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Thread: Tracksaw blade not staying perpendicular to surface during cut

  1. #1

    Tracksaw blade not staying perpendicular to surface during cut

    Hi all, I recently bought a track saw (Mafell MT55cc) for breaking down sheet goods and jointing edges. The cuts start perpendicular, but don't stay that way over the duration of the cut.

    I have been testing by cutting 2' lengths of half inch MDF. I'm using the only lightly used (maybe 50 cuts) stock 48 tooth blade that came with the saw, a 62" rail, and have supported the rail on both ends and clamped it to my workbench.


    • The cut starts at 90 degrees (I've used the set screws on the bottom to tweak)
    • By the time the saw reaches the middle of the cut, it's 1-2 degrees off (to the left, i.e. -1 degree)
    • When the saw reaches the end of the board it takes a chunk out of the last half inch or so. But only the last half inch, consistently.


    end-terrible.jpg
    Here's a shot of the very end of the cut. You can see it's slightly off square, and the extra material that is getting removed. You can also see the splinter guard strip on the track looks slightly narrower in that spot where it met the end of the board.

    I have tried:
    • Continuing the cut (i.e. keeping the saw plunged and spinning) well past the end of the board
    • Snugging the saw to the track
    • Snugging the bevel lock knob
    • Removing, cleaning, and reinstalling the blade nice and snug.
    • Pressing the saw firmly down during the cut
    • Only pushing the saw from behind during the cut
    • Pushing slowly and pushing quickly
    • Everything else recommended in this post
    • Cutting a smaller piece with my shorter track


    But this happens every single time regardless of what I change. The floor of my shop is now a heap of 1" slightly off square MDF test cuts

    I'd like to use this saw for very precise cuts that are ready for screws and/or glue but obviously can't in this state. Any ideas?
    Attached Images Attached Images
    Last edited by Aaron Karp; 03-25-2021 at 10:53 AM.

  2. #2
    "stock 48 tooth blade "

    Replace the blade with a new blade and see if results repeat. Make sure your feed rate is appropriate. I rarely use a circular blade with that many teeth. I would try a 24 or 30 t ripping blade to confirm your saw is capable.

    Also, it appears you are using dust collection. That is good. But it is possible that the collection is unable to clear the mdf from the gullets while still in the cut, causing deflection. A coarser blade with deeper gullets will eliminate this possibility.

  3. #3
    Join Date
    Feb 2009
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    I agree with the blade being a culprit. Without the track, you'd probably be fighting it to stay on a pencil line. The other possibility is the track groove not being in line with the blade. So the blade is being forced along at an angle, deflects as it goes, and then snaps back at the end of the cut leaving the divot. I could probably duplicate this with my Festool by not having the ripping attachment dead straight.

    But I think it more likely the blade is shot.

  4. #4
    Join Date
    Sep 2018
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    I recently replaced the lightly used stock blade on my Dewalt tracksaw with an Oshlun that was relatively inexpensive. 48 teeth on the new blade to the original bladeís 42 teeth. Cuts are now amazingly smooth and accurate. Havenít tried hardwood yet though.

  5. #5
    Thanks. I had read that 40t+ blades were better for clean plywood cuts. Is that not the case? Still, no harm in picking up 16t and 24t blades for test purposes. Even if they don't fix the problem I'm sure they'll come in handy for other work.

    I'll add that I also tried cutting at both a minimum depth to clear the material (say, 15mm) and full depth to use more of the blade (50mm) and saw the same results.

    And I considered trying it without the track, but figured I bought the thing to work on the track, so I want to resolve this use case. If it would be helpful (and safe -- you mentioned fighting the saw) from a diagnostic standpoint to try cutting without the track, I can give that a shot later today.

  6. #6
    Join Date
    Apr 2007
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    Columbus, Ohio, USA
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    3,191
    What stands out to me is that:


    1. It happens every time
    2. It is always at the end of the cut


    I assume that this is NOT related to a specific track location (trivial to test).

    The interesting question for me is.... Does this occur at the front part of the cut or the back part of the cut. My guess is that this is during the back part of the cut. By that, I mean as the back of the blade is leaving the the board. If the starting portion of the cut is fine, then things are well behaved at the front of the saw as you enter into the cut.

    A test:

    What happens if you stop pushing the saw and turn it off before the blade exits the wood? Let it finish the cut, but perhaps the center of the blade is near the end so that you just finished making your cut.

    Also, I assume that everything is supported (say on Styrofoam or similar) so the problem is not that the cutoff is falling and pushing the blade.

    I am wondering if the blade is not supported if the back flexes for some reason.

  7. #7
    The higher tooth count will indeed give you a cleaner cut - especially across the grain. When cutting WITH the grain, on the show (bottom) face, there isn't much of an issue with tear out.

    The fact that this happens even after the 15mm scoring cut is really perplexing because that should solve the issue of blade deflection for the reasons I thought.

    The other issue might be work supporting. Are you sagging? Are you reaching at the end of the cut in a way that causes the saw to tilt?

  8. #8
    The spring back at the end of the cut is indicative of a blade being out of parallel to the direction of the cut. It causes the blade body to ride away from or into the work. I'm not familiar with this saw in particular. I do know that on the Festool it could be the base being out of whack. It could be the bushings that ride in the rail track being sloppy. Of course, user error could be the issue. check that there is no slop when the saw is on the rail.

  9. #9
    Join Date
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    You can check it the same way you'd check a miter slot parallel to the blade, using the guide rail.

  10. #10
    Join Date
    Dec 2010
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    South Coastal Massachusetts
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    What supports the board being cut?

  11. #11
    I do not see how the blade affects part of the cut and not all of it. My DeWalt track saw uses a 48 tooth blade and I have occasionally needed a ripping blade for deep cuts but have used it in 1 inch hardwood this week and 3/4 inch several times with good results. I jointed all 6 boards in my 10 foot dining room table with my track saw and all but one of the joints is really tight. One has a couple hairline cracks presumably due to my technique.

    So it can work. Is it possible your track varies? Have you measured the thickness in the area the saw cuts square versus the area where it cuts tilted? If it is thicker on one side in the tilted cut area that would explain it. But I think you said you've used more than one track. So that would only work if they are all that way.

    The deviation at the end looks like technique to me. I have done that but I generally do not now. It is important to make sure you push along the cut. It is possible to push the saw a little to one side or the other with improper technique. The tilting could be technique too. Another possibility is the dust collection hose. Could it be pushing the saw or pulling on it resulting in the tilting? I haven't had that problem but it seems possible. My darn hose likes to get in the way and fall out sometimes.

  12. #12
    Join Date
    Jun 2007
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    Roseville, MN
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    328
    Check to see if the blade is Parallel to the sole and the track the back tooth should be slightly toed out

  13. #13
    Join Date
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    The blade is being warped into a dish shape by being driven 'sideways' thru the cut. The guide rail forces it that way. Without it, it would probably want to turn as it cuts. I've got an old Skilsaw here that was doing that to me until I got a new blade for it.

    As it exits the cut, the area of the blade holding it warped gets smaller until there's little enough area that the trailing teeth can cut clearance. That results in the divot at the end.

  14. #14
    Thanks everyone for the advice so far. The results of the experiments are now in, and they're interesting!

    - The blade is not perfectly parallel to the sole. Using Wes's suggestion of checking it way you would check a miter slot (combo square + marking one tooth), it looks like the marked tooth is maybe 1/32 " further from the left edge of the shoe (which rides the track). Calipers confirm, about .035" difference. That means the front of the blade points right (away from the track) and the rear of the blade points left (towards the track).

    - My original test cuts were not supported on both sides (I was just cutting an inch or two off the side of my workbench). I went back and did a test cut just now fully supported. I included a photo of the pre-cut setup below.

    - I ran two new test cuts, both fully supported and clamped. The first one I ended right when the center of the blade was over the end of the material (Andew's idea). Lo and behold, this time there is *extra material remaining* on the end of the piece (the opposite of what I originally posted about). This is shown in the photo below with only one cut piece next to the track.

    - The second test cut I pushed the saw all the way through and this time it did the same thing as my original post. This is shown in the photo with two cut pieces next to the track.

    So the evidence seems to suggest that the blade is not parallel and that's causing the issue. Would be cool to film in ultra-slo-mo and see if the blade is rebounding but I don't think my phone camera could capture it. I removed the blade and as far as I can tell it is perfectly flat, although I didn't try anything sophisticated to check it. Just put it on the MDF surface and couldn't find any gaps under the teeth. So I'm guessing it must be something about the arbor being out of alignment? Which probably means first try and new blade and if that doesn't work, call Mafell?

    I'll add that the saw is only a month old, bought new, never been dropped or otherwise mishandled. The edge of the shoe appears to be perfectly straight, as does the track.

    cutting setup.jpggap.jpgended-early-extra-material.jpgfinished-cut-missing-material.jpg
    Last edited by Aaron Karp; 03-25-2021 at 11:12 PM.

  15. #15
    I think you need to send it in for a warranty repair unless there is a user adjustment for this. I would expect the base to be moved a little to align it to the arbor. But I suspect that there is no user adjustment. I am pretty sure there is none for my DeWalt and it has not needed it. I don't think a track saw should need it. Your saw cost more than mine too, so it is far from a cheap one. I would be surprised if there was an issue getting it addressed. Seems like an obvious manufacturing defect.

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