Squareness of MFT when taking off and reattaching hardware

[ear3]

This has happened a couple of times now, but when I unmount the support brackets and protractor to move the table to a new location, and then put them back on (placing them back in the exact same position using the stops), I've noticed the assembly to be slightly out of square -- and so I have to realign it.  It's not a big deal -- I tend now to keep everything attached if I'm only moving it a small distance.  I'm just wondering where the imprecision might be coming from -- I've notice the brackets can rock a little as they're sliding down, and the rail may skew at a slightly sharper (or softer) angle depending on how you tighten the nut attaching it to the bracket.  But the theoretically, it should be all about the position of the brackets and the fence.  Anyone else experienced this issue?

 

[roblg3]

If the rail is loosened, squaring is necessary.  I wouldn't call this an issue.  EXACT square will change on the table if you place a very heavy object on the table, shim a leg, or most likely if you bumped it hard enough to move it from the spot where it was resting.  The lightness of the table makes it portable and easier to knock out of square.

 

[ear3]

Thanks.  So it is the rail then.  I wasn't concerned so much as curious about which of the components was creating the imprecision.

If the rail is loosened, squaring is necessary.  I wouldn't call this an issue.  EXACT square will change on the table if you place a very heavy object on the table, shim a leg, or most likely if you bumped it hard enough to move it from the spot where it was resting.  The lightness of the table makes it portable and easier to knock out of square.

 

[ck1]

I would never expect my mft to be square after moving and resetting.  Indeed I check squareness a couple times a day.  I also check the gibs on my 75 plunge saw frequently.  Any sloppiness will ruin the splinter guard.

 

[SoonerFan]

I would never expect my mft to be square after moving and resetting.  Indeed I check squareness a couple times a day.  I also check the gibs on my 75 plunge saw frequently.  Any sloppiness will ruin the splinter guard.

Same here.  I check with a Wookpecker square every so often to be sure it is exact.  Never had an issue unless I takedown and setup MFT/3.

BTW, Welcome to FOG!

 

[ck1]

The most accurate way to square your saw is as follows: you need a board as wide as your saw will cut:  mft, 24", kapex, 12" and about 4"; with one straight edge.  I rip and rerip my test pieces.  Crosscut one end of the board then flip the board, keeping the same edge against the fence and cut the other end.  Measure fence end and non fence end.  A difference of 1/16" tells you the cut is 1/32" out of square.  The 4" board is to check the Kapex bevel angle.  My favorite board material is 1/8" masonite. 

 

[Tinker]

Using dogs, I set the fence along a row of holes.  If the fence is not parallel to the MFT holes, all else will become problematic.  Once I am certain the fence is properly set, then I square the rail to the fence.  Using dogs again, the rail should be parallel to a row of MFT holes 90º to the fence.  If the fence was set up properly, a large square will get your rail parallel to to the other row of holes. 

If all you are cutting is 90º cuts, then a good square fr alignment is all that is necessary and it makes no difference if the fence is properly aligned. 

If you are trying to make 45º cuts, then it is very important that both fence and rail are in proper, and 90º alignment.
Tinker

 

[Sparktrician]

Using dogs, I set the fence along a row of holes.  If the fence is not parallel to the MFT holes, all else will become problematic.  Once I am certain the fence is properly set, then I square the rail to the fence.  Using dogs again, the rail should be parallel to a row of MFT holes 90º to the fence.  If the fence was set up properly, a large square will get your rail parallel to to the other row of holes. 

If all you are cutting is 90º cuts, then a good square fr alignment is all that is necessary and it makes no difference if the fence is properly aligned. 

If you are trying to make 45º cuts, then it is very important that both fence and rail are in proper, and 90º alignment.
Tinker

I'm with Tinker on this.  The dogs have become my best friends when aligning the fence to the MFT top, and subsequently when aligning the rail to the fence.  I'm fortunate to have the Woodpeckers 450mm Precision Carpenter's Triangle just for this purpose. 

 

[Tinker]

With 3 MFT's, i have the fences for each one.  I also have a 12" carpenter's triangle square.  With the fence I am using, i still have two others.  I set the fence to xact parallel.  Then, using the 12" triangle, and the shortest of the left over fences, I square the rail. 
Tinker

 

[ear3]

I prefer the dogs to the triangle, but even with those there is still potential for small error, because it is possible to have both ends of the fence touching the dogs, yet have one side exerting more pressure and thus go out of alignment once you back it off.  My favorite method now, since I have a 32" T-Square that I trust, is to use a scrap board the width of the table (with one straight edge against the fence) and match the rail to the line on the board.  Even if there are a couple of pieces of the splinter guard chewed out, you can immediately tell if it's squared because the line runs the entire length of the rail.

 

[rst]

I made gauge blocks to reset my fences using the dogs, two for the rail and two for the fence.  Mine are such that the saw kerf falls between the dog holes.  I made these using a digital micrometer to ensure accuracy.