Bosch 5412L SCMS - getting tearout

[GaryA]

I've had this saw for a year now, but just started really putting it to work this past weekend. I love the saw...it makes great, clean cuts with the standard Bosch 60T premium blade, but when cutting some poplar, I'm noticing that I'm getting a bit of tearout. Is there a blade that would do a significantly better job (this one is supposed to be a great blade)? Also - is there such a thing as a zero clearance throat plate insert like on a TS?

[poolhound]

Most of the CMSs have a very broad throat opening. You can just remove the TP and make a ZCTP for it. I made a new one for my Dewalt CMS only last weekend. I used a 1/4 mdf insert. It really helped improve the cut.

Jon

[GaryA]

Thanks Jon....i'll give it a shot....did you use true MDF or hardboard?

[poolhound]

I used MDF but to be honest I just seached through my sheet scraps to see what I had that was closest to the needed thickness so I wouldnt need to plane it down or shim it. As long as it has a supportive surface once you cut the kerf and the thickness brings it directly under the work piece the nit should work.

Depending on how much you are cutting you could just place a sacrificial backer piece to your workpiece. At least for a test this will tell you wether making a ZCTP with your current blade will help at all.

Jon

[mschrank]

I lurk on another forum (DIY'ers not allowed to post), and ran across an intriguing idea to deal with this problem.

Make a plate to fit your miter saw, then rout a shallow dado down the center to match the width and thickness of a piece of self stick melamine edge banding. That way, you can replace just the piece of edge banding after making a bevel cut (which destroys the zero-clearance gap for a 90 degree cut).

Here's the link, though I'm not sure you'll be able to see the pics without signing up: http://forums.jlconline.com/forums/s...ad.php?t=30087

I would post one of the pictures, but I'm not sure if that's proper forum etiquette?

[LarryG]

The stock blade on my CMS was truly crap, so I quickly replaced it with a Forrest Chopmaster. MUCH better, but I still get some minor tear-out on some woods.

My saw (Delta 36-255L) came with an uncut insert plate that had to be cut to make a ZCTP. It worked fine until, as Mike says, I made some beveled cuts and opened up the slot. By coincidence I have some replacements on order (yeah, I know, I could make them myself; but at only four bucks a pop, I'll take the lazy way out). I'm going to hang onto my original insert for beveled cuts, and for use with the stock blade when I'm cutting aluminum or pressure-treated material.

To prevent tear-out on the vertical backside of the workpiece, I often position a scrap slab of 1/2" MDF between the workpiece and the saw's fence, long enough to bridge across the gap between the fence halves. I've also been to known to wrap a strip of blue painter's tape around dowels and the like.

[drumpriest]

My makita is setup nicely for this, you can typically attach a wood fence to your saw's fence, and as Larry states that'll help with back edge tear out. There are some holes in my Makita's fence for doing this, perhaps there are some on your bosch as well. In my experience I don't get tear out along the bottom edge, just the back side.

[GaryA]

Another good idea...thanks Keith. Yep...got mount holes on my fence. I was trying to find a picture of this, but I'm pretty sure I know what you mean. Basically, just a backer piece mounted to the fence, and run the saw right through it for a zero clearance fence on the backside, right. I guess on a chopsaw this would be more important on the bottom, but on a slider, the back would be where you'd get a majority of the tearout if not supported?? Starting to make sense why my cuts are the way they are....