table squareness / wood thickness

[Capt Weasel]

Ran into an odd problem. My new 788 been cutting like a dream. Found out it wasn't square early and fixed it. Been great ever since, until.
I starting delving into stack cutting and its been going good until I found that it wasn't cutting square. I checked and rechecked the sqaureness and it was dead on. Cut a smaller 1/4" piece and it was fine. Then I cut a 5/8" puzzle out of poplar (not stacked) and the pieces were tight and a tad off. I had to abandon my 2 1/4" oak pieces because the bottom one was to thin in spots.
What's going on? I haven't been doing anything different that I can tell and I still use the same blades. I used a FD-SR 5 on the poplar and 1/2" oak ( stacked ). Is it the blades, me or the saw? Only thing I can figure is maybe the blades are undersized for the wood and I pushed to hard. Any other ideas?

[CanadianScroller]

The only thing I can think of is front to back squareness.
If the blade is square to the table when looking head on, then maybe the upper or lower blade clamp is off slightly.

[Capt Weasel]

How do I fix check that or is it in the owners manual?

[Neal Moore]

Generally, especially with hard woods, you want to use the biggest (thickest) blade that will work for the size cuts you are making. Smaller (thinner) blades tend to bow while cutting thicker wood and it gets worse if you apply any side pressure to the blade. Also check the upper and lower blade clamps. There is a set screw on both that can be adjusted in or out to ensure the blade passes through the center of the hole in the table on a true vertical plane. Front to back squareness of the table really isn't mechanically adjustable. You can look at the bushing on the table adjusting knob and make sure it's seated properly inside the trunnion or semi-circle opening that the table rides on when being tilted. Hope this helps a little

[sheltiecarver]

Captain,
When I encounter stuff like you described, it is 99% handler error - I pushed too hard or hurried - and I can correct it by going s-l-o-w-l-y, letting the saw do all the cutting, and keeping a really light hand on the wood - so there is as little as possible distortion front to back or side to side on the blade. The other 1% is a non-sharp blade - easily remedied by replacing it.
For puzzles from thick stock, I use a rather undersized blade if it is for adults (so that the pieces fit rather snugly), and a bigger blade if it is for youngsters - to make it a bit easier (also the youngster's puzzles usually have less detail)
Be sure to let us know how you solve the problem (I'm positive you will)
Sandy

[Capt Weasel]

Figured it out. I was using to small a blade and it gave it bowed just enough when it started getting dull and when I had to apply a little more pressure because of it. I don't know what I was thinking when I used a #5 on 5/8" thick wood, duuhhhhhh????? I went to a #7 and it worked great and cut straight. That and during some long cuts where I don't have to release the blade to reinsert I occ. stop and let off tension, unclamp blade and let it straighten up then retighten clamp and reapply tension. This seems to help because as the blade stretches it loses tension so unclamping/reclamping helps. I finally cut a puzzle that'll stand up and not fall over. My first one did but I cut it out of 1/2" instead of 5/8"

[lucky788scroller]

A #5 should be fine on 5/8 thick.I use a 5 on 3/4 thick hardwoods all the time without problems. One thing that wasnt brought up is the direction you cut. Always cut in the same direction. What I mean is, get in the habit of always having your good piece on the right hand side of the blade, your waste on the left side. It can be described as cutting clockwise/counterclockwise, but that gets people confused, as it depends on if its an outside cut, or an inside cut. Even the smallest variation in your table angle can be noticeable if you cut some parts in one direction, and others the opposite.On something like a puzzle, where there is no waste, it shouldnt be that big of a deal, but for stack sawing (which I do regularly on clocks and such) I ALWAYS ALWAYS cut with my waste to the left side of the blade. I hope that made sense, and didnt confuse you. Dale

[Sawdust King]

And that is why us southpaws never make any large pieces. The waste is always left to us.

I know how to fix that though. Sit behind the saw when I cut.

[Capt Weasel]

I did notice however that my #5 blade has a good bit of flex to it after it is tightened down. I can easily push a 1/16" either way and that is with the tension turned to 4 - 4 1/2 on the 788. I figured that was where my problem was and I didn't get that the #7. I usually start with the tension on 3 1/2 and go up as blade stretches. When I cut a piece of 3/8" oak with the 5 I have no problems, just on the 5/8" poplar. Could it be the blades?

[will8989]

After much, and I mean much, trial & error and blade breakage, I found that anything over 3/4" I just automatically use a #7 blade. Depending on the hardness of the wood and what I'm cutting, I sometimes use a #9. This has saved me much frustration and unfinished pieces!!! I read somewhere, when I first started cutting "The thicker the wood the higher # blade, the faster the speed." As I have a hegner I can adjust tension & speed while cutting. This seems to work 99% of the time for me, the other 1% I just walk away until another time I did find that if I am cutting alot of intricate cuts, I will let my blade "rest" for a minute or so to cool off after a few cuts. I am finding I have much less blade breakage and burning.

Betty