Is it normal for SDS Plus drills to have slight wobble?

[Tony Kay]

Hi, I have almost always used rotary drills with keyed chucks and found even cheaper ones have drill bits straight and without wobble. I wanted to upgrade and purchased a Hitachi SDS Plus drill - 850 watts(~£150) and find when the chisel bits or masonry bits are put inside the drill, they seems to be having slight play and are not fixed into it rock solid. When I drilled with it into a brick wall using 6mm Bosch masonry drill bit, due to wobble / play, the hole tended to be slightly bigger and out of shape. This drill is exceptionally powerful and makes the holes with so much ease. But to say the least, I am gutted to have spent so much money on a drill and find the drill bits wobble. Could someone please HELP!? Is it normal for a SDS plus drill bits to wobble or can it be that I have received a defective drill machine?

Many thanks in advance for your help!

Tony

 

[footprints]

There is usually a bit of slack in the chuck as the bit needs to be free to give the hammer action, i have never found it a problem though, are your bits straight?

 

[crank39]

Due to the way the bit is held in the chuck there is going to be some degree of play, in and out and sideways, 2 totally different beasts a rotary and SDS and it appears you may have just been used to one?

 

[Tony Kay]

Hi 'Footprints' and 'Crank39', Many thanks for your replies.

I thought some slack in the drill bit might be normal. The masonry bits are Bosch, so hopefully reasonable quality. I will try to put the drill in a rotary drill and check if they spin in a wobble free manner. I wanted to be sure that the drill is not defective, if there should be zero wobble and I got a wonky piece. But still the wobble in drill makes it shake a little when using it, which is something I didn't realize when I purchased it.

I intend to use this SDS plus drill with diamond core drill bit to make a hole in kitchen wall for extractor fan - so was wondering if the slight wobble can be an issue with diamond core drilling?

It is true, I have only used rotary hammer drills all my life. This is a Hitachi DH28PX 240v 850w SDS Plus and the reviews for it are simply outstanding - its supposed to be as good, if not better than a Makita. I was expecting it to drill a straight clean-cut hole in the wall. May be there is a learning curve for me how SDS plus drills handle!

By the way I also bought a 22 mm SDS plus Auger bit for wood and when I stick that into the drill, I could see the front tip of the auger bit was making slight circular motion and not steady like rock (as I expected). BUT when I put the Auger bit and drill to task on a piece of wood, it made an amazingly clean and quick cut into wood.

I must add, the power in the drill is awesome - it makes it so much easier to drill holes in a brick wall. I was putting up a new stairs handrail and had to drill about 30 holes.

More comments on above are welcome.

Cheers guys

 

[crank39]

Well I'll just add that once you've used an SDS you'll never go back to a rotary and wonder what took you so long to convert, same goes for an impact driver, have you got one yet!

Bosch bits are good so to are dewalt

 

[Tony Kay]

.. I didn't know much about SDS (in fact still don't) and only the diamond core drill made me look for drill with safety feature - clutch and power, so ended with this Hitachi. I didn't know much about impact drivers either, so never bought one - but now you have ignited my curiosity!

Going back to wobble in SDS plus drills - how do we get it to drill a clean-cut, straight hole when the damn thing wobbles! This is quite contrary to the image of better technology / quality tool. Honestly I am almost thinking I should have stuck to rotary drill as I knew I can get a straight clean hole every time, even if it took little longer!

One more question - when I look inside the Hitachi drill when it is running, I can see very small white sparks - perhaps this is another novice question and is normal!

 

[Chud]

I'm not sure it should wobble as much as you're describing - the holes I drill with my SDS drill are usually a cleaner more accurate hole than I get from hammer action on a rotary, not worse!

 

[footprints]

On my Bosch you change the chuck for "normal" drilling. SDS is mainly good for brick masonry etc not normally chosen for wood or metal where the "slackness" would be more of an issue. If you want to get a precisely centered hole in a wall start with a very small drill then go up to the size you want.
One very important point is NEVER use hammer action with a diamond core drill it will ruin it.

 

[Deleted member 174758]

I intend to use this SDS plus drill with diamond core drill bit to make a hole in kitchen wall for extractor fan - so was wondering if the slight wobble can be an issue with diamond core drilling?

In masonry drilling differences in the structure of the material (hardness, etc) combined with the presence of aggregate particles, rebar, etc will always make for some variation in drilling. That's why when you are drilling to put brown (7mm) plugs into very soft brick or lightweight blockwork it is sometimes better to use a 6.5mm or even a 6mm bit so that your fitting is nice and snug. When you think about it there are very few, if any, occasions when a DIYer would need to drill a aircraft precision hole. What would that achieve?

I also bought a 22 mm SDS plus Auger bit for wood and when I stick that into the drill, I could see the front tip of the auger bit was making slight circular motion and not steady like rock (as I expected). BUT when I put the Auger bit and drill to task on a piece of wood, it made an amazingly clean and quick cut into wood.

Because an auger bit is pulled-into the wood by the threaded point and the spurs and the first part of the helix are pretty much what determines how accurate the hole will be, not the chuck, unless the chuck is massively out of concentricity

Going back to wobble in SDS plus drills - how do we get it to drill a clean-cut, straight hole when the damn thing wobbles!

OK. My Bosch GBH2400 wobbles a bit, so did my Makita BHR241, so does the BHR242 which replaced it, as does my Milwaukee PHE26X (3kg) and even the brand new "works" Hilti we've been loaned. But, none of them wobble significantly and none of them drill poor holes - i.e. 7mm holes are good for brown plugs, etc. So, have you compared your tool with any others?

One more question - when I look inside the Hitachi drill when it is running, I can see very small white sparks - perhaps this is another novice question and is normal!

Every brushed motor tool I've ever owned does this to a greater or lesser extent (generally lesser, but there are the odd ones), especially when the brushes are either new and bedding-in, or when they are old and at the end of their lives

 

[JBR]

To be honest, I haven't noticed my SDS drill bits wobbling. Naturally, they vibrate in a forward direction but not laterally. If I start slowly and once the hole has started, the end product is no wider than one done by non-SDS means. Of course, that must depend upon the material into which you are drilling.

 

[Tony Kay]

Ignore this line.

 

[Tony Kay]

Ignore this line.

 

[Tony Kay]

In masonry drilling differences in the structure of the material (hardness, etc) combined with the presence of aggregate particles, rebar, etc will always make for some variation in drilling. That's why when you are drilling to put brown (7mm) plugs into very soft brick or lightweight blockwork it is sometimes better to use a 6.5mm or even a 6mm bit so that your fitting is nice and snug. When you think about it there are very few, if any, occasions when a DIYer would need to drill a aircraft precision hole. What would that achieve?

Many thanks for your detailed reply. When I used 5.5mm drill instead of 6, it some times the wallplug was getting stuck just before it went fully in. Perhaps I need little more practice. It might not be absolutely essential but I enjoy doing a precise job if possible.

Because an auger bit is pulled-into the wood by the threaded point and the spurs and the first part of the helix are pretty much what determines how accurate the hole will be, not the chuck, unless the chuck is massively out of concentricity

I wonder how I can test the Auger (I have 3) for its front tip being centered well? I don't have friends who are interested in DIY and I can't thinking of any way to test it at home. I tried putting the SDS Auger bit in rotation drill to see if I can rotate it slowly it but it is not the right fit.

OK. My Bosch GBH2400 wobbles a bit, so did my Makita BHR241, so does the BHR242 which replaced it, as does my Milwaukee PHE26X (3kg) and even the brand new "works" Hilti we've been loaned. But, none of them wobble significantly and none of them drill poor holes - i.e. 7mm holes are good for brown plugs, etc. So, have you compared your tool with any others?

It is VERY interesting you say all your SDS drill have a bit of wobble but the question is what is 'normal' wobble and if my drill is within normal limit? I think I will need a professional's help to test it!

Every brushed motor tool I've ever owned does this to a greater or lesser extent (generally lesser, but there are the odd ones), especially when the brushes are either new and bedding-in, or when they are old and at the end of their lives

The sparks are very small and not worrying me. I think this Drill Hitachi DH28PX 240v 850w SDS Plus - probably has brushed motor.

I bought this drill - having read about it that it is a quite good quality, perhaps its bit over the top for normal DIY use but I wanted good one that is joy to use for years. Now I feel like an idiot that doesn't know how to use it and the 'wobble-or not to wobble' game is keeping me guessing!

I'm thinking now I will pop into my local B&Q if someone there might be willing to look at the drill and comment!

 

[JBR]

I'm thinking now I will pop into my local B&Q if someone there might be willing to look at the drill and comment!

Perhaps Screwfix might be a better idea!

 

[crank39]

Just been looking at the specs and what have you and it says for coring its rated from 30 to 50mm and I noticed you want to cut 100mm with it presumably for an extractor, for that you'll probably need a 3kg drill