a new metric discussion

tallgrass

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Oct 25, 2007
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Ok, here it is. Not that i did and do not enjoy the endless debate over imperial vs metric.  Here is the problem and i m asking how all of you deal with what i consider the course mm. 25.4 of an inch. which makes the mm1/25th ish of an inch.

here are the questions.

do you think it is fine enough ?if not how do you increase the resolution? . in the standard you do 1/16 to 1/32 to 1/64  1/128 ect until you get the measurement unit of the size you want.

do you go to micro meters? how do you get the resolution finer than the mm. I mean this in an in the shop how do you solve this problem for your work kind of way?
Again this is not a comparison thing.

I am an ME and do lots of metal working so i have all the precision metal working stuff in metric and standard. I know it can be done. i am just wondering how you do it in tape measure land without bringing a metrix lab with you.

I ask this because all of my festool stuff is metric and i get grumpy with the whole mm stops on the saw every once in a while and when my metric tape measure lets me down.
Ok i am now going to duck and cover! [big grin]

 
Tallgrass, nearest 0.5mm (half a mm) is more than accurate enough in cabinet making and joinery work.
Nearest whole mm in carpentry.
Applying engineering tolerances to timber is, frankly, a waste of effort due to the nature of the timber.

When it comes to angles I work to the half degree, as anyone should be able to judge halfway between two marks on a protractor.

I understand what you say about the whole mm depth stops on the TS55, on friday I needed to make a cut for the edge of a door panel,
for a raised panel in a door I was reducing in width. 3.5mm deep...let me find a pic.

Manston%20Museum%20186.jpg


so I could do this:-

Manston%20Museum%20187.jpg


Did it at 4mm instead and you cant see the difference. Would be nice if Festool went to the 0.5mm but we can't have everything we want.

ATB Rob.
 
                 

            I would say 1mm is fine for working with wood.Your piece of wood will move of it's own accord anyway.As Rob says engineering any further is unessessary.A lot of folks seem to get carried away with ultimate precision but timber is a natural  material......we have been here before [scratch chin]
 
you see i m one of these Japanese marking knife guys.Big mistake , i did not realize how wide the pencil mark is. :-\
your example of the panel you made is a good example.
You are right you can can get lost in trying to bring too much precision to a material like wood, but here is an example of problem. Using a nice hand plane or chisel taking off thin little shaving, a mm is huge.
you guys are also right about allowing for expansion. But these mms can add up into real dimensions. [big grin]
O, your panels look nice.
 
Would be nice if Festool went to the 0.5mm but we can't have everything we want

You can adjust Festool tools in infinite (or completely variable) increments. Those adjustments aren't part of the obvious user interface but are pretty easily accessed by a savvy owner.

Tom
 
slightly [off topic] but seen the news this morning that the Eu is going to ban selling eggs by the dozen  [eek]
 
what they going to do then sell them in 5's in stead of half dozen. just not going to work with the packing either that or just 10's
 
Deansocial said:
what they going to do then sell them in 5's in stead of half dozen. just not going to work with the packing either that or just 10's

I guess the pack would be round for the 5 pack wierd or what...........
 
Over here it's been pretty much impossible to get a dozen carton for alsmost as long as I can remember.
You can still buy them by the tray, but the usual supermarket cartons are either 6 or 10. Cartons of 4 exist, but aren't comon.

No big deal.

Regards,

Job
 
Just a bag of eggs  [big grin]

Rob, spot on.  1mm for carpentry work & .5mm for cabinet or furniture making.

Tallgrass, i have Japanese knifes & they are good but try the Sabatier marking knifes, soo thin & sharp  [thumbs up]

Woodguy
 
well i am going to enjoy my standard eggs, boy buy 10 eggs and you can not make 4 3 egg omelettes ....see how stupid the metric system is!!! [big grin] [big grin]
The thing i like about the japanese marking knives is that they are right and left sided which is nice.

Or are you talking about kitchen knives? if kitchen then yes the high carbon steel is very nice indeed.
 
Festoolfootstool said:
slightly [off topic] but seen the news this morning that the Eu is going to ban selling eggs by the dozen  [eek]

Deansocial said:
what they going to do then sell them in 5's in stead of half dozen. just not going to work with the packing either that or just 10's

They are not going to ban selling them by the dosen.

The packaging isn't going to change, what is happening is that the amount of eggs must now be named by weight instead of number. So you will still be able to get a dosen of eggs only officially they will now name it 720 grams of eggs (1 egg has an average weight of about 60 grams).

This new measure has nothing to do with metric vs imperial. It's a simple change of measuring goods from 'amount' to 'weight'.

It sure does sound like a stupid measure though. I don't know what's going on in the European parliament, but it sure isn't democracy and they sure don't seem to have the welfare of the common man in mind.

 
Who's gonna tell the hens that they have too produce uniform weights of eggs? Mine never did and sometimes Red would produce a double yolker!

Anyway the topic is not about eggs but trying to inform people about the merits of the Metric scale as applied to woodworking in it's several forms.
My earlier post pretty much covers it and nicely seconded by Woodguy.

I might add that any good joiner or cabinetmaker, should they label themselves thus, would use several other devices for measurements other than or in combination with a retractable tape measure (regardless of the scale used) that would include steel rules, a vernier caliper and possibly a vernier angle finder.

I use 300mm, 600mm and 1mtr steels rules, a vernier caliper (for checking material finish sizes agree with the scale of the thicknesser etc.) the vernier angle finder and also use a metric micrometer. ( for checking tooling sizes etc)  [big grin]
But to be fair I did train for two years in mechanical engineering and did metal work rather than woodwork at school (teacher-student conflict in woodwork class) and had hoped to follow my brother into the toolmaking industry. Lucky for me jobs were just not there when I was looking for one so I ended up in a carpentry & joinery apprenticeship and found a passion for the craft. ;D
Some of the old M.E. tolerances instilled in me are hard to forget, but I try hard not to let 'em loose!

Rob.
 
I thought I was the only weirdo....... using a vernier caliper [big grin] [big grin] [big grin]
 
I'm doing more and more of my work in metric and enjoying the easy math immensely.  What I don't understand, though, is why woodworkers in the US insist on using non-decimal fractions for measurements.  (I presume it is historical, that when the craft took its current form it probably wasn't feasible to make an affordable ruler marked in 10ths and 100ths.).  Most of the things I see relating to metal use decimal fractions, e.g. 1.5 or 1.625, why can't we do that with wood?  It would make the math so much easier.

As to the degree of precision required for woodworking, I make high end furniture like chairs and drawers with hand cut dovetails.  I almost never measure anything smaller than 1/64th and if I did the measurement would darn well be in decimal fractions instead of some silliness like 53/128ths.

When high levels of precision is required, I never rely on the gauges built into tools.  With a router, I always measure the travel distance between the stop and the depth adjustment rod with a caliper, rather than trusting the guide.  Same principle with saws, etc.  If precision is vital, I always make a test cut on scrap to ensure the setup produces the desired result. 

So, I can go either way - imperial or metric.  I think the main thing, though, is to pick a measurement system for a project and stick with it.  Using some imperial dimensions and some metric ones is just asking for trouble.

Most of all, I never measure unless I absolutely have to.  Most of the time in woodworking the key is making two or more pieces the same length or width and the actual length is immaterial.  When I'm making furniture, I often do a full sized drawing on a thin piece of mdf and erase and redraw until it looks right, then cut out the shape and fair it.  Then I have a template to mark wood with and to compare the current shape of the wood to its intended shape.  I have no idea how inches or meters tall my chair is or how many degrees the legs splay, but each one is exactly the same as the others and they are all as long as they need to be.

The virtue of high end tools such as Festool is not so much that they measure something accurately, but that once they are set, they keep their settings long enough to produce consistent results throughout the project.

Sorry this is so long, must have 'pressed a button' for me. :o
 
Jesse

Would love to see some of your stuff if you wanted to post some pics.  Sounds like you do the kind of stuff that i wish i could do  [big grin]

Woodguy.
 
Why do we have to pick one system? I like both and use both, sometimes on the same project.

I have to disagree that .5mm is accurate enough for Joinery. A .5mm gap is huge.
 
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