Drilling problems into concrete

But let's not make the mistake of stifling discussions - so that we can learn...

Cheers JimK

Not my intention - just passing on experience. A heavy (and cheaper) model might make more sense if mainly used for breaking up concrete paths, etc.

Remember the hammer in a SDS is waggling in both directions - so there is no nett thrust. All you need do is counter the reaction from striking the bit. The inertia of 2kg of drill is adequate to accelerate the bit largely in preference to the machine.

Yup exactly. With a conventional hammer drill, all the hammer action comes from the force you apply - it never actually hits the bit - it just pushes the drill away from the wall and then lets go. You push it back and the momentum of the machine hitting the end stop on the return is you hammer effect. But since the travel is only about 1mm you don't get much chance to build up any speed!

I find you can usually feel the hammer oscillation if you run the drill in free space - especially at low speeds.

understood ;>) Cheers JimK

on 17/05/2010, JimK supposed :

Put no pressure on and there is no hammer, put too much pressure on and there is some hammer, but the effect peaks at a point between the two extremes.

My metabo doesn't drive the hammer mechanism unless you put a small pressure on the bit. Likewise, it disengages the hammer mechanism when there's no pressure on the bit, except the disengaging is now getting rather sluggish and it now carries on operating the hammer for about a second after you stop pressing on the drill, whereas it used to be instant.

With my one (Makita 2450) there is no hammer at the bit without pressure on it, but you can still feel the weight of the internal piston oscillating.

I bought the drill from LIDL

It doesn;t seem to have a clutch - oh well..

I tried it out on a brick and it worked fine - only problem is that the drill bit seems to be stuck!

Any ideas on how to get it out? I am pulling the release down and pulling the drill bit forward but am having no luck.

mmm there were references earlier to "twist and lock" (tho my cheapo doesn;t do that) - do the destructions indicate whether the bits need twisting as part of the insert/release procedure?

Cheers JimK

JimK wrote in news: snipped-for-privacy@r9g2000vbk.googlegroups.com:

I think you twist it when you put it in

I tried both ways anyway

Even tried pulling it out with a pair of pliers but tis proper jammed

innews: snipped-for-privacy@r9g2000vbk.googlegroups.com:

mmm quick trip back to LIDL for another (tested working) / refund? - unless the stuck bit happens tobe the correct size for the concrete post drilling job?.....then would seem a shame to waste the opportunity for another test or two to confirm it's shagged.......;>)

Cheers JimK

JimK wrote in

I was thinking that, lol

unfortunatley I need a 14 to do what I want to do and I was testing it out with an 8 that came supplied.

Shame, I wanted to see what the chisel would do to the brick.

could do holes to 8mm then at least your 4/7ths the way there :>)

If you use masonry screws (no plugs) you may get away with an 8mm hole? I'm just doing some shelving in the workshop fixing battens to concrete block - drill 6mm hole and the masonry screws just cut their own thread in the concrete block when driven in (with cordless drill)......

Cheers JimK

You are not alone.

From reading this I'd say, grease rather dry and now full of brick dust, does not encourage bit removal. A squirt of WD40 may dissolve the grease and let you pull out the bit. More ideas:

It happens that mo formulated :

Is the bit stuck in the hole you drilled in the wall, or the bit stuck in the drill?

Try a firm grip on the drill and putting it in reverse for the first, so it winds its way out of the hole.

For the second you need to pull the black plastic sleeve back away from the bit, to release it.

Harry Bloomfield wrote in news: snipped-for-privacy@NOSPAM.tiscali.co.uk:

It was the drill stuck in the holder and no matter what I tried would release it. Tried some WD40 to no avail.

I took it back to LIDL and they gave me a refund as they didn't have any left.

I'll have to go with my tail between my legs to my mate who told me 'you get what you pay for' from LIDL and I said they offered good value!

I will probably just hire one unless a similarly good deal comes up soon.

In article , mo scribeth thus

Just fork out for a good one. Had a mate the other day couldn't believe how the Makita bored a 20 mm hole thru 1 foot thick reinforced concrete the other day in around half a minute:)...

I decided I was going to hire one out.

My lcoal place does it at £10 a night BUT you have to buy your own bits. Which would have set me back £10 for the ones I wanted at Toolstation.

I went down to toolstation and saw they also had a deal similar to LIDL - an SDS drill with chisel and some bits. It was a 5kg and a lot beefier but I thought I might as well because it seemed good value.

Got home and used it. It sailed through the concrete post BUT I did feel the dreaded 'drill bit stuck in the wall' thing almost straight away - almost took me off the ladder AND twisted my wrist slightly.

I have another hole to do tomorrow (couldn't be bothered to risk it tonight) but I might try and take it back on safety grounds. Surely they shouldn;t be selling such items to DIYers ESPECIALLY when the booklet makes no mention that it could happen.

perhaps have it on hammer-only so there's no twisting?

And start with the thinnest dripp bit you've got.