My New Bosch Miter Saw Is Defective. :-(

That's too bad. I always wondered about the stability of that saw with all those connections and travel in the arm. You picture does point to simple blade wobble, however. The solution would be to not stop the saw until you raise the blade. But that could cause tear-out on the top and you really shouldn't have to deal with that crap with a saw that costs that much.

Amazon has some pretty good customer service so you should be ok with a return. Still sucks to have to deal with all that. For a saw that costs that much, that is unacceptable.

I also asked the Bosch tech about side to side movement when the head unit is extended as far as possible towards the user. I did notice some, but had not measured it. He said that 1/32" is normal/acceptable, even a tiny bit more. Anything approaching 1/16" is way too much. When I got home I measured it with my standard 1/32" measuring device: A hotel key card. ;-) The card was snug in the gap between the blade and the wood, so it's right at 1/32".

I agree.

Bummer! BTW, the board(s) you cut... quality time test cut(s) or what's the new project? That board doesn't look like scrap.

Sonny

the new project? That board doesn't look like scrap.

Well, considering that the board was bought at Home Depot and required the hold-down clamp to flatten it against the saw's table, it is definitely scrap.

The "project" is to test various techniques for applying MinWax Navy Blue s tain. My sister asked me to assemble and finish a Secretary's Desk kit that she bought. I needed a pine board that matched the wood used for the desk. For $10 I got a 4? 1 x 12 that I could not only get a bunch of test pieces from, but I could also test the full range of the new saw.

So is it the saw or the board that is the problem? Could the board be moving once the blade stops? Have you tried a different board?

I wonder of the force of the rotating blade is causing some stress that causes it to move during the cut.

I'm going to stop and pick up a perfectly flat 1x12 later today. There's a lumber yard near my work where I can get good wood.

I don't think the board is moving because it is clamped to the table to keep it flat. It's the clamped side that's showing the groove. I'll test a few more things and removing the possibility of the board causing the problem is my next step.

New Zealand Radiata pine? A few years back I built a whole bathroom of cabinets with it. Home Depot carries it.

Dave in SoTex

A piece of MDF or plywood should work if you have a scrap laying around.

I do have some 1/2" MDF out in the shed that might work. I need to make sure that it is at least as wide as it needs to be to require a sliding cut so that the teeth end up against the end of the board after the cut.

I don't recall how wide the cutoffs are. I guess I could use a spacer but I don't want add another variable.

Thanks for the suggestion.

That photo makes me wonder if there is end play in the arbor/shaft such that under power the arbor/shaft and blade move away from the motor and then as the blade comes to a rest they move back towards the motor.

I wonder this based on prior experience...

It be the saw.

Here is the 1/2" MDF:

I tried 2 different blades and I tried both with and without the hold down clamp. The groove might be ever so slightly shallower without the hold down clamp, but it's still there.

I also tried to eliminate user error by keeping some left-ward pressure on the head unit throughout the entire cut. Theoretically, this should have pulled the front of the blade away from the board, eliminating the groove. As you can see, it did not.

The call goes into Amazon tomorrow.

Dammit!

That sucks..I don't have a slider but is it common practice to stop the blade while in the kerf?

Sometimes when you pull the blade back out of a cut, it will pull some fuzz up on the top of the cut, or chip the top veneer of plywood or melamine. So, it's a valid technique to stop the blade "in the cut."

It shouldn't do what's happening in his pics... certainly not for 6 bills.

Yes. You'll find comments like this all over the web and in most instructio n manuals:

"Tip #3: Stop before you lift.

After making a cut on your mitersaw, always allow the blade to stop spinnin g before lifting the saw. Prematurely raising it could score the end of you r workpiece. The spinning blade could also snag the cutoff and dangerously propel it at a high speed."

"Wait Until the Blade Stops

Be honest: How many dangerous missiles have you launched from your miter sa w? We?ve all done it. Small cutoffs are the worst, of course. But i t?s not rocket science to figure out how to ground them: Don? ?t lift the blade until it stops. Make the cut, let go of the trigger and count to five. That?s not so hard, is it?"

I should add that the above comments are not just for sliding miters. The practice should be used with all miter saws.

...and use negative rake blades.

Blade brake pulling the blade or arbor shaft to the side?

Well that sucks. I would not give this particular saw a third chance... Did you by any chance check the serial number or determine when it was built? Wondering if this was one of the early ones that had issues.

I just spoke to Amazon. I have to give them props.

As in the past, it took less than a minute on hold to speak to a live person. After I explained the situation and let her know that I wanted a replacement, she put me on hold for a few minutes and when she came back she told that the return authorization will be sent via email, the replacement saw should arrive on Friday and UPS will pick up the broken one tomorrow.

It's supposed to be a busy weekend for me, but I'll set the saw up as soon as possible and do some more testing. Stay tuned!