Can someone help me explain what’s going on with my tablesaw?
I own a Delta contractor tablesaw and have noticed that it always seems to produce a slight concave edge to the boards. My first thought was perhaps the first edge was slightly convex so when I ran the board through the saw, the other edge would be slightly concave. However, I recently created a sled that rides in the miter slots to cut straight edges on the first board edge. When I flip the board over and run it through the tablesaw blade, I still notice a slight concave edge to the board. This curve is especially noticeable on long boards, such as the 6-8′ boards I recently ran through the tablesaw.
When I’m cutting the board, I’ve always noticed that the board tends to want to move away from the back of the fence and into the backedge of the blade, which is where the concavity of the cut edge is coming from I’m sure. However, I can’t understand for the life of me why the board wants to wander away from the back of the fence. I’ve added a featherboard to push on the wood just ahead of the blade, to no avail. I’ve adjusted the fence parallel with the right miter slot. I’ve adjusted the blade parallel to the left miter slot – but I don’t have a dial guage so I attached a board to the miter guage, cut it, and listened for how the blade hit the board and adjusted the trunions. Is a wandering board a sign that the blade still needs better adjustment? Is this a sign my miter slots are out of alignment (I’ve got a sled that rides just fine in both slots without binding so I don’t believe this is an issue). Something with my blade, my technique? I’m at a a loss….
Any ideas to help my boards from wandering would be appreciated. Thank you!
-Mark
Replies
Do you have a splitter installed?
PlaneWood by Mike_in_Katy
PlaneWood
Yes, I forgot to mention that I do have a splitter installed. Without the splitter, the wood will sometimes wander way off the fence after the cut, leaving a gap of probably 1/16" between the wood and the fence. The splitter does help minimize the problem, but it doesn't solve it.
-Mark
Tune up of the table saw is a critical item.
I would start by by checking that the center line of the saw arbor is EXACTLY 90 degrees to the edge of the saw slot.The saws I am familiar with have enough slop in the bolts that hold the table to the base to allow this adjustment.Next the face of the fence must be parallel to the table slots and to the line of cut of the saw blade.
Some advise that the fence alignment be a little open on the outfeed side of the blade.I consider a splitter essential.I made a special splitter from polycarbonate.The thickness is slightly thinner than the width of the saw kerf. I have it adjusted to just touch the edge of the kerf on the side next to the fence. There is just enough spring in the plastic splitter to hold the work tight against the fence.
I edge glue joints for the panels for blanket chests ditect from the saw. The material is red cedar. The sawn joint is much better than one from the jointer due to the absence of pulled out knots and rough snearly grain.¬¬¬¬¬¬¬PAT¬¬¬¬¬¬¬¬
Does it do the same thing with a different blade?
PlaneWood by Mike_in_KatyPlaneWood
Unfortunately I only own one blade - a 40 tooth combination blade - so I really don't know. Perhaps I need to spend the money on a new blade and experiment....
-Mark
I had this same problem when I bought a CHEAP blade for cutting some scraps of stuff - didn't want to use the "good" blade.
When I put the good blade back on, the problem went away.
Jamie
MM, your rip fence is way out of line with the blade. Specifically, it's toeing out at the back, in a big way. Fix that and your problem will disappear. How that relates to the mitre gauge slots is neither here nor there when it comes to ripping.
Now I'll wait for the 'toeing out' advocates to advance their case, non existent as it is-- ha, ha. Slainte.
I'll have to try toeing the fence in again. I'm sure I tried that once before but then the wood seemed to compress against the rear of the saw blade, bogging it down and burning the wood. Perhaps I toe'd it in too much?
I'll try it again later today and see what happens.
-Mark
Try this.
Use a square to set your miter at 90 degrees to the blade. Get a 6" wide scrap board and mark a 90 degree line on it. Clamp the board onto your miter with a long reach clamp with the blade alligned to the line. Slowly push the board thru and see if the blade tracks exactly on the line. If it doesn't then there are two things wrong. 1) bad blade, or, 2) the blade is not alligned with the miter slot.
1) or 2) could cause the problem u describe when using the fence. If you can get 1) and/or 2) cured, then you know it's got to be the fence.
Also check for blade wobble. An easy way to check this is to cut a slot in a piece of hardwood and measure the width difference of the kerf using 0.001" brass shim stock. Some blades wobble only when running at speed. Small amounts of wobble can be corrected with blades shims. Wobble can sometimes be caused by the shaft arbor, but is not usually the case.
Also, blades can be sharpened incorrectly causing them to drift. Dulling on one side of the teeth moreso than the other can cause the problem too.
PlaneWood by Mike_in_KatyPlaneWood
I'll try to reset my blade and miter guage. I've noticed that when I go to tighten up the trunnion to the tabletop after squaring the blade to the miter guage, the top twists just a bit, enough to throw it off. Perhaps I didn't get it right last time. Perhaps it's time for me to get a dial caliper.
Regarding the blade, maybe I'll take it in to get it sharpened and see if that makes any difference. It's a nice pricey blade (can't recall the brand name now) and I think it's always done this, so perhaps it was just missharpened from the shop.
-Mark
Mike,
My two cents for whatever it's worth: does your saw also do this when cutting sheet goods (mdf, plywood, etc)? Sometimes when ripping down the middle of a wide board, tension in the wood is released, resulting in not just a concave surface on the cut edge, but a bow in the whole thing. Test it on plywood first, which is unlikely to cause this problem, before assuming it's a problem with the saw. (You probably already knew this, but maybe some didn't.) GP
Thanks for the reminder. It doesn't seem to cut the arc with sheet stock, and I've run enough boards through to tell when pressure is being released in the cut and this isn't the problem.
I'll keep experimenting....
-Mark
Some great input here everyone! Above and beyond I can add that a nice trick to do in adjusting your fence is run your stock test piece and then take a pencil and lightly shade the side of your cut edge. Often times you will see an XXXX pattern on your cut edge and that would suggest a toeing or drag of some kind.
Wax up your saw table top and eliminate any drag from that surface. Then parallel your blade to the fence with adjustments either way the shaded marks suggest. The type of blades you are using counts big time also. Believe it or not, steel blades work much better on wood then carbide one's in some cases. You say you have a Delta, is it the uni-fence? Unless your arbor isn't bent you should be able to adjust it out from this stand point also using the allen wrench set screws.
Feather boards and power feeds set up on the table saw bring about uniform and safe cutting techniques but in hardwoods, unless machined beforehand, expect a lot of movement. The chart link I saw was GREAT! Unless you want to hand pick your lumber go with these waste percentages and more then charge it to your jobs automatically.
Edited 1/9/2003 7:42:47 PM ET by protagora
Protagora,
What links are you refering to about the amount of waste to expect when cutting projects? I'd love to see them and help incorporate the figures into my estimates.
-Mark
MM
One thing I have not seen mentioned yet, Is the fence straight? You can set up the fence so the distance from a mitre slot is exactly the same at the front of the table as it is at the back and if the fence is bent this distance would be different at the middle of the fence. If the distance is less this would make the stock appear to be moving away from the fence at the rear. If bent the other way it would crowd the stock into the rear of the fence. The section of fence from the front of the table to the front of the blade is what determines how the stock is being presented to the blade. Think of the short fence concept. If the fence is bowed with the high spot toward the blade it can be adjusted to work. If bowed the other way it will always crowd the stock into the rear of the blade causing problems the greatest of which is kickback. I will leave it to you how to go about checking this as there are many methods depending on what equiptment you have available, any where from a stick with a nail in it to dial indicators. Good luck with it.
RichThe Professional Termite
http://www.woodbin.com/docs/reviews/cutlistplus.htm
I had a Delta Contractor saw I bought 5 years ago new. I didn't have the particular problem you are having but I did have a problem aligning the blade with the mitre slot. It wouldn't' stay aligned, there was some problem with the trunions. Delta worked with me for over 2 years trying to fix the problem, they ended up buying the saw back. Check and be sure that setting hasn't changed. I would line mine up as perfect as I could and make a few cuts and it would be out again, very frustrating.
Have you tried calling Delta? They worked very well with me trying resolve the problem.
God Bless and Good Luck
les
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