My final attempt at setting up the BT3100 and some final thoughts

[sailor55330]

First off, I want to start by thanking everyone who took the time to respond to my questions and who offered advice, opinions and help.

After spending a collective 14-16 hours in trying to align my SMT on my new to me BT3100, I have been unable to reach an acceptable alignment. After replacing parts, leveling the saw and stand, cleaning, following mulitple procedures and methods, I am at my wits end. The closest I was able to come to alignment was between 6 and 7/1000's on the SMT base. I have used 3 different blades and measured the runout at 4/1000ths. As someone stated, that is roughly 1/200th of an inch. Upon reaching that, I was unable to align the miter gauge to 90 while using an acryllic drafting square. I followed the procedures to the exact letter. The eccentrics simply didn't allow for enough adjustment to bring the table top into parallel. Adjusting and re-adjusting each eccentric (all were new along with the slides) did not fix this. I have yet to be able to acheive a 90 degree cut over a 12 inch span. I know I have done everything correctly and have finally come to the conclusion that there must be something with this particular saw. I have even read on here that a select few of the 3100's produced were simply out of alignment from the factory. Many of you have excellent success in alignment and have great works to show for it. I have not been so fortunate.

At this point in time, I have decided that this is not the right saw for me. I am going to try and sell the saw. Hopefully someone will have better success with it than I did.

Again, thank you all and best of luck and be safe in the shop.

[phi1l]

you know that there is about 1/8" play in the bolt that holds down the miter fence. you have to be very careful when tightening it down, or it will shift.

[Brian G]

I have yet to be able to acheive a 90 degree cut over a 12 inch span.

In which direction is the cut out of square? By that, I mean, is it out of square going into the cut (leading edge) or out of the cut (trailing edge)?

I fussed and fussed until I realized that the stock was drifting away from the blade as I passed the stock through the blade. This caused a slight out of square cut where the leading edge had a heavier cut than the trailing edge.

No matter how firm I thought I was holding the stock against the fence, I'd get an out of square cut because the stock would push slightly away from the blade.

I affixed some adhesive-backed sandpaper to the face of the SMT fence and the problem went away. A stop block clamped to the fence works, too.

[sailor55330]

Brian,

The corner of 2 freshly cut sides are at 90, but the farther away from the corner, the farther out it gets, which would make it the trailing edge of the cut if I am interpreting your post correctly. The gap at 10 inches was nearly 1/16th of an inch.

[Black wallnut]

If your base is .007 out of parallel there is no way for the eccentrics to compensate. The base must be parallel for the SMT table to run parallel. Only one of the eccentrics is for adjustment, the other two are for slop removal.

That said I'm not sure .007" is a deal breaker but if you've lost confidence in the saw then you may be better served with something different.

[LinuxRandal]

At this point in time, I have decided that this is not the right saw for me. I am going to try and sell the saw. Hopefully someone will have better success with it than I did.

Again, thank you all and best of luck and be safe in the shop.

The way I read that, you think this forum is ONLY for people with that saw. If my impression is correct, know that it isn't (only for people with that saw).

No matter what, please stick around! Find a saw YOUR happy with, and to location with anyone else's opinion.

[sailor55330]

I have followed every piece of advice given to me to the letter. I have performed every alignment procedure that I could find in the manual and most that I have read on here. I honestly can't believe that every single BT3X owner out there has taken the measures that I have. I have aligned this saw to .007 with a dial gauge. I was able to achieve this only after countless attempts. I read accounts on this site of people aligning the saws with nothing more than a block of wood. It's very hard to believe that anyone can be more accurate with that method.

Why is it so hard for you to accept that there may be something wrong with the saw instead of user error?

[herb fellows]

'Why is it so hard for you to accept that there may be something wrong with the saw instead of user error?'

I think you're taking it the wrong way. I'm sure you are beyond frustrated at this point, but virtually everyone here has had a 'Homer Simpson' moment with many tools, not just this saw. Not to say that it couldn't be the saw, just that we have all on occasion gone to what we thought was the max, and then a light suddenly goes on. People are just trying to help you.
Where are you located? Maybe someone with serious experience with this saw is nearby and could possibly lend a hand or give it a look? Just a thought.

[Uncle Cracker]

If my car has a bad wheel, I don't buy a new car. Perhaps you can find another SMT at reasonable cost. Otherwise, you're just throwin' the baby out with the bathwater. And it will be hard to recoup your investment if you are honest with prospective buyers about not being able to get it zeroed in.

[pecker]

I thought that the clamps that hold the SMT base to the rails can be loosened and adjusted to get the base parallel first, before adjusting the SMT sliding portion.

I don't see any mention of this being done first. Did you?

[Eric]

I was never happy with the SMT on my BT3100. Never got very good results with it, so I never used it. I'd use the miter slots with a home made miter gauge with better results, or use my CMS.

I know a lot of people have had good luck with the SMT, but I sure wasn't one of them, I do like the idea of it though.

[cgallery]

I was never happy with the SMT on my BT3100. Never got very good results with it, so I never used it. I'd use the miter slots with a home made miter gauge with better results, or use my CMS.

I know a lot of people have had good luck with the SMT, but I sure wasn't one of them, I do like the idea of it though.

+1.

Instead of selling the saw, consider building a miter extension of your own.

Here is mine:

http://www.bt3central.com/showthread.php?t=26598

It it 30" long (extends past the front of the saw just like the SMT. This actually makes the surface 3" deeper than a Unisaw.

This way I can easily support/cut 24" deep panels.

I can't easily move my fence to the left of the blade because of interference, but I never need to do that.

I know it sounds nuts, but I wouldn't trade my setup for a brand-new Unisaw.

[Sawatzky]

I also never had much luck with the SMT. I think the parts that make it up are just too weak (soft aluminum and plastic slides). I could also never keep the miter bar set, as it always wanted to move. The idea was good, I just hated fussing with it, and never trusting it. My saw now has miter slots, and I built a miter sled. It works great. If possible, try to add a miter slot and build a miter sled. You will be much happier.

[dbhost]

I guess I got lucky. My SMT runs .003 which is plenty accurate for what I am doing. But honestly, I mostly use it from crosscutting, for dead on painfully accurate miters, I use the miter saw... However I have crosscut 16" wide projects (LOML's Christmas cutting board) and checked square with known accurate engineers squares, both mine, and a square from a friend of mine that is a completely OCD engineer type... Dead on square...

I wish I could give you some pointers on adjusting the SMT, but I just haven't needed to yet. Hopefully when I get to that point, I won't have the nightmares you have.

[sailor55330]

Once again, thank you all for the input.

I messed with the saw again today (another 2 hours) and was able to "tweak" the SMT base to within .003" (to put this in perspective, a sheet of copy paper is .00318 on average so we are techinically talking a difference of less than a sheet of paper) I was able to pull the miter gauge within square using an acrylic drafting square. I then glued sandpaper to the fence, added a stop block, clamped down my work and made 12" cuts off of the factory milled side of the MDF, which I verified as straight with 2 different known straight edges. Now, please tell me if you agree, but this should remove 99% of the alignment and 99% of operator error. Also, I have measured and calculated the run out (blade + arbor) at .004" The blade is a brand new 40t carbide

The cuts are still running out between 1/16 and 1/8 over approximately 12 inches. I have taken every step here to eliminate any variables. It does not seem logical or possible that a .003" variance would account for 1/16 of an inch over 12 inches. 1/8th of an inch is equal to .125". My alignment is .003. That means in 12 inches, the gap is expanding by a factor of 41 if my math is correct (.125//003). How can that be?

My next step is to offer a plane ticket to anyone who thinks they can align this saw better. The caveat is that if you fail, you owe me the price of the ticket plus a steak dinner