Board Measurment Question

[Ivanq]

Just finished building a few sleds and had the machine measure them. Most of them were pretty close to what I wanted as they are only off a few hundredths. :D

When I get into Designer and create a new project I set the board width according to what the machine told me the width was but then Designer adjusts the number in a way that doesn't make sense to me. I put in 12.44 and Designer adjusted it to 12.438. Does the same thing on length. Not that any of my patterns require that type of accuracy at all but it just wondering why?

Cliff in Roswell

[Kenm810]

Hi Ivanq,

It's really no big deal the Machine and Desiger program like to to use
three decimal points for everything, So if you put an inch and a half as
1.5 it will read out as 1.500 the same with 1.25 well be 1.250
If the machine sees another fraction of an inch more or less then you have entered in Designer
it will correct it in the third decimal position.

[DocWheeler]

Clif,

Darned if I can figure that out, I just tried entering 18.440 and it changed it to 18.438 like you said. So, even entering to the thousandth does not stop it from converting. It may be that .440 is hard for the computer to do. That was hard for me to swallow when I first got into programming that some numbers are hard to represent internally in binary - still doesn't make sence to me.

[Kenm810]

Hi Ken.

It's true in Designer with any of the third place numbers,
the program will round off the third decimal position
you can try any number combination.
Like 10.101 through 10.109, all or most third numbers will revert to 101 or 109
the same happen using 12345678 or 9 in the second decimal position,
they will all change the third number to only a few different two digits combinations. http://www.carvewright.com/forum/images/smilies/icon_confused.gif

[Digitalwoodshop]

Anyone remember the Movie "The Hunt for Red October"....? In that movie Jones the Sonar Tech told the Captain that when ever his Sonar Software got confused it would run home to MOMMA.... And report the noise as a Seismic annomolity.... Just like that Software, I believe the rounding to strange numbers is the LHR Software running home to MOMMA....

It all comes down to resolution.... Not the New Year's type but the digital resolution of the ENCODERS... Remember this picture I posted in the summer of the encoder. There are 360 degrees in a circle divided by the number of lines or pulses on the encoder. I believe the rounding is the software putting your keyboard or designer input into the closest DIGITAL Equivalent of you number. Hence the unexpected rounding of numbers. It all comes down to resolution or the smallest step of the encoder.

I could be WAY OFF here but something in my Navy Analog and Digital Fire Control Computer training tells me that this "Could be true"..... It would be up to Chris Rauls to give it a THUMBS UP or a VERY BIG THUMBS DOWN....


In the picture see the light shadow of the increments of the encoder. Each line breaks the light beam and produces a pulse.

AL

[HighTechOkie]

Al is correct in that it is related to resolution. Looking at the math, it works out to the software measuring in 1/128 fractions (0.0078125"). In Cliff's case, 18.44" would be closest to 18 56/128". In Ken's example of 10.101 (10 13/128) and 10.109 (10 14/128), any value between those would be rounded to the closest 1/128th.

HTO

[Digitalwoodshop]

Now my head is going to swell and my hat won't fit..... Snicker....

AL