FS WA out of square
- Thread starter LiranB
- Start date
mino
Member
FS-WA is always "out of square". The notches are only orientational.
When you need precision, you need to calibrate it always when you change the set angle.
There are two basic approaches:
A) calibrate the square itself - more convenient
B) calibrate the set of a square connected to a (specific) rail - more accurate
procedures in short
A) you need a reference machinst square that fits with the square (high precision one, generic ones are not precise-enough, needs DIN Class 1 or better/equivalent), calibrate the square and there you go
B1) you do not need any devices, just some sheet of ply, MDF etc.
- set the square to the 90 degree notch and make a cut using the square+rail set though the middle of a reasonably big sheet (3'x3' at least
- flip the off-cut over the cut piece and align the reference edges so they are aligned )using 3rd sheet good piece
- check for any in accuracy (note: the difference you will see will be *twice* the adjustment to do in next step
- put the off-cut BACK where it was, but put both pieces right pushed to each other, the cut line being the "joining" surface of the pieces
- place the rail as if you were to re-cut the cut and clamp the cut-piece and the off-cut so it does not move, do NOT clamp the square or the rail
- place the square as if tyou were doing a cut, release the knob and adjust the position of the rail - reflecting the adjustment needed you have from earlier check step, once adjusted tighten the knob
- take the square/rail set away from the piece and place it there once more the same way you would if making a fresh cut
- make a cut along the "already-cut" line, effectively re-doing the cut, ruight through the middle of the old one
- repeat the check and the calibration adjustment as/if needed once more
Using above I am able to get within 0.2mm/m (0.01"/4') accuracy on my setup which is just about as good as the reference edge can provide for cross-cuts.
B2) Requires a big engineer's square - like 3'x2' big which usually go for $200 or so, this allows you to calibrate the whole rail-square asssembly against it, avoiding the multiple cuts method but also a bit out-of-reach for a hobbyist.
Lastly, you will want to validate your overall accuracy using the 5-cut method.
Apologies but no videos.
When you need precision, you need to calibrate it always when you change the set angle.
There are two basic approaches:
A) calibrate the square itself - more convenient
B) calibrate the set of a square connected to a (specific) rail - more accurate
procedures in short
A) you need a reference machinst square that fits with the square (high precision one, generic ones are not precise-enough, needs DIN Class 1 or better/equivalent), calibrate the square and there you go
B1) you do not need any devices, just some sheet of ply, MDF etc.
- set the square to the 90 degree notch and make a cut using the square+rail set though the middle of a reasonably big sheet (3'x3' at least
- flip the off-cut over the cut piece and align the reference edges so they are aligned )using 3rd sheet good piece
- check for any in accuracy (note: the difference you will see will be *twice* the adjustment to do in next step
- put the off-cut BACK where it was, but put both pieces right pushed to each other, the cut line being the "joining" surface of the pieces
- place the rail as if you were to re-cut the cut and clamp the cut-piece and the off-cut so it does not move, do NOT clamp the square or the rail
- place the square as if tyou were doing a cut, release the knob and adjust the position of the rail - reflecting the adjustment needed you have from earlier check step, once adjusted tighten the knob
- take the square/rail set away from the piece and place it there once more the same way you would if making a fresh cut
- make a cut along the "already-cut" line, effectively re-doing the cut, ruight through the middle of the old one
- repeat the check and the calibration adjustment as/if needed once more
Using above I am able to get within 0.2mm/m (0.01"/4') accuracy on my setup which is just about as good as the reference edge can provide for cross-cuts.
B2) Requires a big engineer's square - like 3'x2' big which usually go for $200 or so, this allows you to calibrate the whole rail-square asssembly against it, avoiding the multiple cuts method but also a bit out-of-reach for a hobbyist.
Lastly, you will want to validate your overall accuracy using the 5-cut method.
Apologies but no videos.
