Weird tracksaw precision

[Holmes Anderson]

I don't think the Makita saw or track is the problem. That isn't a surprising amount of error for trying to square up a panel along that length of cut relying on a 12" combo square and pencil line. The problem is that even small deviations from 90 degrees create unacceptably large errors over a long span because the error increases in proportion to the length of cut. I think a deviation of only 0.1 of a degree will result in the error you describe. You might try squaring up the beam edge of the track against a big t-square like an accurate drywall t-square but for efficiently and accurately squaring up panels with a track saw I think you need something like an MFT (emphasis on efficiently and accurately). Better yet, get a sliding table for your table saw. If you have unlimited time and patience then I guess try a bigger t-square.

[andrew whicker]

https://www.ebay.com/itm/174607604637?

These look pretty nice.

[Holmes Anderson]

Maybe someone could recommend a rail square for the OP. I haven't used one and they seem too short to get an accurate cut across a full sheet but I am curious whether anyone has had good results with any of them.

[Patty Hann]

Maybe someone could recommend a rail square for the OP. I haven't used one and they seem too short to get an accurate cut across a full sheet but I am curious whether anyone has had good results with any of them.

https://tsoproducts.com/tso-guide-ra...e-rail-square/
Spendy, but apparently it works really well. (And it's not made in China or Taiwan)
I found out about it from a youtube video.
I will buy it in a few months (when my VISA card recovers from the last couple of months of "Specials")

[Russell Hayes]

Don't buy the TSO. TSO makes a Festool branded rail square that is identical but considerably cheaper and on Amazon. Go figure? Ships from UK free but takes a little while. I got one for $109 a few months ago but now $130. Comparable to the $189 one on your link.

[Patty Hann]

Don't buy the TSO. TSO makes a Festool branded rail square that is identical but considerably cheaper and on Amazon. Go figure? Ships from UK free but takes a little while. I got one for $109 a few months ago but now $130. Comparable to the $189 one on your link.

Found it. Thanks

[Frank Martin]

I have not used my track saw in ages since I got a sliding saw. When I used the track saw (Festool), most accurate cuts I was able to get were when I measured distance from the reference edge on both ends of the intended cut to make sure they were the same. This is the same concept as using parallel guides. I couldn’t get better accuracy using squares. I have not purchased the TSO or the Festool rail squares, but I suspect for long cuts accuracy may become an issue as small deviations from square may result in an unacceptable error.

[Patty Hann]

I have not used my track saw in ages since I got a sliding saw. When I used the track saw (Festool), most accurate cuts I was able to get were when I measured distance from the reference edge on both ends of the intended cut to make sure they were the same. This is the same concept as using parallel guides. I couldn’t get better accuracy using squares. I have not purchased the TSO or the Festool rail squares, but I suspect for long cuts accuracy may become an issue as small deviations from square may result in an unacceptable error.

I was reading the reviews on the TSO/Festool square(s) and that is exactly the problem a number of users mentioned...a long cut (8 ft) can be out of square by 1/16"...1/32" was typical.
After reading all the user comments I decided I could do better just using a good shop square on both ends of the material before cutting, as you described. (And I already have the "red aluminum" squares. )

[Jim Becker]

I think it's a "best practice" to manually check track positioning, especially for longer cuts where tiny variation gets amplified. It's just part of the process of using these tools. No matter how good a track squaring device might be...and they generally are pretty darn good..."measure twice, cut once" still applies.

[Jeff Bartley]

Dave,
After cutting one 8’ edge use a 3/4/5 triangle to layout the 90 degree cut then just set your track on the lines. Are you clamping the track to the sheet?

[Jim Dwight]

If I used a rail square for a wide cross cut I would also clamp the free end of the rail after checking to make sure it was square to the workpiece. I am also skeptical that a rail square is very precisely square on a 2-3 foot crosscut.

[Patty Hann]

If I used a rail square for a wide cross cut I would also clamp the free end of the rail after checking to make sure it was square to the workpiece. I am also skeptical that a rail square is very precisely square on a 2-3 foot crosscut.

From reading a lot of reviews I gathered that it was the models "from the east" that were unacceptable for all cuts, long or short.
And even the TSO/Festool square was downgraded a few times for inaccuracy on a less than 4 ft cut.
"You pays your nickel, and you takes your chances."

[johnny means]

It's obviously easier to cut parallel straight cuts w/ the tracksaw. So cut the parallels first then use your square to ensure it's square from both sides for your cross cut. When you have 3 sides cut, you can use the X measurement method to check square and mark the 4th cut via that method. If the measurements don't make sense, you can re-cut your 3rd cut (your cross cut) accordingly.

I made a pretty sweet wet bar with +/- 1/16" accuracy on my panels (using tracksaw cuts and table saw cuts when I could) so I'm not totally sure what the problem is with 1/16" accuracy on a side panel. Heck, I'm sure that one of the panels was even an 1/8" off... I agree the correct method is sub'ing out / owning a large CNC and I do remember the assembly / glue up wasn't as fun as could have been w/ zero precision problems, but I did get it done and everything assembled pretty well at the end.

One thing I learned w/ those tracks is that the sacrificial cut line can be off pretty easily (by 1/32 or 1/16). They seem to get torn at times vs cut cleanly. The real surface you are using for reference is that dado on the track (as you know). So when extending my track with two tracks, I use my 60" straight edge against the dado to ensure they are straight vs butting them together cleanly (and assuming the track manufacturer made perfect 90 deg cuts). I like the idea of having that quick tool that references the dado to mark the cut line. I'll have to make one of those. That would definitely reduce error.

As the person above said, I also double check the measurement to back of the track.

Measuring an x doesn't guarantee square, only that both sides are pitched in or out equally..

[Greg Quenneville]

Measuring an x doesn't guarantee square, only that both sides are pitched in or out equally..

As I (incompletely) understand geometry, the only time the two diagonals are exactly equal is when the corners are 90.0°

[Eric Arnsdorff]

Both of you are correct but with a little additional information.

The only time the two diagonals are exactly equal is when the corners are 90.0° **and the opposite sides are equal.**

Measuring an x doesn't guarantee square, only that both sides are pitched in or out equally **but the opposite sides won't be equal either.**

As I (incompletely) understand geometry, the only time the two diagonals are exactly equal is when the corners are 90.0°

Diagonals.jpg