have done 3 fans with it and although not as fast as a proper diamond cutting one it does the job! i used my sds with clutch 240 drill!!

 

[Amp David]

Don't understand the difference between diamod and TCT, why choose one from the other?

 

[DurhamSparky]

uh uh!! i went with cheap and nasty!

 

[Amp David]

uh uh!! i went with cheap and nasty!

Aslong as it paid for itself, doesn't matter does it?

 

[RODDERS80]

diamond cores are much better/longer bit and if you use a good sds like my £140 110v bosch sds and a keyless chuck or simular then your good for as many cores as you like - just dont put a sds core shank into the drill - you must use a hex shank with key/keyless chuck to save damaging your sds chuck and if its a odd core here n there then your well sorted will last you 12 months or more !! then only a new £40 diamond core will be needed no expensive repairs cause your drill thinks it was only powering a keyless chuck ! JOB DONE ;-)

 

[Spudnik]

I have sheared the bit off in an sds chuck of a core drill.

SDS drills are ok as long as it is powerful enough and you get a smooth action.

Its when the bit jams and the tool clutch starts operating is when the stress is put on the bit.

 

[pennywise]

Don't understand the difference between diamod and TCT, why choose one from the other?

TCT are usually used on hammer and can be cheaper than diamond cores, then again you can spend a fortune on both types if you use expensive brands