118" Guide Rail-- uneven cut??? Help?

Yeah, it looks straight but I don't have anything that long and perfectly straight to test it with.
 
Just snap a chalk line on the floor or something else for a test line. A tightly pulled string gives a perfect line if you are careful while doing it.
 
A sheet of MDF with tension in it, showing up in pieces as wide as shown, much greater than the 7  1/4 inches width of a Guide Rail?  I doubt it.
Re checking your Guide Rail against that chalk line, check both the front (splinter strip) edge and the back to see if they match the same against your reference line.  If you made the cuts with the rail and MDF flat and supported throughout the cut, it sounds like your Guide Rail may be slightly curved.  I think it interesting how gradual and smooth that curve appears to be.

Dave R.
 
We were talking about Eli using wood stock with his messed up back up 119" rail, not MDF Dave.
 
Are the rails covered with 3 years warranty as well ? I just got a 2700 but I suppose you cannot register the rails (no serial number) you must just keep you receipt ?

Still have not used mine yet had it a week our prices just went up here in the UK i payed 137 pounds now they are 188 pounds  ;D
 
Here's what I would:

1. Lay out the rail like you have in your picture on a long piece of lightly colored material...your MDF works fine.
2. Take a #5 or #7 pencil and draw a line along the rubber the whole way down the rail, or atleast as far as you can.
3. Move the rail over a fraction of an inch...or mm, flip the rail end to end and draw the line again.
4. The result will either be two straight lines, or you will have inward or outward lines.
5. If you're really feeling ambitious, you can take the rubber off, and do it.

See the attached image for what I mean...

[attachthumb=#]

...read #5 again....."that's what she said"  ;D
 
intermod said:
Thanks for the suggestions. The surface I'm cutting on is pretty flat. It varies a little but not much. Around a 1/16". I'll try correcting that to see if it helps. MDF shouldn't have any tension. I've been working with it for over 10 years and have never experienced anything like a post cut warp. Festool is sending me a replacement rail. But I still don't get what's happening. Maybe it is just a bad rail.

no im sure iv had mdf with tenstion.
 
Are you using the clamps with the rail?  This may prevent bad things from happening due to unintentional sideways pressure.  Also, is the bottom of the rail clean (not covered in dust)?  Having a clean rail will also help prevent sideways movement.
 
Off Topic and no particular point. Not meant to be an answer to your problem.  Not even an observation of value.  just something I dragged out of the old memory bank.

When i went into my HS geometry class in sophomore year, our teacher told us all to draw a straight line for him useing any method available to us.  Each and every classmate made the best straight line possible within their abilities and equipment at hand.  After a few minutes, Mr. Jones  (not his real name.  However, if anybody here went to Staples high in Westport, CT in the mid 40's, they have backup to my statement and know exactly who I am talking about, he went thru this with every math class he taught) took a strole around the classroom.  When his strole had completed, he stood at his desk and told us all that nobody had drawn a straight line.  "There is no such thing as a straight line.  We can only make a representation of a straight line"  And then he would go into a short lecture about just why it was not possible, but that we would spend a full semester trying to prove him wrong.

And then there was my shop teacher who had learned his trades in actual aprenticeships of sorts.  A little less pollished in speech and manner  than any of his peers on the teaching staff.  One of his sayings, that he drummed into those of us who showed any signs of sincerity towards learning actual skills, "There' no such a thing as gud enuf.  It's gotta be purfec' "

I don't know if i have even come close to expectations from either of those good men, but somewhere along the way, i might have tried.
Tinker
 
Back to earth.
I recently ran into a problem with straight cuts and cut quality.  I suddenly noticed an extra amount of vibration while cutting hard maple.  At finish end of cut i noticed some burning (rip cuts only).  Knowing that burning can be caused by dull blade and I am still using the original blade from 5 +/- years ago, I made a note to buy new blade and begin search for a quality sharpening service.  the company i have used for years has recently gone out of biz.  A new blade should cover the burning part, but i was puzzled at the vibration.  I am not looking forward to a new saw to replace my old ATF 55, but I do ocasionally need to cleanup the drool when I take a look and feel of the newer TS 55. that can be bad news. OOPS!  back to topic>>> 

Also, I was trying to cut narrow strips and realised they were coming out looking like sled runners having a decided cup/hump from end to end.  I tried on a piece of pine and found the same thing happening.  I played around with all of the adjustments and still the vibration and movement of material. 

Finally, I realized the guide rail had a slight up and down movement at the start of cut.  i looked under the rail and noticed that with out the weight of the saw, there was a slight space of about 1/8" from one side of the support to the bottom of the rail.  I did some fiddeling and adjusting and finally got the rail support adjusted correctly to level and made some sample cuts.  VOILA!  Purfec' cuts.  no vibration (well some vibration.  i am running an ATF after all) Glueable edge cuts and straight line  (???  see my above post) cuts with parallel edges.  No more burning at end of cut, or anywhere along the cut.

I could even rip pine, fir and red oak with no clamps.  I have never tried ripping hard maple without clamps, but I could cut red oak without clamping. 

Well, sorry Festool.  I will just have to put off that new TS 55 for another time.  (For once, I might have  even be a reasonable reply to a reasonable question. ) 
Tinker
 
I have two 1400mm rails and I noticed bowed cuts. I put the two rails back edge to back edge and there is a gap of just less than 1mm in the centre when the ends are touching. With further investigation, I have found one rail to contain the bow. The rails are both less than 3 months old. I will be contacting the supplier for a replacement, but I am surprised at the number of people who appear to have these issues.
 
Yeah and so many people say these things are tough. They are not.

I suggest you handle the rails with kids gloves. I know some of you throw these things in the beds of your trucks, but come on guys are returning these for little waves and 1 mm differences. I think that shows in itself the rails are NOT a very durable item by their nature at all, as some think they are. To me they are one of the more delicate things in my shop.

I keep mine separate and safe and have never had an issue with them.
 
Because of this thread, I have started checking the long rail against the long side of new panels, ply or melamine or MDF. So far I have only had total contact on both the long rails I have. I am assuming that the panels factory edges on the long way are straight.
 
This issue is more wide spread than most believe it. I have a 3000 rail and it is not straight and has the same bow as others described. I talked to Mark Kalin at Festool and he indicated that there was a batch of rails produced that did have a bow in them. I had a tight wire jig made up so that I can check both my 3000 and 5000 rail to see if they are straight. On these long rails it is easy to bend them just a bit when lining them up to a mark. By using the tight line jig and a couple of center clamps I believe that I'll be able to keep my cuts on solid surface straight. Bill in Seattle will surely have a comment here as he builds lots of solid surface counters. I'll try and post pics later of the jig.
Steve
 
I checked my 3000mm rail and it is bowed a small amount as well... disappointing to say the least.  I have only used a few times breaking down some ply in my shop, otherwise it hangs on the wall, never transported.  I've had it since last year and bought it from Mcfeely's.  I never thought to check it when I got it.  My guess is its not covered under the 3 year warranty so I'm probably just out the money.
 
Hey Steve,

Your tight wire jig sounds interesting and useful. Could you give us some details?

Tom in SE Pennsylvania
 
I bought a 2700 rail at christmas just before the prices went up here in the UK its sat in my workshop on the bench since as I have not needed to use it yet. I think I better get out there and check it for straightness.
 
Gentlemen

In almost every shop I've ever worked in we have practiced the double rip, or basically splitting your widths out of a panel and then re ripping it. Most panel

stock have some inherent tension in it and splitting out rips allows them move to were they want to. My method leaves rip widths .5" to .75" oversize allowing

me enough meat to straight line one edge and rip against the fence on the other. Time consuming-yes but you gain it back with the increased accuracy at the

assembly table and when sanding the edge banding.

T-bone
 
Tom,
Here are some pics of the jig. The parts fit real snug so there is no play in it at all. At first I was going to move the jig between the guide rails but now I'll just get another set made. The rail can be out up to 1/32" easy. I have yet to try it on the 5000 rail which is still in its box waiting for my next solid surface counter job.
Steve
 
t-bone has it spot on ive never know it called the double rip but never the less it is good practice to trim rips to get over this issue

lee
 
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