Festool TS55 REBQ not cutting straight at 45°

[SamDupont]

Hello!

I have a TS55 and it works like a charm, it's the mastertool in my shop. However lately ive been doing miters with it and i have noticed that my boxes did not come out square. I investigated and found that when i tilt to 45° and make a cut, the sawblade wanders away from the track at the end of the cut. At first, i thought it was me as the saw is pretty akward to handle at 45°. To help with this is bought the clams so that i can use both hands to guide the saw but still the same problems.

When i cut at 90° i have no problems whatsoever. Has anyone expierenced the same or do you have ny idea why this is happening?

 

[squall_line]

We had a related conversation recently in another thread:
https://www.festoolownersgroup.com/...s-with-ts55-on-cms-table/msg635214/#msg635214

See if there's anything in there that describes your experience?

There's also a discussion in there about how easily confused I get by "mitre" and "bevel".  Any time I hear "tilt", I think "bevel", rather than "mitre", so it may help to take a couple more pictures of what you're seeing from a few more angles to help explain the concern.

 

[ChuckM]

Got a picture of the box to show? Were you cutting miters or bevels?

 

[Frank-Jan]

My guess is that the rail isn't laying flat, this wouldn't matter if the cut is 90°. Try supporting the rail with scraps the same thickness of the material you are cutting.

 

[Crazyraceguy]

There's also a discussion in there about how easily confused I get by "mitre" and "bevel".  Any time I hear "tilt", I think "bevel", rather than "mitre", so it may help to take a couple more pictures of what you're seeing from a few more angles to help explain the concern.

In general, it is assumed that a "miter" is done across the width of the board. This would be like a moulding which would go around a window or door frame, where the stock lays flat.
Yet at the same time, a base board wrapping around an outside corner is called a "miter", even though it would be defined as a bevel cut?
Also when trim wraps around an outside corner, like a column or wainscoting, it is a bevel cut, but the technique is called "miter-folding".

 

[SamDupont]

Here on a different, wider box piece. I cut straight until the last 5 cm, here it wandersz about a mm. I let the sawblade excit the wood completely so it can't be the back teeth that recut the wood. I have nog idea what causes this. This piece is fairly flat and if anything it dips in the middle but i have this problem on plywood as well... The track is clamped and i guide the saw with two hands. Any ideas?

 

[squall_line]

If you put a square on the end, is it square?

If you put calipers on the splinter guard, is it the same thickness from the rail at both ends?

When you cut 90 deg, does it stay next to the splinter guard the whole way?

If the concern is that you're moving away from the splinter guard at the end of the cut, I'm wondering if the splinter guard itself is actually parallel/square and it's possibly an optical illusion?

 

[Michael Kellough]

Beveling with the plunge saw is tricky. Subtle details that don’t matter when square cutting matter a lot when beveling. Foremost is that the vertical distance of the saw to the work is critical. If the guide rail sits high the work will be over cut (resulting in a concave line from end to end) and if it is clamped tight the work will be under cut.

From your description and the pictures I think you’ve clamped the rail too tight at the ends. The reason the under cut edge (the part that sticks out) is at the end of the run instead of at both ends is that you don’t have enough stable rail at the start (not fully plunged before cutting?) and you haven’t got the saw balanced yet, as indicated by the dark blade marks on the beveled workpiece.

Use a longer rail or move the square a little closer to the end. Put another piece of wood the same thickness as the workpiece under the start end of the rail. Practice keeping the balance of the saw consistent from start to finish.

 

[SamDupont]

The rail i am using is the 800 mm one and my piece is 42cm... I have had the problem with the 1400 mm track as well a few months back but did not bother back then. Ths rubber is stilkl good, the 800mmtrack is brand new as wel. When i cut at 90° there is no problem. I have tried recutting a bunch of times with different techniques and putting pressure at different places. Nothing really works...

 

[Birdhunter]

With the saw canted over to 45 degrees, the lateral forces are at their highest. I think getting a true 45 degree bevel cut with a track saw will be very difficult. If you have access to a really good (heavy) table saw, this cut is very easy.

 

[Michael Kellough]

Keep practicing, and you’ll get it soon, but you do need to refine your methods.

When you drive the saw past the workpiece your technique must be perfect. At the start and end of a cut it is generally less than perfect (for most everyone) so you should increase the length of the run using the 1400 track and suitable scrap wood at each end. Since the clamps will only engage the scrap you should tape the scrap to the workpiece, and everything should be well supported by a flat workbench or table.

Assuming you are familiar with photography, imagine you are taking a picture of a painting of a grid and you want all the lines to be straight but you don’t have the very best lens. Around the periphery of the lens the lines get distorted. But in the center (the sweet spot) the lines remain straight. If you move the camera away so the painting only occupies the un-distorted center of the lens then the grid will have straight lines.

If you make the transit with the saw long enough that by the time it passes the real workpiece (the sweet spot) your technique is un-distorted then you’ll get a nice bevel. And then you can practice making the fine adjustments to ensure that the bevel is the exact degree you intended.

While the above still holds, have you checked to see if the splinter guard is over cut at that end of the track and simply making it appear that the wood is “sticking out”?

Also, while the guide rail will conform to a gently bent workpiece and allow you to make a good consistent bevel, if the workpiece is not really flat there will be gaps in the joint even is the cut is perfect.