Accurate cross cuts

Page 1 of 2  
What is the best piece of equipment to use (and who makes it) to obtain accurate cross cuts? I have a Sears radial arm saw and it seems like I spend all my time adjusting it. Any recommendations would be appreciated.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Larry, that wasn't a very "humane" thing to do was it? Give it to ...Humanity I mean? \
wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Are you asking how to use your RAS better or for recommendations for new equipment?
I have a 25 year old Sears RAS and it stays in adjustment quite satisfactorily as long as I change in in the bevel and miter modes. If I switch to rip mode or move the motor in the vertical mode for surface planing, then I have to at least check the alignment when I go back to cross cut mode. The big advantage of a radial arm saw is its flexibility, but you pay for this in terms of more frequent adjustments.
If you are looking for recommendations that involve other equipment, then I would suggest a miter saw (chop saw) dedicated to cross cutting smaller width pieces or a table saw with a cross cut sled. If you work with large width pieces, then you might invest in a panel saw.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I too have RAS, made by Ridgid. My complaint is not flexing, but the fact there is no indexing of the arm at any angle, much less 90 degrees. The only way to really set it is to use a framing square off the fence, and then do a crosscut on a broad piece of wood, flipping it over to see if the gap is closed on the cut. A hassle, don't like it, but dealing with it..Otherwise, I like the flexibility of cuts you can make..

spend
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

If you have an accurate square, you already have all the equipment you need. NOTE: if your square also came from Sears, you do not have an accurate square. Accurate squares come from specialty dealers catering to woodworkers or machinists. Starrett is a particularly good brand. A bit pricy, but worth it.
You can make accurate, repeatable 90-degree crosscuts with this saw, provided that you (a) take the time to align it dead-on to 90 degrees using an accurate square, (b) have a good straight, flat, and smooth fence board, (c) never budge it off of 90 degrees once you have it set up (or take the time to realign it to 90 after you change the angle), and (d) check periodically to make sure it's still square.
It is not possible to accurately set *both* the 45- and 90-degree stops on this saw. Setting one of them accurately misaligns the other by a fraction of a degree.
Another option is a good-quality table saw (these also don't come from Sears), and a precision miter gauge for it, such as one of the Incra miter gauges (www.incra.com). I have an Incra 2000 that I'd be willing to sell, so that I can buy an Incra 3000; if you're interested, email me at the address shown in my sig line and we can talk about it.
-- Regards, Doug Miller (alphageek-at-milmac-dot-com)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

This is sufficient to demonstrate approximate squareness, but is not sufficiently precise to determine a truly accurate square.

Actually, that will work a *lot* better. You need a machinist's square of known precision, a straightedge also of known precision to base them against, and a set of feeler gauges to measure the deviation between them.

Oh, no, not *that* debate again (Strickland vs. Bennett).
-- Regards, Doug Miller (alphageek-at-milmac-dot-com)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

woodworking, and

0.001" over

from the

seconds).
For anyone keeping score at home, 99.9% of normal people use a speed square for rough carpentry since they don't want to bang up their combo square in a rough carpentry environment.
A marking pencil or knife is going to be significantly thicker than .001 rendering that sort of accuracy useless for woodworking. Additionally, unless you're using a robotic arm to mark, the line is going to waiver as your arm moves the knife or pencil. You can also add in blade deflection, wood movement, etc. and figure out that .001 accuracy is complete overkill in woodworking.
So get the cool .00000001 accurate tools if you want but please don't think that they're going to do any better for you than a .01 tool.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
FINALLY! the voice of reason. well said, Steve
dave
Steve wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Maybe I should have been a bit more specific.... I use the Starret square for aligning my woodworking tools, principally the jointer and the table saw.
Then again, maybe you should have read more carefully, too, and not made up your numbers. I said a square accurate to 3 minutes (0.05 degrees) isn't good enough in my opinion, but one accurate to 17 seconds (0.005 degrees) is. I didn't comment on the adequacy of "a .01 tool" but for the record I'd imagine it's good enough. But you won't find a square at Sears that's that accurate.
Accuracy of results will be no better than accuracy of setup. If you're content with your results using squares from Sears, fine, more power to you. I bought the Starrett square specifically because I was *not* content with the results I achieved using the inaccurate stuff from Sears to set up my tools.
I am very pleased with the results I get using better equipment.
-- Regards, Doug Miller (alphageek-at-milmac-dot-com)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
if you are talking setting up the equipment, I agree that AFFORDABLE accuracy is imperative to excellent woodworking results. Rather than spring for Starrett stuff, I check the squares for reasonable accuracy. The one I picked up at a WW show last year is fine. The framing square I've had for years is a joke. It would work for rough-in, but that's about it.
BTW, I DO have one Starrett product: a digital tape. Now that's a contradiction. If you use the digital readout, accuracy is worse than 1/64, at best!
dave
Doug Miller wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

for
Yep - propagation of errors theory. Makes perfect sense to me that the "first line" tools should be as "dead-on" as possible, not dead-on as practical.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
come to think of it, I rarely mark a piece with pencil. I cut all similar pieces (crosscuts OR rips) with the fence set on the TS. For crosscuts, I use a 1" thick aux fence as a stop when using the sled. No fiddling around with a square or pencil. that's a time waster and completely unnecessary to get accurate 90 degree crosscuts.
dave
Steve wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Well said.
Have a nice week...
Trent
Cat...the OTHER white meat!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 20 Aug 2003 16:02:02 GMT, snipped-for-privacy@milmac.com (Doug Miller) wrote:

I consider it accurate if I get an accurate cut across the entire length of the work area...usually 8 to 12 ft. for most of my work.
What device are you using?...to discover that a square is off .05 degrees? lol And are you drawing that 'square' line with an 8' for 12' square? Or are you putting another fallible scribing tool on the work to finish the line?

Correct...by a 'measuring' device'.

I meant 'dead-on' for my purposes, of course. Why would you think I meant differently?
How far off do you think the bubble on a LEVEL is? lol
Its all relative. If you think a line drawn with a square should be dead-on...meaning NO deviation whatsoever...then I have never had a proper square.
And I don't think you have, either.

Obviously, its very different.

Hardly accurate across 100 ft. But just as accurate as any of mine...for woodworking.

Yes...it is.

I've got several 'squares' that I've built...2'x4'...2'x8'...etc...that are 'dead-on'...for what I want to do.

Sears doesn't just sell Sears stuff. There are some good quality tools...all kinds including powered...that come from Sears. Some even have the Sears name on them.
My last take on this.
Have a nice week...
Trent
Cat...the OTHER white meat!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Feeler gauges to determine deviation. Quick mental calculation to determine deviation per unit length. Calculator to convert deviation per unit length to deviation in fractional degrees. It's simple trigonometry.

As I mentioned in another post, I'm using the square to align my table saw, jointer, and radial arm saw. I never mentioned using it to scribe lines, and in fact I don't do that.

Then you're using terminology incorrectly. Dead-on is an absolute term, not a relative one. There is no such thing as "dead-on for your purposes". It's either dead-on, or it's not.
What you meant was it's close enough for your purposes. And I have no quarrel with it, stated that way.

Irrelevant.
Quite so. I *do* have one that's accurate to +/- 0.001", though. You don't.

No, it's not. Align your table saw with your square. Then use that square to set your miter gauge at 45 degrees. Now cut a mitered frame, say 30 by 38 inches (which happens to be the size of my living room coffee table). Assemble the frame. Then measure the gaps at the joints. Maybe you're happy with what you see.
When I do this, the joints have no visible gaps, and a 0.002" feeler gauge (the thinnest I have) cannot be inserted.

If it's good enough for you, fine. But don't claim that it's "dead-on" when you understand neither what the term means, nor how to measure it.

"Good enough" is *not* the same as "dead on".
-- Regards, Doug Miller (alphageek-at-milmac-dot-com)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
For those of us just getting up to speed, would you care to explain the best way to check the squareness of a square? I've always heard the thing about putting it up against a straight flat edge of wood, whether jointed or a sheet good factory edge, and draw one line, and then flip the square over and draw a second line parallel to the first, and then measure the difference (hopefully none). Most of my squares, whether carpentry, try, or large/small combo squares seem reasonable on by this method (I have a framing square that needs adjusted, it seems), but I question how accurate the method is, especially w/ that little 6" combo square (not a very long line to pick up error on). Any suggestions would be helpful.
Thanks,
nuk
--
I know more than enough *nix to do some very destructive things,
and not nearly enough to do very many useful things.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Couple more questions:
1) how are the Incra Guaranteed squares as a 'reference' square? Any others of similar design i.e. reference square that would be worth investigating?
2) I've heard a bit o' rumbling here and there about the combo square not being the best choice for a 'trusted' square due mainly to the moving parts. Any comments in that department?
I've been eyeballing some Starrett equipment to go along w/ some Mitutuoyo that I have for some other uses (digital calipers and micrometers). Suggestions on places for the best prices?
Thanks,
nuk
--
I know more than enough *nix to do some very destructive things,
and not nearly enough to do very many useful things.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Couldn't say about the Incra, never seen one. If you have a metal lathe and the ability to use it well, a reference square can be made, accurate to .0002-.0003 per foot, fairly easily. If you want to buy one, do a Google search on "cylindrical square".

In theory, that is quite correct. In practice, a good combo square, well maintained, will be more accurate than what you can get out of woodworking tools.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
No, if you have a cylindrical grinder and are really pretty good using it, you can make a reference square to a few tenths per foot. You'd be a pretty long time getting that on a lathe, and it would be by luck not skill in the end.
Brian

and
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Horseshit.

woodworking
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Site Timeline

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.