Kapex laser adjustment

[vlahtein]

I bought Kapex KS120 about ten days ago. I need the most accurate SCMS for segmented turning projects. I have been trying to adjust lasers like Mr. Christopherson's supplemental manual describes it: "the laser lines split the edge of the kerf" (p.28). The left laser works fine and can be adjusted to split the edge (the beam in the middle of a pencil line => the pencil line is cut half). The problem is that I can not get the right beam to its position, not even to "just outside of the kerf"-position without lost of brightness. It disappears when I adjust the lateral movement towards the centerline. I returned the saw to Finnish Festool importer, they adjusted the lasers, and said that they are now in the manufacturer's tolerances and there is nothing wrong with the lasers. They had adjusted the right laser slightly out of vertical and to "just outside of the kerf"-position. Perhaps it is now in the Festool's tolerances, but I can not be very satisfied. I tried to figure out what causes the asymmetry and ended up to an assumption that a blade is not perpendicular to the pivot line of the saw head. As you can see in the third picture, the right laser hits the saw blade quite near the center line up there close to the laser unit and causes the beam to disappear. The left laser can be adjusted vertical and even beyond "split the edge"-position towards the blade centerline without loss of brightness!

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Picture 1. The beam is adjusted vertical and is just starting to disappear slightly before "just outside of the kerf"-position is reached, when adjusted laterally towards the center line.

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Picture 2. ... and this is how it looks on the table.

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Picture 3. This is how it looks when adjusted to assumed "the laser lines split the edge of the kerf"-position, nothing visible on the table.

Dear FOG members, your answers, advices and comments to the following questions are very appreciated:
1. Can you adjust both lasers to "the laser lines split the edge of the kerf"- position?
2. Does the right laser look same in your Kapex as in picture 1?
3. Can you imagine any other explanation to the problem than misalignment of the saw blade axis (it moves vertical in plunge action, but is slanted)
4. Is the product "in the tolerances"?
5. Is it possible to remove and put back the laser unit covering sticker cleanly? Just for the case I end up to return the saw and ask for another one to be adjusted before purchase...

By the way, do you have same amount of height differences (0.15mm and 0.20mm) in the table as in mine (see pictures below)?

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[ForumMFG]

I'd be interested to see the response.  I even took my Kapex into festool to have them adjust it.  By the time I got home and made the first cut, the right laser was off but the left laser was perfect.  After a couple more cuts both were off.  I can adjust them to be dead nuts but after the first cut of each adjustment, the lasers are off.

 

[Rick Christopherson]

First off, the easy question; to the best of my knowledge, yes, the turntable should be flush or slightly higher than the wings. This keeps your workpiece on the turntable. If it was permitted to be below the wings, then there would potentially be a gap between the workpiece and the throat.

As for your lasers, I believe you need to try to tilt the laser slightly toward the bottom of the blade. This is why your laser is disappearing when you adjust it to split the cut line...it is being split by the blade too. The laser is mounted above the blade, so if you try to have it perfectly parallel to the blade at the same time as splitting the kerf, it is actually an impossible situation.

First, move the laser slightly away from the blade (the lateral adjustment), and then tilt it back toward the kerf. As long as you don?t tilt it too extreme, it should not be an issue for variations in the height of the motor head.

 

[tbellemare]

Am I misunderstanding something here?

The only way I see to have an accurate laser for various work piece thicknesses and motions of the motor head is to have it parallel to the blade and the inside of the laser's width marking the outside of the kerf.

What am I missing that could make any other set up accurate for different uses?

Also, how is "splitting" the laser or having the laser "straddle" a mark as accurate as having the kerf and the laser edge-to-edge?

When I mark something that I want to cut accurately, I know which side of the mark is the side to align with. I see the use of the laser the same way.

Tom

 

[WarnerConstCo.]

Mine have a tendency to move, the few times I have traveled with the saw.  The right one does it more than the left.

I also like them to line up with the kerf, not spliting.  Or better explaination is right lide of left laser is the cut, laft side of right laser is the cut.

 

[vlahtein]

Thank you all for replies!

This is why your laser is disappearing when you adjust it to split the cut line...it is being split by the blade too. The laser is mounted above the blade, so if you try to have it perfectly parallel to the blade at the same time as splitting the kerf, it is actually an impossible situation.

After spending couple of hours playing with laser adjustments, I believe it is not impossible. Pictures 1 and 2 shows how the left beam can even be adjusted closer to the center line than splitting position and vertical.
 
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Picture 1. Left laser adjusted closer to center line than splitting position, motor head down

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Picture 2. Left laser adjusted closer to center line than splitting position, motor head up

The beam seem to go between the blade bits (?), see picture 3.

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Picture 3. Laser hitting blade bits.

Also, how is "splitting" the laser or having the laser "straddle" a mark as accurate as having the kerf and the laser edge-to-edge?
When I mark something that I want to cut accurately, I know which side of the mark is the side to align with. I see the use of the laser the same way.

I certainly do not argue against that. I will try edge to edge method. Up to now I have felt simple and quite accurate to align two lines concentric, see pictures 4 and 5.

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Picture 4. Most measuring tapes and rulers have the actual measurement in the center of a line, do they?

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Picture 5. No mater how wide or crisp the lines, adjusting center to center feel quite easy and accurate

All kind of information and advices, like replies above are welcome. Just to keep the focus on my quite acute problem, any kind of answers to the questions 1-5 are especially valuable. I have to make decisions quite soon. ... Is there something wrong with my Kapex and am I asking too much accuracy ...

Ville from Finland

 

[vlahtein]

First off, the easy question; to the best of my knowledge, yes, the turntable should be flush or slightly higher than the wings. This keeps your workpiece on the turntable. If it was permitted to be below the wings, then there would potentially be a gap between the workpiece and the throat.

What is slightly higher? I would like to use the saw for segmented turning projects (based on the recommendations by Malcolm Tibbetss), in which it is common to cut short pieces. If I have a short piece clamped like in the picture 1, it would be 0.7mm off the table on right end. The throat (the black plastic pieces?) is below the turntable level a millimeter or so. On the other hand, cut is quite square if the piece is supported only on the  turntable, but long pieces are cut out of square so that nobody would call that "dead square".

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Picture 1. problem with a short piece clamping.

I have checked some other accuracy issues after last posting. I have read nice words about "out of the box accuracy" of Kapex as a thing that makes it worth the extra price. I checked squareness of the cut with a half meter long piece and it was not square as mentioned above, but a short piece supported by hand only on turntable was cut very square. I have not tested the scale, but the index piece is not correctly aligned (see picture 2).

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Picture 2.

I checked the mitre angles with six 30 degrees cuts (3 triangles) and they summed up 180 degrees very accurately. So cutting with detents works great, but accuracy of the scale is not what I excepted (see pictures 3-5). I can not calibrate it (compare pictures 4 and 5).

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Picture 3

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Picture 4

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Picture 5

I have continued struggling with lasers and found out that they can be adjusted quite accurately to the blade (parallel with it). I have growing feeling that there is a misalignment of the motor head hinge relative to the blade axis, but I can not be sure or prove it...

What I really like in the saw: good quality guides, speed adjustment, good blade, small footprint and many other design innovations. Based on advertisements and reviews my expectations were probably too high.

Please give your opinions to the following:
1. Do you have same level of accuracy in your Kapex
2. Do you think that I am just asking too much and that issues I have pointed out do not really matter in practise?

 

[vlahtein]

Ii looks like I'm having this conversation mostly by myself, but perhaps it is fair to tell how the story had happy end. I got my Kapex #1 changed and none of  the problems exist in my Kapex #2. The turntable is flush with the wings (or actually _slightly_ above), both lasers can be adjusted just how I wanted (split the edge of the kerf or edge-to-edge and fully vertical in both cases), there is no problem in the mitre scale, and as an extra advantage the turntable rotates easier. 

I cut a little test in 5 minutes just relying on lasers and scales of the saw. It makes me smile. It is so easy to do accurate sawing.

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If you are going to buy a Kapex, I would not recommend to do it from a webshop. Check at least the following before accept the product:
1. Squareness of the fence in relation to the table
2. Straightness of the fence and the table and height difference between them
3. Mitre scale 45 ... 0 ...60 degrees
4. Lasers with a piece of board, ask them to be adjusted if they are not how you like them to be

I have many Festools and have had no reason to complain before. As a mechanical engineer I feel sorry when I saw this kind of "waist of good work". I mean that the product is designed very well and without primarily targeting cost savings (very very rare in these days), good or the best materials available are used, and good quality components as well, BUT then some avoidable little mistakes mostly in assembly and final adjusting result in quality problems. ... or at least that is how it looks to me...

After all, I am happy now and agree with reviews in that Kapex is the most accurate SCMS available ... if you just manage to get good one, and you should, because it is waist of natural resources to have "high-end rifflescope in a shotgun".

Ville
(I have a hotel in every French town  )

ps. sorry about my poor english   

 

[WarnerConstCo.]

I exchanged my first one because of laser issues.

The one I just got seems to be better in every way as well.

It's a darn fine saw.

 

[Brice Burrell]

Ville , glad your new Kapex is working out well for you.

 

[monstrol]

Hi Ville,
I also do segmented turning and I make my cuts with a sled on a table saw.  I have had a hard time getting the accuracy needed to join the segments.  When I assemble my rings I glue up half the ring and cut the ends on a sled that allows me to shave off the difference between the short points and log points. The ends align perfectly and the difference between the points doesn't matter because it will be removed when I turn the piece.  Be careful cutting those pieces on a SCMS.  Check out Ray Allen's work. There are a couple of yahoo groups that deal with segmented turning.  How do you flatten your ring segments?  I have been using a thickness sander and I am always looking for other ideas.
Matthew Jones

 

[vlahtein]

Hi Mathew,

When I assemble my rings I glue up half the ring and cut the ends on a sled that allows me to shave off the difference between the short points and log points. The ends align perfectly and the difference between the points doesn't matter because it will be removed when I turn the piece.  Be careful cutting those pieces on a SCMS.  Check out Ray Allen's work. There are a couple of yahoo groups that deal with segmented turning.  How do you flatten your ring segments?

This is going a bit off-topic, but my answer is linked to the previous posts, so here is how I have done it lately.
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The halves are hot glued on to a plywood

So far I have made segmented blanks mainly because it is relatively fast and economic use of standard wood material. In the future I will probably aim for nice details and then I have to improve my methods. I believe that the first things to do are to make a zero clearance jig and fine tune my Kapex (as adviced in Rick's supplemental manual). I have tried sanding, but my disc sander don't make it straight. The disc is straight but it eats more where the diameter is greater(!). There is a warning about this in Ray Allen's book (or was it Malcom Tibbetss's, I'm not sure). My disc sander is of low quality and small (10") but there is no big play in the bearings or other problems.

So far I have flattened my rings/staves in the lathe, which is a slow method, but I don't have room in my carage for thickness sander. Perhaps, in the future, I'll make a lathe drum sander by following one of many instructions in the net...

Ville