Author Topic: Wonder if I messed up my hammer drill  (Read 2755 times)

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Offline jefm

  • Posts: 26
Wonder if I messed up my hammer drill
« on: June 22, 2017, 08:19 PM »
Opener: I hate hammer drilling. Always loud, violent, with above average danger. I don't know if I do it wrong, just seems to take forever to get near nothing done, it's hard on the tools, etc whining. And I never hammer drill often enough either so each time I'm thinking "how'd this go?"

So today I'm trying to hammer drill little 3/16" holes for Sharkies to hold cable management to a ceiling. Using my new-ish Makita cordless, I'm on a nice safe platform ladder so that's good but I'm still holding the tool overhead and just generally not having fun. In all my genius I thought I'd use my shoulder to push the drill up, it touched my cheekbone, instantly dropped that plan for fear of dislocating my retinas. Also, this whole time I've got a Festool DE with the hole drilling attachment going. I had specs ear guards and a hard hat on but the din must have been stupendous.

Swearing along as the drill finally goes 0.001" into the concrete and I get a Great Idea. I screw a a few pieces of scrap together, fit an expanding vice grip onto it, bungee it to the ladder, boom, a twelve foot tall drill press. Vacuum on, fit in the drill, and vice vice vice vice. With the ladder putting pressure on the drill for me, I could annoy tenants both upstairs -and- downstairs, simultaneously. I even rigged up my vacuum extension cord and hoses, so the attachment wouldn't fall off the ceiling and hit me in the thinker every time I forgetfully unplug the DE.

Three holes later (about one hour per hole on this project) realized I'd been lazy and didn't have charged packs ready. No more drilling. Not only that, but the battery was stuck fast in the drill. Actually the whole drill was hot to the touch. Maybe I'm a bit dandy but I'm pretty sure the fan exhaust would have burnt me, I actually ran it a bit no load just to cool it. And the chuck seems to have wobble. Maybe I'm imagining it but even my old Makitas have tight collars.

A piece of scrap wood, rubber mallet, screwdriver to hold the button open and proper thwacking got the battery pack off the drill. But am I punishing my drill? Should I go rent a corded one and beat the tar off it instead?

Offline Brice Burrell

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Re: Wonder if I messed up my hammer drill
« Reply #1 on: June 22, 2017, 08:29 PM »
Are you using a cordless drill/driver with hammer drill function, or a dedicated cordless rotary hammer/hammer drill?  If its a drill/driver with hammer function they aren't really meant for drilling hard material like concrete.  Softer masonry like brick or block is more of what they can handle. 
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Offline Bob D.

  • Posts: 1152
Re: Wonder if I messed up my hammer drill
« Reply #2 on: June 22, 2017, 08:33 PM »
With the right tool drilling three 5/16 holes even 4 inches deep is a 5 minute job.

Any rotary hammer drill should be able to do this. If you are using a drill/driver
with impact function they are meant for light duty drilling in block or brick, not
It's a table saw, do you know where your fingers are?

Offline Dovetail65

  • Posts: 4617
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Re: Wonder if I messed up my hammer drill
« Reply #3 on: June 22, 2017, 08:38 PM »
Using an under powered tool for a certain task is a problem. The set up can be just as problematic.

If your tools power was sufficient you would not think rental. Any task that could damage the tool means the tool isn't suited to that task. When  we use a screw gun we have expectation the screw gun will drive a screw without the tool breaking down. It's the same for a hammer drill, it isn't going to break or get damaged if you are using it within it specifications. IF you feel your work is within the tools stated capabilities and the tool isn't working possibly its a poor tool, possibly your method is wrong. It sounds like you suspect the tool you used was the wrong tool for the job.

If you felt everything ran smooth and the tool worked fine you would not have given it a second thought. Because you posted means you know darn well there is a better tool, possibly a better technique.

It sounds like you you needed a corded drill(possibly a more powerful cordless) with a modified work method.

What you described sounds precarious, I am sure I have done worse.
« Last Edit: June 22, 2017, 08:46 PM by Dovetail65 »
The one who says it can't be done should avoid interrupting the person doing it.

Offline jefm

  • Posts: 26
Re: Wonder if I messed up my hammer drill
« Reply #4 on: June 22, 2017, 08:53 PM »
Sounds like I'm doing the wrong stuff with the wrong tool.
This isn't bricks/mortar it's probably fifty year old concrete. My poor little drill...
Thanks for the reality check. Now for the whole rent/buy internal debacle.

Offline antss

  • Posts: 1453
Re: Wonder if I messed up my hammer drill
« Reply #5 on: June 22, 2017, 11:54 PM »
How old is the building / concrete ?

New drill bit , or one with some mileage on it ?

Sure you were drilling into rebar / tension cable , steel / copper just below the concrete ?

3/16" isn't really all that large a diameter, so I'd expect my 18v combo drill - hammer drill - driver to bore three of those in well under an hour.   In fact, I just put in a wall anchored with 4 tapcons using a used 3/16" bit and I got all four holes drill in less than 10 min.  The concrete was pretty new though.

If I had a dozen or more to drill I'd use an SDS plus drill and make short work of it.

Offline aloysius

  • Posts: 336
Re: Wonder if I messed up my hammer drill
« Reply #6 on: June 23, 2017, 03:31 AM »
Even the cheapest SDS drill will comprehensively outbore just about anything with a pair of waffle discs (st'd. hammer drill).  I too hate hammer drills.  Where possible these days I prefer to buy dedicated cordless & corded drills without hammer settings, and use cordless & corded SDS + & SDS Max drills for boring, chiselling, chasing & breaking up the hard stuff.  All appropriately sized to the particular task at hand.

A big hammer will also make light work of asphalt, hard foundation digging, breaking new ground in the garden etc.  The only thing that holds them back is solid rock.  You'll require even more brute force for that, esp. in such denser types as dolerite & basalt, etc.

A few years back I had to do some major demolition/renovation work in an old series of student residential blocks.  Mostly surface mount stuff using Hilti plugs. in 7 x 3 storey buildings over about a year.  Apart from the bigger access holes, chasing etc there were about 30,000 odd plugs used: 5mm x 25mm (25/127" x 125/127").   All in poured & suspended slab concrete floors, ceilings & structural concrete brick to a depth of about 1 23/127".  The holes would only take about 5 seconds or so to bore with the littlest 18v Bosch SDS drill using Hilti CX bits.  Apart from the speed and ease, I find that the little SDS battery drills are every bit as small & light as any other Li-powered cordless drill, and so much quieter and better shaped (handle @ the rear, motor @ 90 degrees to the axial conrod & piston assemblies) that it makes one handed operation simple, safe and straightforward, even at the top of a ladder or reaching into less accessible areas.  Having suffered most of my life from carpal tunnel, it would be impossible for me to sustain the long-term pressure required for hammer drilling, whereas the speed & relative lack of noise or vibration from a quality drill & bit package allowed me to bore, core, drill & chase for several hours per day without exacerbating my symptoms.  In all I ended up using a total of 9 my own different hammers on the job, plus a few that were initially borrowed too off & on, but soon settled for a "core" fleet of 3 to cover most all the tasks required.

One thing that was immediately noticeable was that the manufacturers' quoted capacities for each tool are wildly exaggerated:  small hammers will only bore the very biggest holes slowly & laboriously.  Big hammers will be awkward for smaller holes too, although both bigger & smaller holes are quoted as within the tool's capabilities.  More honest manufacturers often list an additional secondary (much "narrower") set of upper & lower capacities that it's BEST suited to.  This maximises speed & efficiency, allowing for minimal bit exchange & the optimum work flow, whilst (eventually) only using 1 main & 2 secondary bit sizes, one chasing gouge and one TCT mortar chisel.

I tend to treat my drills as precision tools, and the rotary hammers as more brute force type tools.  I've always considered Robert Bosch hammers to be the creme de la creme.  Biggest range, best performers.  Likewise, I regard Hilti CX bits the best for SDS, and any of the German bits made by Hawera (Bosch, Metabo, Kango, Elu, DeWalt, Makita, Milwaukee et al.) the best SDS Max bits. 
« Last Edit: June 23, 2017, 10:21 AM by aloysius »
FOG-wit since '95:  Some say since birth...

Offline rdr

  • Posts: 78
Re: Wonder if I messed up my hammer drill
« Reply #7 on: June 23, 2017, 06:29 AM »
If you aren using a cordless drill/driver its probably a percussion action that your drilling with which isn't the best for hard stuff. You need to use a proper hammer drill. Bits are important as two bits side by side can be night and day with one making no impact and the other gliding through concrete like it was butter.

What you have described should take less than 1min per hole with the right kit which would make the process all the more satisfying and enjoyable for you, its Friday so treat yourself to a new tool [smile]

Online six-point socket II

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Re: Wonder if I messed up my hammer drill
« Reply #8 on: June 23, 2017, 03:14 PM »

It can't be said often enough: a percussion drill is not the right tool do drill into concrete, especially not if it's reinforced (like most ceilings/floors/foundations are) So to answer your initial question, yes you "tortured" your percussion drill. I'd go as far as to say that if it doesn't smell burned it's probably not damaged but it likely suffered and might need a premature trip to service at some point.

BUT having to remove the battery with brute force doesn't sound to good to me. >>I<< (because I have seen what damaged LiIon (and also LiPo) cells can do) I would defunct this battery immediately. Sounds like it expanded due to heat...

With that out the way, while a percussion drill has a very high rate of impacts/minute, these impacts are weak and you constantly have to press the drill hard into the material. A percussion drill needs/uses/relies on your strength/power.

What you need for this type of job and to make it a lot easier for/on you is a rotary hammer. Rotary hammers use a piston mechanism that deliver much stronger blows with a LOT less of your energy/strength being involved/needed.

Additionally, as it has been mentioned before, you want really good drill bits. Hilti have been named, which indeed perform flawless. As do the new Bosch SDS-plus-7X. I have never used the Festool SDS drill bits, judging from the pictures they are one "generation" behind, compared to current SDS-Plus drill bits. So I'd recommend the two afore mentioned, you'll receive amazing results with them. Doesn't mean the Festool drill bits are bad, but in terms of cutting head and transportation of bore dust (especially with smaller sized drill bits) the new generation drill bits do much better -  you are also less likely to experience deflagration while drilling smaller size holes with high powered rotary hammers.

Kind regards,

Kind regards,
Kind regards,