Replacement Makita SDS drill also faulty

[david lang]

Agreed, but I find my cheapo SDS (which has variable speed) drills much more accurate holes than a percussion drill. Less wander on starting and a tighter fit for the plug.

Dave

[John Rumm]

Alot depends here on if the OP is just mistaking the (normal) play inherent in the SDS design for a fault, or whether there is a genuine fault in the one(s) he has.

[John Rumm]

I find the same - probably because you can make the hole so much faster there is far less time for the bit to wander off centre.

[Ian White]

He certainly seems to be mistaking a few cm of 'whip' in an unsupported

1m bit as a fault; which it isn't. It's completely normal, and would still occur with a chuck that is perfectly centred.

[Chris Melluish]

OP here.

I believe that if it were slack in the chuck then, when drilling a hole at slow speed, I would be able to manipulate the body of the drill so as to eliminate the 'wobble'. I cannot do this.

-- Chris Melluish

[Chris Melluish]

Basically that this was normal, I obviously didn't understand how the drills were made, and that they were all the same. He kept going on about me using chuck adapters and I kept telling him I was not using one - I was fitting SDS drill bit directly into the machine.

He kept going on about how these drills have to have some slack in the chuck to allow the hammer action to work.

I pointed out that my old Wickes drill still drills perfectly straight holes, with no wobble at all, after seven years of abuse. The problem with it is the hammer actions is not working too well. He said he did not believe me.

I also asked him whether it was counterfeit, and he confirmed it was genuine after I described the label to him.

-- Chris Melluish

[John Rumm]

That does sound like a faulty unit (or possibly batch). Generally I have not felt any wobble in my one (using a SDS bit directly in the machine) nor any of the other two examples of the same model I have tried, although on one occation I did get something like what you describe which IIRC turned out to be the nose cone of the drill not springing back into correct alignment. This was while the drill was very new, a bit of a wiggle in and out sorted it, and it has not happened since.

I might be inclined to drill a dozen test holes into something hard just to make sure it is not a case of something needing to "bed in".

[John Rumm]

Don't know if this is any help, but I was in the workshop a little while ago and thought I would try an experiment to see what happens with my one:

Using a 10mm 400mm long SDS bit in the drill with hammer off, I pushed the tip lightly against the workbench and spun it up slowly. I noticed that if I allowed the bit to carry the weight of the drill (i.e. holding it only by the back handle) or pushed the body of the drill to the side a little I could see some wobble at the front of the drill (not much, perhaps half a cm). I found that by holding the drill by both handles I could however find a middle position where there was no wobble. I repeated this with another bit and got simmilar although slightly different results. It seems the amount of wobble I could get was partially dependent on the drill bit. So my guess is I was just feeling / seeing the amount of slop alowed by the flutes on the shank of the bit at certain angular positions.

I tried with a 7/180mm bit and could not feel anything while using it as descibed above, although when holding the drill horizontally with the bit turning in free space I could see approx a 1 to 2 mm of latteral movement on the point of the bit.

It sounds like you are seeing much more movement than this though?

[Matt]

So the counterfeiters can copy a drill almost perfectly but not the label? :)

[Stuart Noble]

So you get the right sized hole but you can't guarantee where it's going to be.

[Dave Plowman (News)]

You can't anyway when drilling masonry. ;-)

[Stuart Noble]

No point putting a spirit level on your shelves then? I think we're being a bit too kind to Makita here. Sounds to me like they're trading on their name and cutting corners, which has to a temptation in a throwaway culture

[Dave Plowman (News)]

Are you saying that every time you drill into masonry the hole is

*exactly* in the right place? Without using a guide of some sort? If so you're far more skilled than me. ;-)

Could be, but if I put a long drill in my DeWalt and run it up to full speed it wobbles about also. I'd not expect anything else with an SDS which doesn't clamp the drill in place - nor expect a drill bit to be made to the accuracy needed to make it run true under this theoretical situation.