SDS & hole saws

[Selfmade]

I hired a KANGA when I was a nipper. Girlfriend wanted a catflap through the main wall of the house so off I go, snags, nearly broke my wrist. Seriously. It was really really sore for weeks.

Ouch!

So I don't mind the slippy clutches now!

Yes, definitely better with the clutch I think!

 

[Selfmade]

the pilot bit went through but then became detached and the cutter just shot along the timber

When I wrecked my Homebase own brand (feel free to laugh), the pilot jumped right out of the hole and the cutter shot along the timber, but missed my forehead thankfully!

 

[Geordie Spark]

I do a lot around 60 - 70mm (I forget the precise sizes I have!) in plasterboard for downlights, though it beats me why people like the things, but hey can't complain! My combi is fine with these, but it does gum it up with plaster dust which I have to clean out.

Stainless holesaws do sound nice but I bet they cost a bit!

Use a plastic carrier bag to stop this.

Take one cheapo ASDA type carrier bag.

Poke a hole in one of the bottom corners big enough to pass the drill chuck through

Place the drill in the bag with the chuck sticking through the hole and allow the bag to hang loose around the body of the drill to prevent possible overheating.

Two advantages of this method are; 1) It stops the draught from the machines fan blowing ducking fust all over the place and 2) it prevents a lot of ducking fust from getting sucked into the drill.

Try it and see.

 

[Selfmade]

The problem with the smaller drills with clutches is they are there to protect the operator for the occasional bind-up,whereas the purpose made core-drills have a clutch which is designed to operate as many times as necessary. The former can be used but set-up and technique will determine life expectancy (the drill,of course).Anyone want a comedy clutchless drill monologue?....anywho...there's me pal,on his barn roof,drilling a 1" hole in a crossing timber purlin,stood on tins,drilling downwards with a homemade 24" auger bit in a 1960's Ally Victor drill,auger jams,side handle hooks his boiler suit,and he goes round and round and round,probably 7 or 8 times before lead parts at top of bit...a HSE video classic :cheesy:

Thinking about this, I can't see it being a big problem if the clutch operates as frequently as I have stalled my poor long suffering combi when using a hole saw, unless the clutch is extremely flimsy. So I'm going to try minimal feed pressure (as has been suggested) and making sure that I cut at exactly 90° to the timber, as the starting point for my technique.

Anyway definitely better to risk the drill's life expectancy than my own, so better with a clutch than without!

Funny how an accident can be so comic! And a home made auger bit? Rather him than me!

 

[Selfmade]

Remember those great big Hitachi drills,with the handle on the back? They were about 1100 watts I think,no clutch either well I had one and a mate wanted a 50 mm hole in the concrete for a rotary clothes line,I said I'd do it but he wanted to,well it jammed and spun him around it was quite funny at the time as he was about 16 stone and couldn't handle it yet there was I about 9 stone at the time drilling with no problems.It's definately about technique,slow and steady with not too much pressure,and a firm grip on the machine,plus ALWAYS use a side handle.

Lol! I'd have been worried about being in his path when centrifugal force took over!

 

[Selfmade]

Hole saws have teeth on them like a saw.

Core drills do not.

Core drills will make holes in brick & concrete. Try doing that with a holesaw and see how far you get and core drills are not very happy about drilling holes in wood either!

Why not use Google to find some pictures of each???

Thanks Geordie Spark - I've seen both, and used the former. I just hadn't realised there was a strict distinction! Thanks for clearing that up!

 

[Geordie Spark]

Thanks Geordie Spark - I've seen both, and used the former. I just hadn't realised there was a strict distinction! Thanks for clearing that up!

Well a core drill probably would make a hole in wood, but it would burn its way through (friction) and take about half a day to do it!!

In a past life, I used to make core drills when core drilling was a very specialist thing. The biggest I made was 3 feet diameter to drill holes in the runway at Heathrow airport. The rig to drive this thing was mounted on the back of an ex-army truck

The smaller stuff included drilling rigs that could be stuck on walls of buildings using nothing more than vacuum and then a 10 inch core drill could be shoved through the wall ..............

Interesting things happened if the vacuum pump failed.

 

[Selfmade]

Use a plastic carrier bag to stop this.

Take one cheapo ASDA type carrier bag.

Poke a hole in one of the bottom corners big enough to pass the drill chuck through

Place the drill in the bag with the chuck sticking through the hole and allow the bag to hang loose around the body of the drill to prevent possible overheating.

Two advantages of this method are; 1) It stops the draught from the machines fan blowing ducking fust all over the place and 2) it prevents a lot of ducking fust from getting sucked into the drill.

Try it and see.

Thanks very much, I will try that! I also thought about a cardboard disc fitted around the arbour between the saw and the chuck. Thought of that after seeing a proprietory "dust cup" recommended in my SDSs manual. Thinking again it would probably be even worse for dending sucking fust all over the place!

 

[Geordie Spark]

Ouch!



Yes, definitely better with the clutch I think!

You big ----- !!!

 

[Selfmade]

Well a core drill probably would make a hole in wood, but it would burn its way through (friction) and take about half a day to do it!!

In a past life, I used to make core drills when core drilling was a very specialist thing. The biggest I made was 3 feet diameter to drill holes in the runway at Heathrow airport. The rig to drive this thing was mounted on the back of an ex-army truck

The smaller stuff included drilling rigs that could be stuck on walls of buildings using nothing more than vacuum and then a 10 inch core drill could be shoved through the wall ..............

Interesting things happened if the vacuum pump failed.

Like. (Like button gone walkabouts.)

 

[Selfmade]

You big ----- !!!

Please don't! I'm not even pretending to be female!

 

[Geordie Spark]

Like. (Like button gone walkabouts.)

That happens with me as well. I need to press F5 to refresh the page to make the button reappear.

I have to use that F5 so much on this forum that the lettering has almost worn off it!!!

 

[Selfmade]

Related question - I owe you guys a lot! Do you cool an SDS bit with water when in use? I quickly took to doing that with ordinary masonry bits after bending and 'untwisting' a few! Might help with the dust in motor issue as well...

 

[shanky887614]

That happens with me as well. I need to press F5 to refresh the page to make the button reappear.

I have to use that F5 so much on this forum that the lettering has almost worn off it!!!

Ctrl+r does it as well

Dont press alt+f4

 

[Geordie Spark]

Related question - I owe you guys a lot! Do you cool an SDS bit with water when in use? I quickly took to doing that with ordinary masonry bits after bending and 'untwisting' a few! Might help with the dust in motor issue as well...

I never did. I think you could make the overheating problem worse by turning the concrete / brick dust into mud which would clog the flutes of the drill.

If yo have to cool it I would suggest a steady blast of compressed air, but then you're getting into problems of where to get it from and the dust that will be flying around.

Your problem with "ordinary masonry drills" is one of speed - you were running it too damned fast! Slow it down a bit and let the drill bit do the work in its own time.

If you want to be a real clever shyte, you can calculate how fast you should be running the drill bit at from the formula N= 12xS / Pi x d

where: N= spindle speed in RPM (this is the bit you're trying to find out)
12 is a constant (cos this formula uses imperial units)
S is the cutting speed of the material (brick or whatever) in feet per minute
Pi is 3.14
d is the diameter (in inches) of the drill.

There is a metric variation on this but I could never be arsed to learn it.

 

[HandySparks]

Use a plastic carrier bag to stop this.

Or one of these:
Holesaw - Dust and Debris Eliminator

Well worth the price.

 

[Geordie Spark]

Or one of these:
Holesaw - Dust and Debris Eliminator

Well worth the price.

I agree.

It's better than the plastic bag because it catches the dust. The plastic bag does not - it only stops it from getting sucked into the machine, but it can be useful for more applications than drilling holes for downlights.

If I were fitting downlights I think I would but one of these gadgets.

 

[Selfmade]

I never did. I think you could make the overheating problem worse by turning the concrete / brick dust into mud which would clog the flutes of the drill.

If yo have to cool it I would suggest a steady blast of compressed air, but then you're getting into problems of where to get it from and the dust that will be flying around.

Your problem with "ordinary masonry drills" is one of speed - you were running it too damned fast! Slow it down a bit and let the drill bit do the work in its own time.

If you want to be a real clever shyte, you can calculate how fast you should be running the drill bit at from the formula N= 12xS / Pi x d

where: N= spindle speed in RPM (this is the bit you're trying to find out)
12 is a constant (cos this formula uses imperial units)
S is the cutting speed of the material (brick or whatever) in feet per minute
Pi is 3.14
d is the diameter (in inches) of the drill.

There is a metric variation on this but I could never be arsed to learn it.

Thanks, I might just try that formula! Certainly low gear full power (600RPM no load) on my combi does nothing on concrete - it just rattles around on the surface. So maybe something in between...

 

[Selfmade]

Or one of these:
Holesaw - Dust and Debris Eliminator

Well worth the price.

Interesting, thanks. I can't help thinking some kind of plastic tub like a yogurt pot only flatter could do the job though...

 

[Selfmade]

I'm off to bed now, thanks so much for all the help and advice! Really makes a difference!