MFT3 Calibration & Accuracy

[jdwhitak]

Hello,

I wanted to get some advice when it comes to calibrating a MFT3 table.

I've watched a number of YouTube videos on this subject. Some produced by Festool and others produced by third parties. Right now I'm following a method shown in a Festool video that uses a square to calibrate the fence and the rail. I'm using the Woodpecker's 2616 square, the biggest square Woodpecker's makes. I've tested this square and there doesn't seem to a problem with it.

So, I use the square to set up the fence and rail and everything looks good. However, when I do a test cut and check it with the same square the cut is off. I done a five cut test and it is off by .006" per foot. The only play I've been able to identify in the system is the slight amount of play where the rail rests on the front pin of the table. I've ordered a Slop Stop to see if that helps.

Questions:

• In the various YouTube videos I've watched people claim dead on cuts. Are people actually achieving this? Or are people exaggerating?
• If getting a MFT3 dead on is too costly or time consuming to achieve what is an acceptable amount for it to be off?
• I'm following the Festool video, but I could be doing something wrong. Is there something that could be causing my MFT3 to be off that isn't obvious?

Thanks!!!

 

[Lincoln]

If everything is locked down and square, then it's either technique or the material you're cutting is moving. Is the workpiece clamped down and your blade sharp? No play in the hinge/rail connection? Saw snugged up to the guide rail rib?
Personally, I don't like the '5 cut method', I'd rather cut two pieces the exact same size and place them face-to-face. I find it a more 'real world' way of checking.

 

[Jason.L.Hagen]

Maybe your saw isn’t tight on the track? I had to adjust the cams on mine a little as it moved ever so slightly.

But I would say 0.006” is probably well within the range of acceptable.

 

[jdwhitak]

I went back over the calibration process and the knob on the protractor head that allows it to move front to back wasn’t tightened. I’ve checked the cams on the saw and it’s good there. Also, I don’t let the cams come of the rail when sawing.

The only thing that has play in it is the front of the rail with the pin. I’m hoping the Slop Stop solves that.

I won’t be able to doing anymore testing till next weekend.

 

[afish]

One other thing to be careful of is the height adjusting brackets have some play in them. So if you are squaring the rail while its flat on the MFT then raising the rail after you calibrate or make a height adjustment later that could throw off your calibration.  The MFT is a good portable solution but square issues are one of the biggest issues with them.  If you do a search you will find lots of threads on the topic.  Long story short, you need to lock everything down so there is no play or slop in any of the components. Ditch anything that can introduce errors (protractor). The fence needs to be rock solid, the rail and brackets also.  My best results came with a heavy piece of 80/20 for a fence and a DIY rail hinge.  I knew the festool hinge wasnt for me and the Dashboard (I think there is a different name for it now) at the time had such a long lead time I couldn't wait.  So I built my own, which actually worked very well.   

 

[Birdhunter]

I get perfect 90 degree and 45 degree cuts on my MFT.

I ditched the protractor head in the 1st day. It hangs in the wall gathering dust. I added a SlopStop to the rail to eliminate side-to-side play in the rail. The SlopStop is cheap and works well.

I use two dogs along the top of the table and butt the top of the workpiece against those two dogs. I clamp the workpiece down at two places. I drop the fence to rest on top of the workpiece and check squareness using the Woodpecker "framing square". Then cut. Always square. I do 45 degree cuts using the same sequence except the two dogs establish the 45.

Before I start a cutting sequence, I check the fence by butting the framing square against two dogs and seeing the rail lining up with the framing square. I remember it was off once. I found a loose bolt where the rail attaches to the hinge.

 

[jcrowe1950]

I've had pretty good results with the MFT but there are a few tricks that Greg Paolini covers in his Youtube video. That said, I am tending to look towards solutions like Birdhunter uses. It is possible to use the protractor for angles but for my use case that almost never is useful. I am using my MFT mostly for cutting square cabinet parts. I wonder if anybody has tried the guide rail brackets from Dashboard?

 

[dashboardpws]

For the record, we are still operating under Dash-Board® Portable Workshop. The latest iteration of our popular guide rail brackets has large improvements from previous versions and some modularity with our upcoming new Track Stars, and they have historically been very well received by MFT users. I do regret our lead times but it's a sign of something good when every batch is sold out before we can even get the parts. We are now working to get larger batches each time with the goal of being able to actually have a little inventory.

Thanks,
Rob

 

[Brewstermmc]

Are you using the fence clamp to secure the left end of the fence? I notice that if I clamp it too tight, it throws it out of square. If you use it (which I recommend) go easy - you don’t have to torque the hell out of it in order for it to clamp securely.

 

[jcrowe1950]

Are you using the fence clamp to secure the left end of the fence? I notice that if I clamp it too tight, it throws it out of square. If you use it (which I recommend) go easy - you don’t have to torque the heck out of it in order for it to clamp securely.

    Using the "Additional clamp MFT/3-ZK" on the end of the fence opposite the protractor is absolutely critical for squaring the fence on the MFT.....everything has to be properly snugged but not overtightened....I have noticed that when you are snugging up the two screws that hold the guide rail onto the flip up bracket...you have to insure that tightening the frontmost screw does not throw the guide rail off of landing on the peg on the front bracket. Again, as with the Festool guide rail connectors, easy does it.....snug but not overly tight.

    As an side, you can also use tall dogs and guide rail clips from UJK to cut square and 45˚ on the MFT. Peter Parfitt has some videos on that as well as using isometrically drilled tops to handle 30˚ and 60˚ angles as well. There's more than one way to accomplish all of this stuff....

 

[grbmds]

So, I use the square to set up the fence and rail and everything looks good. However, when I do a test cut and check it with the same square the cut is off. I done a five cut test and it is off by .006" per foot. The only play I've been able to identify in the system is the slight amount of play where the rail rests on the front pin of the table. I've ordered a Slop Stop to see if that helps.

If the cut is off by .006 inch per foot and I understand the 5-cut method, the final amount out of square for each cut is 1/4 of the total. This means that for each cut you are off square .0015" per foot. Since you can really only reasonably make about a 3 1/2' crosscut on the MFT, that means your cut could be off by about .005" or I think about 1/200". In practice this isn't really a noticeable amount when assembling furniture or cabinets or other pieces. Wood would swell and contracted more than that from season to season. I'm quite a perfectionist and the most precise I get is 1/64" and that is tough to get a good measurement on. If you are concerned you can install a product called Slop Stop on the rail. When installed correctly there is absolutely no play side to side when doing crosscuts. By the way, unless you've dropped your Woodpeckers square, that isn't the problem.

 

[sancho57]

I asked Alan K some questions on adj my MFT.

First loosen everything up on the pro tractor pick that little knob up and turn it loose in the Alan heads on the protractor before you do any adjustments.

you don’t tighten the screws to the rails without it sitting in the groove. Raise and lower the rail a few times to ensure that the rail will set into the pin on the hinge.

I also found that that little black thing that attaches to the fence will cause the fence to go out of alignment if it’s tight and too hard just slip the thing into the groove of the fence and snug not tighten it.

Once everything appears to be aligned or squared then you tighten everything up.

Push that little black knob on the protractor down while tightening it it will pull the protractor out of alignment

He also showed me that once you lock the hinges in place you don’t have to move them to adjust anymore however when you raise or lower the rail you need to push the hinges  against the stops then tighten the lever.Nothing for full just enough to stop it from moving because the metal pieces on the hinges will move and they will throw off your adjustments by about what you’re getting

He told me that’s his method and it’s not in a video.

 

[Df1k1]

Honestly I spent hours…and I mean hours…searching this site trying different tricks etc.  it all comes down to height change. Once I changed height…boom. Out of square
I hate encouraging people to spend more money to make an expensive product better but honestly buy the guide rail bracket set from dash board. Game changer. Totally.  It’s honestly one of the best improvements I’ve made. 
Plus he’s a stand up guy. Gets back with you almost immediately

 

[sancho57]

@ Df1k1

That’s what Allan told me and showed me how to stop misalignment during raising and lowering the rail see post above

I’ll repeat again and add so,e additional info to make it clearer

He also showed me that once you lock the hinges in place you don’t have to move them to adjust anymore.

however when you raise or lower the rail you need to push the hinges against the stops then tighten the lever they do have some play in the hinges

pushing them against the stops each time with yer thumb will ensure
The hinges are back in the same place repeatedly.

.Push with yer thumb while raising or lowering just enough to stop it from moving

because the metal pieces on the hinges will move they have some slack and they will

Slightly throw off your adjustments

He told me that’s his method and it’s not in a video.

Not taught by Festool on any of their training.