Thread: 850w gmc rotary hammer drill

I bought the $99 one not sure what it is called from memory.

it was a case where I needed to pull up a heap of marble tiles and thought I would hire a mini jackhammer, but they wanted $80 for 4 hours so I thought why not give it a go. I figured if I cooked it on the first day I could get a refund.

anyway I got the tiles up with it. it was no where near as good as what I would have hired, but then it is probably $600-700 cheaper.

I also have a metabo 650w drill with hammer. the $99 one is actually better than the metabo for punching through brick and concrete I feel. but I suppose it is partly due to the fact that it is designed specifically for that where the metabo isnt and so they had to make a few compromises.

I havent had any issues with the drill but it does tend to get warm if used for extended periods. probably more so than what I would have expected. but other than that I cant complain, given I was going to spend that much anyway to hire something.

but if I was going to purchase it outright I would maybe consider the GMC to see how it feels (they didnt have the GMC out when I bought mine) or look at how much extra you neeed to spend to get a name brand and consider how much use you think it will get. It does have a cheap feel to it, although it is still pretty solid.

I dropped into Bunnings on the way home today and spied the GMC 701 watt hammer drill. I wanted an extra as my big Ryobi currently sits in a tilting drill guide so at $24.95 what the hell.

I didn't read the specs or features and was pleasantly surprised when I ducked out to the garage a few minutes ago to have a play.

Besides the hammer action which I will rarely use it is also reversable and variable speed. It goes slow enough to use as a high torque screwdriver and in the workshop may replace the old and weary B&D cordless in this roll.

For the price I would give this drill a good look.

Yeah, i saw them.

i want one that can be used as a mini jack hammer with a chisel bit. Like clint said, used for lifting old tiles.

I had a good look at the Bunnings Drills the other week. The GMC was absolute crap. The guys in the tool section and I went through about a dozen of them and we couldn't find any that didn't have a bent shaft.

Now they might be good for chiselling tiles off the floor or wall. However, they would be useless for drilling holes.

Well good news folks, bunning finally got them in.

Im a proud owner of a new 850w Rotary Hammer Drill.

for $109.00 you get a bonus drill bit set with the hilti style ends [sds]. plus 2 chisels and a scoop bit. the drill itself comes with an adapter to enable standard wood/metal drill bits to be used with the sds connection. it weights 6 kilos and looks like a mini jack hammer.

i gave it a breif run today breaking up some small rock in the yard and the hammer action + the weight is excellent.

its going to be great not having to use the old bosch when drilling into masonary.

well worth checking out. the bits themselves are worth $109.00

G

What is the model number?

Well my happiness has turned to despare. Like gregs comments this too has a slightly bent shaft. i disovered it when i was using the chcuk adapter to drill into timber. i rang GMC and was told by their call center that this however is not normal. i shall soon find out tomorrow when i take the drill back to bunnings.

Oh well, it was good while it lasted. other than that its an awsome drill.

The model number is RHD850k

The kind folk at bunnings replaced the offending drill today. But i am thinking the wobble was due to the chuck adapter and not the drill. the SDS drill system has a bit of play anyway and combined with a small drillbit in the sds chuck adapter, it may have been the case.

when i tried a masonary bit and drilled into concrete with the new drill there was no signs of the wobble.

Strange indeed. The people at bunnings said i was the first to return this model. [but im not so sure on that]

On my second gmc after only about 10 minutes. It too had the wobbily chuck but i wasn't too concerned as I plan to use it for rough timber drilling only. The biggest problem was that the gearbox had seemed to seize up. I was trying to change the top knob back from hammer (for chisels) to Hammer drill. Perhaps something didn't turn properly because suddenly there was only very little rturning and lots of loud noises. Thats when it started to get really hot. As an afterthought I checke the grease in the gearbox. It certainly wasn't packed full.
Anyway Bunnings happily swapped it over and I'll give the second one a try soon. Has anyone got any tips about turning the top knob ? Yoou seem to have to lift it to turn it but nothing seems to change. Anyway I wonder if I could go through 30 drills in 30 days???

i gave mine a workout on the weekend with the 20mm masonary bit that comes in the box with the drill. i drilled into 25MPA grade concrete to a depth of 150mm. it worked fine except on accation the drill would stop as if there was a load clutch built into the drill. I am not sure.

Yes, you have to lift the top knob up to turn it. I must check the grease on mine when i get home.

I will have to give it another go to see if it "stops" then return it back to bunnings if its not up to the job. The Dynaforge one is looking good at the moment. I wonder if gmc just sell the drillbits separate?

G