Table Saw blade depth workaround

[dalpets]

My table saw has a maximum cutting depth of 87mm.

I need to to be able to cut to a depth of 89mm, on edge, so I have experimented by setting my blade to 50% above the table top to try to minimize any miscuts ie., when employing a second reverse cut. This still always results in the blade not completely following the first cut. It seems reasonable that this should occur since there are obvious diffences in the physical conditions at play between both cuts. I have tried to use consistent down pressure on the piece & pressure towards the fence but there is still a raised anomoly of about 3 to 4 mm on the second cut, usually about 6 inches in from the start of that cut.

I don't want to have to resort to corrective sanding or planing, if possible, so I would like to know if there might be some other ways to obviate the problem.

Thanks for any help.

[double.d]

I used the same technique for a long time up until i bought a band saw and i could never get it right. The relationship between the fence, blade and table is the key, are your blade and fence at true 90 degree with the table?. Your blade will also deform a little in a captive cut because the heat generated has nowhere to go.

Sorry i don't have a solution, my remedy was to cut slightly thicker and run it through the planer.

[Wrongwayfirst]

No expert but 3-4mm is a lot is your fence flexing? How long is your cut maybe the timber has a slight bow?

Cheers

[havabeer69]

rather then doing it in two cuts... can you do it in 3?

so do your first pass/cut
then flip the log 90 degree's so you have part of the first cut to act as a guide
then flip it 180 degree's and do the left overs

[elanjacobs]

Are you using a proper rip blade? Deep cuts need a really low tooth count to reduce heat, clear chips, and keep the blade stable

[ian]

Are you using a proper rip blade? Deep cuts need a really low tooth count to reduce heat, clear chips, and keep the blade stable
:whs:

[havabeer69]

ignore my suggestion, i thought you where talking about a cross cut.... not a rip cut.

[orraloon]

On top of what the others have said the wood needs to be strait and squared. Cant flip a wonky board and expect two cuts to line up.The same strait face against the fence for both cuts. If the two halves are going to be tall and thin and likely to fall over when separated then best not to cut all the way through but do the last little bit with a hand saw.
Resawing Thick Stock with a Tablesaw - YouTube (https://www.youtube.com/watch?v=5B76IKGXBMo)
Now remember the guy in the clip is from a country where real men have contempt for anything to do with safety so there is no riving knife shown.
Regards
John

[Alkahestic]

Now remember the guy in the clip is from a country where real men have contempt for anything to do with safety so there is no riving knife shown.

And the further insanity is that it takes about 10 seconds to fit the riving knife into a sawstop. The riving knife must have been oppressing his freedoms.

[Sam]

Can the 89mm piece be reduced to 87mm ? Rip the 2mm off on your table saw !

[Damienol]

Perhaps, general safety guidelines aside, from what I understand, a standard 10” table saw takes a standard 254mm (10” blade)

The Festool Kapex takes a 260mm blade. Perhaps you could try a blade like this in your saw??

[clear out]

Dunno what saw you have but a Wadkin Bursgreen 10” AGS takes a 12” blade no probs.
Just leaves 1” sticking up when fully wound down.
Your saw May take larger blade ok.
H.

[Mobyturns]

On top of what the others have said the wood needs to be strait and squared. ( preferably with parallel pairs of faces ) Cant flip a wonky board and expect two cuts to line up.The same strait face against the fence for both cuts. If the two halves are going to be tall and thin and likely to fall over when separated then best not to cut all the way through but do the last little bit with a hand saw.



Are you using a proper rip blade? Deep cuts need a really low tooth count to reduce heat, clear chips, and keep the blade stable


Dunno what saw you have but a Wadkin Bursgreen 10” AGS takes a 12” blade no probs.
Just leaves 1” sticking up when fully wound down. Your saw May take larger blade ok.
H.

A little info about the boards dimensions, the saw and blade being used may help to resolve the issue.

From your comments its 89 mm on the face parallel to the cut, so how wide / narrow is the board?

In addition to the above valuable comments things to look at are,



a dedicated high quality rip blade will give far better results than a "combination" blade.
blade kerf width and riving knife thickness. Are they compatible?
is the riving knife vertical / square to the table, parallel and in alignment with the blade.
table insert - does it fully support both halves of the board during both cuts? A zero clearance insert may assist.
is the board fully supported by, and held against the fence with finger boards etc?


Other things to keep in mind are


you should flip the board end for end so that the same board face is in contact with the fence for both cuts
any out of square errors introduced by the squareness of the stock, saw blade / fence / riving knife are compounded i.e. twice the error in the cut or "flatness of the board." Is the cut face flat, convex, or concave? and the opposing cut face the opposite?
released tensions in the board may influence the accuracy of the second cut
infeed alignment and board support will minimize potential causes.
you have rather high expectations in achieving a "perfect" face from two cuts - unless everything is in exceptional alignment, does not flex/move in use, and your processes are spot on.


I rip quite a lot of thin stock from "narrow boards" on both the Woodfast TS250 table saw and Woodfast BS500 band saw. Quite often I may split a 19 mm thick x 70 mm wide board into three consecutive strips of 6-7 mm; 2.5-3 mm; and 6.5-7 mm to maintain grain match; or split a 10 mm x 70 mm into two 3.5 to 4 mm thick strips for inlay banding construction. However I do not solely rely upon the board to be cut for alignment as I will often use a jointed DAR sacrificial block (clean pine dunnage) to align and support the board to be cut. I apply a PVA wash or hot-melt to join both.

To achieve what I require from that special board etc I may use some unconventional techniques including high count thin kerf "glue finish" blades to perform the rip task. In doing so you must take into account all of the factors above, use slow feed rates ,etc. Not recommended, however not impossible and can be undertaken safely with appropriate skill, experience, knowledge and awareness of the hazards, plus how the board "should" react etc.

[Durham Lad]

Re Oraloons post, I fully understand the need for a riving knife but I had an incident with my table saw about 5 years ago which made me think twice about having one. I was cutting a piece of Huon 15mm thick which was quite dense and had a swirly grain pattern to it. Once the piece passed through the blade the kerf closed up and and stopped dead on the riving knife and then all hell broke loose, the huon broke into pieces and the biggest piece flew back at me and hit knuckles on my right hand which had been holding a push stick resulting in me having surgery to repair damaged tendons in two knuckles. All fingers are now working well but was a painful experience. Cheers Brian.

[clear out]

No offence but I witnessed a similar incident at Canberra School of Art wood course where the Pom in charge didn’t believe in riving knives.
The whole board after closing up on the rear of the blade was flung onto the students hand smashing several knuckles.
Exit one student.

I guess if I was sawing a board as cranky as you were I’d be using my bandsaw to rough it in two first.

Had another mate a boatbuilder take two fingers off when his left hand was dragged thru the blade after trying to pull in thru without a riving knife on the saw.
H.

[elanjacobs]

the Pom in charge didn’t believe in riving knives.
The whole board after closing up on the rear of the blade was flung onto the students hand smashing several knuckles

Came here to say that. It's waaaay worse without a riving knife.