DEWALT 20V Die Grinder DCG426B wobble issue

[naim]

I purchased a DEWALT 20V Die Grinder (DCG426B). Upon putting a carbide in it and using it, I noticed that it was bouncing off the metal quite a bit. I tested the same bit in my pneumatic die grinder, no wobble/issues. Tried this with a couple other bits, same results. Playing around with the DEWALT 20V Die Grinder, I notice that if a feather the trigger so it runs real slow, I can clearly see the bit wobble. Figured maybe I got a fluke I got another DCG426B Die Grinder to test and damn, same thing.

Possible I got 2 bad grinders? I cannot believe this is considered normal as my Ingersoll Rand & my cheapy HarborFreight die grinders both have like zero runout.
Anyone else have the Dewalt cordless die grinder, what have you experienced?

 

[oilslick]

I am considering getting one for myself, this sounds concerning. Thanks

 

[tyyost]

Remove your collet completely from the grinder, and inspect it and the collet seat. Look for dirt, debris, or any burrs. While apart test and see is there is runout in the collet seat/nose of tool. If not then Clean and reinstall the collet and bit and try again. If similar results to first time I’d contact Dewalt or return it.

 

[GaryM909]

Mine runs smooth. I just used it a few days ago with a 3" zip disc.

 

[strutaeng]

I don't have experience with that specific tool, but I know die grinders are difficult to control. The pneumatic one I have does this. Those cutters have a specific side of cutting too.

Is it the actual bit that's chattering or the entire tool?

...oh dang, this is an older post.

 

[Half-fast eddie]

...oh dang, this is an older post.

Just last October … you’re still good.

 

[naim]

Remove your collet completely from the grinder, and inspect it and the collet seat. Look for dirt, debris, or any burrs. While apart test and see is there is runout in the collet seat/nose of tool. If not then Clean and reinstall the collet and bit and try again. If similar results to first time I’d contact Dewalt or return it.

Posting an late update (for some reason I did not see an notification with all the activity in November).

Anyways getting back to this, I followed tyyost's advice and thoroughly cleaned out the collet seat, gave the tool a whirl and much much better..
That seemed to have solved it. I know I inspected the collet seat before but assumed if I could not see something, it was not the issue.

Thanks!!!

 

[Trucky]

This is an old thread but I figured I would throw my very recent experience in the ring for anyone experiencing this issue (and probably trying to Google it, as I just was).

My die grinder, of the same model as the OP, manufactured in 2023 (week 47?), does not hold fully-inserted bits on center. It took me a minute to figure out why, as shorter bits spin directly on center in this tool. Upon examining the spindle, there is a tooling mark (Probably a remnant from an off-center rough drilling operation) at the bottom of the spindle. If you insert a bit the whole way in until it touches this mark, the bit will get sort of jammed in there, and when the collet is tightened, it forces the bit off-center. Then, when you turn the tool on, you can see the bit wiggle. No good. Carbide bits "wiggling" at high RPM is not my favorite thing to see. (And could be the Last Thing I See if I'm not careful - reminder to wear your eye pro.) The current 'workaround' is to insert the bit fully, but pull it out a bit (maybe 1/8") before tightening the collet nut down. Should be good to go then.

I'm going to contact DeWalt and see what they say about it.

The attached pictures show the inside of the spindle at 2 different rotations (angles)... you can see the off-center area I'm talking about that touches the end of the bit. (I do have a video of the bit spinning off-center if anyone cares, but if you have this issue you should be able to see it instantly.)

 

[GeoBruin]

I never seat a bit all the way down in any kind of chuck/collet holder for fear of this very thing.

 

[darkzero]

I'm going to contact DeWalt and see what they say about it.

Perhaps yours might be a result of manufacturing variations but I'd be surprised if they would do anything about it.

I was taught to never bottom out a tool/cutting bit in a spindle no matter what the tool or machine for this very same reason. That is unless the tool holder is designed for indexing like using endmills in my ER collet holders that have adjustable stops.

If it was designed to be bottomed out they would finish the bottom of the hole by grinding or machining at the least. Then again carbide burrs don't usually have precision finished ends on the shanks either. They don't need to be as they are designed to cut radially.

 

[RTM]

I was taught to never bottom out a tool/cutting bit in a spindle no matter what the tool or machine for this very same reason

On my Dremel I need to push down to dislodge my bits, so it's become a habit to make sure they have room before I tighten, on any collet or chuck.

 

[darkzero]

On my Dremel I need to push down to dislodge my bits, so it's become a habit to make sure they have room before I tighten, on any collet or chuck.

Good point. That's another reason. I was also also taught that on some collet types, if you bottom out the tool shank, you'll may have a heck of a time getting the collet to release. I haven't had that happen to me on a Dremel that I can remember but then again I use the keyless chuck most of time. But I have had that happen to me before.

I was also told bottoming out the tool bit shank could cause damage to the shank or collet or collet nut when tightening down but I don't know if that's actually a common thing.