figuring corner radius

[Bert Kemp]

319960is there a way to figure what numbers to put in the corner radius boxs to get them to come out a certain length?

[Jerome Stanek]

draw it 8 inches on a 22.5% angle

[Mark Sipes]

A*A + B*B = C*C since a and b are equal 2 ( A*A) = C*C you have the C actual the length so A = C*C /2 sqr rt


Give us a number and see if it works


so if you need a 8" length.. (8 x8) /2 = 32 the sqrt = 5.656854 that is the number you enter in corel bevel radius.





Wow Me don't like math.

Draw a 8 x 8" box in corel.... rotate 45* and reduce the box to the number you want 8" now rotate it back to 0* and read the measurements......much easier.. 5.657


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[Scott Shepherd]

.7071 x Length across that leg (8" in this case) = length

[Bert Kemp]

yikes guys there has to be an easier way. corel will do radius, but I need to know what number to enter into the boxes. If I enter 8.25 looking for 8.25" lines its not right th lines are way to long,319964there about 11 inches long.

[Tony Lenkic]

Bert,

Are you trying to make octagon with 8" each side?

If so, you can get this in corel by drawing square of 19.375 than go to Fillet/scallop/chamfer docker and enter 5.625" in Chamfer and it will generate you 8" sides

[Bert Kemp]

No I'm trying to get 8.25 on two sides my sq is 21.25


Bert,

Are you trying to make octagon with 8" each side?

If so, you can get this in corel by drawing square of 19.375 than go to Fillet/scallop/chamfer docker and enter 5.625" in Chamfer and it will generate you 8" sides

[Bert Kemp]

I think this is it Scott. if I multiply .7071 x the length I want and enter that number in the radius boxes I thunk it come out right. Thank you.? how did you come up with .7071???


.7071 x Length across that leg (8" in this case) = length

[Mike Null]

Bert

This may be the hard way but make your square and convert it to curves. Make two squares 8.25" and rotate them 45 degrees. Position them right and top aligned and left and top aligned. Make a node on each side where the chamfer meets the square. then delete the corner node.

[Glen Monaghan]

Like others said, you can enter 5.656854 (= .7071*8) in that dialog box to generate an 8" bevel. Since the bevel is at 45 degrees, the horizontal distance (A) from start to end of the bevel is the same as the vertical distance (B), and you want the bevel (C, the side you are creating on the 45 degree slope) to be 8", then it is as Mark explained, you use A squared plus B squared equals C squared. And A equals C so that reduces to 2 A squared equals C squared, or C = A times the square root of 2. And Scott rewrote that as .7071 * 8. QED

[Glen Monaghan]

This may be the hard way but [...]
Yes... ;^)

[Kev Williams]

I'm not exactly sure what your after, but--

if you know the radius and you want the diagonal measurement (as shown in your diagram), multiply it by 141.4%...

Conversely, if you know the diagonal measurement and want to know the radius, multiply by 70.7%...

[Scott Shepherd]

I think this is it Scott. if I multiply .7071 x the length I want and enter that number in the radius boxes I thunk it come out right. Thank you.? how did you come up with .7071???

Bert, .7071 is the Cosine value of 45 degrees. Cosine(45 degrees)= (Adjacent side)/(hypotenuse)

.7071= X/8.000
X= .7071*8.000
X=5.565 (doing this from memory, so that number might not be exactly right)

[Mark Sipes]

So the final answer is 5.834 produces a diagonal of 8.25"


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[Bert Kemp]

Thanks guys I think Scott's method is the easiest:) as I have the number to work with,I don't understand all the other math, basic algebra was 45 years ago long forgotten, hated math.LOL.
I'm going to assume this number only works as long as I'm using a 45° angle

[Scott Shepherd]

I'm going to assume this number only works as long as I'm using a 45° angle

That is correct Bert, there's a different number for every angle. Don't worry, Algebra wouldn't have helped much, it's Trigonometry ;)

[James Rambo]

Try using the trim tool:



Sorry you will need to shrink the page to see all of it..

[Dave Sheldrake]

Quick note Bert, Radius and Chamfer are different in pretty much all CAD programs (just as a note, in case you ever need to use keyboard commands)

[Bert Kemp]

Thanks Dave, James were is the trim tool?

[James Rambo]

Sorry Bert I am not at home. Just cheating at work and looking at the internet. I have a tool bar open at the top of my Corel Draw page that has the 'weld' 'trim' 'simplify' and as couple other tools on it.

[Bert Kemp]

i see it under arrange then shaping.What confuses me with this method is getting the 2 small sq's in the proper place. Kinda hit and miss doing it by eye. isn there an easy way to get them in the right spot. So far Scotts method is the easiest.


Sorry Bert I am not at home. Just cheating at work and looking at the internet. I have a tool bar open at the top of my Corel Draw page that has the 'weld' 'trim' 'simplify' and as couple other tools on it.

[James Rambo]

The way to find the corners of this square is to select the square. Then select 'arrange' and 'transformation'. In the transformation flyout unclick 'relative position' and click the corner that you want to find coordinates of. Select the small square and locate it on center at the coordinates of the corner. Click 'arrange' 'shaping' 'trim'. And delete the small square. Do the same with the other corner.