45 Crapshooter

[Ray Sametz]

Your right Andy, the answer is even longer then what I posted. The trig table is only listed in degrees and minutes, you could figure seconds on infinitetum. :blink: ...

 

[steve wood]

.100 degree? Or .1 degree? What tool do you use to measure .100 degree?

sine bar

 

[steve wood]

.100 degree? Or .1 degree? What tool do you use to measure .100 degree?

I agree that .1 degree is important. Isn't .1 degree the same as .100 degree?

I just had to asked because Steve said there was no typo. To write the extra zeros is Significant.

Writing .100 degree is to indicated the measurement was measured with an instrument that is accurate .001 or that the measurement is Expected to be within that tolerance. If .1 is written then it is expected that the tool used was only accurate to .1. It would be out of conformation to write .10 or .100 If the tool was only good to .1

I think most Smart levels are good to .1 degree.

It's simply the proper science of significant figures.

been in the trade for over 43 years. we never say "a tenth of an inch" we say a 100 thoundsandts of an inch". thats why i used .100. thats the way i dimension things

 

[Andy Brown]

.100 degree? Or .1 degree? What tool do you use to measure .100 degree?

I agree that .1 degree is important. Isn't .1 degree the same as .100 degree?

I just had to asked because Steve said there was no typo. To write the extra zeros is Significant.

Writing .100 degree is to indicated the measurement was measured with an instrument that is accurate .001 or that the measurement is Expected to be within that tolerance. If .1 is written then it is expected that the tool used was only accurate to .1. It would be out of conformation to write .10 or .100 If the tool was only good to .1

I think most Smart levels are good to .1 degree.

It's simply the proper science of significant figures.

been in the trade for over 43 years. we never say "a tenth of an inch" we say a 100 thoundsandts of an inch". thats why i used .100. thats the way i dimension things

Yes, Steve and that only makes sense because as a machinist most of your tools will measure .001 or better. You're not walking around the shop with a yard stick. But when you write .100 degrees for strut adjustment increment and then add that there is no typo it would seem to me that you are saying every zero counts. .001 degree is a very fine increment. And I realize most everyone here didn't think you really meant .001 degree of accuracy was required as the difference between a good strut setting and a bad setting, but literally, that is what your statement said.

If we clamped a very stiff, very straight 100 inch long bar to the strut and rotated the strut .001 degree, the end of the 100 inch long bar would only move .0017". For a .1 degree rotation the 100" bar would move .174". A big difference.

Marty wrote 1.3 degree which follows true with the tools we use for this measurement. Your proper follow up should have stated that 0.1 degree makes a difference.

I know!...I'm being picky, but your statement did make me wonder if you were using a more accurate measure device than we normally use.

 

[steve wood]

even a crapshooter would have a hard time draging around that 100 inch long bar

 

[Marty Davis]

.100 degree? Or .1 degree? What tool do you use to measure .100 degree?

I agree that .1 degree is important. Isn't .1 degree the same as .100 degree?

I just had to asked because Steve said there was no typo. To write the extra zeros is Significant.

Writing .100 degree is to indicated the measurement was measured with an instrument that is accurate .001 or that the measurement is Expected to be within that tolerance. If .1 is written then it is expected that the tool used was only accurate to .1. It would be out of conformation to write .10 or .100 If the tool was only good to .1

I think most Smart levels are good to .1 degree.

It's simply the proper science of significant figures.

been in the trade for over 43 years. we never say "a tenth of an inch" we say a 100 thoundsandts of an inch". thats why i used .100. thats the way i dimension things

Yes, Steve and that only makes sense because as a machinist most of your tools will measure .001 or better. You're not walking around the shop with a yard stick. But when you write .100 degrees for strut adjustment increment and then add that there is no typo it would seem to me that you are saying every zero counts. .001 degree is a very fine increment. And I realize most everyone here didn't think you really meant .001 degree of accuracy was required as the difference between a good strut setting and a bad setting, but literally, that is what your statement said.

If we clamped a very stiff, very straight 100 inch long bar to the strut and rotated the strut .001 degree, the end of the 100 inch long bar would only move .0017". For a .1 degree rotation the 100" bar would move .174". A big difference.

Marty wrote 1.3 degree which follows true with the tools we use for this measurement. Your proper follow up should have stated that 0.1 degree makes a difference.

I know!...I'm being picky, but your statement did make me wonder if you were using a more accurate measure device than we normally use.

Andy:

I had never really though about the difference in .1 a .100 but you are correct.

Bottom line is that the result is only accurate to the input that has the least places to the right of the decimal point.

I am doing some calculations of area to design head buttons. One of the measurements generated has 4 places and one has 5 places. Guess the result is then limited to an accuracy of 4 places. I realized that, but knew that the accuracy that I was looking for was only 2 places so I was good to go. Just never changed the output in AutoCad to 2 places.

Thanks for the lesson.... I bet that you learned this first hand in all the machinging that you did on the Mazak.

Are we going to see you and John at any races this year?

 

[Andy Brown]

.100 degree? Or .1 degree? What tool do you use to measure .100 degree?

I agree that .1 degree is important. Isn't .1 degree the same as .100 degree?

I just had to asked because Steve said there was no typo. To write the extra zeros is Significant.

Writing .100 degree is to indicated the measurement was measured with an instrument that is accurate .001 or that the measurement is Expected to be within that tolerance. If .1 is written then it is expected that the tool used was only accurate to .1. It would be out of conformation to write .10 or .100 If the tool was only good to .1

I think most Smart levels are good to .1 degree.

It's simply the proper science of significant figures.

been in the trade for over 43 years. we never say "a tenth of an inch" we say a 100 thoundsandts of an inch". thats why i used .100. thats the way i dimension things

Yes, Steve and that only makes sense because as a machinist most of your tools will measure .001 or better. You're not walking around the shop with a yard stick. But when you write .100 degrees for strut adjustment increment and then add that there is no typo it would seem to me that you are saying every zero counts. .001 degree is a very fine increment. And I realize most everyone here didn't think you really meant .001 degree of accuracy was required as the difference between a good strut setting and a bad setting, but literally, that is what your statement said.

If we clamped a very stiff, very straight 100 inch long bar to the strut and rotated the strut .001 degree, the end of the 100 inch long bar would only move .0017". For a .1 degree rotation the 100" bar would move .174". A big difference.

Marty wrote 1.3 degree which follows true with the tools we use for this measurement. Your proper follow up should have stated that 0.1 degree makes a difference.

I know!...I'm being picky, but your statement did make me wonder if you were using a more accurate measure device than we normally use.

Andy:

I had never really though about the difference in .1 a .100 but you are correct.

Bottom line is that the result is only accurate to the input that has the least places to the right of the decimal point.

I am doing some calculations of area to design head buttons. One of the measurements generated has 4 places and one has 5 places. Guess the result is then limited to an accuracy of 4 places. I realized that, but knew that the accuracy that I was looking for was only 2 places so I was good to go. Just never changed the output in AutoCad to 2 places.

Thanks for the lesson.... I bet that you learned this first hand in all the machinging that you did on the Mazak.

Are we going to see you and John at any races this year?

Hey Marty!

Hope to see you at a race soon...was hoping to make Brandon...but I just can't get away this time.

Yes, it's a simple rule of significant figures. If you have, lets say, three different number inputs from three different measuring devices of different accuracy and you add them together, your final number can have no more decimal places the the input with the least places.

Example 0.333" + 0.1112" + 0.22291" = 0.667" Not = 0.66712" Now if the same tool was used and the inputs were 0.33300" + 0.11120" + 0.22291". This would correctly add up to 0.66712". Writing 0.33300" indicates that the tool used to obtain the input was in fact accurate to 0.00001".

For me it actually came from back in college chemistry and physics. I think it's simply called the rule of significant figures.

Interesting note about the Mazak. All of the rotational axises can be programmed to and are accurate to 0.0001 degree of rotation.

I clamped a 2 foot long bar in the b-axis and rotated it to see if in fact it would accurately rotate .0001 degree.

Even at the end of a two foot bar the change was to be 42 millionths(.000042")according to Trig calculation. My 10 thousandths indicator(.0001")showed the movement of about one half hash mark which would be somewhere around 50 millionths, but of course was not fine enough to accurately say it was in fact a 42 millionth movement.

Again because the tool was only good to .0001" I could only report .0001" or report the machine was accurate to .0002 degrees not .0001 degree even though it may have been.

Good luck at the brandon race,

Andy