Drill questions

[anonymouscoward]

Hello,
I am looking to buy a drill. I would like to have one, good quality drill that does as many jobs as possible (not a lot of space in the garage). After having tried to drill into concrete with a normal hammer drill, I thought I'd get an SDS+ drill To be able to do other jobs, I'd like a changeable chuck. I had a look at the following models:

Metabo UHE 22
Makita HR2470T
Bosch GBH2-26DFR

My first choice is the Makita as it is the cheapest of the three, but still a good brand. I'm no pro, but I live Belgium where everyone is DIY mad, and I was hoping to be able to also use it for light demolition work next time I get invited round to remove someone's fireplace (the novelty of using a mallet wears off pretty quick). After doing a fair amount of forum browsing etc, I have the following questions:

1) The Makita and Bosch have a max RPM of around 1000, whereas the Metabo can go up to 3000 RPM. I notice that most ordinary hammer drills also go up to around 2500 RPM. What difference does this make? What kind of jobs need high speed drills?
2) Are the quick-change chuck systems reliable? (i.e. will it work like a normal drill for non-SDS stuff, or are changeable chucks a gimmick?)
3) What kind of things can you chip with the SDS+ tools? For example, I have some marble skirting board-type stones that I'm trying to recycle for a friend. I need to chip the mortar/tile glue off the back of them before I can stick them on the wall. Would a chipping tool with one of these drills be appropriate or will it smash the stone to pieces? (any suggestions for alternative means of mortar removal gratefully accepted).
4) Some descriptions of SDS drills suggest they are much more likely to shatter bricks, or take chunks out of a wall when drilling all the way through. How much of a risk is this? How can it be avoided?

Thanks!

 

[xerxes]

Since no one else has given you an answer yet, I'll have a go.

Any of these drills should make a very good SDS drill. The greater speed range of the Metabo will make it more versatile for drilling a variety of materials.

Don't expect them to be fit for 'light demolition'. Compare the energy, measured in joules, with the specification of beefier machines designed for that. But they are still useful for cutting chases and similar work.

The quick change chucks ought to work very well. I have a larger Metabo; the quick change chuck system on that is excellent.

I can't advise on how well one of these will work for removing the mortar from the backs of the tiles you refer to; it rather depends on how hard and how brittle the mortar is, and how well stuck on. It would be important to support the tile properly, for example by fixing some thin battens to a board to hold it in place.

Breakout when drilling through holes is unavoidable; if you can, deal with it by drilling from the outside of the wall to the inside, to keep the facing bricks good, then make good on the inside. If you can't locate the position easily from the outside, drill a small diameter pilot hole first from the inside, then enlarge it.

 

[anonymouscoward]

Thanks very much for the information. As I'm still very new at all this, can I ask for some further clarification?

> Any of these drills should make a very good SDS drill. The greater speed range of the
> Metabo will make it more versatile for drilling a variety of materials.

What sort of materials need a higher speed? If it is only for some very specific tasks that you need more than 1000 RPM then I will go with the Makita, but until I know what needs that sort of speed I'm not sure if I can get away without it. I've done some wood drilling with other drills before, but I don't know what speed they were. How about metal? Does that need high speeds?

Sorry if these are basic questions. I've tried to search the net for some recommendations on drill speeds, but drew a blank. If there is a FAQ style answer, please post the link.

 

[noseall]

There is no other (mainstream) sds drill other than Bosch pro (blue).

They are indestructible, powerful and are serviceable, should they need it.

Mine is over a decade old, and is battered. It has never missed a beat and has never been out of service. It has been abused, dropped, left out in the rain (once), you name it.

We not only use it for regular fixing jobs but also stitch drill all knock outs! That is a heck of a lot of drilling, many many holes.

I have borrowed a friends drill, when within easy reach, and realise that Bosch are unique.

Only a fool would buy anything else. Except maybe Hilti that is..........

 

[noseall]

By the way, hire shops, that service power tools will tell you the same story, in that Bosch drills are built very well.

A good sign.

 

[xerxes]

There's a chart of drilling speeds in different materials here.

 

[Bilioustrumpstaine]

I must be a fool then as I have had a Makita for a good many years and it has always given good service without any problems.

I had a Metabo before that and that also gave good service until some barsteward nicked it

For what you need I would go with the Makita, you won't be putting it under anywhere as much pressure as noseall does with his Bosch.

As for knocking chunks out of brick walls when drilling through, I will always drill from the outside in as it is easier to repair plaster than try and repair brickwork.

 

[neds]

As for knocking chunks out of brick walls when drilling through, I will always drill from the outside in as it is easier to repair plaster than try and repair brickwork.

This is a top tip, easily overlooked when you get overexcited getting the SDS out One small hole you can drill from the inside to out so you know where your drilling though!

 

[anonymouscoward]

Hello all,
Thanks a lot for the replies. Thanks also to Xerxes - that chart has given me an idea of what sort of questions to ask! Without wanting to get too philosophical, sometimes it is harder to know the right question than to find an answer to the question you already have BTW, (at the risk of posting flamebait) do you guys really still use imperial measurements for drill bits? :-O

 

[xerxes]

do you guys really still use imperial measurements for drill bits? :-O

It's those Americans, I'm afraid. The chart I linked to was from a source in the USA; I'm sure more diligent searching would have produced a chart with proper measurements in. Sorry about that.

Having said that, I do have far more imperial drill bits than metric ones, though all my linear measurements are in mm.