LumberJocks

Miter Saw Blade Deflection

  • Advertise with us

« back to Power Tools, Hardware and Accessories forum

Forum topic by jay443 posted 10-24-2016 12:27 AM 1529 views 0 times favorited 11 replies Add to Favorites Watch
View jay443's profile

jay443

16 posts in 637 days


10-24-2016 12:27 AM

I’m having a heck of a time with miter saw blade deflection when cutting miters on tall stock.

No matter what I do, I can’t seem to get a nice miter. You can see it in the picture below. A few more details:
-Only happens when trying to miter at an angle. A zero degree cut is just fine.
-Doesn’t matter how much I try to pull straight down on the miter saw head, it’s always here
-The deflection can happen at the top or bottom of the piece—can’t seem to figure out a pattern

My miter saw is a Dewalt DW717, 10’’ sliding miter saw. I read the “tune-up” series at thisiscarpentry.com and I aligned the saw.

Any suggestions? Thanks.


11 replies so far

View firefighterontheside's profile

firefighterontheside

16913 posts in 1692 days


#1 posted 10-24-2016 12:40 AM

Does it happen when cutting a board in half or when just trimming a bit off. I use a very thick blade with 96 teeth to prevent this from happening. I’m thinking it’s a thin blade and it deflects when it hits differences in the grain of the wood. Kind of like a screw that wants to go in and follow the grain.

-- Bill M. "People change, walnut doesn't" by Gene.

View jay443's profile

jay443

16 posts in 637 days


#2 posted 10-24-2016 02:00 AM

It happens during both, unfortunately. It drove me crazy because I tried going really, really slowly through the board and pulling straight down, and it came out worse than when I went quickly. I am using a thin kerf blade, though, a Freud Diablo 60 tooth. I wonder if it would be worth finding a full kerf blade.

View splatman's profile

splatman

586 posts in 1234 days


#3 posted 10-24-2016 02:07 AM

That might explain some of the issues I’ve had when cutting on my 10” CMS. Do try a full-kerf blade and tell us and show us the results.

View wichman3's profile

wichman3

49 posts in 456 days


#4 posted 10-24-2016 03:18 AM

Are you clamping the piece(s) when you cut? do you have a non-slip surface on the mitre saw fence (180 or better sandpaper)
If the results are worse when you cut slow, then I would suspect that the piece is slipping while you cut.
Also, are you using a tall auxiliary fence?


It happens during both, unfortunately. It drove me crazy because I tried going really, really slowly through the board and pulling straight down, and it came out worse than when I went quickly. I am using a thin kerf blade, though, a Freud Diablo 60 tooth. I wonder if it would be worth finding a full kerf blade.

- jay443


View MadMark's profile

MadMark

979 posts in 1288 days


#5 posted 10-24-2016 04:27 AM

Are you pressing the stock (too) hard against the blade? Test: set the miter and clamp the piece in place and cut ‘no hands’. if problem stays, tool is broke/bent. If the cut is correct then always clamp.

M

-- Madmark - Madmark2150@yahoo.com Wiretreefarm.com

View jumbojack's profile

jumbojack

1673 posts in 2459 days


#6 posted 10-24-2016 05:06 AM

I think Madmark has it. Start the cut s l o w l y. Be sure the material is firmly clamped or otherwise fixed so No movement occurs. I don’t think you mentioned the blade you are using but a quality full left blade will certainly help.

-- Made in America, with American made tools....Shopsmith

View mike02130's profile

mike02130

167 posts in 508 days


#7 posted 10-24-2016 11:59 AM

Check the fence to see if it’s vertically squared to the table. The DeWalt come with a high sliding fence. They’re never square. I added some strips of painter’s tape. Helps some.

Why cut vertically rather than flat?

-- Google first, search forums second, ask questions later.

View firefighterontheside's profile

firefighterontheside

16913 posts in 1692 days


#8 posted 10-24-2016 12:11 PM

Wichman has a point. If it’s happening only on miters, the angle of the blade wants to slide the board in the direction the blade is facing.

-- Bill M. "People change, walnut doesn't" by Gene.

View wichman3's profile

wichman3

49 posts in 456 days


#9 posted 10-24-2016 12:23 PM

Here’s an idea to try: Keep the blade at 0, tilt the blade to 45, lay the piece flat and then cut. Check the results.

View jay443's profile

jay443

16 posts in 637 days


#10 posted 10-24-2016 12:30 PM

Thanks everybody for the replies! I will try out all of your suggestions. But I can say that currently I wasn’t clamping the piece because I felt like I had a good grip on it. I will try these things tonight:
- check the fence for perpendicular
- clamp the piece and cut at a 45 deg miter
- lay the piece flat and cut a 45 deg bevel to create the same miter

View mike02130's profile

mike02130

167 posts in 508 days


#11 posted 10-24-2016 01:14 PM

Try my suggestion first. It may save you some frustration. I don’t know much but I’m usually right. I just cut a miter with a 1×6 standing vertically against the fence and this is what happened.

When I put a square against the fence, it shows that it is tilted back almost a 1/16. Hard to tell by the picture but it shows you how and where to set your square.

No need for a clamp, no need to cut slowly, just hold and cut like you would normally do.

-- Google first, search forums second, ask questions later.

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com