Should I expect the mft factory guide rail stops to be accurate and precise?

[grandpoobah]

I bought a mft 3 and ts55 saw last week and set it up and everything seemed pretty good.  Not perfect, but I figured it was me. I  was able to get sqaure cuts using the system but it took some tweaking.  Like most new users here, I watched hours of videos and it seemed that everything was going to plan.  But things just seemed a little off so today I took my new Starrett 6" combo square and put a festool clamping dog and measured the distance from the guide rail to dog.  I took this measurement at the top and then repeated the measurement at the bottom of the table.  I was right, my guide rail was not parallel to the holes on the mft.  There was an 1/8" difference in the two measurements.  So I removed everything and went step by step and installed the guide rail again.  I was very careful about ensuring everything was tight against the factory stops, I lowered the rail on the table and it slipped effortlessly in the tab with no significant slop.  I gently but firmly tightened everything down.  I then lifted the rail to its up position and then set it down again and once again it fit perfectly.  Then I measured.  And still off by 1/8". 

So I call festool service and the guy was nice but I'm not happy with his solution.  He basically said to move the one rail piece away from the factory stop and should be good to go.  I asked him "shouldn't I have an expectation that the factory stops to be absolutely right on."  He so no, they are meant to be close.  I actually couldn't believe my ears, but that's what he said.  Well, I move the piece with the tab that holds the rail over 1/8" and now the guide rail is parallel to the mft holes.  The problem is that when setting the guide rail down on the table it doesn't set down exactly on the tab and has to be pushed gently into the slot. I don't like the way that feels. 

Here are my questions.

1.  Should I expect the factory stops to be dead on or is this typical? 
2.  I don't like his solution so I was wondering if I should move the factory stop?  btw, are they movable?
3.  What would you do? 

Thanks for your thoughts. 

 

[WarnerConstCo.]

I have never really used my mft3 for any sort of cross cutting, but you can set the fence to the rail to make sure it is 90 to the rail. 

I would not use the holes as a reference to the location of the rail on is flipper things.

 

[peter halle]

First, Welcome to the FOG!

If my memory is correct, the stops are installed using a jig or template of some sort.  Is it possible that one of the stops (called feather keys in Festool-speak) moved?  Sure.

The Festool design of the table is that the rail will be set up to be at a 90 degree angle to the the protractor head.  The holes in the MFT come into play for clamping only.  Adjusting the stops is easy.

If you wish to take the approach that you want to have everything parallel and perpendicular to the table holes, then most likely you will have to move the feather stops.  

I personally now like to have my rail parallel to the holes and the fence perpendicular to my fence (and bought a set of aftermarket "dogs" to achieve that), but as long as the fence and guiderail are aligned perpendicular to each other that is all that matters.

Peter

 

[Administrator_JSVN]

Welcome to the forum.

If your guide rail is perfectly perpendicular to your fence, just loosen the two bolts that attach the rail to the "bracket" in the rear. Sit the rail on the front bracket so that it aligns and then re-tighten the bolts. That should correct the feeling of it not seating properly when you sit the rail down. Shown around 1:20 in the video below.

Like Peter said, the stops are factory set using a jig and should be pretty darn accurate. Is it possible that the stop moved before it was tighten, yes. They can be moved. Just a set screw that hold them in place. They are meant to be very close, but I don't know the exact tolerance. I think anyone doing precision work would check it with a good square for accuracy. Squaring and tuning techniques @ 4:00 in the video.

I actually just added a new video on our YouTube channel about setting up and calibrating the MFT/3, as well as common tasks like sawing, routing, sanding and clamping.

 

[mouppe]

I don't think it is normal to expect the holes to be dead square/ parallel to the stops. The top is replaceable so even if the top it is shipped with is in line, the next top may not be so.

The stops provide a repetitive way of placing the guide rail in the same place. So if you square the rail to the fence- and implicitly the stops- you can be assured of accuracy.

There is an alternative method using Qwas dogs in the MFT holes and squaring the rail to the holes, but this bypasses the stops.

 

[Administrator_JSVN]

The holes are CNC'ed, pretty sure. So they should be dead on from one to the next, meaning they are square to one another. The table top can be adjusted some as I recall using the threaded inserts, but I've never tweaked the position of the top. Never had a reason. Like Peter, I use the holes for clamping purposes, not alignment.

 

[sancho57]

Couple of things

Did you trim the factory edge off the ply you are cutting?

Do you have a precision square to square up the guide rail and fence (this was my mistake when I 1st got my MFT)?

I suggest using qwas dogs to 1st square up the fence, then square the rail using the precision square.



http://www.youtube.com/watch?NR=1&feature=endscreen&v=AKHNEBpKnSI

dont be scared by the guy in the second video, he is a star wars fan :>)

http://www.bobmarinosbesttools.com/qwas-dogs-and-guide-rail-square/p/QDGS/

 

[panelchat]

grandpoobah- i had the same headaches when i set mine up, and others on this forum have too. (if thats any consolation...)
i do think the table is superb overall, but it was surprising to have to tinker with it to make it work well for accurate cross cuts for cabinetmaking.
one problem is that you have to buy more stuff for setting or checking square- either qwas dogs or similar precision dogs, or a very good square from woodpecker, starett, etc.

one way out of this is to use a nice factory produced panel component- say a slab door from an ikea cabinet, or any other medium sized panel, that you can verify to be square, or one that you cut yourself by hand to very square, and use that to initially set 90 deg at fence and rail...

i use the qwas dogs 100% of the time on the MFT and consider them integral to its use. the hole set does appear to be set at a very high 90 deg. tolerance, - this can be easily double checked when setting the table up. the hole set does not need to be perfectly square to the four extrusions on the sides.

shane- that's a very clear, descriptive video! (unlike most other Festool instructions...)was it made by Festool USA? thanks for positing it.

 

[peter halle]

Shane let me know that his access today to the forum might be spotty, so to answer the question, Yes, that video is a Festool USA production.  He has written here that they have been working on several.  You might want to check out Festool TV to check out other ones.

Peter

 

[Administrator_JSVN]

Just to confirm Peter's statement, yes Festool USA produced that video. We also have the OF 1400 and CMS videos that are in the same style, and more on the way.

 

[fastbike]

The precision CNC grid is the best thing about the mft3. Not using the holes to align the fence and rail isn't using the system to greatest advantage.

I have never really used my mft3 for any sort of cross cutting, but you can set the fence to the rail to make sure it is 90 to the rail. 

I would not use the holes as a reference to the location of the rail on is flipper things.

 

[panelchat]

I'll second that, the hole set is as useful as your imagination can take it. Great for planned out, careful 90 deg. reference work, as well as quick ad hoc holding, bracing workpieces for sanding, assembly, edgebanding panels, whatever, with precision dogs, or other clamps or arrangements. Now I want a 4" by 8" perforated top!

 

[Nick C]

A square cut is determined by the relationship between the guide rail and the fence that is attached to the miter gage. These parts need to be set to 90deg, then immobilzed. To immobilize the guide rail, the hinged bracket and the receiver bracket need to be set to the correct height, so that the rail fully engages the tab when the rail is dropped into position. The miter gage fence is immobilized by a fitting that fixes it to one end of the table. Assuming the guide rail is roughly perpendicular to the end of the table, the fence has sufficient play to permit it to be set to an accurate 90deg. If the required adjustment of the fence seems to be excessive, the guide rail brakets themselves can be repositioned, by simply loosening the stops, moving the rail brackets as necessary, and retightening the stops in the new position. In fact, there is no reason why the stops should fix the guide rail at any particular place--or even be used. I sometimes use a longer guide rail, with the brackets attached to the table ends, to make guided rip cuts for edge banding or drawer slides. I don't even bother to move the stops.

Although it is reassuring to have the guide rail drop down in alignment with the holes, it isn't necessary to achieve a square cut. Nor is it sufficient. The miter gage fence would still have to be set at 90deg to the rail. True, the fence could be aligned with a set of holes as well, but you might as well just set the fence to the rail directly, without bothering with the holes. I think it is unrealistic to expect the table extrusions and insert to provide the accuracy we typically demand for panel crosscuts.