Mt55cc Mitre cutting offset

Have you tried tweaking your saws alignment using the various adjustment screws incorporated into the MT55ccs alloy base?

Step 1: make sure the top tracking adjustment thumb-screws are adjusted for a slop-free glide along the track:



Step 2: (only if your issue isn't solved by the above thumbscrews) you might try adjusting the T20 torx screws on the underside of the saw base, to see if you can achieve an improvement in consistency between 90 degree and 45 degree alignment with the edge of the sacrificial rubber track strip. However, please be careful, because you don't want to throw your saw further out of alignment, so due diligence will be required:




To be completely honest with you, IF you have ensured no slop when running along the track (i.e. you have successfully adjusted the upper-side thumbscrews, as outlined in Step 1) but the behaviour you described still persists, then the type of behaviour you describe makes me suspect vertical misalignment of the pivot points of the saw, rather than horizontal, but, although I can see a grub screw on the underside of the base, near to where the blade-shroud door says 'MT55cc, this does not appear to have any relationship to pivot adjustment in any axis. There are also 2 other grub screws on the underside of the saw base, running along the dead centre of the casting, but those are only to accurately adjust the 'end-stop' of the 90 degree setting of the bevel function, when it is being returned to 90 degree after an angled bevel has been cut.


If overt vertical misalignment isn't to blame, then another possibility could be wear&tear in the bevel-pivot components, during the past 2 yrs of usage - can you sense any play in these components?

whose rail / track are you using?

Just to confirm all my tracks are Mafell and I am talking about putting a full 45 cut , mitre , along a sheet (mdf) .

This is strange because the pivot guides are thick laser cut pieces of steel and the pins are steel as well. For blade to travel away from the splinter guard when tilted almost would mean 

It is either:
- pivoting around an axis designed for a 5-mm rail
- pivoting around an axis for no rail
- pivoting around something else.

1) Measure where the pivot point is:
Take a 6-mm thick piece of something and tilt the blade at 45, and then double back tape that piece onto the base - with it pressed up against the blade.
The straighten the blade up to 0 and see what the gap is.
The gap should be 6-mm - 2.5-mm
If it s a 12-mm piece than the gap should be 12-mm - 2.5-mm

2) Measure the thickness of the rail:
(A rail 2-mm lower than the 5-mm would have the pivot 2-mm away.)

That 2-mm sounds close to 2.5-mm...

Jun 27, 2017 15:18:26 GMT 1 mark1 said:
"Just to confirm all my tracks are Mafell and I am talking about putting a full 45 cut , mitre , along a sheet (mdf) ."

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OK, but that is generally considered as being a bevel-type cut rather than a 'mitre' in the traditional sense, even though you may well be mating 2 bevelled pieces, along their length, to yield a 90 degree L-shape (or eventual box shape, etc.). Semantics is a fickle mistress! LOL


As I remarked in my original reply, I (as holmz has also mentioned) feel that the behaviour you have described points more probably towards a vertical misalignment of some sort occurring (which would lead to a horizontal misalignment of cut being experienced only when the blade is angled/bevelled, and not when at 90 degrees to the baseplate). My suggestion to take a look at the horizontal adjustment screws was partly because I was wondering if there was some play in them (little knocks, here & there, during 2 yrs, can easily occur). Any such play could have particular relevance, in relation to bevel cuts, as bevel cuts sometimes have a greater tendency to draw the saw sideways, than do vanilla 90 degree cuts, even though that might sound counter-intuitive.

If no play (or wear&tear to the pivoting components of the saw) is evident, then I have another question for you:

Do you still have the anti-slip rubber strips mounted on the underside of the guide-rail, or has one or both of them been damaged, abraded flat (by continual rubbing on abrasive materials), removed, or lost, during your 2 yrs of ownership?



In particular, if the anti-slip strip nearest to the sacrificial cut-line rubber strip is absent or abraded flat, then this would lead to the track sitting approximately 1mm lower than intended, and thus the saw also sitting 1mm lower (on the identical Mafell & Bosch rails I just photographed, the anti-slip strip protudes approximately 1.2mm from the aluminium underside of the rail). So, the abrasion, or absence, of this rubber strip could yield sufficient vertical misalignment, to send the top surface of a 45 degree cutline approximately a millimetre away from the sacrficial rubber cut-line strip (similarly, if one unwisely doesn't bother to clear detritus from the top surface of the aluminium guide rail, before applying the saw to the track, the opposite scenario can happen, whereby the 45 degree angled blade can cut more material away (including some of the sacrificial rubber cut-line strip) than was intended).


A further point worth considering is that bevel cuts can have a greater tendency to induce the guide rail to creep across the material surface, so, even if you are experienced with getting good 90 degree accuracy with your saw and guide rails, without using the guide rail clamps, I suggest you always use the rail clamps when doing bevelled cuts (this creep-tendency, during bevel cutting, has sufficient potential to be the reason for your saw-line deviating from intended, so it should be investigated seriously).