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Best Method for Cut / But First a Rant

Posted: Tue Dec 18, 2012 9:43 am
by mrhart
I was using the table saw and it does frustrate me. Of all the features of the SS, I like this one the least, unless I am working with a quick small cut here or there. I have the 520 set up and I have all my tables on, fresh coat of wax, I've sqaured things up as best as I can with the tools I have. I tried making a few cuts with my miter square and the slop side to side in the miter track makes my cuts out of square. So I bolted on my little extension, that makes it worse. I tried to find something "flat" to stretch across all my tables to make sure I have a flat surface, I swear none of the tables are flat to the next even with the extension bars through them. I don't like the little legs that twist, I'm on my knees then back up to check for level, then back on my knees, then to the other side...and then God forbid if I need to change the blade height. Not to mention the fence issues, which from a previous post, I have better than it was but I'm going to have to order new rubber pad thingys to try and grab the rail better. If I don't reef down on the lower handle hard-it moves. (I've tried adjusting it to a "sweet spot" but that doen't exist.

I guess whats frustrating is I have things to get done for others (xmas) and my time in the shop is limlited, so I don't want all this squareness and frustraton time, I just want to produce with nice results. When I finally make it to the garage, I want to work with wood, not always adjust, align, check ect. I may be one of those folks who end up with a dedicated table saw..:eek: oops..I said it..it slipped out..forgive me all.:o

Please give me your best method for the following cut(s) in the table saw mode. I want them to be square, but also cut safely.
Have 3/4" thick hardwood 5-1/2" wide, 12" long. Need to cut 1-3/4" strips from that, there will be 3, with a thin piece of scrap.
The last time I did this I cut between the fence and the blade with the SS pushstick. I think last time I finally took the bladeguard off because it was tight and my work hangs up sometimes.

Every time I go into Woodcraft for something, I walk by the fancy dancy table saws and lock the fence or slide the miter up and down. They seem so tight and solid. I have no funds for such an advancement or the room really for that matter, but it is frustrating. I like my SS and SPTs but the #-*>"! table saw makes me cranky. :mad:

Posted: Tue Dec 18, 2012 10:30 am
by dusty
I think that your frustrations are likely exacerbated by the time crunch.

When working with pieces the size that you mention here, the slop in the miter track should not create enough of a deviation in squareness to make a noticeable difference.

However, what you really need is a good cross cut sled. I would suggest a sled about 48" wide and 36" deep. A sled with two well fitting runners will eliminate the effects of the miter slop. Once aligned, the sled is a very stable and accurate work surface.

In lieu of a sled, consider a miter gauge with a miter bar that is adjustable. The Incra V120 for Shopsmith immediately comes to mind. The V120 miter bar is adjustable and you can eliminate the miter bar slop completely.

Another thought is to use two standard Shopsmith miter gauges with a fence between the two of them.

Posted: Tue Dec 18, 2012 10:36 am
by dusty
Oops!

I reread your original post. Miter gauges won't help you to cut those narrow strips at all.

Those strips are wide enough, however, that cutting them between the fence and the blade should not be a problem or a hazard.

Set up using a feather board to keep the stock firmly against the fence. Make sure that you push the materials all the way through the cut. Don't reach over the blade to rescue the cut off. To rescue the cutoffs from the floor, ermploy either a helper to catch them or use your outfeed table. You do have an outfeed table right.

Posted: Tue Dec 18, 2012 2:50 pm
by JPG
I am struggling to understand the out of square results from a sloppy miter gauge bar.

A slop of 0.010" introduces an angle error of less than than 0.032 degrees.

Is there perhaps something else affecting the angle?:confused:

Is the miter gauge 'pivot' loose allowing angular variation?

Posted: Tue Dec 18, 2012 9:21 pm
by charlese
mrhart wrote:...Please give me your best method for the following cut(s) in the table saw mode. I want them to be square, but also cut safely.
Have 3/4" thick hardwood 5-1/2" wide, 12" long. Need to cut 1-3/4" strips from that, there will be 3, with a thin piece of scrap.
The last time I did this I cut between the fence and the blade with the SS pushstick. I think last time I finally took the bladeguard off because it was tight and my work hangs up sometimes.
...

Hello my friend! Let's not talk of the miter guage now - just answer your question of making 3/4"x3/4"x12" strips.

First check to see if your main table is perpendicular to the blade. After that check, set your rip fence 3/4" + away from the saw blade. (I would set the fence about 1/16" greater than 3/4" so I can plane down the extra width.)

Now install your upper saw guard and a feather board in front of the saw blade to push the board into the fence. Using a fence straddling push block go on with the ripping. You will need to adjust your feather board each cut.

Posted: Wed Dec 19, 2012 10:17 am
by mrhart
Thank you all for your help.
As with the miter gage, it appears the factory scrw has been replaced with another and it doesn't stay very tight, as I tightened it not long ago. That was a piece of the puzzle. Afterwards, the miter bar does have a little slop and I'd love to tighten it up if anyone has some tips. If I look at the tip of it farthest from me it does wiggle back and forth more than I would think it should. There is a second hole on the miter bar, is there supposed to be a second screw and wheel on the bottom?
As far as the cut. I did them last night. I used the SS crosscut sled with a stop block to make sure the length of all my pieces were the same. (that miter bar has a little slop too-this must be normal) Then I positioned the fence and used the hand held push stick to run my work through (forgot about the straddling block).
The next issue became the riving knife. It isn't centered directly behind the blade and was tweaking the wood slightly out of square if I didn't apply pressure to keep it straight or tight to the fence. I took it apart and tried to align it better. Do these need to be shimmed maybe with a thin washer?? I also found the riving knife to have some burs on it from the PO where he must of made conattc with the blade. Sanded and smoothed that up a bit.
I don't have any fancy measuring tools as of yet, but my cuts were coming out pretty uniform.
As far as my instuments and my eyes can tell, my fence is square with the blade. However, the waste (left) side of the pieces I ran through look nice and no burn marks. The 1 3/4" pieces that were between the blade and the fence all have burn marks to some degree, some worse that others. Also on some there are marks almost like bandsaw cutting would leave and those burn marks kind of correspond. I will take pics tonight.
My uneducated thoughts were that there may be a problem with either the fence stll not square to the blade or something wrong with the blade itself. (can't see anything). Remember my little plywood kickback last week (different thread) Is it possible I damaged my new blade?

Everthing is disk sandable so my projects moved forward.

Posted: Wed Dec 19, 2012 10:43 am
by dusty
You are working with hardwood so there is a bit more heat generated than would be otherwise. However, the burn marks are very likely located right where you hesitated as you were feeding the wood into the blade. If the wood stops moving during a cut, you are very apt to get burn marks.

Slow and steady with no hesitations = less chance for burn marks (unless you are cutting cherry and for that I have nothing to offer).

Posted: Wed Dec 19, 2012 2:57 pm
by JPG
Methinks the exit end of the fence is closer to the blade than the feed end.

With a good short(but 'tall')square piece of wood against the fence, make a shallow cut. Stop the blade. While keeping the 'fence' edge of the piece facing the fence, move it to the back side of the blade. Push the piece into the blade and note where the blade comes into contact with the previous kerf. Manually rotate the blade(from the other shafts). Any front rear difference should be apparent.

This is easier to do than explain.

If the piece is only slightly fed into the blade with the blade fully exposed(front nearer to the front end of the fence), and the face that was flat against the table is facing the blade after it is moved to the rear will provide the max indication of fence 'runout' since the test points on the fence will be further apart.

You have determined the miter slots are parallel to the blade? If so the slots will align with the fence if the fence is correct.

That kick back incident is also an indication of fence squeeze at the exit side.

Posted: Wed Dec 19, 2012 3:43 pm
by fjimp
If one is having issues with a screw not staying tight, perhaps locktite is an option. Jim

Posted: Wed Dec 19, 2012 7:57 pm
by charlese
Hi Again! The proper screw that goes into the miter guage bar is a tapered screw. The farther in the more the bar spreads. This screw should be advanced far enough to make the bar rub - but slide easily - through the miter slot. If wanted you can tighten the screw enough to tightly hold the miter guage in the slot. This is used for vertical drilling.

Since you are seeing burning on the rip fence side of your cut pieces - that means the fence is closer to the rear of the blade than the front. You can fix this is two ways. The best way is to align the main table to the blade so the miter slots are parallel with the blade. There are 4 bolts that hold the main table in place and they can become mis adjusted with rough handling. Doing this alignment is somewhat chore-some. Loosen all four screws and rotate the table until the slot is parallel to the blade. From here you can barely snug the two front nuts. Now tilt the table and snug the back nuts. If not parallel to the blade, you can rotate the table a bit to make it so. Once aligned, you can finish tightening the nuts.

One method of making the slots and blade parallel is to mount a long allen wrench in the miter guage and slide it to touch one tooth of the blade. mark that blade and rotate the saw until that same blade can be touched by the same mounted wrench. There is a hole through the miter guage that you can slide the wrench and there are set screws in the top of the guage to tighten the wrench in place. Once the table is aligned, you can test the rip fence and check if it is also parallel to the blade.

To answer you concern about the riving knife - there is a screw near the bottom of the upper saw guard mounting hole that can be adjusted to align the riving knife.

once aligned, you will probably not have any more such problems.