Radial Segment?

[1CMM4ME]

B&S "One" ,version 4.1 Cad
Another newbie question: Yes, I searched the other threads too.
Got a part today: It is a segment of a 156" diameter. The part is 3 " wide, with a radial segment angle of 30" for short. The part is 1" thick. The drawing asks for the chord length from outer diameter edges ( intersection of ends of the part to the end of the segment radius). Well, I figured no problem.I established the plane, (3 points), made a line, then swept the inner radius.
I did an alignment. Now, I made another line at the other end of the segment.
I wanted to construct a point at the intersection of each line I created to the the end of the arc of the segment, so I could get a distance measurement between both points. Well, I could not get the machine to do that. Is it because the machine thinks there is a whole diameter of 156" to deal with, because it sees it that way? I am not for sure how to do this.
I can't wait till next week for training. I know what I want to check, but can't get this rascal to cooperate. Or on the other side of the coin, the machine can't get me to cooperate.
Thanks for the help..........Just think! after next week, I may ask some more delirious questions. Thanks again to the board.

[Barry Dawson]

Gday,
What type of point did you try and create sometimes a cast point works, or maybe even reverse the line your trying to find the inersection with. Could be barking up the wrong tree though! give it a try while your waiting for a guru to answer. Goodluck!
the_cougar.JPG
The Cougar

[1CMM4ME]

I made sure the vectors were pointing towards the radius , but I did not use a cast point, as I am not familiar with utilizing them at this point in time. I am persistant, as I will figure it out. May not have alot of hair left after the battle, but I will conquer. Thanks for the help, I will give your thoughts a try on friday.

[Wingman]

Hard to visualize from your description. But you can construct a pierce point between an arc and a line. Sounds like that is what youwant but I cannot tell for SURE from the text. If this is what you want then construct POINT and pic the arc and the line. Do this on BOTH sides of the arc and you have your points. But, it just may be that I don't understand what you want. Can you draw a sketch?

[1CMM4ME]

I don't if this helps. I drew it in word, but you can get the picture.
Thanks.

[Wingman]

I don't if this helps. I drew it in word, but you can get the picture.
Thanks.

I don't see the file. I don't think it posted. Try Paint and save as jpg (that is the easiest way i have seen to post)

[cmmguy]

The easiest way to do this(and because the radius is so large) is to actually just measure a very short line segment at the ends of the radius on both sides and intersect those line segments with their respective side lines. Dont screw with the arc measurement since your fitted results wont be accurate enough.

[1CMM4ME]

Well, I hope this image shows up now. I sketched this up real quick at home this morning. This is basically what the part looks like , aside from some counterbored holes that are in the actual part. I did construct a point at each end of the part, utilizing a small line at very ends of the radius. The measurment appeared to be fairly valid. Thanks for the help from everyone.
Now that I am familiar with how to upload on to the site, it will make things alot easier for everyone to explain what I am doing wrong.

Happy 4Th To All.

[dandrewsca]

Listen to what the CMMGUY says... if that doesn't work then construct a small plane at the end of the radius on each side and pierce the line through the plane. Have fun...
Dan

[Wingman]

The easiest way to do this(and because the radius is so large) is to actually just measure a very short line segment at the ends of the radius on both sides and intersect those line segments with their respective side lines. Dont screw with the arc measurement since your fitted results wont be accurate enough.

Not true. If you use three hits on the arc - one very near each end and one in center you will have VERY accurate intersection. Easier to capture and more accurate than small line segments.

[Snaggy]

If you are happy with the measurement for your arc i.e you have the correct radius, then measure a line at each end and construct a pierce point between the rad and the line. If the point flies off into space, construct a reverse line and try again.

You haven't told us what tolerances you are having to work to, but with a rad this large you could get some wierd results when measuring it

[#2#]

The easiest way to do this(and because the radius is so large) is to actually just measure a very short line segment at the ends of the radius on both sides and intersect those line segments with their respective side lines. Dont screw with the arc measurement since your fitted results wont be accurate enough.

Well, I hope this image shows up now. I sketched this up real quick at home this morning. This is basically what the part looks like , aside from some counterbored holes that are in the actual part. I did construct a point at each end of the part, utilizing a small line at very ends of the radius. The measurment appeared to be fairly valid. Thanks for the help from everyone.
Now that I am familiar with how to upload on to the site, it will make things alot easier for everyone to explain what I am doing wrong.

Happy 4Th To All.

What are you two doing on the forum on July 4??? Some 'round these here parts would call you un-American for thinking about work yesterday. Watch out or they'll want to deport you.

[Wingman]

If you are happy with the measurement for your arc i.e you have the correct radius, then measure a line at each end and construct a pierce point between the rad and the line. If the point flies off into space, construct a reverse line and try again.

You haven't told us what tolerances you are having to work to, but with a rad this large you could get some wierd results when measuring it

Definitely treat the arc with profile. However, for corner construction purposes it is not necessary to 'nail' the radius size or location. You just need to do a 3 point arc. That way you are guaranteed that the arc surface passes through the points. Two of the points need to be as near the corners as possible. The third point in the middle. Your results will be very accurate regardless of what the radius size and center point would report.

[1CMM4ME]

Well, I'll be going into work tomorrow, as I will give it a try. I will get the actual dimensions off the print and update my sketch. I did, on the first go round, take points on the outside of the radius, then contruct a line on each end of the part. But when I tried to create a point at the end intersections, the points were out in left field. It may have been that I did not take the points of the radius really close to the ends of each side, which the software didn't like. I did make sure the vectors on the sides of the part were facing towards the outside of the radius, if that would make a tremendous difference or not.
As far as "pierce" points go, I am not familiar. I will look up previous posts to learn how to use those. Thanks again.
Oh....by the way..........no deportation required. I do have my pass to be here.

[#2#]

Pierce points are what you want to use. It may be that when you created the points before it did use pierce points but pierced the wrong side of the circle (a line not tangent to a circle intersects the circle in two places). As Snaggy said, if you get the wrong side of the circle, create a reverse line of the one you've measured and then try piercing with that line.

I've never figured out exactly the rules for where a pierce point will be created given the circle's vector and the line's vector. I just do it by trial and error.