LumberJocks

All Replies on I'm Stumped - Weird Table Saw Behavior

  • Advertise with us
View Ardubya's profile

I'm Stumped - Weird Table Saw Behavior

by Ardubya
posted 04-26-2016 02:01 PM


30 replies so far

View splintergroup's profile

splintergroup

3774 posts in 1992 days


#1 posted 04-26-2016 02:34 PM

Perhaps your fence is not truly straight and flat? A small bump in the fence towards the back could ‘kick’ out the board when the end reached the bump.

View Nubsnstubs's profile

Nubsnstubs

1723 posts in 2500 days


#2 posted 04-26-2016 02:38 PM

Are you getting any burn marks or burnishing before exiting the cut?
Are you using carbide?
How thick is the blade?
How new is the blade?
Is the blade flat?
Have you checked the flanges on the arbor to verify they are the same diameter and setting flat on the blade when tightened? Take the blade out, and put the outer flange back onto the arbor, tighten it like you would do normally, and check for a gap.
Is your piece you’re cutting straight or bowed when exiting?............... Jerry (in Tucson)

-- Jerry (in Tucson) www.woodturnerstools.com

View JayT's profile

JayT

6402 posts in 2981 days


#3 posted 04-26-2016 02:40 PM

My best guess is that it is related to technique.

Do you have an outfeed table of some kind to push the pieces onto or are they tipping up and going to the floor as they exit? If the latter, then it might be that corner of the workpiece rubbing the blade just a bit as it tips up and out. As the piece exits the cut, there just isn’t much support from the fence and it is very easy for leverage to take over and move the board just a bit. I used to have a similar problem on the table saw and that was the cause.

If you don’t have one, try adding an outfeed support and see if that helps.

-- https://www.jtplaneworks.com - In theory, there is no difference between theory and practice. In practice, there is.

View ScottM's profile

ScottM

747 posts in 2916 days


#4 posted 04-26-2016 02:40 PM

You’re talking about “extra” off of the left back corner; the corner on the operator side that last touches the blade?

My Ridgid R4510 does the same thing. I’ve also been through everything many times and have yet to find a reason for it so I’m also curious what others think on this one.

View Ardubya's profile

Ardubya

73 posts in 1914 days


#5 posted 04-26-2016 02:42 PM

Splintergroup – that’s a good thought and I will double check. I’m using a really nice EZ Square fence system from Peachtree Woodworking. Thing is, I have experienced this same phenomenon on the two other saws I have used as well.

After I measured and aligned everything, my first thought was that maybe it was something I was doing when feeding the board through. But I have even experimented with that – hand feed vs push block feed, feed rate, board size, nothing seems to get a different result.

View Ardubya's profile

Ardubya

73 posts in 1914 days


#6 posted 04-26-2016 02:48 PM

Jerry (In Tucson) – good questions.

Using an almost brand new Diablo thin kerf 40 tooth general purpose blade. Generally the wood I’m feeding is square. Have tried plywood (medium grade from big box store), S4S from big box, hardwoods (maple, walnut, cherry) from local hardwoods supplier. Thickness is half inch to 1 inch, but most is 3/4 inch.

Blade is flat, no issues with arbor or mounting. Have done very fine adjusting using techniques viewed on YouTube (reputable sources).

All this said, the thing is that I have experienced this not only on my current higher grade saw but the other two stock saws I have used.

View Ardubya's profile

Ardubya

73 posts in 1914 days


#7 posted 04-26-2016 02:50 PM

ScottM – you are correct. When the wood is facing down, it’s the corner on the blade side, the last surface to touch the blade as it exits.

View Kelly's profile

Kelly

3006 posts in 3714 days


#8 posted 04-26-2016 03:06 PM

1) Are you using good blades? If you have blades that wobble under load, being in the wood can stabilize them, somewhat, but when you get to the end it may wobble a little before straightening.

2) Are you using good push shoes, rather than just sticks. Shoes allow you to hold the wood down AND against the fence far better than [the far less safe] push sticks.

View pintodeluxe's profile

pintodeluxe

6150 posts in 3583 days


#9 posted 04-26-2016 03:22 PM

If only the end of the board is out of square, I wouldn’t suspect blade or fence issues.
Usually it is due to the board dropping down as it becomes unsupported on the outfeed side. At the same time, you are referencing less and less of the fence against your workpiece, so there is a tendency for the board to move sideways as well. If you don’t use an outfeed table, try adding one. If you already use an outfeed table, try adjusting it level with the TS surface. I use adjustable furniture leveling feet on my outfeed table to set it just where it needs to be.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View knotscott's profile

knotscott

8382 posts in 4145 days


#10 posted 04-26-2016 03:23 PM

Basic question – has the wood been flattened and straightened to provide a flat reference face to put against the table and a square straight reference edge to put against the fence?

-- Happiness is like wetting your pants...everyone can see it, but only you can feel the warmth....

View johnstoneb's profile

johnstoneb

3144 posts in 2942 days


#11 posted 04-26-2016 03:27 PM

The weak point on that saw is the fence. If that is the factory fence is is moving out of square. I finally replace the fence on my 113 with a T2. I could never get the factory fence to stay square. I would measure to the miter slot front and rear, tighten down, remeasure and after a cut it would be out one way or the other. The new fence made a new saw out of it. The T2 would stay square. I would measure both end of the fence to the miter slot and see if it is staying square.

-- Bruce, Boise, ID

View Ardubya's profile

Ardubya

73 posts in 1914 days


#12 posted 04-26-2016 04:16 PM

Kelly – yes, using good blades and GRR-Rippers
Pintodeluxe – I have a semi-outfeed table in that I have built a contiguous surface on the sides and back of the saw
Knotscott – some of the wood I have experimented with has been professionally flattened and squared (by the hardwood vendor) – same result
Johnstoneb – I’m using a nice aftermarket fence – EZ Square – from Peachtree

View splintergroup's profile

splintergroup

3774 posts in 1992 days


#13 posted 04-26-2016 04:31 PM



Splintergroup – that s a good thought and I will double check. I m using a really nice EZ Square fence system from Peachtree Woodworking. Thing is, I have experienced this same phenomenon on the two other saws I have used as well.

- Ardubya

Ahh, ok. This does tend to put the finger on technique versus any mechanical issues.
Do you experience the same problem(s) if you move the fence to the other side of the blade and make a cut?

View CharlesNeil's profile

CharlesNeil

2501 posts in 4640 days


#14 posted 04-26-2016 05:17 PM

ok just a suggestion , Many people when they push wood thru a table saw, tend to direct the pressure more to ward the blade than the fence, when you do that as the material exits the blade it tends to try to scoot toward the blade, this is more prevalent when using a push stick of sorts.

Its like using a jointer where you need to direct the downward pressure more so on the out feed table than the in feed, once the material has engaged the out feed table

Try directing your pressure toward the back of the fence as an aim point .

View Woodknack's profile

Woodknack

13383 posts in 3150 days


#15 posted 04-26-2016 07:22 PM

Charles Neil nailed it. What you are experiencing is normal. An outfeed table helps me so the wood isn’t bouncing around.

-- Rick M, http://thewoodknack.blogspot.com/

View teejk02's profile

teejk02

504 posts in 1895 days


#16 posted 04-26-2016 07:50 PM

I think that is normal behavior for any saw I have ever dealt with. My Delta does that but only ruins about 1/8” of the end…I could probably work harder to avoid it but 1/8” of wood vs. fingers seems like a no-brainer to me.

View CharlesNeil's profile

CharlesNeil

2501 posts in 4640 days


#17 posted 04-26-2016 08:03 PM

you dont need to expose your fingers, just keep the pressure pushing forward and towards the fence more so, of course you still use a push stick and so forth , just kinda aim at the end of the fence rather than towards the blade, the objective is to keep the pressure pushing the wood into the fence and not the blade.

View oldnovice's profile

oldnovice

7556 posts in 4137 days


#18 posted 04-26-2016 09:13 PM

Yup, Charles Neil got it!
An out feed table also hepls!

-- "It's fine in practise but it will never work in theory"

View teejk02's profile

teejk02

504 posts in 1895 days


#19 posted 04-26-2016 09:19 PM



you dont need to expose your fingers, just keep the pressure pushing forward and towards the fence more so, of course you still use a push stick and so forth , just kinda aim at the end of the fence rather than towards the blade, the objective is to keep the pressure pushing the wood into the fence and not the blade.

- CharlesNeil

I understand the mechanics…but the way I figure it is that the internal tension of wood comes into play. Until I get to the end of the cut the board is controlled between the fence and the blade and everything is fine (unless I get into one of those rare rips where the board insists on closing beyond the cut in which case I hit the red button…nothing good ever happens there). For me it’s quicker to leave the board a bit long and cut to finished length later. Maybe because I cut meat for years and then got into woodworking…I cringe/shudder/close my eyes when I even watch a cooking show where somebody gets too close to a sharp knife in a way I learned not to do. Probably just me.

View pete724's profile

pete724

70 posts in 1578 days


#20 posted 04-27-2016 12:41 AM

I also think Charles neil has it correct but I must ask a couple questions.

Are you describing a kind of “downwards tearout”?

This leads to the question; What throat plate are you using? One with a big ole gap?

You might want to get or make a zero clearance plate.

Whatever throat plate you have, is it leveled properly?

View dwaynebernard's profile

dwaynebernard

1 post in 1651 days


#21 posted 04-27-2016 01:05 AM

use a magnetic stand and a drop indicator on the far side of the fence . . .now you can see fence movement in real time.

-- dwayne

View 45Charlie's profile

45Charlie

7 posts in 2123 days


#22 posted 04-27-2016 01:20 AM

You mentioned that you are using a thin kerf blade. If you have a full kerf blade, try it and see if the problem persist.
I had a similar problem a few years ago using a thin kerf blade. A blade stabalizer from Forrest Mfg. Co.solved the problem with my Woodworker II thin kerf blade. Thin kerf blades can have a slight vibration when running that can never be seen during a normal saw set up with the blade not turning.

View marc_rosen's profile

marc_rosen

175 posts in 3951 days


#23 posted 04-27-2016 02:41 AM

Ardubya typed in post #6 that he is using a thin kerf blade. I don’t see if he mentioned in any other post if his blade guard mount (or MJ splitter, if installed) is of the same thickness. Could a narrower saw kerf pinching a normal size splitter cause any problems?

Marc

-- Windsurfing, Woodworking, Weaving, and Woodducks. "Most woodworkers are usually boring holes"

View Tim Royal 's profile

Tim Royal

318 posts in 2256 days


#24 posted 07-12-2016 10:06 PM

My .02 put that splitter on there… my old 113 hit me with some nasty kickback with a good fence… I now have a ZCI and a Micro-Jig splitter (narrow kerf). Problem solved and I get much more consistent cuts as well.

-- -Tim Royal -"Pride makes us artificial and humility makes us real." -Thomas Merton

View Plain's profile

Plain

157 posts in 1468 days


#25 posted 07-12-2016 10:38 PM

Your saw might not be rigid enough. When you push wood through the blade it deflects. When the stock leaves the blade the tension is relieved and thd saw returns to the original form, cutting a small bit of the wood.

View jumbojack's profile

jumbojack

1690 posts in 3394 days


#26 posted 07-13-2016 02:06 AM

I had the same problem until replaced the arbor bearing. Seems the slight run out was causing. I was pretty confident it was not my technique as I had better results on my brothers newer saw.

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

View Ardubya's profile

Ardubya

73 posts in 1914 days


#27 posted 07-13-2016 04:15 AM

Hello everyone – thanks for all the comments so far. Lots to go through and I’m catching up. I’ll be sure to reply to follow-up questions soon. This is a topic that is quite interesting and I’ve learned much already.

Cheers!
Ardubya

View xeddog's profile

xeddog

298 posts in 3777 days


#28 posted 07-13-2016 04:39 PM

The saws you have listed are not the pillars of rigidity and strength. I would wonder about the fit and finish of all of the supporting mechanics under the table. Play in the trunnion bushings and that sort of thing. Also, feeding too fast might be causing some parts, like the arbor support to flex a little, and that flex would relieve itself at the end of the cut. Just as a test, feed your workpiece through very slowly using only enough pressure to get the piece to move.

Wayne

View RandyinFlorida's profile

RandyinFlorida

257 posts in 2837 days


#29 posted 07-13-2016 04:46 PM

I am reminded of the old adage “If you always do what you always did, you’ll always get what you always got.’ doesn’t help on bit. I know…

-- Randy in Crestview Florida, Wood Rocks!

View Jon Hobbs's profile

Jon Hobbs

147 posts in 1474 days


#30 posted 07-13-2016 08:02 PM

Is your throat plate/ZCI flush with the table top? If it’s sitting slightly below the table top, then any downward pressure you’re applying could to the board could cause that corner to dip down and/or over a smidge.

That said….You’ve had the same issue with 3 different saws. What’s (who’s) the common denominator? Most likely an operator technique error. I’ve experience similar issues, almost always because the piece is not properly supported on the outfeed side (as others have said). Once I provide proper outfeed support and take care to apply pressure to the board properly and push it completely past the blade, the problem goes away.

-- Jon -- Just a Minnesota kid hanging out in Kansas

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