core drill help

[rochdalegas]

going to splash out on a drill and attachments probably drill around half dozen flues a year so its not heavy use, question do you have to buy a dedicated diamond core drill or can you get away with a decent regular drill (would be good to have the option for regular drilling on hammer ). If so any reccomendations ?

have seen a makita at around £240+ (dedicated diamond core drill but would prefer an all rounder if I can get away with it?)

and a set of rothenburger bits at around £100+ (any better buys out there)

also can anyone tell me why dimond core drills are that much more expensive where the extra money goes and benefits ?

 

[swbjackson]

A diamond core drill will be more powerful and have a very good clutch. Just imagine the carnage if a 5" core bit jammed and the drill continued spinning.

 

[Mark Br]

Personally I wouldn't dream off drilling a core hole without using a drill with a clutch.

 

[RF Lighting]

The time you save actually drilling the hole will pay for the drill. I've struggled for years trying to core fans out with SDS drills. My made lent me his dedicated corer drill, and I could not beleive the difference.

I put probably about 5 or 10 holes through a year, but I wouldn't use anything else now.

There's no point buying a full set of corers if you just want to put flues through. Just buy the size you need.

 

[Threadjacker]

I'm very happy with the 1100W Sparky diamond core drill, it takes abuse and is very fast and powerful. It can also be used as a regular drill.

 

[EddieM]

The whole point of a dedicated diamond core drill is that they have a low'ish rotation speed, but loads of torque, and safety clutch(es) to save you snapping ur wrists if it binds.

 

[Norcon]

Used to core with a big hitachi drill with no clutch. It caught once and spun out of control in the hole.
The trigger lock button was pressed accidentally. (always sawed them off afterwards)

You should have seen it wound the lead around itself until the lead was slashed in two and live copper wires hanging all over the place.

 

[ChrisR]

Diamond core drills need higher than SDS drill speeds. That's especially true for smaller(around 2 inch) holes, but also for 4-5 inch.
I started with a Bosch Multi-drill - heavy and takes forever because it's too slow.
They do NOT use loads of torque, or you just wear it out fast. You want about 1000-1200 rpm unless you've got a weedy drill. Same as you don't have a high torque angle grinder, you have high speed.
I've used 3 different core drill drills. They're all a load bettter than SDS drills. The common Makita (2406?) is nothing special, but perfectly OK. A Hilti was better (faster) but much heavier.
You may as well buy one of the cheap kits of cores. I use 115 and 125mm (and 150mm) for flues. You get the waste pipe size ones in the box, which you'll use from time to time - they're very quick to use. You need the extensions etc which come in the box of bits and would cost a lot to buy separately.
Most walls are soft so any core bit will do. Occasionally you'll get something harder, then a better quality core bit like a Marcrist designed for harder materials comes into its own. If you don't have one, you can drill a ring of 10mm holes, it makes it much quicker.