All Replies on precision

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by Ritty
posted 04-05-2011 04:42 AM

23 replies so far

View Moron's profile


5032 posts in 3918 days

#1 posted 04-05-2011 04:46 AM

learn how to cut to the pencil mark, cut the pencil mark in half, cut the pencil mark off

otherwise use a clamp and a stop block

measure, test

measure test

measure test

-- "Good artists borrow, great artists steal”…..Picasso

View Loren's profile


10476 posts in 3673 days

#2 posted 04-05-2011 04:59 AM

Use a marking knife.

I always use mechanical pencils in woodworking because the line is
always the same thickness.

A dial caliper has many uses in woodworking. It’s a good tool to help
your thinking about tolerances.

I’ve usually found working to “relative accuracy” works better than
working to absolute accuracy.

View devann's profile


2246 posts in 2717 days

#3 posted 04-05-2011 05:14 AM

Learn how to accurately set up you machines to true zero/square settings.
Make test cuts to see if you’re really cutting where you think are.
Along with tools mentioned above a good square is a must have item.

-- Darrell, making more sawdust than I know what to do with

View David Kirtley's profile

David Kirtley

1286 posts in 3023 days

#4 posted 04-05-2011 06:39 AM

The number one thing that will increase your accuracy is good work holding and fixed positioning. That is why people fret so much over a workbench. It is not a table. It is a clamping device. It is also why people fret over their chucks on a lathe. There are just too many ways for the workpiece to move. Clamps, holdfasts, bench hooks, vises, sticking boards, and many other auxiliary work holders are available to add to your arsenal for holding things in place while you are cutting and guiding your cuts.

The real trick is not to expect to plow through and make a well fitting piece with one pass. It really is not that reasonable to expect to have a finished piece with one cut. Rapid stock removal and precision cuts are two different things. You are fighting a constant battle to try to do them both at the same time. Take a roughing cut to get it into the ball park and then tune in with precision tools. For making precision cuts to length, use fixed stops that are set to predetermined positions where you do not have any choice but to cut to the proper dimension. Clamp things down carefully where they cannot move while cutting. That is why miter boxes and miter saws have clamps on them.

If you are talking about hand tools for close fitting, planes and scrapers can be really useful in making microscopic adjustments. A well set plane can take off just a few thousandths off. Also floats and files are great for making small adjustments.

For power tools, routers with good fences or templates can make clean repeatable cuts. For most parts, I will cut roughly to size on a bandsaw and then sneak up to final measurements with planes, spokeshaves, files, scrapers, sandpaper, rotary tools, or anything else handy to get to the final dimension. I am predominantly an advocate of hand tools but I am not a purist. I also have a table mounted router with an Incra fence.

I am not a fan of tablesaws. They make good cuts but for the most part, their work holding sucks. The only exception I would make would be the big ones with sliding tables where you can clamp the work in place and move it through the cutter. Yes, you can add things like panel jigs and such but they don’t usually have the same precision unless you spend a lot of time getting them adjusted. The real problem with tablesaws is not the crosscutting. It is the ripping.

-- Woodworking shouldn't cost a fortune:

View Lee Barker's profile

Lee Barker

2170 posts in 2875 days

#5 posted 04-05-2011 06:50 AM

Good precision doesn’t start with the tool. It starts with knowing how the material will behave when it meets a tool.

All the setups and workholders that come roaring out of the pages of the wishbooks add up to weak attempts to convince you that you can become a good woodworker in a weekend.

Congratulations on asking the question. That impresses me more than I can convey in mere words.

Wood is fibers. Different species have different fibers arranged in different ways. Watch them, touch them, study them.

All the nobility in your head soaked up there through your hands.



-- " his brain, which is as dry as the remainder biscuit after a voyage, he hath strange places cramm'd with observation, the which he vents in mangled forms." --Shakespeare, "As You Like It"

View rhett's profile


742 posts in 3692 days

#6 posted 04-05-2011 02:15 PM

Use the same measuring device for the entire project.

-- Doubt kills more dreams than failure.

View Gene Howe's profile

Gene Howe

10534 posts in 3453 days

#7 posted 04-05-2011 03:05 PM

All suggestions and cautions above are excellent ones. I’m sure you will receive more good ones, too.
However, Loren’s last comment in his post, ”I’ve usually found working to “relative accuracy” works better than working to absolute accuracy.” will serve you exceptionally well throughout your quest for “precision” in working with a non-precise medium.

-- Gene 'The true soldier fights not because he hates what is in front of him, but because he loves what is behind him.' G. K. Chesterton

View Ritty's profile


63 posts in 2822 days

#8 posted 04-05-2011 10:10 PM

thxs guys all of your comments have been read and will be used at some point this weekend. also im thinking of buying a starret combination square, never had one and always wanted one what do you guys also think about that? good choice ? i have always herd of their quality

View David Kirtley's profile

David Kirtley

1286 posts in 3023 days

#9 posted 04-05-2011 11:48 PM

Starrets are wonderful tools. I would never steer anyone away from them if they are ready to pony up that much. I have the big 24” contractor’s square and it is a joy to use.

Of course there is no way on earth I would buy one at the retail price. I picked mine up at the flea market for $30-$40 if I remember correctly.

I have few others ranging from 4 inch to 12 inch along with protractor heads and stuff that I have picked up here and there used and paid little for but I can’t say I would personally go buy a new one for the price.

On the other side, I have some cheap harbor freight squares that I reach for just as often as the Starrets. I don’t get upset if I splotch them up with glue or otherwise worry about. If I am measuring something accurately, I grab the calipers first anyway.

Usually though, it doesn’t make any difference to me. If I am making a table, I don’t care if the legs are 28 in long or 27-3/4. As long as they are all the same it is fine with me.

-- Woodworking shouldn't cost a fortune:

View Loren's profile


10476 posts in 3673 days

#10 posted 04-06-2011 12:01 AM

Starret quality is great and the tool will hold some resale value,
but for woodworking you don’t need a fine square like that.

A cheap combo square can be tuned square easily enough with
a little filing. Starret squares are machinest tools – and overkill
for woodworking.

Not to dissuade you.

I’ve found the little 4” pocket squares very useful in setting up
joints and I also like the Veritas Cabinetmaker’s square. Veritas
makes a bunch of little specialized layout tools and I’ve found
them to be real time savers.

View DLCW's profile


530 posts in 2679 days

#11 posted 04-06-2011 06:32 PM

A marking knife, power tools for rough cutting and hand tools (chisels, planes, etc.) for fine tuning the cuts.

Even as a professional woodworker, I still use this process (even in the “time is money” environment of a business). Even after fine tuning all my machinery to “get close”, for really fine furniture, that isn’t enough. Another process I use is to use the pieces you’ve already cut to do your next machine setup. For example, when you’ve finished cutting the mortise (super fine accuracy not required – that comes when cutting the tenon) for an M&T joint, use that part to set up your table saw to cut the tenon. Sneak up on the thickness leaving the joint very snug, then fine tune with a shoulder plane. Perfect M&T joints everytime. No measuring required.

-- Don, Diamond Lake Custom Woodworks - - "If you make something idiot proof, all they do is make a better idiot"

View MinnesotaMike's profile


28 posts in 2665 days

#12 posted 04-06-2011 09:44 PM

Good topic! Like how “sharp” is “sharp enough”; just how “close” is “close enough”? I know, depends on what your doing and varies accordingly, but evenually there is an optimal “inth” degree for every project.
For that answer, it’s the personal experience that matters.

View Rick's profile


9725 posts in 3058 days

#13 posted 04-07-2011 07:33 AM

Good Post. I can’t add anything to what’s already been said other than it’s sometimes the “Skill Level” of the person behind the tool, not the tool. Practice and persistence might be the key to that.

With all due respect I’m wondering why you Posted this in “Site Feedback” instead of “Woodworking Skill Share” or “Woodworking Tools…etc.etc.” . You might get more advice in either of those as they have a much higher “Topic Count” (More Interest and Views) than here and I think Your Topic relates to either of those Forums.

-- LIFE is what happens when you're planning on doing Other Things!

View Ritty's profile


63 posts in 2822 days

#14 posted 04-08-2011 10:27 PM

ya but this is my 2 forum and still dont know what im doing but ill get the hang of it and thx you guys all your comments really help me maube ill post it again on woodworking skill share

View BritBoxmaker's profile


4611 posts in 3061 days

#15 posted 04-22-2011 09:45 PM

Experience – Get to know your tools. Get to know your materials. Make mistakes. Learn from them. You’re never too old to learn. I’ve been at this for over 40 years ago now but last week I made an expensive mistake. I won’t do it that way again

Practice – It won’t happen overnight. Skill is acquired, not bought. A skilled person can make something good with old and worn out tools. An unskilled person can only make expensive sawdust with new and expensive ones.

-- Martyn -- Boxologist, Pattern Juggler and Candyman of the visually challenging.

View Ritty's profile


63 posts in 2822 days

#16 posted 05-02-2011 03:56 AM

well poot thx

View gfadvm's profile


14940 posts in 2715 days

#17 posted 05-02-2011 04:38 AM

Dial caliper is a great tool because yuo can measure ID,OD,and depth with the same tool.Im not big on the battery powered ones. The other thing that helped my precision was when I built my Super Sled. It not only allows repeatable identical cuts but really improves table saw safety at the same time. Hope this helps.

-- " I'll try to be nicer, if you'll try to be smarter" gfadvm

View Ritty's profile


63 posts in 2822 days

#18 posted 05-10-2011 03:49 AM

thx im actually thinking about building one of thos

View David Grimes's profile

David Grimes

2078 posts in 2665 days

#19 posted 05-10-2011 06:04 AM

Relative accuracy… I couldn’t agree more. I was a machinist early on where 10,000ths was measured, then later millionths (Tecumseh refrigerant scroll compressors). Then into the rubber industry (tires) where hundredths pretty much took care of most of it. In trim carpentry on pine I swear I prefer to use a good tape measure and my thumbnail (no pencil). Quicker, as easy to see and hard to lose that “pencil”.

When i am making something “fussy” (stain grade hardwood dentil crown over ogee, for example) i will use a scale in inches, tenths and hundredths. Tighter tolerance by default in the measuring stage than fractional to 64ths. Its like playing snooker for the two hours before the 9 ball tournament… Lord it makes the regular pockets look like the Grand Canyon.

Yep, relative accuracy. Thanks for that.

-- If you're going to stir the pot, think BIG spoon or SMALL boat paddle. David Grimes, Georgia

View Jim Jakosh's profile

Jim Jakosh

20594 posts in 3130 days

#20 posted 05-10-2011 06:19 AM

Hi Ritty, I used to be a toolmaker and sometimes I find I’m spending too much time trying to get things to fit too good, but I’ll always walk away satisfied that I did the best I could do.
To begin with, you need good measuring tools to determine what size to cut a piece to. Get a good quality tape measure and a good 6” steel rule and good quality 12” square that is really square. Starett ,Lufkin or Browne and Sharpe are the top tool makers in my book. I like to use a digital caliper for small measurements and for thickness measuring when planing. They are cheap now at Harbor Freight and durable Stainless Steel tools. They have ads for a 6” digital caliper for $9.99. I have several and also a 12” one.

Then when you have measured accurately, you need to transfer that size to the board to be cut. Use a fine pencil or a wood scriber to make a fine cut line. To get down to the finished size, you can make the cut just larger than the line and then measure and move the stop or board accordingly to creep up to the dimension. Haste makes waste as you get close to the final cut( unless you have a wood adding-on tool).
For repetitive cuts of the same size, always use a stop block/end gauge set in place after cutting the first piece to size. Then clean out any sawdust for the next use so the next boards are not too short due to dust between the gauge and the board. If you have an expensive piece of wood or a part that will take a lot of time to remake if you screw up, set your gauge for the cut with a piece of scrap wood. Once you hit the size you want, cut the good piece with assurance.

I don’t know what you have for cutting tools, power saws, etc, but get to know the accuracy of each one. Using a good square, cut scrap pieces to see if the saw cuts square in the x-y surface and also in the z plane. Out of square cuts can drive you crazy with fit up of pieces. I started with a Sears radial arm saw and every time I used it, I would cut scrap piece to check the squareness because just bumping that arm ( by you or someone else) can throw it off even if it looks set to 90 degrees.

Drilling holes can be another place for error. If you use a drill that is not sharp or is sharpened off center, it can walk in the wood or drill an oversize hole. Check critical hole size in a scrap block of the same kind of wood.
I always like to use a center drill after I lay out a hole pattern on a piece of wood, steel, aluminum or what ever. I did that as as tool maker and I have found it is very important in wood if you are not drilling through a drill bushing. If you use a twist drill, the grain of the wood can throw off the center of the hole quite a bit- especially in oak. The center drill, like a forstner bit, is rigid and follows the center very well .

Good luck , buddy. We look to see some of your fine work in the future….......Jim

-- Jim Jakosh.....Practical Wood Products...........Learn something new every day!! Variety is the Spice of Life!!

View MrRon's profile


4794 posts in 3268 days

#21 posted 05-19-2011 10:04 PM

My take on this topic is: get a Starrett combination square, but not for everyday use. Get another less expensive square and use the Starrett to check it. Use that square for everyday shop use. An inexpensive square is usually accurate enough for woodworking, but if accuracy is important, drag out the Starrett. A digital caliper is good to have. I don’t like marking knives because the scribed line is hard to see. I use a .5mm mechanical pencil. I like to make setups before cutting wood.I take a trial cut on scrap, measure it; readjust if necessary before commiting my good wood to the cut. Due to wood shrinkage, one can never hold a measurement. I try to work as close as I can to the true mark. That way, if the wood wants to shrink or expand, it will still be within limits. Machinists work to thousands of an inch. Although woodworkers don’t have to, the closer you can work to it the better your project will turn out. I think working to ±.015” (1/64”) is doable and not too extreme. Building a fence outdoors isn’t critical at all, so you can usually work to ± 1/4” and get away with it. There is accurate, close enough and sloppy. Try to be between accurate and good enough, but closer to accurate.

View miles125's profile


2180 posts in 4030 days

#22 posted 05-19-2011 10:20 PM

I’m thinking you get precision to a large extent by your personality type. I have good friends who just never aquired the patience to ever do anything like precision woodwork. Theres nothing wrong with that and they are perfectly fine and functional people. Just different.

-- "The way to make a small fortune in woodworking- start with a large one"

View Ritty's profile


63 posts in 2822 days

#23 posted 06-05-2011 05:49 AM

thx guys, im happy to say i have recently be handed a starret square and all its goodies like a protractor head and center finding head, but the level is broken but beggers cant be choosers, i also have a really nice and easy to read vernir caliper, along with some nice 6 inch rulers that read into the 64ths of an inch and have been using them well, thx for your help and in the near future i will have some saw horses for u guys to look at thx again

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