Tool accuracy

[Dangermouse]

well agree with Jacob on that one . (hammer)

 

[custard]

There's no such thing as a general target for accuracy, even for an individual woodworker.

0.1mm makes a very big difference in the fit of a tenon, so I'll aim to be more accurate than that. But in terms of adherence to the dimensions of a piece of furniture, I'll usually aim to be within one mill of the plan, but no better than that.

By the way, regarding the OP, I expect my thicknesser to be within a 0.1mm total tolerance from side to side, so +/- 0.05mm between any two points. That's about the most I can get from my machine without an undue amount of faffing about, but it's still not quite enough to drop a machined board into a dado housing every single time without a little bit of tweaking. I know workshops that use drum sanders to finish veneered boards who work to tolerances way beyond that!

 

[MARK.B.]

My dad used to say to me when i were nowt but a nipper that if its a "Cats c**k hair" either side of where it should be then that's close enough :wink:

 

[Mr T]

Hi

I think a good maker knows when it's important top be accurate and when accuracy is secondary. This ability makes for faster working. Working to extraordinarily fine tolerances takes time setting up etc that may be unnecessary. But one needs to be able to doit when required.

Chris

 

[DTR]

I very rarely measure anything, let alone work to a tolerance (homer)

 

[No skills]

I've been watching this thread with interest, all the previous talk of 0.0 whatever of a mill both made me wonder if I had linked to the wrong forum and had me seriously doubting if I could ever make anything of 'quality'.

Lucky I realised this is all waffle and personal goals. I make something 'to fit' - not really interested how many decimal points are involved. Obviously different jobs have different tollerances.

I don't want this to be a dig at the previous posters, its not ment to be. If you enjoy that side of the hobby/work then good for you, I just like to make 'stuff'.

 

[Dangermouse]

I use some VERY thick glue :-"

 

[mailee]

My measurements are so long and a bit. :lol: It is not often I use a measure but prefer to use a rod when I am building. I do use a measure on site of course. :wink:

 

[Mar_mite]

How thick is a sharp pencil line? If I want something tight I leave the line in when I cut, or take it off if it's not important.

 

[JimF.]

I generally like things to be within a 0.01cm tolerance but as you said it depends in what I'm building. My new work bench was within that tolerance but I built some scenery items for a play and I wasn't so concerned about the outcome.

It would help in this debate if we all knew what we were talking about. And then those of us replying could be certain that our knowledge / opinions / ignorance were soundly based.

SuperAB - you edited your original post to say 0.01cm, then further on in the thread you say you get 1mm tolerance. 1mm = 0.1cm (there are 10 millimetres in one centimetre). So there is a factor of ten discrepancy between your posts.

Personally, I always aim for absolute accuracy. Aim being the operative word! Eyesight, poor lighting, the thickness of the rule & pencil / knife lines and general cackhandedness, all contribute to the "rustic" quality of my efforts. My only comfort is that I am aware of my short-comings and may be able to improve.

 

[bugbear]

It would help in this debate if we all knew what we were talking about. And then those of us replying could be certain that our knowledge / opinions / ignorance were soundly based.

Absolutely (no pun intended)

BugBear

 

[devonwoody]

I was brought up on proverbs etc. and one I remember was "a blind man would be pleased to see it" so I have never tied myself down to perfection in my life. Alright suits me.

 

[Rhossydd]

By the way, regarding the OP, I expect my thicknesser to be within a 0.1mm total tolerance from side to side, so +/- 0.05mm between any two points. That's about the most I can get from my machine without an undue amount of faffing about, but it's still not quite enough to drop a machined board into a dado housing every single time without a little bit of tweaking.

Thanks, nice to have one answer to the question I posed.
0.1mm seems a good level of accuracy to achieve.
The Leigh dovetails jigs, as an example, quote cutting depths to 0.0X mm and their guide bushes are calibrated by 0.05mm units. Certainly to get good fits one needs accuracy of 0.5mm.
I'm happy to spend some hours getting the machinery as optimised as reasonably possible, because I know that will pay dividends when actually getting work done. The difficult part is where "undue amount of faffing" stops and reasonably care over set up stops and if that level of precision is possible with my own machinery anyway.

 

[bugbear]

0.1mm seems a good level of accuracy to achieve.

1/32 in old money. It's actually rather easy when working wood to get much closer than this in terms of fit and accuracy, although often not to a measurement.

If two pieces are planed together, they will be extremely close to identical, far closer than 1/32".

Similarly, when shooting (on a board) to a line, there's no reason that the work shouldn't be accurate to the thickness of a shaving, and 1/32" is a thicker shaving than most choose to take.

BugBear

 

[Spindle]

Hi

0.1mm equates to about four thou actually or 1/250"

1/32nd is a tad over 31 thou and 1mm is around 39 thou

Therefore 'in old money' 1mm equates to 1/32"

But anyway and to slightly hijack - Bugbear, I've tried to find info re the 'scant, bare and full' measures but can't find anything - can anyone enlighten me or point me in the general direction?

Regards Mick

 

[Rhossydd]

Similarly, when shooting (on a board) to a line,

Did you get as far as reading that my question was about the tolerances for machinery ?

 

[bugbear]

Similarly, when shooting (on a board) to a line,

Did you get as far as reading that my question was about the tolerances for machinery ?

Actually, you said:

what sort of tolerances are people expecting their tools to work to ?

That "to" on the end is important.

BugBear

 

[Rhossydd]

Similarly, when shooting (on a board) to a line,

Did you get as far as reading that my question was about the tolerances for machinery ?

Actually, you said:

what sort of tolerances are people expecting their tools to work to ?

That "to" on the end is important.

Did you get to the last line ?
" I'm curious to know what people expect from their machinery"

 

[bugbear]

Did you get to the last line ?
" I'm curious to know what people expect from their machinery"

Yes I did.

Again, that appear to be about the results, not the machines. I find both interesting, as it happens.

I don't really see where you're going with this. Whilst your question is yours, it is only the starting point for the discussion.

BugBear

 

[RogerS]

A joiner says 'That's near enough'.

A carpenter says 'That will fit'

A furniture maker says 'That's spot on'

Runs for cover ..............