are these accurate enough for aligning shooting boards or bench hooks for 90 and 45? Any other fairly low cost suggestions if not?
Attachment 387560
http://www.leevalley.com/us/wood/pag...=1,42936,42944
Printable View
are these accurate enough for aligning shooting boards or bench hooks for 90 and 45? Any other fairly low cost suggestions if not?
Attachment 387560
http://www.leevalley.com/us/wood/pag...=1,42936,42944
Checking the accuracy on a 90º gauge is easy. Draw a line, flip the scale and draw a line next to the first one. Any deviation of the lines is twice the error of the square.
Most of the time my angle checking is done with fixed try-squares, a fixed 45º miter gauge or a combination square.
The ones above appear to require lining up the edge to the cut. With fixed squares and others the edge lays on top of the piece being checked. This makes it much clearer where any gap may exist by letting light shine between the blade and the work piece.
jtk
Per the specifications from LV those angles are accurate to +/- 1/10 degree. Should be plenty good for those uses.
I have a Shinwa identical to A/B. My 6” Starrett precision square it shows it to be spot on.
I have the miter square and the square square (!), and both are accurate per my Starrett machinist fixed square and my Starrett combo square, for the miter.
For setting up a shooting board, the clear plastic - and cheap - drafting triangles are spot on.Quote:
Any other fairly low cost suggestions if not?
Regards from Perth
Derek
Being a retired draftsman, I agree with Derek. I am also very high on speed squares.
For low cost I would get a 6 inch try square. I make my own squares for larger sizes, but you could also get a cheap 12" combination square. I would also get a cheap bevel square and protractor. At my local store a serviceable bevel square is less than $5.Quote:
Originally Posted by Steven Lee, NC
I haven't used a shooting board in decades, but the best measure of precision is how the joints come out. For instance if you shoot a 45 degree miter on two straight sticks and put them together, any inaccuracy due to the shooting board will be doubled when you put them together to make a right angle. And if you make four pieces each with miters on both ends as in a small picture frame, there will be eight miters; a one degree error will be 8 degrees when they are all together. This kind of testing is more accurate than what you can do with layout instruments because even with perfect instruments there would be error due to your workmanship.
Likewise if you arrange 90 degree cuts in such a way that error is additive and not canceling each other out, you will have a good gauge of accuracy.
For shooting boards, I have given up on fixed fences. I always build my boards with a fence that is held in place with two half-inch bolts. This allows me to move the fence to a 45 degree position and back to 90. It also allows me to adjust the the fence to put it back into perfect alignment. I check it every couple of months and cinch the fence down with a socket wrench.
As for your speed squares. The problem I have with low-cost squares and other layout gear is that a certain percentage of units on the shelf at the big-box store are OUT OF ALIGNMENT. The one you buy may be spot on - but others on the rack may be off by a substantial margin. You don't know which is which until you get home and check it out.
Can you show a picture of your shooting board? I was considering doing something similar.Quote:
Originally Posted by Ted Phillips
While we are waiting for Ted here is a post on my current shooting board with some guides for shooting angles:Quote:
Originally Posted by chris carter
https://sawmillcreek.org/showthread....hoot&styleid=3
Derek Cohen has a few write ups of shooting boards on his site > http://www.inthewoodshop.com < My recollection it is in the section on Shop Made Tools.
jtk