Greetings all...

I have been constructing a new crosscut sled, and the thought came to me,
how close does this need to be to make nice joints...

Instead of using a square I cut the sides off an 8" square of birch
plywood, I then ripped a strip off the first side and measured the
difference with a dial caliper, and over 8" there is less than 1/128
difference, but that would be compounded over 4 cuts right?

So would you guys try to get it closer of just leave it as is?

"DCH" wrote in message
8...
Greetings all...

I have been constructing a new crosscut sled, and the thought came to me,
how close does this need to be to make nice joints...

Instead of using a square I cut the sides off an 8" square of birch
plywood, I then ripped a strip off the first side and measured the
difference with a dial caliper, and over 8" there is less than 1/128
difference, but that would be compounded over 4 cuts right?

So would you guys try to get it closer of just leave it as is?


I might try to get it closer but some times measurements can deceive or may
not be done accurately. Sawing technique can often render measurements
useless.

Use some scrap wood, make a frame and ask yourself, is that good enough?

Keep in mind that opposite parallel sides must be exactly the same length
also or even perfect 45's will not close properly. Use a stop to insure
same length "opposite" sides.

"Leon" wrote in
:


"DCH" wrote in message
8...
Greetings all...

I have been constructing a new crosscut sled, and the thought came to
me, how close does this need to be to make nice joints...

Instead of using a square I cut the sides off an 8" square of birch
plywood, I then ripped a strip off the first side and measured the
difference with a dial caliper, and over 8" there is less than 1/128
difference, but that would be compounded over 4 cuts right?

So would you guys try to get it closer of just leave it as is?


I might try to get it closer but some times measurements can deceive
or may not be done accurately. Sawing technique can often render
measurements useless.

Use some scrap wood, make a frame and ask yourself, is that good
enough?

Keep in mind that opposite parallel sides must be exactly the same
length also or even perfect 45's will not close properly. Use a stop
to insure same length "opposite" sides.



its kinda funny....but I was able to get it almost perfect, within a
needles width on the dial caliper, I would think that would be close
enough, but last night I had painstakingly straightend and squared the
bit that would become the main fence and after all that I managed to
install it with the wrong face to the saw....after switching things
around my test cuts came out much better....

On Apr 22, 12:56 pm, "Leon" wrote:

Use some scrap wood, make a frame and ask yourself, is that good enough?

I couldn't agree more with everything Leon said, not the least being
to try it out to see for yourself.

You are talking about making a wooden device that you think will hold
tolerances to within one 0.0078125th of an inch. Think about it; a
wooden jig that will hold completely true through humidity changes,
temperature changes, techniques differences, movement of the sled in
response to different weight, density and size of material, etc.,
etc. Not happenin'.

Don't cheat yourself For dead bang spot on, buy a calibrated miter
gauge.

Or... just use your miter saw. I for one have never understood the
folks that have to use their tablesaw for everything from precision
miter work for small pieces like building picture frames to making
raised panel doors.

Maybe its just me. I could see it on really large pieces I guess, but
even then... how often does one need a miter on a 12" board?

Robert