Can you hand saw to within a 1/1000"?

[Brian Sommers]

I'm in the process of tweaking my table saw. I just have a Dewalt 7491RS contractors saw. I checked the front to back of the blade to the miter channel. I was off 22/1000". I was able to tweak it to 2.75/1000". Much better. I will be building a crosscut sled for it and I hope to tweak that within a 1/1000"

now, before everyone thinks I got lost and ended up in the wrong forum....

I'm about ready to forget the cc sled and buy me a bad axe for my crosscuting. But can you hand saw say a 12" board and stay within .oo1" from front to back?

[Nick Stokes]

I wouldn't have any way to measure that.

[Dave Parkis]

I certainly can't saw that accurately, but I wouldn't try. I (and I suspect most) saw just outside the line and then plane to the line/knife line.

[Malcolm Schweizer]

I certainly can't saw that accurately, but I wouldn't try. I (and I suspect most) saw just outside the line and then plane to the line/knife line.

What he said. Dead accurate with a well-set-up shooting board and plane.

[Archie England]

I certainly can't saw that accurately, but I wouldn't try. I (and I suspect most) saw just outside the line and then plane to the line/knife line.

Oh, yeah! That's the plan!!!!

It's also why I've migrated more toward handtools: I'm now capable of snicking up on a line.

[Prashun Patel]

Man it seems like there's so much power tool vs hand tool debating these last few days!

I don't tune my table saw to anything more than my engineer's square and my eye can see. None of my squares are completely perfect. My hand sawing isn't perfect.

I'm in the camp that supreme accuracy doesn't seem to matter on most builds. Now, if I were a cooper or building octagonal miters or something, maybe. But for most joinery - even dovetails, the work seems to look much better once it's finished, and usually my attempts to be perfect are more academic exercises than ones with any practical benefit.

[Tom M King]

333256This siding was sawn with a hand saw. It looks tight, but it's floating on the nails in drilled holes. You can push each board in and out with a fingertip some, as you can all the rest of the boards on that house. I don't know if it's within a thou or not because none of it was measured. It was all marked with a preacher, and sawn with a 10 pt. handsaw I sharpened. It was not touched with anything after the saw. The top board on any section was cut first, nail holes drilled, and that board used as a "jig" to drill all the holes below it.

This was a house I built in 1991, and picture taken a few years ago. That was just a place on that house that didn't have so many spider webs on it to take a picture. It has a porch all the way around it, so it's not directly in weather, but it's never had anything on the Cypress. The downsized picture doesn't really show anything very clearly.

I saw siding with a handsaw because it can't be sawn like that with a power saw. If you spring one piece in tight, it will open up the one below it sometime in the future. This picture is something past twenty years since I built that house.

I can use power tools too.:)

[Malcolm Schweizer]

^^^ Tom King wins. We can all go home now. Very impressive. My arm hurts.

[Bill McNiel]

Man it seems like there's so much power tool vs hand tool debating these last few days!

I don't tune my table saw to anything more than my engineer's square and my eye can see. None of my squares are completely perfect. My hand sawing isn't perfect.

I'm in the camp that supreme accuracy doesn't seem to matter on most builds. Now, if I were a cooper or building octagonal miters or something, maybe. But for most joinery - even dovetails, the work seems to look much better once it's finished, and usually my attempts to be perfect are more academic exercises than ones with any practical benefit.

I could not agree with Prashun more. Almost every day, when I'm in the shop, I think about all the posts regarding a thousandth of an inch accuracy and wonder how I have managed all these years just making stuff. I don't have a stance in the great hand vs. tailed tools debate, I guess I'm a hybrid- whichever approach I believe will provide the best finished product is what I use. Same with taking the tool to the work or the work to the tool, whatever is easiest and provides the finish level I seek.

[Jeff Heath]

The guys that want to debate .001 accuracy in a woodworking tool or procedure are typically the same guys who never actually make anything in the woodshop. .001 accuracy is for metalworking. The eye can't even see that difference, and the wood is going to continue to move more than that.

Make some sawdust and shavings, and don't worry about it. If it doesn't fit, smash it with a big hammer. You can steam out the dents later with a micrometer-based steamer that will count the exact number of molecules of H2O separated by the steaming process......

[Mike Henderson]

I'm in the process of tweaking my table saw. I just have a Dewalt 7491RS contractors saw. I checked the front to back of the blade to the miter channel. I was off 22/1000". I was able to tweak it to 2.75/1000". Much better. I will be building a crosscut sled for it and I hope to tweak that within a 1/1000"

now, before everyone thinks I got lost and ended up in the wrong forum....

I'm about ready to forget the cc sled and buy me a bad axe for my crosscuting. But can you hand saw say a 12" board and stay within .oo1" from front to back?
If your blade to miter slot is within 2.75 thousandths, you're never going to get to 1 thousandth with a crosscut sled. The 2.75/1000 is your limit and the crosscut sled will add some additional error.

At least I can't see any way of getting better accuracy from a system with a certain amount of built in error.

But I agree with with Prashun. I often cut to fit, even trim to fit. The last thing I worry about is a few thousandths of an inch.

Mike

[Ron Bontz]

Well your contractor saw would never be as accurate as my Uni. or other higher end cabinet saws, but despite any claims, no hand saw will ever be that accurate. Better to have a shooting board handy and sneak up on it as mentioned. Even plywood or metal expand and contract. Just not as much as solid wood.
Thanks for posting. Good food for thought.

[Allan Speers]

Another advantage here is that the stock will always move on you after that first cut, at least a little. Letting it rest, then planing or shooting gives better results than a TS. Also, sneaking up on the fit can be a life-saver, if you're the picky type.

[Jim Koepke]

One of the things I learned early in my woodworking is the more measuring of 16ths or 32nds the more likely things would be ill fitting.

Cutting to fit or to comparison is easier and looks better in the end.

As others have said, cutting to a particular measurement to 0.001" isn't really for woodworking it is for metalworking.

When I cut slats for a potting bench top they are usually treated to a couple of swipes on a shooting board. When the pieces are finished their isn't a detectable difference in length by feel or by eye when they are stacked.

So with a shooting board and care it is likely possible to make pieces within 0.001" of each other.

The question becomes where is it necessary?

jtk

[Frederick Skelly]

I'm about ready to forget the cc sled and buy me a bad axe for my crosscuting. But can you hand saw say a 12" board and stay within .oo1" from front to back?

I'm certain that I'll never be able to do that. But, for the work I like to do, I don't need to. I think it's a neat exercise to set up your TS to be hyper-accurate - just the challenge of doing it is kinda neat. But in my mind, it's an exercise, not a "need".

It is an interesting question though. Thanks for posting it.
Fred

[Pat Barry]

333256This siding was sawn with a hand saw. It looks tight, but it's floating on the nails in drilled holes. You can push each board in and out with a fingertip some, as you can all the rest of the boards on that house.

I saw siding with a handsaw because it can't be sawn like that with a power saw. If you spring one piece in tight, it will open up the one below it sometime in the future. This picture is something past twenty years since I built that house..:)
Hi Tom, that's nice work that you did there but I fail to grasp two key points that you make and I'm wondering if you could expound a bit on them? I underlined them in your quote above. Why is it important that the boards be floating (loose) as you describe? Second, why can't you do that with a miter saw?

[Adam Cruea]

Cutting to fit or to comparison is easier and looks better in the end.

Sage advice.

Though, OP, to answer your question: Bad Axe saws are some really, really good saws, and Mark's website is a wealth of information. I have 4 saws from him (rip/x-cut jack, x-cut sash, hybrid dovetail). They're pricey, but you get what you pay for.

My only regret is that I can't buy more saws from Mark (or try Ron Bontz's). A man can only use so many saws, especially when that man doesn't have a saw till (sigh).

[Daniel Rode]

You're comparing Porches and pickups.

I
I'm about ready to forget the cc sled and buy me a bad axe for my crosscuting. But can you hand saw say a 12" board and stay within .oo1" from front to back?

However, I use my cross cut sled all the time. I don't know if it's within 1/1000 over 12". Never measured (never will). It's dead square when I check the cut by eye with a known square. When it's not dead square, I (A) adjust the square or (B) clean it up on the shooting board or (C) Both. Quite often, I take the perfectly square saw edge and clean it up on the shooting board anyway. The smooth edge is nice for marking accurately for joinery and it's how I insure to pieces are exactly the same length.

I feel like I can be MUCH more accurate with hand tools.

[george wilson]

Of course you cannot hand OR power saw to .001". The wood moves,and in the case of both saws,especially the hand saw,too much FUZZ on the sawn surface to be measurable to that accuracy.

Oppenheimer got in a tizzy because he could not get the lid to fit onto the atomic bomb at Trinity test site. Some one else had to remind him that the bomb's casing had to adjust to the heat of the desert. Then the lid fit. You KNOW that the machining on that bomb was beyond reproach. Too bad they had to later BURY all those super fine lathes,etc.,due to contamination.


THIS IS ANOTHER SILLY THREAD!!

[Mike Brady]

Can you cut your finger off before you even know it with a handsaw? I bet not.

[Chris Fournier]

Depending on the type of work I will either machine to fine measurements or cut/trim to fit. There is nothing wrong with working to very tight tolerances as long as you keep the big picture in mind, wood is not metal and not all fitment has to be watertight!

When learning to target shoot an elderly gentleman approached me as I blazed away at a target that was essentially a 6" diameter black circle (demarcation was too fine to see down range). He told me to aim small and if doing so I would miss small. He gave me an 8.5" X 11" sheet of paper with five .75" dots on it - centre and four corners. Sure enough as I began to shoot at this target my accuracy improved instantly. This same principle will serve you well in the wood and metal shop too.

[george wilson]

So,did you learn to shoot to .001"? :):):)

[Adam Cruea]

Can you cut your finger off before you even know it with a handsaw? I bet not.

No, but I can tell you from experience, you can cut pretty deep before it registers.:p

[Dave Anderson NH]

A couple of notations on this thread. Even with a perfect tablesaw arbor and perfectly flat and true blade there is going to be some lateral movement in the blade as it cuts (whip if you will). As for fitting hand cut parts for joinery to within .001", even if you are able to do it, your parts must be assembled within seconds or minutes or wood movement will not allow a fit. Note though that a good and well fit mortise and tenon joint cut by hand should fit within about+/-.005" to +/-.010". Anything looser and you will have a sloppy fit. We regularly work to very tight tolerances with wood without realizing it whether we actually measure or not. Shaving, rasping, and other forms of sneaking up to the "perfect" fit are all done regularly by skilled hands. Measuring whether it is by caliper, ruler, story stick, or any other means is just to get us in the neighborhood. Fine tuning will always be required.

[Chris Fournier]

So,did you learn to shoot to .001"? :):):)

Still working on that George but I can reload and get my COAL to within a .001". Well most of the time anyway!

[george wilson]

I agree,Dave. I like to PRESS IN my inlays. But,as you note,this fine fitting is in small areas such as joints. They do require "sneaking up" to obtain the fit.

Joints which you can see the 1/8" gaps even on television,AIN'T MAKING IT,as Clint Eastwood would say!:)

Chris,it is amazing how accurately a simple .22 rimfire will shoot(within its practical range),compared to most,much more sophisticated high powered rounds.

[steven c newman]

On a good day...
333282
I can even split a line....

[Matt Evans]

No, but I can tell you from experience, you can cut pretty deep before it registers.:p

Yes one certainly can. One of my Sandvik saws cut nearly through the tip of one of my fingers a few years ago, through the fingernail, flesh and a little into the bone. Might have been half a stroke of the saw.

[Brian Holcombe]

For mortising I think it's more important get a friction fit than to hit everything within .001". Wood moves, as mentioned, more importantly wood compresses and often times an exact fit is a loose fit once the fit is checked and the parts are compressed. A part which compresses slightly to fit will remain tight....slightly is key and judging how slight is easier, IMO with a chisel than with a table saw.

As far as crosscutting goes, if you have stops set you can probably saw as accurately as a handsaw and shooting board. It will be more difficult to adjust your work, if need be.

[Patrick Chase]

I'm in the process of tweaking my table saw. I just have a Dewalt 7491RS contractors saw. I checked the front to back of the blade to the miter channel. I was off 22/1000". I was able to tweak it to 2.75/1000". Much better. I will be building a crosscut sled for it and I hope to tweak that within a 1/1000"

now, before everyone thinks I got lost and ended up in the wrong forum....

I'm about ready to forget the cc sled and buy me a bad axe for my crosscuting. But can you hand saw say a 12" board and stay within .oo1" from front to back?

Enough with these "can you hand tool people do X" threads.

For the record, the answer is "no". I would further argue that the inherent resolution limits of the human visual and muscular systems mean that nobody can possibly do that while cutting freehand (obviously with the right guide you can do anything, since at that point the only difference from a machine is the energy source. See: Jointmaker Pro).

[Pat Barry]

Can you cut your finger off before you even know it with a handsaw? I bet not.
Yes it can easily be done, not be me of course because I don't keep my handsaws sharp enough :) but I honestly knew an old carpenter who did exactly that. He cut his thumb clean off in a single stroke as he was crosscutting some lumber for a house he was building. No Lie.

[Pat Barry]

Depending on the type of work I will either machine to fine measurements or cut/trim to fit. There is nothing wrong with working to very tight tolerances as long as you keep the big picture in mind, wood is not metal and not all fitment has to be watertight!

When learning to target shoot an elderly gentleman approached me as I blazed away at a target that was essentially a 6" diameter black circle (demarcation was too fine to see down range). He told me to aim small and if doing so I would miss small. He gave me an 8.5" X 11" sheet of paper with five .75" dots on it - centre and four corners. Sure enough as I began to shoot at this target my accuracy improved instantly. This same principle will serve you well in the wood and metal shop too.
This same principal is a big thing in what separates the pros from the low handicap amateurs in golf. The pros aim to very tight locations (6 ft diameter), the low handicap amateurs aim for quadrants of the green, hackers aim for the green itself, beginners aim to not hit it in the water or in the sand or out of bounds.

[Malcolm McLeod]

Maybe a better question is why you would need such precision by any means?

Most woodworking joints would be classified as friction fits. A friction fit is typically 0.1% to 0.2% of an assemblies overall size - so figure an 8.0000" part needs a 8.0100" socket - - if working in metal with a moderately smooth surface finish and a d&^% good set of calipers/micrometers. There will be virtually no difference in assembly force required if you miss either dimension by 0.001".

Now throw in the surface finish of your average wooden mortise & tenon; you need twice the 'gap' to get the same friction fit. But the wood compresses on assembly. Or swells. Or thermally expands. Or you made the cut DURING a heartbeat. But then the humidity changes. Or you move from Houston to Tucson. ....Doh!! I breathed on it.

I like precision, but I like cutting more than 1 joint in a lifetime even more!:)

[Mark Fisher]

I'm an engineer and I remember when I worked on my first project....I was working with a pattern maker on a model of a pump for what eventually became the Osprey tilt rotor. I had my drawing all ready and dimensions to .001 and all. Damn, I was smart back then.....or so I thought. He taught me a valuable lesson. Even with quarter sawn mahogany (pretty darn stable), wood just won't stay put for .001 tolerances. That isn't to say you shouldn't try to do the best you can, but wood moves way more than that so super precision isn't something to expect. That is why people prefer to cut-to-fit even if their sawing, etc. is nearly perfect.

[Patrick Chase]

I'm an engineer and I remember when I worked on my first project....I was working with a pattern maker on a model of a pump for what eventually became the Osprey tilt rotor. I had my drawing all ready and dimensions to .001 and all. Damn, I was smart back then.....or so I thought. He taught me a valuable lesson. Even with quarter sawn mahogany (pretty darn stable), wood just won't stay put for .001 tolerances. That isn't to say you shouldn't try to do the best you can, but wood moves way more than that so super precision isn't something to expect. That is why people prefer to cut-to-fit even if their sawing, etc. is nearly perfect.

Every mechanical engineer has that sort of experience (I certainly did), but usually only once. By the time I started in industry (1993) we didn't do wood models any more, though, because we had access to stereolith, the original 3D printer - expensive, and not-so-good parts. Sounds like you started between a few years and a couple decades earlier, depending on whether you're referring to the MV-22 Osprey itself or the XV-15 proof-of-concept that first flew in the 70s.

[Jim Koepke]

That is why people prefer to cut-to-fit

In my days as a drafter it was common to hear someone jokingly say, "cut to suite, hammer to fit, paint to match."

jtk

[Malcolm McLeod]

In my days as a drafter it was common to hear someone jokingly say, "cut to suite, hammer to fit, paint to match."

jtk

"Cut to print, hammer to fit, paint to hide." (I work with a much more devious class of craftsmen.)

[Patrick Chase]

Of course you cannot hand OR power saw to .001". The wood moves,and in the case of both saws,especially the hand saw,too much FUZZ on the sawn surface to be measurable to that accuracy.

Oppenheimer got in a tizzy because he could not get the lid to fit onto the atomic bomb at Trinity test site. Some one else had to remind him that the bomb's casing had to adjust to the heat of the desert. Then the lid fit. You KNOW that the machining on that bomb was beyond reproach. Too bad they had to later BURY all those super fine lathes,etc.,due to contamination.

The physics package (Polonium initiator, Plutonium core, Uranium tamper, explosive lenses in that order from inside out) wouldn't fit into the bomb case because it had expanded due to heating from the core's radioactive decay. As you say the fix was to wait for the case to warm up. A close relative was a division chief at one of the two principal bomb-designing labs, so I've head bits of lore. An old crowd favorite is the one that overachieved (https://en.wikipedia.org/wiki/Castle_Bravo).

The machining tolerances weren't as tight as you might think. IIRC they packed foil into all of the air gaps when they assembled the physics package. Keep in mind that the bulk of the physics package (by volume) consisted of machined explosive lenses.

[george wilson]

Well,they were burying Monarch 10EE's. One of the finest model of lathes ever made in the USA. They have a bunch of them down here at NASA. I have a Hardinge HLVH,which some argue is as good,but it doesn't cut the range of threads that a 10EE will do. I like my HLVH though,as it is very light on the controls.

As I am also a m achinist,I can tell you that on objects of metal in any significant size,even .001" can be problematic. Metal expands too.

[Tom M King]

Hi Tom, that's nice work that you did there but I fail to grasp two key points that you make and I'm wondering if you could expound a bit on them? I underlined them in your quote above. Why is it important that the boards be floating (loose) as you describe? Second, why can't you do that with a miter saw?

It's important to let wood be able to move, especially on raw wood that's outside all the time, especially in this part of the country where we get both extremes in humidity multiple times a year. I don't know in terms of thousandths, but you cannot slide a piece of paper in any end joint, and it still is able to move. Cypress is very durable wood for outside, but it does split easier than a lot of other woods if tied down tight. Look at the nail height on the boards, and you will see that it's above the bottom edge some more than you might normally see. Any kind of wood siding here that's nailed close to the bottom puts two nails, top and bottom, at each location. All of that on an old house will have split somewhere on the board. Usually the split is at the top nail, but not always. Twenty five years after I built that house, not one board has split. They pay me to check on it periodically. If you look at the "roofing" page on my website, it's the house with the copper roof. I can't post a link here, but there should be one to find if you click on my name.

As far as a miter saw, it just can't be done that precisely as quickly. By marking with a preacher, it doesn't matter if the angle is a hair off a perfect right angle to follow the line with a hand saw. It would take a lot of trial and error with any end joint that was a bit out of square to set a miter saw to cut that accurately. Especially when working on an old house, it's much easier to not worry about what angle the end of a board needs to be. I use a miter saw anything it's the best tool for the job, but in this case it's not. The boards are cut on a couple of saw horses right in front of the section of wall where they will go up. It's a lot easier to move a handsaw, and a couple of sawhorses, than keep moving or walking to a miter saw. I'll post a separate thread on using a preacher.

By the way, I'm very particular with how the line is marked too. I use a sharp Berol Mirado no. 4 pencil. Those pencils haven't been made for a couple of decades. Marked beside the preacher, you take absolutely no more than the line. The line is very fine, but I've never measured it. I'm sure it's less than the thickness of a piece of paper though. Aim small, miss small.

I don't like to use caulking on the outside of a house. If one is going to get painted wood siding, I cut the boards the same way, and paint each end before it goes up.

[Mark Fisher]

Every mechanical engineer has that sort of experience (I certainly did), but usually only once. By the time I started in industry (1993) we didn't do wood models any more, though, because we had access to stereolith, the original 3D printer - expensive, and not-so-good parts. Sounds like you started between a few years and a couple decades earlier, depending on whether you're referring to the MV-22 Osprey itself or the XV-15 proof-of-concept that first flew in the 70s.

Yeah, that was probably the fall of 1983 or so and it was for the GE27 engine that was proposed....the Pratt engine won, I believe. It really is a shame that pattern makers went by the wayside so quickly and completely. On the other hand, I wouldn't give up my SLAs, CNC machining or laser cutting for my work.....I just don't want to do that at home!

[Patrick Chase]

Well,they were burying Monarch 10EE's. One of the finest model of lathes ever made in the USA. They have a bunch of them down here at NASA. I have a Hardinge HLVH,which some argue is as good,but it doesn't cut the range of threads that a 10EE will do. I like my HLVH though,as it is very light on the controls.

Yep, the Monarchs were (then and for some time after) used to turn the Plutonium pit, which was the second-to-innermost layer of the physics package for Fat Man. Maybe also the tamper and pusher, but I suspect not the explosive lenses.

[Patrick Chase]

Yeah, that was probably the fall of 1983 or so and it was for the GE27 engine that was proposed....the Pratt engine won, I believe. It really is a shame that pattern makers went by the wayside so quickly and completely. On the other hand, I wouldn't give up my SLAs, CNC machining or laser cutting for my work.....I just don't want to do that at home!

Allison (https://en.wikipedia.org/wiki/Rolls-Royce_T406), subsequently bought by Rolls-Royce

[Tom M King]

Ospreys have been filling the sky around the lake here at nights lately. I can see multiples at any time, with each one covering some small number of square miles doing a lot of turning inside a grid flying at maybe 1,000 feet. I'm sure they're practicing for something.

[Niels Cosman]

Every time I saw, I saw to within 0.00001 +/-0.000002 or better!!!!

0.00001 +/-0.000002 from where I don't know.
Somewhere probably +/- 0.01 from where I was trying to cut. :D:D:D:D

[Pat Barry]

It's important to let wood be able to move, especially on raw wood that's outside all the time, especially in this part of the country where we get both extremes in humidity multiple times a year. I don't know in terms of thousandths, but you cannot slide a piece of paper in any end joint, and it still is able to move. Cypress is very durable wood for outside, but it does split easier than a lot of other woods if tied down tight. Look at the nail height on the boards, and you will see that it's above the bottom edge some more than you might normally see. Any kind of wood siding here that's nailed close to the bottom puts two nails, top and bottom, at each location. All of that on an old house will have split somewhere on the board. Usually the split is at the top nail, but not always. Twenty five years after I built that house, not one board has split. They pay me to check on it periodically. If you look at the "roofing" page on my website, it's the house with the copper roof. I can't post a link here, but there should be one to find if you click on my name.

As far as a miter saw, it just can't be done that precisely as quickly. By marking with a preacher, it doesn't matter if the angle is a hair off a perfect right angle to follow the line with a hand saw. It would take a lot of trial and error with any end joint that was a bit out of square to set a miter saw to cut that accurately. Especially when working on an old house, it's much easier to not worry about what angle the end of a board needs to be. I use a miter saw anything it's the best tool for the job, but in this case it's not. The boards are cut on a couple of saw horses right in front of the section of wall where they will go up. It's a lot easier to move a handsaw, and a couple of sawhorses, than keep moving or walking to a miter saw. I'll post a separate thread on using a preacher.

By the way, I'm very particular with how the line is marked too. I use a sharp Berol Mirado no. 4 pencil. Those pencils haven't been made for a couple of decades. Marked beside the preacher, you take absolutely no more than the line. The line is very fine, but I've never measured it. I'm sure it's less than the thickness of a piece of paper though. Aim small, miss small.

I don't like to use caulking on the outside of a house. If one is going to get painted wood siding, I cut the boards the same way, and paint each end before it goes up.
Thanks for the explanation Tom. Theres a lot more to it than I was seeing at first appearance. Your method would have saved me a huge amount of measuring and remeasuring and then cutting incorrectly and re-doing boards when I was re-siding my house.

[Tom M King]

It's not really "my" method. I learned it from really good old carpenters (all gone now) when I was a young man, although I have refined it a bit. I expect it was done that way much longer than it's been done the measure and power saw method.

[Patrick Chase]

Yeah, that was probably the fall of 1983 or so and it was for the GE27 engine that was proposed....the Pratt engine won, I believe. It really is a shame that pattern makers went by the wayside so quickly and completely. On the other hand, I wouldn't give up my SLAs, CNC machining or laser cutting for my work.....I just don't want to do that at home!

Totally OT but... your engine went through a long strange odyssey of improvements and cancellations (lost V-22 bid, chosen for P-7 in turboprop form but then that was cancelled) before finally emerging as the GE38 (https://en.wikipedia.org/wiki/General_Electric_GE38) for the upcoming CH-53K (and also serving as the core for a business jet turbofan). You probably know that though.

[Jim Koepke]

Every time I saw, I saw to within 0.00001 +/-0.000002 or better!!!!

0.00001 +/-0.000002 from where I don't know.
Somewhere probably +/- 0.01 from where I was trying to cut. :D:D:D:D

Shazamm!

jtk

[Art Mann]

It doesn't matter if the saw is absolutely perfect. You still aren't going to achieve that level of accuracy repeatably due to variables you can't control. You will be lucky to get 0.005". That is what I shoot for milling the thickness of hardwood lumber that is going to be precision V-carved with fine details on a CNC router. Most calipers aren't even accurate to 0.001". Take a look at your goal of 2.75/1000". That is the same as 0.00275". The implied accuracy is +/- 1/100,000". You just can't measure those kinds of dimensions outside a lab environment.


I'm in the process of tweaking my table saw. I just have a Dewalt 7491RS contractors saw. I checked the front to back of the blade to the miter channel. I was off 22/1000". I was able to tweak it to 2.75/1000". Much better. I will be building a crosscut sled for it and I hope to tweak that within a 1/1000"

now, before everyone thinks I got lost and ended up in the wrong forum....

I'm about ready to forget the cc sled and buy me a bad axe for my crosscuting. But can you hand saw say a 12" board and stay within .oo1" from front to back?