Miter saw rigidity

[brianlanning]

I stopped by berland's house of tools on saturday. It's a fun place with lots of tools out on display so you can play with them. I'm sort of shopping for a miter saw. I've considered everything from a 12" miter saw (not sliding) to the big 12" delta radial arm saw with the turret arm. I was able to make a few disturbing observations.

For the sliding CMSs the side to side motion when everything is locked down seemed unacceptable to me. On most, I could deflect the blade an

1/8" with one hand grabbing it by the handle. The non sliding miter saws were much better, but still not as rigid as I think they should be. The real shocker for me though was the delta 12" turret arm RAS. It was every bit as bad as the sliders. It seems the round part that holds the motor and slides on the track has some visible play in it. I'd say I could probably get several playing cards into the gap between the top half and bottom half of this part. This is magnified at the tip of the blade producing about 1/8" of play. Maybe if I found a way to bolt that hinge in place, it wouldn't deflect. I wouldn't be able to rip on it (who cares), but at least it would be accurate.

Am I being unreasonable here? I'd say 1/32" is acceptable play with a fair amount of lateral force. Manufacturers go to all this trouble to make the angle setting lock down tight, and for what? 1/8" has to equal out to a couple degrees. How can you accurately cut crown moulding this way? I had been seriously considering dropping $1800 on the delta RAS to avoid this problem, but now I'm glad I didn't. Does anyone make a miter saw that doesn't deflect?

brian

[David]

I posted my observations (unscientific) of most of the leading brands SCMS's side play, about a month ago. There were only 2 that I felt led the pack. An otherwise nice unit, the Bosch was one of the sloppiest.

Dave

[max]

I noticed the same thing. Remember that these saws have not been adjusted. I was reluctant to buy one after seeing the slop but the one I came home with is very tight. max

[David]

I believe the issue that Brian and I both observed has to do only with design and construction; nothing to do with any adjustments.

Dave

[brianlanning]

Which saw do you have, and how much deflection does it have?

brian

[brianlanning]

I was thinking about the delta RAS though, maybe there's a way to shim the turret or tighten the center bolt to clean up the play.

Maybe the sliders have some sort of adjustment also. It's not clear to me exactly where the play is coming from. Most likely, it's small amounts of error added up throughout the mechanism.

brian

[David]

From what I can see, it's just the housing, arm and slider all giving a bit each, adding up to noticeable movement. It's NOT simply adjustments to the slider mechanism. I WISH it were that easy. When side pressure is placed on the saw, you can see a bending motion all along the way from the handle, back to the pivot point.

Dave

[Dave Jackson]

FWIW, just about any saw I've ever used that slides, whether it be radial or scms, will deflect if pushed in a certain direction. The operator just has to make a smooth cut with the saw and not push it very hard to one side or the other. Even with the tightest of saws, the blade can also deflect (especially 12 inchers) if pushed to one side or the other creating a bad cut, so learning to let the saw do the work and just "guide" it with the least amount of effort has worked best for me. Granted, some saws have more/less slop than others, but technique is very important too. --dave

[Leon]

Snip

As far as the Delta RAS is concerned, I would never trust the setup of a display unit. I would be shocked if there were no adjustments for all the locks.

[Chris Friesen]

I wonder if the design of the new Hitachi (where the head slides on fixed rails) might allow for sturdier construction.

Chris

[noonenparticular]

Dave,

I agree that technique matters a bunch, but mostly when dealing with crosscuts. With any angled cut, the tendency for the blade is to wander as either the right or left edge of the teeth engage the material ahead of the opposite edge. This is where the slop will show up the most.

jc

[max]

Brian I have a Dewalt 12 inch non sliding right now. The cuts are dead square and I can deflect the blade itself but not the carriage or head. I had the 12 inch sliding Dewalt and the 10 inch sliding Hitachi and both were tight. The Hitachi is still tight after being used in a shop for 5 years. max max

[brianlanning]

And this is exactly where need the rigidity the most. I've watched norm walk up to his miter saw, cut a 45 degree angle, and end up with perfectly mitered corners. Maybe you can do that on his older PC miter saw, but I wouldn't rely on the ones I saw to be able to do that.

I have a cheapo delta 10" miter saw with a lot of issues. It sounds like I'd be better off just using that to get close, then making a very accurate miter sled for the table saw.

brian

[brianlanning]

Yeah, now I'm thinking that I could do a lot to the delta ras to clean it up whereas maybe I couldn't to a miter saw.

brian