CAMheads CNC Router Forum By: CAMaster CNC

Go Back   CAMheads CNC Router Forum By: CAMaster CNC > Software > General Discussion

Reply
 
Thread Tools Display Modes
  #1  
Old 03-18-2018, 11:38 AM
Brian O Brian O is offline
CAMhead Legend
 
Join Date: Oct 2011
Location: Sykesvile Md
Posts: 502
Default line on circle

How would you draw a line of known length from a fixed point on a circle so it would intersect the circle at the other end.
__________________
Brian O

stinger III x3

vcarve pro
Reply With Quote
  #2  
Old 03-18-2018, 01:12 PM
Gary Campbell's Avatar
Gary Campbell Gary Campbell is offline
CNC Tech & Trainer
 
Join Date: Dec 2012
Location: Marquette, MI USA
Posts: 2,655
Default

Brian...
Can you explain what you are trying to accomplish?
__________________
Gary Campbell
CNC Technology and Training
The Ultimate Woodworking Machine
GCnC411@gmail.com
https://www.youtube.com/user/Islaww1/videos

"There are 10 kinds of people in the world. Those that understand binary logic, and those who don't"
Reply With Quote
  #3  
Old 03-18-2018, 03:41 PM
rcrawford rcrawford is offline
Cobra Owner
 
Join Date: Dec 2011
Location: Alberta
Posts: 2,177
Default

Quote:
Originally Posted by Brian O View Post
How would you draw a line of known length from a fixed point on a circle so it would intersect the circle at the other end.
You would draw a circle, centred on the point you know, with a radius the same length as the line. Then draw a line from the known point to the intersection of the two circles, and you know that line will the the length you want.
__________________
Russell Crawford
Cobra 408 ATC with recoil
Alberta, Canada
www.cherryleaf-rustle.com
Reply With Quote
  #4  
Old 03-18-2018, 11:13 PM
Brian O Brian O is offline
CAMhead Legend
 
Join Date: Oct 2011
Location: Sykesvile Md
Posts: 502
Default

The attached file is a generalization of what I am doing. In this case I drew a half of a circle instead of a arch the lines will connect to. I then draw the other circles the diameter of the line length. Next I draw a line at the intersection of the smaller circles, this give me what I want. I was hoping there would be a better method. Is this what you were describing Russel?
Attached Files
File Type: crv lines on arch.crv (15.5 KB, 36 views)
__________________
Brian O

stinger III x3

vcarve pro
Reply With Quote
  #5  
Old 03-19-2018, 09:23 AM
BradyWatson BradyWatson is offline
CAMhead Legend
 
Join Date: Oct 2014
Location: 1 hour South of Philly
Posts: 258
Default

Using the circular copy array tool you can easily copy out the lines and circles using a common center point. You'll need to know the exact XY coordinate of the center point - Make your model space bigger and put a horizontal and vertical line in the center of the workspace to make crosshairs or just set the center of the model at 0,0 from the beginning.

Looking at your file it is possible to do what you want several different ways. When using the circular array tool, I find it best to put the line horizontal and then copy it out using the number of copies required. You can grab the corresponding circle in the copy as well. At first glance, it looks like you could also just create a polygon with the number of sides required at a specified radius (circumscribed in a circle) - the value will be the radius from the center to the points on the polygon.

Standard CAD rules apply with this stuff....meaning, never draw more than you have to when you can use an array copy or mirror.

I don't know what you are ultimately trying to do, but if your intention is to make a pattern, such as a sacred geometry type thing, be sure to be as precise as you can. Mirroring over can be helpful in lieu of other methods as well.

-B
__________________
IBILD Solutions - High Definition 3D Laser Scanning Services - Advanced CNC Training and Consultation - Vectric Custom Video Training IBILD.com
Reply With Quote
  #6  
Old 05-01-2018, 09:02 AM
kjoiner kjoiner is offline
CAMaster Owner
 
Join Date: Sep 2016
Location: Work - Duluth, GA, Home - Roswell, GA
Posts: 98
Default

Hello,

Are you trying to draw a chord of a fixed length inside a circle of a given diameter?

http://www.mathcaptain.com/geometry/...-a-circle.html

Kyle
__________________
Kyle Joiner
IPA LLC
www.thinkipa.com
Duluth, GA
CAMaster Stinger 1 23
FTC, Laser Cross Hair
Vectric V Carve Pro
Remote Handheld Keypad
Solid Edge ST10
Reply With Quote
  #7  
Old 05-01-2018, 11:43 AM
Ger21 Ger21 is offline
CAMhead Legend
 
Join Date: Apr 2014
Location: Shelby Township, MI
Posts: 299
Default

Quote:
Originally Posted by rcrawford View Post
You would draw a circle, centered on the point you know, with a radius the same length as the line. Then draw a line from the known point to the intersection of the two circles, and you know that line will the the length you want.
+1
This is how I do it.
__________________
Gerry

JointCAM - CNC Dovetails & Box Joints

Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 05:59 PM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.