Resizing a shape

[redvanth]

Hello

I am very new to the world of cnc, been using trila of V carve pro.

I need to draw a shape, for example 2000mm in width.
the shape is basially a rectangle with a step up at a 45 degree angle approximately 300mm from each end.

I need to be able to resize this shape to either a smaller or larger size
with out changing the 45 degree angle.

I have been able to use node editing and select points and stretch yet
this will change the angle as i stretch...

can anyone help

Thanks in advance
Redvanth

[Tony Mac]

Hello Redvanth,

Save and email the file to me so I can see what you are
trying to achieve.

Tony

[Dennis Rech]

It is probably easiest to select the item (group it first if it is made of individual items) and select offset. Offset larger (or smaller) as needed. You will then have the new larger item plus the original item on the screen. Then chose node editing to move whatever points necessary to maintain the angles.
Then delete the original item.

[Tony Mac]

Not sure this approach will work because grouping individual entities
doe not link them together for an offset operation - not sure that
offsetting is correct either.

Email the file - tonym@vectric.com - and I'll take a look

Tony

[Dennis Rech]

Not sure this approach will work because grouping individual entities
doe not link them together for an offset operation - not sure that
offsetting is correct either.

Hi Tony,
I just tried it again, Seems to work fine for me and I use it all the time to do what redvanth was inquiring about. It took 9 mouse clicks. With a more complicated object, either using "Weld" or any of the "Join" commands links the objects fine for offsetting.
One can also just select the object and then scale either x or y to the new dimension and then node edit the final point for the 45 degree angle. Since the original shape goes away with "scale", one will need to draw a separate 45 degree construction line before scaling to know where the 45 degree node should be. (Just click on the line and drag it to where you need it. Maybe select a new layer color.) Took 12 mouse clicks.
One can also "copy-paste" an identical object, slide it over to the side and node edit it. Maybe change colors and then slide it back over the original to make sure the critical points are still in the correct position.
None of these methods should take more than 15 or 20 seconds.
I have been using V-Carve for about 4 years on my ShopBot and I just love this program.

[Tony Mac]

Thank you for sending the additional information + files

As you have found by experimenting – Resizing and Offsetting does not give the required results.

It is possible to,

Place Guidelines at the required positions
Node Edit
Drag to select all of the required nodes – include the angled region

Place cursor over a node > Click > Drag > Snap to the required Guideline location

But this is all very manual and I don’t think it’s the appropriate method.

You probably need to be looking for Parametric CAD software that allows the designs to be modified programmatically.

Sorry we couldn’t be more helpful and good luck with the project

Regards,
Tony

[Dennis Rech]

Hi Tony,

Just out of curiosity, the shape was described as a rectangle with two angled ends and the ends need to be closer or farther apart. What was the additional information?

Seems like the object could be selected, node mode turned on, cut two straight lines with "C", pull the halves apart to the correct distance and stretch the lines back together with the mouse cursor.

Just wondering about the rest of the story.

[Tony Mac]

Node editing + selecting and dragging nodes etc. is not
the answer, plus there are other shapes that need extending
and inserting continuations of the design.

A more automated approach is the way forward.