Made My First Cut, Now the Questions!

[DJB]

I spent the last week, at 15-30 minutes that I could squeeze in each evening, aligning my new BT3100-1. Last night I made my first cut. (Yay!) Now I have two questions...

1. How smooth should the face of the cut be? I made a cross-cut in a 1/2" x 2-1/2" board using the SMT. When I feel the cut edge, it is not smooth. Instead, there are "grooves" in arcs that seem to correspond to the travel of the blade. They are not deep, but if you run your finger across the cut edge, you can feel them. Is this typical, or do I have a problem? If a problem, what is my next step?

2. I tried checking the height of the SMT against the height of the fixed table. The back isn't bad, but when I tried checking the front of the SMT, I found that the center groove that the SMT fence clamp slides in is higher than the rest of the SMT surface! If I lay a straight-edge left-to-right across the front half of the SMT, I can rock it. If I push down one side (say, the left), then the other (right) side of the straight edge lifts off the table, roughly 1/6" at the far (right) side of the SMT. Again, is this typical, or do I have a problem? If a problem, what is my next step?

Thanks,
Dave

[scorrpio]

My BT3 cuts are glass-smooth. The citcular grooves are a tell-tale sign that your workpiece 'drifts' during the cut.

It might be:
1. SMT travel is not parallel to blade. You'd need to realign it if that's the case.

2. As you guide the piece through the blade, either miter fence rotates from initial position, or workpiece rotates from fence. If you indeed have a 'ridge' on the SMT, it could result in miter fence not holding in the fixed position. If the ridge is caused by a burr left on the sides of miter fence slot, you might be able to remove it with a few passes with a file.
If it is workpiece rotating from fence, (happens often if workpiece is long), you need to adjust rails/SMT to support workpiece as close to its center as possible.

3. As you make the cut, the workpiece slides against the fence slightly. The proper way of correcting it is to secure the work to SMT (with clamp or hand), and then sliding the SMT. Some people tend to hold the miter fence to their work while they guide the workpiece through the blade, and this results in a bad cut. I personally prefer to secure the workpiece to miter fence with a clamp, and use both hands to slide the table.


P.S. Rotating the work mid-cut almost always causes kickback or burning. If neighter is oserved, the problem is either workpiece sliding against miter fence, or SMT travel being not parallel to blade.

[jlake1998]

setup square cut

Im a new member and it took me quite some time to setup my saw and get square cuts.

I dint know about the cause of the ridges was the miter table moving as scorppio describe. So learned somthing new today.


I went through the smt smt adjustments for several days very carefully and still had problems.

Start with a new square would not be a bad idea or as one person posted a draftsmans square, since everything you cut from here on after will be based upon it.

here is what i finnaly did to see the movement after i had been thought the book.
SAW UNPLUGGED
I got a 1/4" piece of hardboard flooring approx. 15" square, I used a good T-square to insure a perfect corner and mark it (or use the square itself). Placed it against the smt fence pulled to the front of the saw set securely at 90 degrees. Then slid the smt till the board is approx. 3/4" past the front edge of the blade (fully raised) and flush with it. I ensure no teeth are in the way. I now position myself on the left side of the table saw. Proceed to slide the smt holding the hard board firmly in place till the last ¾” edge of the hardboard is left to push past the trailing edge of the blade. (there is there is a 1/16" gap). I do this dozens of times to confirm what I see. It looks as the board walks away evenly as it separates and the gap increases between the board and the blade as i slide the smt toward the rear of the saw. This does not look as there is a angle. I go though the adjustments in the manual several more times.

I finally realize that in using a 15" square of hardboard im looking at 38.5" of travel instead of 10" blade with a square and getting a larger picture of what is happening. 15” before plus 15” after the blade is 30” plus the blade 10” for a total of 40” minus the 1.5” blade overlap front and rear.

I come to the conclusion i am going to have to make some other adjustment.

Now I set the smt so there is exactly 3/4" gap between the rear portion of the main saw and the rear of the smt (measurement within 1/2 inch from rear of main table) (smt just forward of the rear screws). This could be 1 1/16 if you wanted but measure precisely. Now loosen 3 adjustment screws & loosen the rear securing arms. Push the rear portion of the table toward the blade 1/16" and measure for a 11/16” gap (used 3/4 initial measurement. Secure screws and securing arms. Test with hardboard n readjust as necessary. ). If the board walks away when sliding the smt toward the front of the saw, move the smt away from the blade in the adjustment. this seems to be holdin up for me.

Also the last thing mentioned in the setup was the 90 degree smt stop is adjustable, has a eccentric screw setup like the underside of the smt. Why its lastly mentioned im not sure.

I put a straight edge on my smt and where the bolt slides is slighty higher and i can rock the table slighly. This does not seem to be causing any issues with mine.

I did find since i have the later model the blade is from china (early models were from italy i think). works well on plywood, im suprised how smooth the cut edge is. But has trouble cuting 1 1/4 hardwood. I will be getting a frued blade soon.
Hope this helps, Happy cutting

[gmack5]

SMT Adjustment

Here's a "bit" I wrote some time ago, it should still be workable.


EVERYTHING, both fences, the Dual Slot Miter Table (DSMT), and the SMT all reference off of the SAW BLADE.

The first thing to do is make sure you're locking down the SMT to the RAIL correctly. Lock down the FRONT two tabs first, then the BACK two tabs. Once you have the Base of the SMT locked down, you can then check it's parallism to the Saw Blade, using the Jig listed below and a 1 1/2" Cube of Aluminum or Hardwood.

To check the SMT Base, mount the Jig to the side of your Saw Blade with the Probe facing the SMT, attach the Jig such that the Probe is at the operator end and the Sliding table is all the way back. Move the SMT Base so that the edge of it is close or barely touching the end of the Probe. Now, Reverse the position of the Jig such that the Probe is towards the rear of the Saw and the Sliding Table is all the way towards the front of the Saw, towards the operator. The end of the Probe should be the same distance from the SMT Base as it was in the front.

Any difference in the distance would indicate that the SMT Base is NOT parallel to the Blade. Adjust the Base in small increments until it's parallel to the blade, using the adjusting screws that hold it to the rails. Once this is done, you can proceed to adjusting the Sliding Table parallel to the Saw Blade.

OK, lets check to see if the SMT is parallel to the SAW BLADE. (This is what you've been waiting for!)

Move the SMT base a little closer than you had it in the last check for the SMT Base, such that the Probe on the Jig is about an inch or so over the edge of the Sliding Table, towards the front of the Saw.

Place the Block on the Sliding Table, such that one corner of it is just barely brushed when you move the Sliding Table towards the rear. Now reverse the Jig so the Probe is towards the Rear of the Saw, without touching the Block and move the Sliding Table farther back so that the Probe just barely touches the Block (the Block shouldn't move at all). If this condition exsists, then your Sliding Table is Parallel to the Saw Blade and no adjustment is necessary.

If this is NOT the case, then follow the adjustment proceedure below to bring the Sliding Table parallel to the Saw Blade.

There are four screws envolved, a "normal" shoulder screw and three eccentric shoulder screws.

The normal screw is the pivot point and should never require adjustment, since the others use it as a reference point to adjust for parallel and to take the slop out of the SMT, with respect to the base.

The RIGHT FRONT screw is the "normal" screw.

CAUTION: the eccentric screws are a little delicate, so be careful that you don't torque them too hard, as they WILL break off.

To make the SMT Sliding Table run parallel to the saw blade, be sure the LEFT front eccentric screw is "snug", but not tight, to the base, loosen the LEFT REAR eccentric screw and make sure the SMT is good and sloppy (Don't want it to interfere with the effort to bring the SMT parallel)

The Right REAR eccentric screw is used to bring the SMT parallel to the saw blade, adjust it by applying a slight pressure to the RIGHT side of the SMT as you adjust for parallel by rotating the RIGHT REAR screw.
Once you're sure you're parallel to the saw blade, lock down the eccentric screw by keeping it in it's rotational position with a screw driver (I find that an offset screw driver works very well for this) from the bottom as you snug up the nut on the top side of the screw.

NOW take the slop out of the REAR end of the SMT by rotating the LEFT REAR eccentric screw, until the SMT is snug, but not tight, you should be able to push the SMT towards the back with very little effort, in other words, it should "glide" smoothly, with very little or no side to side play. Now snug up the Left Front Eccentric Screw, if needed.

Be sure you hold the screw in position with a screw driver to keep the screw from rotating as you tighten the nut on the top of the screw.

Your SMT should now glide parallel to the saw blade!

Your Miter Fence, while not directly envolved in the adjustment, needs to be adjusted also. This is accomplished by adjusting the "Quick Stop", located on the Left side of the SMT, about mid-way down the side.

Adjust your "Quick Stop" (the little tab that swings up on the left edge of the SMT) so that it brings your MITER FENCE square to the blade (it's also an eccentric screw) when you gently swing the miter fence up against it.

You can also check your Rip Fence with the same Jig by mounting the Jig with the Probe towards the Rip fence, just barely touching it. Now reverse the Jig with the Probe at the back of the Saw, if the Rip Fence is the same distance from the Probe as it was with the Probe near the front of the Saw, then it's parallel, if not, there are two Screws near the front of the Saw on top of the Rip Fence that are used to adjust the Rip Fence Parallel to the Saw Blade. I would only loosen ONE of them at a time, using the other one as a pivot when aligning the Rip Fence.

One other thing to be considered.... The Clamp for the Miter Fence consists of a 5/16-18 bolt that passes thru a plastic bracket that provides the clamping pressure to hold the Miter Fence in whatever position you put it. The hex head on the clamping bolt rides IN a grove on the bottom of the SMT. The groove is sized in such a way that it prevents the bolt's turning as you tighten the knob on top of the bracket.

If the Clamping Bolt is properly installed (head in the groove) there is no way that it could deform the Sliding Miter Table, since it merely clamps a piece of Aluminum (the SMT Sliding Table) between the Miter Fence and the Hex Head of the bolt. If you put a washer under the clamping bolt (on the bottom) in an effort to straddle the sides of the groove that it was designed to ride in, it might deform the SMT when pressure is applied by clamping the Miter Fence with the Clamping Bolt improperly installed.

NOTE: The washer that's supplied as a part of the Miter Fence Clamping Assembly goes on TOP of the plastic Clamping Bracket under the Clamping Knob (it's there to keep the Knob from binding on the Plastic Clamping Bracket when tightened).

That should do it!

You should be good to go!

[gjat]

Thanks gmack!
As a rule, I like to think I'm pretty handy around tools and can read directions, but I have to admit, when I set up my saw, I printed out your little spiel and referenced it a few times. Don't get all cocky and stuff, but I printed out the above too.

[BasementDweller]

1. How smooth should the face of the cut be? I made a cross-cut in a 1/2" x 2-1/2" board using the SMT. When I feel the cut edge, it is not smooth. Instead, there are "grooves" in arcs that seem to correspond to the travel of the blade. They are not deep, but if you run your finger across the cut edge, you can feel them. Is this typical, or do I have a problem? If a problem, what is my next step?

DJB,

I've faught the same problem since day one. This is my biggest headache with the saw. I was actually just working on this again today. I after some work I noticed that I only have this problem when ripping. So I tend to agree with the poster that said it has to do with the wood traveling back across the blade. I swear I can even hear, at the end of my cut, the back of the blade cutting the wood again on the "up stroke" is that supposed to happen? And even if it does, shouldn't it be just as smooth as the "down stroke" from the front of the blade?!?

Sorry I can't be of more help! Perhaps try ripping something and see if you have the same problem on the rip. If you have it both places could the blade be warped or something?

[Khany]

Just want to add a little bit of what I learned since I bought this thing. First, I followed the instructions to set up the saw. Then I made test cuts. When ripping if the test board have saw marks at the rear end but not at the front, then I adjust the rear of the fence away fron the blade a little at a time until I have no saw marks. Same method with adjustting the SMT. When checking the blade for perpendicularlism to surface, I cut the test board at a steep angle. If the cut edge is perpendicular to the top and bottom edge of the board, then the blade is perpendicular to the base. If not, I just adjust the blade until the test cut is good. Another thing, if you find too much resistance
as you push the board, most likely the blade guard split is in the way. Adjust the blade guard split by replacing the base shims so that it does not excessively press the board against the fence.


The thing is: I can't really depend wholy on the instructions in the manual to tune the saw. There are too many factors that affect the outcome of the cut. The instructions only get you to the close proximity of a properly tuned saw. What matters is how the cuts come out. My way is: adjusting the fence, SMT, or whatever after each test cut to get to where I want the saw to perform.


khanh

[DJB]

I'm not ignoring everybody---I had to take a business trip. I'll try the suggestions for alignment when I get home. Thanks!

I think I'll also give Ryobi a call about the non-flat SMT.

Dave