jig for cutting blanks on a table saw

William:

Piece of plywood - smooth and square

Get two pieces of 1/8 metal or plastic 3/4 wide by say 12" long. (2nd one can/should be longer) (Miter slot inserts)

Attach one miter slot insert so board sits in miter slot of bandsaw when board is place on top.

Draw a line on top of board - mark with ruler. (This will be your reference for the slot....

Cut a slot on top of plywood - 90 deg to slot on bottom. 3/8 X 3/4 By width of plywood - or even longer. Make slot so left edge is even with blade.

Now - put nail in (close to) left hand edge of top slider... Drive all the way through. Mount slider with nail sticking up.

Place blank on jig. Center over the nail. Pound or push on - depending on blank hardness.

Cut wood on bandsaw by spinning around nail.

That's what I did - used it for stool seat cut-outs etc.

There are lots of variations -- but that's how they all work. Spinning the blank around a metal nail....

search on "segmented wood turning" for the Yahoo group, and more.

Cut out a circle in cardboard 6" diameter. Continue to make them but increase each by one inch until you reach the swing of your lathe. stack them on top of one another and then drive a nail through the centre. This is how they are stored. Now take the appropriate size template for your half log blank that is face down and tack the cardboard circle on the top of the blank. cut out the blank following the edge of the carboard circle. Not an exact science but close enough.................

Sheesh, wonder what _I_ was thinking?

Anyway, unnecessarily complicated

figured out from here about the same as I use.Then there's Duginskie's book, and any other woodworking text. Since they're so easy to make - two sticks and a piece of plywood - I keep a couple premade for 10 & 12" circles.

If I tried to turn a bit of wood I was cutting on my table saw it would be grabbed by the blade and flung backwards at about 250 miles an hour.

One must be precise in these newsgroups -- or you get your nose tweaked.

ROTFLMAO

--=20 Will R. Jewel Boxes and Wood Art

power of accurate observation is commonly called cynicism by those=20who have not got it.=94 George Bernard Shaw

One must be precise in these newsgroups -- or you get your nose tweaked.

ROTFLMAO

That's all right. I answered _both_ for saws.

Will, be careful. I think you got it right, but you might get your nose tweaked for saying "precise" if you meant "accurate". I did once and I still don't understand the difference. Or care! I think it has to do with repeatability. Maybe somebody will set both of us 'cynics' straight (ie.without curves or angles) )

Turn to Safety, Arch Fortiter

I just visited one of my mentors this afternoon. When I saw his large Bandsaw without any sawdust on it I asked him are you still using it? He replied, I am getting pretty good with the chainsaw and I no longer bother using the big Bandsaw anymore. That gave me food for thought

Ah what the ....

If you mean numbers -----

Don't say 1.23456789 when at best you are 10% accurate (say in reading a =

ruler) -- in other words 1.2 is ok -- the extra digits represent=20 precision - but are meaningless. (BS baffles brains -- IOW -- if you=20 want the _precise_ mathematical terminology. Now If you want=20 _mathematical_ precision I will scan the entry from (one of) my=20 Mathematics Dictionary and post it.)

Saying 1.235 to carry on a calculation - keeping the 3 and the 5 as=20 "guard digits" would be ok -- as long as you remember to present only=20 one decimal in the final answer -- in this example... If on the other=20 hand you are within 1% you can present 2 decimal places of precision=20 (and it will be considered _accurate_) - and carry one, or two, (or even =

three if you are a mathematical heretic) guard digits -- depending on=20 your mathematical religion and the capacity of your numeric processors.=20 Hope that is clear. WARNING! Other mathematically inclined people are=20 likely to choke on this definition as I have not demonstrated the=20 required rigor, nor have I inserted the required squiggles. But dinner=20 is waiting and I know my priorities.

If you want the examples in mod 2, 7,8,5(bi-quinary), 11,13, 16 64 or=20 base 256 (represented as Hex) [as opposed to base 10] I can do those=20 quickly -- if it would make you more comfortable. Other bases will make=20 me think overly long and I will pop a mental fuse as there is a very=20 delicate balance these days. I refuse to do it in the natural logs - but =

leave that to the interested reader (insane of course.)

I have made no attempt at rigor here. But _could_ bore you into a seven=20 year nap if you are an insomniac and need relief...

Just responding to the nose tweak.

However, here, precise was used in a different modality. I believe I=20 meant exact -- which I believe to be a correct usage -- but will change=20 my language if it offends. LOL

Hope you never ask a question (make a point) like that again and I have=20 done my best to see that you don't. ROTFL

But -- if it was a new usage -- I claim copyright and first dibs and all =

that stuff. Clear?

Gotcha! Wake up D***It!

--=20 Will R. Jewel Boxes and Wood Art

power of accurate observation is commonly called cynicism by those=20who have not got it.=94 George Bernard Shaw

I must apologize - I forgot the following..

When multiplying or dividing -- the percentage of error adds absolutely, =

when adding and subtracting, the absolute error adds absolutely.

That would make it clear why you have the rules about guard digits and=20 places of precision.

For example if you multiply two number together, (and you had been able=20 to make the measurements and obtain the two numbers to 5% accuracy...)=20 The resulting answer would be accurate to 10% -- so any digits beyond=20 the first decimal place would be guard digits or used for rounding...

So you could haver 5 decimal places of precision -- but the number would =

be accurate to All kidding aside -- you should remember this when doing calculations=20 when you multiply or divide measured numbers.

Adding or subtracting..

1 1/2 (+- 1/16 ) + 1 1/4 (+- 1/16) is 2 3/4 (+- 2/16) or 2 2/4 (+- 1/8 ) in other words... Because it is the ABSOLUTE SUM of the=20 two estimated errors that is the error factor.

Now you made me think... That was terrible. But --- Not too bad for a=20 guy with a degree in Basket Weaving huh?

Anyone with eng, phys or math degrees - don't even hassle me about this=20 or I will pop a cork. LOL

You asked for it. You got it. Don't complain.

--=20 Will R. Jewel Boxes and Wood Art

power of accurate observation is commonly called cynicism by those=20who have not got it.=94 George Bernard Shaw

uh 2 3/4 (+- 1/8 ) in other words... Because it is the ABSOLUTE SUM of=20 the two estimated errors that is the error factor.

Now you know why it was basket weaving...

--=20 Will R. Jewel Boxes and Wood Art

power of accurate observation is commonly called cynicism by those=20who have not got it.=94 George Bernard Shaw

this is what they told us at university Accurate means "capable of providing a correct reading or measurement." In physical science it means 'correct'. A measurement is accurate if it correctly reflects the size of the thing being measured. Precise means "exact, as in performance, execution, or amount. "In physical science it means "repeatable, reliable, getting the same measurement each time."

However, in light of the recent plaigarism thread, I should admit the previous post was not my rhetoric. I cant now give credit where it is due as I cant remember where I found it. mick

If a band saw is sitting on a table does that make it a table saw? Instead of a bench saw?

Is a table saw one that is used for cutting tables?

How can one be PRECISE?? with an imprecise language?

Walt C Wasting bandwidth in MN.

Actually that definition would not be very useful for eng., scientists, stats. types and other mentally challenged workers.

Typically there you need to talk about "degrees of accuracy" -- hence the need for agreed upon precision.

But this is boring stuff -- and I only care about the +- for the micrometer on the lathe these days. (Just kidding)

The definitions are very important if you work with compound angles and are designing multi component systems - particularly with spindles being linked at compound angles -- as recent experience has reminded me. If you forget to account for error factors the parts won't mesh -- or they shove each other to the wrong place and something further down the line doesn't work. You need to _know_ how much slop to design into a system... Even then you normally have to _tune_ the fit at the end of the process where the errors became excessive in the limit points..

(It's an issue in the above because you must work with Tangents (rise/run) sines, cosines and so on and multiple calculations -- not allowing for error gives pretty ugly results)

...Then the theoretical knowledge is like manna from heaven -- wonderful to have at the right moment...

Arch was just tweaking my nose -- but as usual he raised a useful topic.

It really is important if you design -- less so if you work with plans

-- or just fiddle.

Walt:

Walt Cheever wrote:

Clearly a fellow adherent to the Red Green School of Fine Woodworking=20 and life philosophy.

These are deep philosophical questions. I shall ponder them at some=20 length -- tomorrow.

Check this post - tomorrow.

Good one. LOL

--=20 Will R. Jewel Boxes and Wood Art

power of accurate observation is commonly called cynicism by those=20who have not got it.=94 George Bernard Shaw