Thread: scribing blade & riving knife

Zed,


Question 1 - Yes.

Question 2 - The scribing blade makes a small cut underneath before the main blade cuts from the top. Stops chipping and tear out etc on cutting laminates as the pieces is cut from both sides.


Peter.

Excellent answer Sturdee.

Would just like to add that neither situation is a guaranteed outcome!

And if Zed's age is correct who helped him type that question and who is gunna be able to get those concepts through to him???

Jamie

Originally Posted by Sturdee

Zed,


Question 1 - Yes.

Question 2 - The scribing blade makes a small cut underneath before the main blade cuts from the top. Stops chipping and tear out etc on cutting laminates as the pieces is cut from both sides.


Peter.

Peter,

Can you stop the scribing blade from doing anything ? Ie can it be stopped from scribing ? can it be lowered below the table so it is in neutral so to speak ? is this of function value for a home workshop ?

barnsey - we learn fast on my home planet Thronebulax - If I wear my own version of Oz's foil hat it helps with data retention...

Hi Zed,


I have a tablesaw with a scribing blade, its really handy when cutting laminated boards. I use it when cutting malemine all the time. It might also come in handy when cutting veneer boards as well.

On my saw I have allen key adjustments for height, lock and moving the blade left/right. The scribing blade is usually tapered so that it will cut wider as it is raised.

Most saws I have seen that are designed with a scribing blade in mind have the ability to lower the blade under the table when its not needed, but you should confirm this before buying your saw, I'd would think on some saws where the scriber is retrofitted it might need to be removed.


Also another thing to check is the maximum blade size when a scriber is fitting, on some tablesaws you must run a smaller blade when using a scriber.

Joe

excellent data thanks Gents, I was in carbatech sydney today droolng over the router table with slider on it and the 12" table saw we've been discussing for a total cost of $5K it'll have to wait. shes big enough but the cashflow aint!

Cheers

I've never tried the following (never had the patience) but I recall reading that you could run your laminated board through your tablesaw with the blade set to cutjust below the surface, i.e, scribing the board. Then flip it over and complete a full cut. As I said, I've never tried this (my 80-tooth triple chip blade does it perfectly well for me). Just curious.

Regards from Perth

Derek

You actually don't need to flip it over to get the same effect as you get with a scriber. Just run it through with the blade just poking above the table and then through again same side up with the blade at full height.

If you want to "scribe" with your main blade then you need to feed the stock in backwards (ie: with the rotation instead of against it). Scribing blades are usually counter rotating.

Mick

Originally Posted by journeyman Mick

with the rotation instead of against it

So, the trick is that you want the teeth to always move from the outside in. The scribing blade does it for the underside and the normal blade does it for the topside. Then using your normal blade for scribing seems quite scary, because it will tend to lift the wood up from the table.
Although it will then trow it away from you, so that's good.

Jasper

True that's how a scribing blade works but you can get a similar result just by feeding it the normal way with the blade lowered to a few millimetres above the table. The idea is that the cutting angle is very low and so you minimise tearout. It works for the same reason that some people recommend lowering blade height in general when cutting melamine. Give it a try.

Not as good as a scribing blade but not everyone can afford a tablesaw with one. If you're cutting a lot of it and don't have a scribing blade, get a TCT blade like Derek's.