Drilling problems into concrete

[spamlet]

Poor Mo,

I think that washing will have dried (or rotted!) on its own by now!

;-)

S

[mo]

"spamlet" wrote in news:31XKn.165379$ [e-mail]:

we had a temp line up! I should hopefully be able to play around with my pulleys tom - undecided on what system to use!

In reply to the other poster. I started off with a 10, then 12 and then a

1. It was on the 14 that it jammed.

[spamlet]

Hope you didn't lose all the pulley threads like I did!

S

[John Rumm]

There is no real need to go up through the sizes with a SDS on masonry - certainly not for bits under 16mm unless you are trying to minimise an exit wound on through drilling.

Using incremental sizes on masonry is probably more likely to make a bit snag. (which is very rare IME with SDS drills)

[D.M.Chapman]

Don't bother with the smaller ones, go straight for the 14mm. It's much less likely to jam then IME.

Darren

[george [dicegeorge]]

I was wrong about starting with smaller bits like in metal or wood, the experts say go straight in with the bigger one.

Even with metal and Wood I dont go through every size of drill bit, but get quite a bit bigger with every new drill bit am I wrong in this too?

[g]

[John Rumm]

Usually with metal drilling you pick the size of the smaller drill such that it clears the quick (i.e. the core diameter if you ignore the flutes) of the final drill size. So say you want a 12mm hole, you could drill a 6mm hole first and then the 12mm.

With wood much depends on the type of bit you are using. With lip'n'spur bits, flat bits, forstner bits, and augers, go straight for the final size. If using a HSS bit in wood then you may get better results stepping up as in steel.

For masonry with a normal drill or percussion drill, then stepping can help for larger hole sizes.

With SDS, usually just go for the final size.

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember mo saying something like:

Oh I dunno. Perhaps they expect the users to have a bit of common sense?

[george [dicegeorge]]

This is the sort of common sense that comes from experience.

Even people with a physics degree and full theoretical knowledge of equal and opposite forces could be surprised by a drill twisting them! [g]

[mo]

Grimly Curmudgeon wrote in news: [e-mail]:

why would the average person expect a drill to suddenly start spinning around on the wall on them?

[John Rumm]

They don't generally, but it can and does happen! Actually getting thrown off a ladder or ending up with a broken wrist also happens in some cases.

This is a feature of all drills to an extent, but compounded with a SDS in that the mechanism does not permit the bit to slip like a conventional chuck can. This is one of the primary reasons why having a safety clutch is a good thing.

Its most likely to happen with things like hole saws and core drills. Enlarging existing holes is also another common one.

Regular readers of the group (and the FAQ on SDS drills) will note that the recommendation to buy a decent 2kg SDS with safety clutch, multi position bit lock, and a decent speed control is frequently made. Now you appreciate better than most why!

[Elder]

I bought a challenge branded angle grinder, 1000watt hammer drill and jigsaw from Argos about 8 years ago. All still going very well. Only used occasionally, but used hard when used.

[Dave Plowman (News)]

IMHO, the best value at the budget end comes from Lidl. You have to keep an eye out for offers, though - they don't keep them in stock.

I've got:- A 9" angle grinder. Electric stapler. Random orbit sander Planer Cordless Hobby drill ( much bigger than a Dremel)

All work just fine. Although I only use them for occasional DIY. But I've bought things from the likes of B&D which aren't even up to that. ;-)