Why am I suddenly having difficulty squaring up sheet goods?

[bonesbr549]

Maybe I'm misunderstanding your note, but I don't see you mentioning a square in there anywhere. If your just measuring each edge you have 4 sides to introduce error (even minor) add all that up and a 1/16" is easy to understand.   Now some have said a 1/16" is not bad and my response is depends. If I'm framing and cutting ply OK but if it's a fine piece of furniture I would think that's a good bit.  Now if it's covered by molding or something else again could be don't sweat it.   I don't see why you should not be dead on.   Rip one side lets say the long side then cut the other face perpendicular to that face (90) as measured by a good square.  then cut the next perpendicular side and repeat. When you get to that last corner if you did the first three right it can't help but be dead on.  

 

[Spike]

Ok...

Let me add some more info to answer the last 3 posts:

1. Guide rail is sitting on 3/4" cherry ply which is sitting on a 3/4" maple ply (all Columbia Forest USA made ply). These are sitting on a dead flat torsion box assembly table that is level in all directions.

2. TS55 guide rail gibs have zero play...I mean zero, but not so tight that I cannot push the saw.

4. Saw is 100% up to speed before plunging or entering the material.

Cut quality is A1 perfect but there is a faint amount of flex in the TS55 that transfers to the blade while plunging and releasing at end of cut. This is apparently causing the blade to cut deeper into the rubber strip during the process. I asked a friend here in town with a TS55 and his does the same, also the store display locally and their guide rail is exhibiting this so I'll bet yours is too.

Should you line the guide rail up to a pencil mark where the deeper notch is only on one end, then go down to the other end of your sheet turn the guide rail in the opposite direction and do the same you are in for a treat...like 1/16" out of square.

 

[Tim Sproul]

Hi all,
I just found this thread in a search as I am having the same issue. I recently posted a topic "Suddenly having a problem squaring up sheet goods".

Isn't this the same thread?

Seems a bit odd to find your own thread through searches....unless you'd completely forgotten you had this problem!?

My TS55 and 75 can be coaxed (without Herculean effort) to cut more or less into the rubber guide strip.  It is good practice in woodworking to try and use the same pressure and direction of pressure throughout a cut to get the most true and clean cut.  This holds true for getting the most precise/accurate work whether you are using the Festool guides and TS55/75 saw or a tablesaw or bandsaw or even a hand saw.  I don't know if that small amount of error would translate into 1/16 inch out of square measurement though.  It depends on how large the work is.  A tiny bit of error on a large piece will give you 1/16 inch out of square, depending on how you measure out of square.

The plunge is also an inherently sloppy mechanism, unless you go to extreme measures.  Those measures would likely make the circular saw too large and heavy to be hand held.

For the best results, I have to plunge before I start cutting and unplunge after the saw has completely finished cutting the material.  For true plunge cuts such as making sink cutouts, those are almost always rough cuts that are finished with a template and router, if they need finishing.

 

[Spike]

Hi Tim,
No...I did a search on the issue and found that thread started by someone else back in 2008, I just added to it and copy/pasted my post in both just in case someone only read on thread and not the other.

Hi all,
I just found this thread in a search as I am having the same issue. I recently posted a topic "Suddenly having a problem squaring up sheet goods".

Isn't this the same thread?

Seems a bit odd to find your own thread through searches....unless you'd completely forgotten you had this problem!?

My TS55 and 75 can be coaxed (without Herculean effort) to cut more or less into the rubber guide strip.  It is good practice in woodworking to try and use the same pressure and direction of pressure throughout a cut to get the most true and clean cut.  This holds true for getting the most precise/accurate work whether you are using the Festool guides and TS55/75 saw or a tablesaw or bandsaw or even a hand saw.  I don't know if that small amount of error would translate into 1/16 inch out of square measurement though.  It depends on how large the work is.  A tiny bit of error on a large piece will give you 1/16 inch out of square, depending on how you measure out of square.

The plunge is also an inherently sloppy mechanism, unless you go to extreme measures.  Those measures would likely make the circular saw too large and heavy to be hand held.

For the best results, I have to plunge before I start cutting and unplunge after the saw has completely finished cutting the material.  For true plunge cuts such as making sink cutouts, those are almost always rough cuts that are finished with a template and router, if they need finishing.

 

[ororaf]

Hello Taos,

I too was having trouble squaring up small sheet goods.  I was aligning my track to a carpenter square before every cut.  I liked the suggestions in the post.  I was planning on testing the solutions.

Yesterday I came across the following You Tube presentation attached to my Festool eNewsletter.  Festool MFT - Part 2 - My Modified MFT  or http://goo.gl/MR9D8 Paul Marcel discusses modifying an MFT 1080 table.  I believe that 1/2 way through the video he shows how to align the track so that it is square.  I am not sure if it will help you as your sheet goods might be bigger than the table.  Good Luck.

 

[GPowers]

I've used this and found it very helpful.  I made a storage tube out of pvc pipe with a screw-in plug on one end to protect and transport it.

http://www.amazon.com/CH--Square-Folding-Triangle-Package/dp/B00004TKDP/ref=sr_1_1?s=hi&ie=UTF8&qid=1285102760&sr=1-1

Added it too my Amazon wish list [big grin]

 

[Laminator]

Just some observations, the plunge action is a little loose and I always plunge completely before the blades enters the material. It would be nice if the hinge was tighter or adjustable.

When going for really parallel edges I don't usually depend completely on the rubber strip on the pencil line. I measure from the cleaned edge to the top edge of the guide rail and  make sure they are exactly the same.  The parallel guide would seem to make this process a snap and if I needed perfectly parallel cuts from the ts55 very often, I would certainly  invest in the guide.

A good square is an almost priceless necessity and the math is simple with a construction master calculator.

I normally get a 36"x96" panel either dead on diagonally or within the thickness of the marks on a stanley tape measure.

 

[pugilato]

I dont know if this will shed some light on the subject, but I am working on a project for my brother to build two fairly large bookcases (63 x 84) that will hang on the wall.  Used the TS55 with two butted 55" guide rails to make the long cuts.  After cutting, I verified the cut was the same width at both ends and the middle.  Did the cross cuts measuring from the end and verifying with a square.  And even with all that, the cut panels were not square.

After a while of this, I put a straight edge against the guide rail where the two 55" rails butted up and was highly disappointed to find that the straight edge was rocking a full 1/8".  Got into the habit of checking that the butt connection between the rails was straight whenever I did the connection, and have not had a problem since.

 

[Wood_Junkie]

I dont know if this will shed some light on the subject, but I am working on a project for my brother to build two fairly large bookcases (63 x 84) that will hang on the wall.  Used the TS55 with two butted 55" guide rails to make the long cuts.  After cutting, I verified the cut was the same width at both ends and the middle.  Did the cross cuts measuring from the end and verifying with a square.  And even with all that, the cut panels were not square.

After a while of this, I put a straight edge against the guide rail where the two 55" rails butted up and was highly disappointed to find that the straight edge was rocking a full 1/8".  Got into the habit of checking that the butt connection between the rails was straight whenever I did the connection, and have not had a problem since.

Hi pugilato, welcome to the forum!

There is a lot of well-documented advice *against* simply butting rails end to end.  The proper technique is exactly what you arrived upon and described:  use a straight to align them.  In fact, leave about 1/8" between rails so you can make this adjustment.  The longer your straightedge, the better.  I recommend at least a 48" straightedge/level.  Once you have a satisfactory line-up, then tighten down the connector bars.  You should be good to go at that point.  And it'll stay straight as long as you don't handle the joined rails recklessly.

 

[tbellemare]

There are multiple methods to join two rails and the most recent method, that is at least semi-officially espoused, involves just bridging the two rails with a saw. This is an interesting and potentially accurate way to align two rails. It has the potential to be as accurate as the the saw's base, which is pretty accurate but is, after all, a painted casting.

The saw base also is not very long in relation to the length of either of the guide rails that one is trying to align. This means that any inaccuracy while attempting to use the saw base as the alignment mechanism is magnified.

The TS 55 base is about 285mm, which means that about 140mm, at best, is effective on either guide rail. 140 vs. 1400 means that error is multiplied ten times. Is that good enough? It may be but there are more accurate methods and Mr. Junkie is describing one, more accurate method. I, personally, use the far outside edge of the MFT... and I sell ultra-long Stabila levels.

I think everyone who wants to align two guide rails needs to determine how straight they want the ultimate cut to be and determine for themselves how to align their guide rails.

Tom