TS55/MFT3: Burn marks on exit of cut & rounded off edge of cut (on exit)

[adcolor]

Hello, while setting up my MFT3, I noticed two things: A small burn mark along the bottom edge of the cut at the exit; and a rounded off cut about 1-1/2" long (35mm). The gap at the end of the cut (from square) is about 0.01"/.25mm. 

I insured I was cutting past the material before lifting the saw up.

Material is 3/4" mdf, blade is the original.  No additional problems with the cut -- it's smooth with no other burn marks.
I also set the bevel to be accurate and put a block of the same material under the track just in behind the fence (in the event that I was pushing down too hard on the saw and flexing the track).

Otherwise, I have the fence adjusted to 90 degrees from the track cutting edge.

I moved the fence forward one set of holes to confirm the track wasn't a problem, plus swapped another section of track in.

Ideas?

 

[Roseland]

I had a similar issue when cutting at a 45° bevel.  I never really understood why, but the problem went away after I flipped the MFT top over.  I think it may have been sagging slightly.

I've considered making a new top using 3/4" ply with maybe a stiffener under the cut line, but haven't got round to it yet because the problem hasn't recurred.

Festool make and use for their road demo kits (but don't sell) a phenolic-faced ply top, which I think would be ideal. The stiffens (flexural modulus) of ply is 2.5 times than of MDF/HDF.

Andrew

 

[Gregor]

Hello, while setting up my MFT3, I noticed two things: A small burn mark along the bottom edge of the cut at the exit; and a rounded off cut about 1-1/2" long (35mm). The gap at the end of the cut (from square) is about 0.01"/.25mm. 

Try:
- supporting the rail at the end side of the cut with a scrap of the material
- when adjusting the rail to the thickness of the material, open the black levers of both rail holders (forgetting the back one might cause your issue as the rail bends near the end)
- make sure that you don't tilt/twist the saw at the end through reaching the end of your arms reach
- do the cut till the back of the blade left the material

 

[adcolor]

I wondered about the mdf sheet and sag. Didn't have time to go down that rat hole.

I did put a block of the same material under the track on the back side of the fence.
I did cut past the material before raising the saw.

Thanks!

 

[adcolor]

A few more details. The lower edge of the cut piece shows the burn mark.  That's about the length of the 'curve' cut as well. About 1.5-2" long.View attachment 1

 

[bkharman]

Can you remount the rail to a different position?  It is also possible that the index pin is making the rail "move" at the end of the cut. If you just lay the rail down (unmounted) and cut, does it do the same thing?

Cheers. Bryan.

Sent from my iPhone using Tapatalk

 

[adcolor]

Fresh blade -- all is well now. Pushing it too hard was causing the curved kerf as the saw left the material.
I like the easy ones -- just wished it was a cheaper solution!
I'll send it out to Leitz and see how it comes back.

Attached picture is the results of a '5 cut' adjustment.  I'm fine with it this close.