Vertical Panel Saw Score and Cut Accuracy

Advice on adjustments to keep the score cut and the through cut aligned on an older vertical panel saw. October 13, 2012

I just installed a 1984 Holz-Her 1203 vertical panel saw. While it has a lot of miles on it, I'm convinced that the heavy Austrian steel has a lot of life left. The setup has been pretty straightforward and so far it cuts nicely. The biggest issue I've had so far is that if I do a scoring crosscut on the upstroke, the kerf is about 1/32" to the left of the through-cut downstroke. I can't figure out where this slop is coming from. The machine is capable of running a scoring blade, but I haven't had a chance to order the parts yet (arbor plates/blade/belt are missing).

Forum Responses
(Cabinetmaking Forum)
From contributor V:
It sounds like the blade isn't running square to the frame. Do a crosscut with the blade fully plunged into the material and check the cut with a machinist square.

From the original questioner:
Yes it seems to be making a nice square cut. It may be irrelevant, but there seems to be a lot of tearout on both sides of the kerf. I'm using a freshly sharpened triple-chip hollow grind blade. The blade toe-in seems straight.

From contributor j:
With that hollow ground blade you should be able to get a clean cut front and back with no scoring.

From contributor V:
To clarify, the cut should be square from the front to the back of the panel being cut or in other words, across the 3/4" thickness. Next question - is there any flex in the panel when you do the reverse score? Even a little bit will throw your cut off so make sure that everything is held tightly and test again. Check for square again also.

What type of material are you getting the tearout on? For the record I donít like hollow ground blades. They are not worth the initial investment or the additional cost to sharpen them. Standard triple chip blades have been performed much better for me on my Striebig VPS.

From contributor J:
Hollow ground is all that works well for me for melamines, but I use triple chip for everything else. You can't have just anybody sharpen hollow ground though.

From contributor V:
Approximately how many sheets of melamine are you getting chip free on the frame side with your hollow ground blades? Yes I said the frame side. I get maybe six-eight with a dozen being the absolute maximum. Even when the blades were new they didn't impress me and the last one that I got was less than a year ago so it is still fresh in my memory, I think. I have also heard that the sharpener really needs to know what they are doing with the hollow ground blades and I will be trying a new one next time around. We'll see if they are any better.

From the original questioner:
Material I'm currently cutting is VG fir on a veneer/MDF core, so you know this stuff tears out if you look at it wrong. Weird thing is that if I make a forward (down) score, then a forward through cut, there is no slop, it's only if I score on the up cut.

I'm wondering if it is because the riving knife is riding on the panel with the up cut? If so, there is too much slop between the saw head and the beam, but I can't see how to dial this out without making the guide screws too tight. I have an ATB blade that came with the saw - wonder if it would work any better?

From contributor J:
I get maybe about a half unit clean on the back and easily a unit or so (more if I'm in a pinch) on the front. Shelves are nearly all that need two side clean. If I stretch blade life out the back side can look pretty ratty sometimes. All this is better than if I use triple chip. I did mess with negative or no hook ATB blades but moved on.

From contributor V:
On my Striebig I can retract the riving knife out of the way for reverse scoring, can you do that on your Holz-Her? If not, how about removing it to make some test cuts to see the results?

From contributor V:
That's incredible. I'll wait to see how the new sharpener does, but I'm not holding my breath.

From contributor C:
I've got the same saw. I also had an issue like you're describing and I ended up adjusting the toe in/out to correct it. When you exit a cross cut at the bottom with the blade fully plunged, back the saw up easily. If the blade cuts in to either side of the kerf you need to adjust the toe in/out accordingly. You can do the same for a rip cut.