TKS80: Burning wood and crosscuts not 90 degrees

[antoniomcs]

Hello everyone.
So far I have been using the TKS80 to cut plywood, and it has served me very well.
Very recently I started a new project, but this time in solid beech wood.
And of course I couldn't help but use the TKS80 to cut the pieces I need.
I needed to rip cut pieces about 30mm and 50mm high and 700mm long.
At the beginning I can push the wood well, but from the middle of its length it becomes difficult to push it, because it seems to me that it starts to get too tight between the parallel guide and the riving knife, since the riving knife is thicker than the blade itself.
When I cut beech, the wood gets very burnt.
Is it because I push it too slowly...?
When I finish the cut, you can really notice the riving knife returning to its initial position.
I have cut plywood and yellow pine with 20mm thickness and did not have this problem.
The blade is new.

Another question is about the miter gauge.
It is not easy to cross cut relatively small pieces: 200mm long x 30mm thick x 70mm wide. The cuts rarely stay square.
Do you have the same problem?

 

[Michael Kellough]

You probably pushed too slowly but the saw might also need adjustment.

Before you do anything else you need to clean the blade as it surely has carbon stuck to the teeth and it will continue to burn the wood even if you do feed fast enough.

I don’t know about beech but some woods (like cherry) have a tendency to burn.

 

[Michael Kellough]

I’m guessing cutting natural wood is new for you. Natural wood may have substantial tension that can be released when cut.

If the kerf in your beech grew wider as it left the blade then the stock between the blade and the fence bowed such that it pushed the stock against the blade causing burning. When that is happening you have to push harder and get the stock past the blade quickly.

Hopefully that was the cause of the burning and you don’t need to adjust the saw.

When using the miter gauge you have to make sure the stock does not slide laterally while cutting. Usually just holding it very firmly against the miter gauge is sufficient. Does the miter gauge fence have a stop? The stop will keep stock from moving. If not, use a clamp to secure the stock to the fence. You can also put small of pressure sensitive adhesive on the fence to reduce lateral sliding.

 

[Birdhunter]

A trick I use on cross cutting real wood is to make the first cut a little proud of the cut line then the second cut is on the cut line.

Also, many boards move when being ripped. They can bind against the fence and burn. That’s not unusual.

 

[ChuckM]

Check the alignment of the fence to the blade; the fence should be parallel to the blade or toe out slightly. A misaligned fence can cause the stock to drag on the back of the blade during the cut.

"since the riving knife is thicker than the blade itself."

Is the knife tapered from front to back? Also check the riving knife is not bent towards the fence.

When ripping long boards, use a featherboard, and feed steadily without pausing.

 

[Frank-Jan]

Also check the position of your ripfence. For ripping wood (as oposed to boardmaterials) the ripfence shouldn't extend beyond the centre of the blade, so the wood gets room to move after the cut.

View attachment 1

It was a bit difficult to find an image, and my saw isn't set up at the moment, else I would have taken a picture, but I took a screenshot from a youtube video about the new batterypowered saw that illustrates what I mean.

 

[Michael Kellough]

Also check the position of your ripfence. For ripping wood (as oposed to boardmaterials) the ripfence shouldn't extend beyond the centre of the blade, so the wood gets room to move after the cut.

View attachment 1

It was a bit difficult to find an image, and my saw isn't set up at the moment, else I would have taken a picture, but I took a screenshot from a youtube video about the new batterypowered saw that illustrates what I mean.

The TKS 80 can do this? Most fences can’t.

 

[Packard]

Whenever I see that on my table saw, I switch to a dedicated rip blade.  So far that has always resolved the problem.

Mostly I use a combination blade, but a rip blade works better for ripping.

Note:  My table saw is a DeWalt.  I am projecting here. 

 

[Frank-Jan]

Also check the position of your ripfence. For ripping wood (as oposed to boardmaterials) the ripfence shouldn't extend beyond the centre of the blade, so the wood gets room to move after the cut.

View attachment 1

It was a bit difficult to find an image, and my saw isn't set up at the moment, else I would have taken a picture, but I took a screenshot from a youtube video about the new batterypowered saw that illustrates what I mean.

The TKS 80 can do this? Most fences can’t.

Most of the european tablesaws have a moveable fence, I think the fences of the tks 80 are very similar to that of my cs70, the long LA fence has an auxiliary fence like the one in the video, but with 2 thumbscrews, instead of 1 central ( that part of the fence can also be slid off, and placed back on the flat, which can be handy sometimes). The fence with the protractor can also slide on the angle-part (and can also be placed on the flat, like the standard position of the fence on the mft3)

 

[ChuckM]

Judging from this statement, the OP's (movable) fence must have been set way past the blade:

"... but from the middle of its length it becomes difficult to push it, because it seems to me that it starts to get too tight between the parallel guide and the riving knife, since the riving knife is thicker than the blade itself."

 

[Packard]

The other thing that can cause the binding (on my conventional table saw) is having the blade set to accommodate a much greater thickness.

So setting my blade to 2-1/2” thickness to cut some 3/4” stock will cause binding.  I have no idea why that is the case, but it will consistently exhibit that behavior when the blade is set to a maximum height.

 

[antoniomcs]

Hello everyone.
I apologize but it's been a hectic few days and I hadn't noticed your responses yet.
Thank you very much for all the feedback.

Attached is a photo of the saw I use, it's the Festool fine cut.
And yes, I don't have much experience cutting solid wood.

[member=57948]ChuckS[/member]
I measured the knife, and it is not tapered.
As you see, I can't use featherboards, because I don't have built-in t-rails on this bench saw.

[member=1993]Frank-Jan[/member]
Thanks, I will use the tip.
How I usually cut the wood is by placing the ripfence slider all together with the ripfence, in it's "close" position.
I am afraid that by placing it in it's "open" position, the stock might not be cut completely parallel, and might "run away" on the last part of the cut towards the rip fence.

When I adjust the height of the saw, only the teeth stay on top of the stock.

Hope this helps to better understand my problem.

 

[Frank-Jan]

...
How I usually cut the wood is by placing the ripfence slider all together with the ripfence, in it's "close" position.
I am afraid that by placing it in it's "open" position, the stock might not be cut completely parallel, and might "run away" on the last part of the cut towards the rip fence.

If you adjust the auxiliary fence so, that it extends past the teeth that cut through the wood, (but not as far as the centre of the blade) the cut has already been made, and the stock will be parallel.
Due to the released tension the cut piece might bend toward the fence, but the cut has already been made, so no problem. (the riving knife will help prevent movement in the other direction)
If the fence extends further, the cut piece might get pushed into the blade causing blade/burn- marks or even pinch the blade so much it can cause kickback, or at least require way to much force to keep it against the ripfence.

as Michael suggested earlier:
[quote author=Michael Kellough]
I’m guessing cutting natural wood is new for you. Natural wood may have substantial tension that can be released when cut.

If the kerf in your beech grew wider as it left the blade then the stock between the blade and the fence bowed such that it pushed the stock against the blade causing burning. When that is happening you have to push harder and get the stock past the blade quickly. [/quote]

 

[cresend]

Throw on a rip blade. Density of beech wood is much higher than the yellow pine you've cut.