Just bought Delta CMS, 90 is square, 45 is off; need help (novice)

[n_o_s_p_a__m]

When I cut at 90, the cut is straight, tested against a square.

However, when I cut at 45, the cut is not square, but slightly diagonal.

The end result is that when the mitered ends of the moulding are put together, they are tight at the top of the miter, but the bottom of the joint has a gap -- that is to say, the gap gets bigger as you go downward.

Note that I made the 45 cuts with the moulding upside-down. (Does that even matter?) If I make them right-side-up, the gap goes in the other direction - tight on bottom, gappy as you go up.

What adjustments should I make to the CMS to make 45 cut straight so the joints are tight?

Thanks to all. I am a super-newcomer to woodworking, and I need help. I just wasted $22 of moulding.

[n_o_s_p_a__m]

I should add that I stood the molding up vertically for the cuts.

[jo4hn]

[snip] Sigh. I bought a Craftsman CMS some years ago, noticed the problem, and ended up selling it. Noticed it again on a friends new Ridgid. Sorry to see it on the Delta also. It works OK for rough carpentry. Otherwise you have to move the blade to the angle you need (45d in this case) and then realign the blade back to 90d to the table. gloom, jo4hn

[Ba r r y]

If the saw cuts perfectly vertical at one miter setting but not at another, bring it back. The two angle different angle settings should not affect one another. Since they do, your saw's frame isn't straight or the saw suffers from another quality issue.

You could readjust the vertical angle each time you change the horizontal, but that's a real bummer and you'll quickly hate the tool.

Inexpensive CMS's often have this problem, but it's not a problem for the typical framer or deck builder who usually buys it. I have a medium priced version which is good enough for interior trim, but I still cut high precision work, like furniture and picture frame parts on a good table saw.

Cheaper saws also usually suffer from excessive "runout" (Shaft curvature or bearing error) or side to side movement of the blade, both which can lower the cutting precision. The blade included with all but the most expensive saws is also not well suited to tight work. Good blades can be had for $50 and up, from manufacturers like Freud, Forrest, Systematic, CMT, etc...

Low grade pine 1-bys are lot cheaper to use for saw setup. until you develop a scrap pile. When you're really new you don't have scrap yet, so I understand why you'd waste the molding

Have fun, Barry

[Prometheus]

There should be a couple of screws in the back of the fence that hold the sucker on. Loosen them up, and apply pressure to the fence to slide it in the direction it needs to go, tighten the bolts back down, then test it on a piece of scrap. Keep at it until you've got it right. This can be a very tedious process, but it's well worth it once you've got things set up right. I've got a cheap Black and Decker that my folks gave me a couple of years ago as a gift, and if I could get that thing set right, you can certainly get the Delta to cut a perfect miter! Aut inveniam viam aut faciam

[jonathan]

Ba r r y wrote in news: [e-mail]:

Is it possible to find a CMS, or Sliding CMS that is accurate for small pieces, like jewelry box parts? It would be so handy if it were.

[Fred]

I have a Dewalt 10" CMS and it cuts perfect miters at 45 as well as 90. It has done that since I took it out of the box. I'm not talking about framing cuts, but trim for furniture. I just thought it was supposed to do that.

[B a r r y]

I've found small tools, like inexpensive bench top models and "modelmakers" tools sold by MicroMark, to often be LESS accurate than the real deal. Good tools fitted with the right blade and zero clearance inserts and fences work great on fine work. I'd be more concerned with my hands being very close to the blade, and the cutoff getting launched into space.

For small parts, you're probably better off with a hand saw and miter box, Lion guillotine trimmer, or shaping the perfect fit with sandpaper. Slightly larger parts can be fitted with a good, sharp, low angle block plane and shooting board(s), as well as all of the methods that work with smaller stuff. Stationary disc sanders are another option.

Barry

[Rumpty]

pieces, like jewelry box parts? It would be so handy if it were.

You want a DeWalt Radial Arm Saw if you want accurate 45's etc. Forget the chops saws.

[Ellestad]

A decent CMS can cut knife-edge joints but you'll probably need to adjust the saw for starters. Also I think you'll find that typical "thin kerf" blades will wander a little - get a full-kerf, heavy-bodied, negative hook, fine-finish blade.

Most importantly, check your saw's table carefully as you tighten the pivot clamp. Many CMS's actually lift the front of the table as the clamp tightens, tilting the table back towards the fence. You won't be making any furniture-grade miter joints with that saw unless you find a way to tighten the table without lifting it. I suspect that the majority of these saws are used for work at the precision standards of framing and the joinery issues aren't discovered.

Tim Ellestad

[Patriarch]

jonathan wrote in news:1116392048.c24b2e13c422b46710665c1c1c3a1a0c@teranews:

Yes. For example: (watch the wrap)