Broken CMS

[Ed Jolin]

I had a major kickback w/ my Makita 12" CMS while cutting some oak; shattered the fence into pieces and left a couple teeth embedded in the aluminum; literally ripped a whole tooth (not just the carbide) off my Forrest Chopmaster - very lucky I was not injured (wakeup call to myself, though I was not doing anything unsafe or marginal).

Anyway, I bought a replacement fence, but discovered the tool can no longer be aligned; the blade doesn't come down in a vertical plane (comes down in a crab fashion, if that makes sense, so it's not the miter adjustment), so I believe the frame is bent. It's not visibly obvious that the adjustment is off, but as we know, minor adjustments in the wrong direction can be serious. I'm not thrilled about selling it to someone in the off chance they decide it's 'close enough' to use as-is, but I also know that many people's threshold for safety is very different from mine.

When I replace it, I probably wouldn't buy the Makita again, so keeping it for parts isn't useful.

So do I sell for fifty bucks as a 'parts only' w/ written receipt to buyer, or simply toss it, or??

Just curious what others might do.

thanks!
-ed

[Jim O'Dell]

If you are that concerned that someone might try to use it in it's present condition, take it apart, and list it showing the pieces you feel comfortable selling. Motor, blade guard, etc. and leave out the parts you think might be bad or damaged. That way you might get something for it, but won't always have that sinking feeling someone might get hurt. Jim.

[Michael Schwartz]

I am just curious how this kickback had occurred, I have had a few myself, one by misusing a stop block and another by leaving a second peice sitting on the saw table while I made the cut. It seems to me that Chop saws are the first to tool get conformable with and the first to cause an accident.

[Ed Jolin]

Thanks, guys. Jim, good idea - I think that's what I'll do. Don't know why I didn't think of that!

Michael - In retrospect, I believe the kickback was caused by two things, both preventable. I was holding the wood with my hand rather than a clamp. And the stock blade insert in the saw (which I never paid much attention to in the past), was not level with the work surface (slightly below).

It was a 1"x2"x~12" long piece of oak, trimming off 2" or so. So, although I was holding it securely, it was not as secure as a clamp or had the piece been 3ft long so I could really hold it with my full palm with good leverage. At 12", it put my hand right next to the 'no hand' zone. I suspect, being oak, that when it shifted enough to catch, it didn't 'give', like softer wood might have. Secondly, with the insert slightly below the work surface, that may have helped give it even more room to move (or caused it in the first place??), causing the kickback. There were no cutoffs on the surface, and no stop blocks. It was really a fairly straigtforward cut, and I was not in a rush since it was only 12" long I was paying particular attention as I was getting closer to the blade than I generally like. Bottom line, use of clamps and a homemade ZCI leveled to the surface would have likely prevented it. Thanks for asking!

[Michael Schwartz]

Thanks

Seems like hold-downs and clamps are really essential with a CMS, and are the definitive way to prevent a kickback in the first place.

I have never thought about the inserts as it is really easy to overlook those.

In general I prefer to cross cut on the table saw, for one I have access to a Sawstop, and two I feel it can be more accurate and safer. For one with the table Saw the blade is visible all the time, you feed the work into the blade, not the blade into the work, and there is alot less exposed blade surface. Although unless you have a sliding cross cut table or something a CMS or SCMS are the only way to do most cross cutting.

Although miter saws are a huge improvement over Radial Arm Saws they still take alot of safety conciseness.

[Roger Wilson]

Had a kickback once on a 12" sliding cms, luckily it didn't take off any body parts. I believe the cause was that I kept the saw on as I brought the blade up and it caught on the teeth, similar to a table saw kickback.

Another problem with the CMS is that I use it to cut rough lumber which tends to be warped in one way or another, so the blade can bind or the wood shift at the end of the cut. All reasons to use hold downs for this sort of thing.

I now always let the blade come to a stop in the down position before lifting it up. I also use the hold down clamps much more often.

I will have to try a zero clearance insert as well, it should reduce tear out on the bottom surface as well.