Reducing rail guide slop when in MFT/3 rail system

[greg mann]

Months later, and the problem still exists with new MFT/3 rails.  After my own frustrations with it, I complained to the shop where I bought it, only to find that theirs had the same problem.  Even the small amount of wiggle translates to cutting errors.

Yours is a good hack to fix the problem.  For all the advertised repeatability of the table and saw, this was Festool's poor design.

There are countless number of us who don't have this problem even though we all acknowledge the existence of play. You need to analyze your approach to biasing the play out of your rail as it is placed over your work. It is not that hard. Sorry to be so blunt but this is not a design flaw, it is up to you to learn how it is supposed to work. Go back and read some of the responses and you will find the answer.

 

[jcierra]

Are we looking at the same thread?  - It is filled with people with the same problem solving it in different ways.

Reducing slop in the rail and getting it aligned to the holes in the table are repeated themes not only here but in discussion on other sites; a table saw with a solid fence does not show this problem.  If your MFT does not have the problem - good for you!

Months later, and the problem still exists with new MFT/3 rails.  After my own frustrations with it, I complained to the shop where I bought it, only to find that theirs had the same problem.  Even the small amount of wiggle translates to cutting errors.

Yours is a good hack to fix the problem.  For all the advertised repeatability of the table and saw, this was Festool's poor design.

There are countless number of us who don't have this problem even though we all acknowledge the existence of play. You need to analyze your approach to biasing the play out of your rail as it is placed over your work. It is not that hard. Sorry to be so blunt but this is not a design flaw, it is up to you to learn how it is supposed to work. Go back and read some of the responses and you will find the answer.

 

[harry_]

Are we looking at the same thread?  - It is filled with people with the same problem solving it in different ways.

I bet you I can find countless people that cannot hit a nail with a hammer with repeatability..... That does not mean that the hammer is of poor design.

EDIT: to fix typos

 

[WarnerConstCo.]

Look at the tab, the rail is meant to have a little slop when it drops in the tab.

I take my fence and rail off my table constantly and ever time I put it back together I follow the few simple steps
and I have a square set-up every time.

It is not rocket science it is just cutting wood.

I am sorry it is hard for you to grasp.

 

[jcierra]

Usually forums are about posters helping others, but maybe hazing is the better idea:  we should not let just anyone off the street use a saw! 

The several people in this thread who described similar problems should have their saws taken away from them for identifying the problems and describing solutions!

 

[WarnerConstCo.]

Usually forums are about posters helping others, but maybe hazing is the better idea:  we should not let just anyone off the street use a saw!  

The several people in this thread who described similar problems should have their saws taken away from them for identifying the problems and describing solutions!

Yup, sounds good.

Seriously, it is a table, saw, rail and fence.  It is not a 1200 pound piece of cast iron like a table saw.

The little play has never effected anything I have done.
Like I said, learn how to set it up and it becomes very simple to do over and over.

 

[score0matic]

we are working in a meduim that does swell and shrink with the weather [blink]

 

[Nigel]

    Not only that but the OP was on about 0.25mm play on  80cm of rail!Swelling,shrinkage and warping will soon straighten that out. ;D

 

[greg mann]

Usually forums are about posters helping others, but maybe hazing is the better idea:  we should not let just anyone off the street use a saw! 

The several people in this thread who described similar problems should have their saws taken away from them for identifying the problems and describing solutions!

There have been several posts dealing with how you make this work without heartburn. This is an issue of understanding and proper technique, not a faulty design. Even precise jig-boring machines have backlash for which the operator needs to compensate. Once the concept is understood it becomes second nature.

And, FWIW, a table saw with a solid fence WILL show this problem if you don't keep the stock firm against the fence. Think of this as keeping the saw and rail firm against the slot locator and it will start to work for you.

 

[jcierra]

You know this is about blue tape, right?  An inch of tape.  And whether someone should use that tape to solve a problem.

Those who criticized the solution could have read the topic and skipped past it.  Or read the article and ignored it the solution.  Or they could have done a hundred things other than slam those who want to solve the problem this way.

What is it about this solution -- this inch of tape -- that troubles people so much that they want to antagonize users of masking tape?

 

[Nigel]

    Hi jcierra,
   
                I was just pointing out that 0.25mm over 800mm is (to me) negligble.Laser lines are accurate to +- 0.3mm /metre so the mft rail combo is as accurate as a laser line.Personally that's good enough for me.You could say the mft/rail is accurate to 1mm over 3.2 metres.Try that on a table saw.Then factor in wood movement,knots etc and this "innacuracy" becomes very small.
If you want to use tape as a solution that's fine.I'm not criticizing the method just questioning whether it is needed.
     
      Regards Nigel.

 

[MarkF]

We forget there is still a Craft to what we do even the though the machines have become so fine.  All machines have issues.  As my Grandfather said "Sometimes it's all in how you hold your mouth."  

Uncompensated Slop (that just sounds wrong [scared]) can really have an impact on wide panels if the panel really needs to be dead on square.  Using a big square or large Drafting triangle (I use an  18" one, elevated 1/2" off the table with scrap ply) to perform my set up helps me avoid issues with this.  

I am finding that over the course of 4 years, the point where the steel locator pin contacts the groove widens.  (Steel vs Aluminum)  This is easily fixed by relocating the guide a few MMs one direction or the other on the pivot end so the pin seats into a clean area of the groove.

 

[Michael Kellough]

You can also move the guide rail in or out a few mm
to get the pin in contact with an un-scratched area.

Those bothered by the play in the fit of to pin to the slot in the guide rail...
just imagine if there was no play. There has to be some play or you have a go/no-go gauge.
If the weather gets warm the guide rail won't fit over the pin.

Festool decided to leave plenty of play so it's easy to engage the guide rail on the pin
without excessively eroding the softer aluminum guide rail. They mitigate the consequence
of play by clamping the guide rail in the hinge in such a way that it is sprung against
the left side of the pin. With the guide rail sprung against the side of the pin (always the same side)
there is no play in practice. It becomes second nature (with use) to pull the guide rail to the left before lifting.

The problem with masking tape is that it does have thickness and it does wear out very quickly.
In which case you'll be sing it the Festool way without even realizing it.