Kapex Blade Deflection? - Problem

ForumMFG

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Today I was cutting maple to put a apron on my work bench i'm making.  I noticed that everytime I made a cut, it was off.  It's a true 45 at the start of the cut but by the time the cut is finished it's not.  I can see this by checking it with my sqaure but you can also see it on the saw.  When the saw blade is plunged all the way down, the top of the wood is resting on the saw blade and the bottom of the wood is considerably spaced away from the blade.  At first I thought it was just the kerf but after I check it with my square I realized it was a problem.  I've had this problem ever since I had the kapex.  It even does it with straight cuts as well.

I the blade deflecting?  Is the blade not fastened tight enough?
 
I would suggest that you try these steps and see if your situation betters:

1.  Make sure that your blade is sharp and the right configuration for the material that you are cutting.
2.  Check the speed of your saw and if it isn't at maximum speed - turn it up
3.  Slow down in the speed that you are feeding the blade to the work - both in chopping motion and also in sliding motion.

Hope that it works for you.

Peter
 
Peter thanks for your suggestions but I have done all 3.  As someone already suggested that maybe that material is moving on me.  At first, I also thought that was one of the problems but I made changes and made sure it wasn't moving and that it couldn't move.  I really don't understand whats going on.  Like I said, I thought it was user error but I checked everything and corrected some issues but I'm still having the problem.
 
In following this post I don't see ay other suggestions but mine yet you reference that others have suggested that the material is moving on you.  I didn't see that suggestion.

Petert
 
I have the same problem on my 10" Bosch slider.... No idea how to fix that either... I even clamped my pieces down, put a new blade in but still, too much deflection! I now cut all miters that have to be precise on the mft and the TS55. Takes a bit longer but the cuts are bang on.

 
After re-reading your posting a couple of times, I believe you are describing making a beveled-miter, where the motor head is tilted instead of rotated. This is an important distinction because it can be very difficult for you to not inadvertently push the motor head sideways slightly as you push the head back. It isn't the blade that is deflecting, but the whole saw.

Don't feel bad. No matter how much experience you have with an SCMS (not just Kapex), it is very difficult to push the motor head back in a bevel cut without applying some side-to-side bias inadvertently. This is the reason why I typically try to avoid this type of cut whenever I can.

If at all possible, you should get better results if you make this as a normal miter cut with the workpiece standing up on edge. If necessary, use the "Tall Miter Latch" for a taller workpiece.

If you haven't done so already, take a look at my Supplemental Owner's Manual, as it covers many of these procedures as well as troubleshooting poor cutting conditions. You will also want to pay close attention to the miter and bevel calibration procedures for best results with your particular cuts.

==========================================

Oh, P.S. Yes, the workpiece can be very prone to moving in this type of cut as someone else pointed out. Also, make sure you are not making both a chop-cut and a push-cut for the same cut. This is described on page 17 of the manual (I think).
 
Rick,

I was not making bevel mitered cuts.  I was making normal miter cut with the workpiece standing up on edge.

-Dave
 
Dave,  is your saw properly tuned?  If your bevel guage stop is out by even a small fraction of one degree, it could cause what I think you are experiencing.  I had to spend some time bringing my saw up to snuff when it was new.
 
Dan,

I never tried to tune it or anything like that.  Is the process explained anywhere?  Is there a way to check it to determine if it even needs it?  I took my square and checked the blade for square and it was right on the money.  Also, this doesn't just happen on miter and beveled miter cuts.  It happens on regular cuts as well.
 
My dealer was telling me about one of his regular customers coming in to the store with a bunch of material. He set up the demo Kapex to make miter and bevel cuts with the goal of building small pyramids. When he was satisfied that the Kapex could do it at the level of quality he wanted he placed an order for a saw. IIRC, he was using maple blocks for the test.

Point is that if you aren't getting what you need get your dealer involved and see what is going wrong. Sometimes it is technique, sometimes it is blade deflection, who knows? Time to do some troubleshooting with a little help.
 
I do not intend to highjack this thread, but...

Does anyone have a copy of Gary Katz's ThisIsCarpentry "magazine" that had the article on how to tune a SCMS.  They used the DeWalt that I have as the model for the article and I want to tune it before I start installing a few hundred feet of expensive trim.

Thanks.
 
GreenGA said:
Does anyone have a copy of Gary Katz's ThisIsCarpentry "magazine" that had the article on how to tune a SCMS.  They used the DeWalt that I have as the model for the article and I want to tune it before I start installing a few hundred feet of expensive trim.

Try this:

Go to http://www.thisiscarpentry.com/

In the help box, with its list of icons, look for the icons representing "Archive" and "Index", so that you know what to look for in the next steps

At the bottom left of the window, click the Archive icon

From the list of (currently 3) issues, click on Issue 02

Issue 02, with a Milwaukee mitre saw on the cover, will now appear on the screen.

At the bottom left of the window, click the Index icon

Next, click on Mitre Saw Tune up

You will now be taken to page 46 where the article starts.

Use the > and < icons at the bottom of the window to move forward and backwards through the pages.

Forrest

 
Thanks Forrest...

I tried doing that and since I missed those icons, it seems obvious I suffered from something that's not repeatable on a family forum.  :-[
 
I am having the same problem with my Kapex, but with small cut offs.  The kerf guide on the table allows small pieces to get caught in it deflecting the blade and ruining a cut.  Anyone know of a replacement kerf guide that is more stable and allows for a zero tolerence cut?
 
Several users have made their own kerf plates for the Kapex.  Search for previous posts and you should be able to find some examples.
 
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