Core drill purchase

[rattlehead85]

Would appreciate some advice on this please.
Got a contract starting next month rewiring 200 kitchens within a chalet complex. They require 6" extractor fans to be core cut through the concrete structure roughly 350mm in depth. I am looking at buying a dedicated core drill to do this. What recommendations do you have for a decent core drill to do this and what size core bit size will i need to complete the job. I have a 7kg DeWalt sds max drill but not sure this is any use as it doesn't appear to have the clutch device which i think is an important safety issue when coring holes this thick.
Thanks[emoji106][emoji106]

 

[sammyshooter]

Must have a clutch, when they snatch up especially on the larger cores it whips around with a vengeance. We have a makita one, 3 years old? Still going strong.

 

[Geordie Spark]

Must have a clutch, when they snatch up especially on the larger cores it whips around with a vengeance. We have a makita one, 3 years old? Still going strong.

Agreed!!

Don't even THINK about using the SDS for this!

1. It doesn't run fast enough.

2. It will try it's damnedest to break your wrist if it jams.

I have a Makita and it's fine, but I think if I were to buy again I may like to try Milwaukee.

 

[rattlehead85]

Must have a clutch, when they snatch up especially on the larger cores it whips around with a vengeance. We have a makita one, 3 years old? Still going strong.

May i ask what the model of your makita is and also what size core bit do i need for the 6" fan hole. I think its a 150mm bit but im a bit confused as i know to fit a window fan 6" you need to cut a 71/4" hole in the glass.

 

[Geordie Spark]

Makita UK

 

[shanky887614]

May i ask what the model of your makita is and also what size core bit do i need for the 6" fan hole. I think its a 150mm bit but im a bit confused as i know to fit a window fan 6" you need to cut a 71/4" hole in the glass.

25.1mm is one inch. so 6" is just over 150mm

 

[LankyWill]

I use one of the Milwaukee dedicated core drills and it's a tank. I've probably done 300+ with it. 4,5,6" is what's it's ideal for. It's very power and reliable. Watch your wrists though because when it catches it's like wrestling a stuck pig. I would personally buy an engineering core drill as it's quicker and less prone to jamming. The ones with the dust extraction vent on the side bite constantly. Wear ear defs and gloves because you need them

 

[Geordie Spark]

I use one of the Milwaukee dedicated core drills and it's a tank. I've probably done 300+ with it. 4,5,6" is what's it's ideal for. It's very power and reliable. Watch your wrists though because when it catches it's like wrestling a stuck pig. I would personally buy an engineering core drill as it's quicker and less prone to jamming. The ones with the dust extraction vent on the side bite constantly. Wear ear defs and gloves because you need them

I agree - and if the OP is drilling a lot of 6" holes then the Makita could be struggling a bit.

 

[sammyshooter]

Makita UK

That's the cookie.

Think it's a 152mm core you need, but seeing as your doing so many fans it wouldn't hurt to take it along with you and offer it up.

Again, looking at the amount of holes you'll be doing maybe get one with thermal overload and stuff.

 

[LankyWill]

It will happily do them. Just takes a bit longer 10minutes or so

 

[Andy78]

6" is 150mm, but you will want a bigger size core hole to fit your ducting through.

for eg, to fit a 100mm/4" fan duct I have to use a 107mm core for poly and steel flexi duct, and a 112mm at least for solid pipe ducting.

 

[shanky887614]

6" is 150mm, but you will want a bigger size core hole to fit your ducting through.

for eg, to fit a 100mm/4" fan duct I have to use a 107mm core for poly and steel flexi duct, and a 112mm at least for solid pipe ducting.

6" is 152 though (ive got a set of digital calipers to hand)

2" holesaw is 51mm so 6" is 153ish as a rough measure

 

[rattlehead85]

I use one of the Milwaukee dedicated core drills and it's a tank. I've probably done 300+ with it. 4,5,6" is what's it's ideal for. It's very power and reliable. Watch your wrists though because when it catches it's like wrestling a stuck pig. I would personally buy an engineering core drill as it's quicker and less prone to jamming. The ones with the dust extraction vent on the side bite constantly. Wear ear defs and gloves because you need them

Milwaukee model you use?

 

[LankyWill]

DD2-160xe2 it designed for dry diamond cores

 

[LankyWill]

I've used the makita one also and it just hasn't got the guts for it. It's too weak and spins at too low an rpm. The design is also weak

 

[Andy78]

6" is 152 though (ive got a set of digital calipers to hand)

2" holesaw is 51mm so 6" is 153ish as a rough measure

What I'm saying is that the stated fan diameter does not necessarily correspond with the outside diameter of the ducting used therefore a larger core drill diameter is usually required.

 

[LankyWill]

What I'm saying is that the stated fan diameter does not necessarily correspond with the outside diameter of the ducting used therefore a larger core drill diameter is usually required.

If you rotate the core drill Inside the empty hole it will gently increase the size to allow for sold ducting. Drill on a bit of an angle an chamfer it around so too speak.

 

[rattlehead85]

I use one of the Milwaukee dedicated core drills and it's a tank. I've probably done 300+ with it. 4,5,6" is what's it's ideal for. It's very power and reliable. Watch your wrists though because when it catches it's like wrestling a stuck pig. I would personally buy an engineering core drill as it's quicker and less prone to jamming. The ones with the dust extraction vent on the side bite constantly. Wear ear defs and gloves because you need them

Do you use a hex adaptor for that or an sds one?

 

[Andy78]

If you rotate the core drill Inside the empty hole it will gently increase the size to allow for sold ducting. Drill on a bit of an angle an chamfer it around so too speak.

All along the length of a 12" long hole ? I'd rather use the correct size core and spare my clutch the torment.

 

[LankyWill]

Do you use a hex adaptor for that or an sds one?

Hex adapter mate, the chuck is really good. It never loosens or starts sticking.

 

[shanky887614]

Hex adapter mate, the chuck is really good. It never loosens or starts sticking.

did your core set not come with an sds max adapter?

 

[LankyWill]

All along the length of a 12" long hole ? I'd rather use the correct size core and spare my clutch the torment.

Or slice along the ducting length and curl it inside of self. These days with the old imperial measurements being used you would need about 4 different sizes of each core drill.

 

[LankyWill]

did your core set not come with an sds max adapter?

We're issued hex core drills so there's no problem there.!

 

[shanky887614]

We're issued hex core drills so there's no problem there.!

just had a look.

if anyone needs one, there 6.99 at screwfix.

 

[Geordie Spark]

If you rotate the core drill Inside the empty hole it will gently increase the size to allow for sold ducting. Drill on a bit of an angle an chamfer it around so too speak.

Rough bugger!!

 

[shanky887614]

Rough bugger!!

im missing memes lol

 

[jackhammerJIM]

Also thought the makita was weak , took much longer to core than the milwaukee which had tons more power .

Both these drills were borrowed and i wouldn't be surprised if the milwaukee was twice the price .

I have since purchased a metabo (can't remember the model)second hand for £100 it is solid with similar power as the milwaukee but has no clutch :wheelchair:

 

[Geordie Spark]

Also thought the makita was weak , took much longer to core than the milwaukee which had tons more power .

Both these drills were borrowed and i wouldn't be surprised if the milwaukee was twice the price .

I have since purchased a metabo (can't remember the model)second hand for £100 it is solid with similar power as the milwaukee but has no clutch :wheelchair:

That could be why it was sold to you!!!

Didn't you notice the seller's arm was in a plaster cast???

 

[jackhammerJIM]

That could be why it was sold to you!!!

Didn't you notice the seller's arm was in a plaster cast???

He arrived on a stretcher Geordie , I arrived on a horse , :yes:

 

[Geordie Spark]

He arrived on a stretcher Geordie , I arrived on a horse , :yes:

Luvitt!!! :laugh:

 

[robsparky1975]

Used a silverline 152mm core bit for 6" envirovent kitchen fans recently,perfect fit with solid ducting straight through the wall,no faffing about at all.About £40 for the diamond bit.

 

[johnsparks23]

Core holes on a large scale? Maybe a specialist contractor way work out cheaper. That task will take up a lot if your time. Unless you've got a decent apprentice or elec mate, who doesn't mind hard graft. Last builder I worked for, we charged £25 per core hole, through brickwork.

 

[robsparky1975]

I used to use the heavy old dewalt unit,powerful and with the clutch,think they are getting on for £700 but you could always sell it after Job if you wanted to,they make light work of drilling holes,seen some people struggling for an hour with useless drills not designed for the Job,imagine 200 units with 1/2 hour lost on each one due to wrong drill = 100 hours,makes you think a bit :biggrin:

 

[LankyWill]

Also thought the makita was weak , took much longer to core than the milwaukee which had tons more power .

Both these drills were borrowed and i wouldn't be surprised if the milwaukee was twice the price .

I have since purchased a metabo (can't remember the model)second hand for £100 it is solid with similar power as the milwaukee but has no clutch :wheelchair:

Yeah my Milwaukee doesn't have a clutch that's standard. It does have thermal cut out. When I approach a core drill I say goodbye to everyone and dance with the devil as the beast eats the brick. With the right technique you don't need a clutch or a pilot bit. I've never used a pilot bit tbf

 

[jackhammerJIM]

I bumped into a friend of mine the other day who is a plumber . Big lad about 6 foot 2 and 16 stone off work for a month after a core drill broke his collar bone !!!!!!

 

[LankyWill]

I bumped into a friend of mine the other day who is a plumber . Big lad about 6 foot 2 and 16 stone off work for a month after a core drill broke his collar bone !!!!!!

Christ! How did he manage that? Did it throw him of the ladder?

 

[jackhammerJIM]

He hired it and after specifically asking for a drill with clutch was given one without . snagged and smashed into his collar bone . Ouch !

 

[shanky887614]

He hired it and after specifically asking for a drill with clutch was given one without . snagged and smashed into his collar bone . Ouch !

keep the drill tight against your body so if it snags it wont break anything

 

[LankyWill]

He hired it and after specifically asking for a drill with clutch was given one without . snagged and smashed into his collar bone . Ouch !

Must of been caught off guard. If you hold them tightly this shouldn't happen. Poor lad I broke my collarbone a few months back, completely ruined me. Snapped in half with 3cm displacement. Still a bit of an arse now in the mornings. Tell him to do physio

 

[Geordie Spark]

He hired it and after specifically asking for a drill with clutch was given one without . snagged and smashed into his collar bone . Ouch !

He could be entitled to some compo if that's the case.

 

[LankyWill]

He could be entitled to some compo if that's the case.

He should have read the instructions

 

[Geordie Spark]

He should have read the instructions

He should have been supplied with the equipment he ordered in the first place!!

 

[jackhammerJIM]

He could be entitled to some compo if that's the case.

He is employed Geordie with mortgage and kids , could be out for 2 months pending scan and operation . He is not sure where he stands on claiming but will definitely be pursuing someone

 

[richy3333]

I use the Dewalt one all the time for 4 and 6 inch holes. It weighs a ton. Preferably get the drilling frame also so you dont have to hold the drill, but you do have to bolt the frame to the wall. With the drill, frame, cutters and extensions I doubt you'll get much change out of £1500. As others have said, it might be cheaper to hire in a diamond drilling company.

 

[Dcf]

I've had a makita for years still works fine.
its the most uncomfortable drill to hold in the fleet though.
i saw a Marcrist one last week that looked ok.
if your flush I would recommend flex core drills. Total beast.

 

[Geordie Spark]

He is employed Geordie with mortgage and kids , could be out for 2 months pending scan and operation . He is not sure where he stands on claiming but will definitely be pursuing someone

In my view the supplier of the equipment has a duty of care towards the customer and when the customer has specified what he needs and the supplier has supplied something different and which has caused injury to the customer then he has breached that duty of care.

 

[LankyWill]

In my view the supplier of the equipment has a duty of care towards the customer and when the customer has specified what he needs and the supplier has supplied something different and which has caused injury to the customer then he has breached that duty of care.

He should have read the instructions Is what there going to plea. You must be doing something wrong to break your collarbone it's not the drills fault.

 

[jackhammerJIM]

He should have read the instructions Is what there going to plea. You must be doing something wrong to break your collarbone it's not the drills fault.

This is a plumber you are talking about Will

 

[LankyWill]

This is a plumber you are talking about Will

He's in a tough situation but doesn't have a leg to stand on

 

[Geordie Spark]

This is a plumber you are talking about Will

And???? :32: