## Help with Geometry

This forum is for general discussion regarding VCarve Pro
carbidetooth
Vectric Apprentice
Posts: 52
Joined: Mon Apr 09, 2018 8:01 am
Model of CNC Machine: ShopSabre Pro 408

### Help with Geometry

Hi all. I'd like to duplicate or get close to this interlocking shape.

I'm being up-front and telling you that I (regrettably)avoided math in school and I imagine this is a geometry exercise. I've been putzing around for a couple of hours without success. I think all sides have to be equal, right? I just don't know how to get there. Help appreciated.

Samson
Vectric Wizard
Posts: 323
Joined: Fri May 02, 2014 10:14 pm
Model of CNC Machine: 4x4

### Re: Help with Geometry

I only spent a few minutes, but this is what I came up with. It's all triangulated. Fairly simple using copy array.

carbidetooth
Vectric Apprentice
Posts: 52
Joined: Mon Apr 09, 2018 8:01 am
Model of CNC Machine: ShopSabre Pro 408

### Re: Help with Geometry

Thanks Samson. I'd love to be able to do that in few minutes. I'm afraid triangulated means little to me in this context. Could you walk me through process it a bit more so I can latch on conceptually? I should add that I think I can manage the array if I can get the process of creating a single shape.

mtylerfl
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### Re: Help with Geometry

Hi Peter,

I made a quickie video (less than 3 minutes long) of one way how to create a shape like what you are working with. The shape can be varied easily via how you alter the original triangle shape that it is based upon.

https://www.screencast.com/t/wZ2uRMWZiie
Michael Tyler

carvebuddy.com

-CarveWright CNC
-ShopBot Buddy PRSAlpha CNC

carbidetooth
Vectric Apprentice
Posts: 52
Joined: Mon Apr 09, 2018 8:01 am
Model of CNC Machine: ShopSabre Pro 408

### Re: Help with Geometry

Michael, you are the MAN! I can't tell you how grateful I am that you took the time to make that.

I muddled through a number of what I thought were reasonable approaches, all ending in frustration of some level or another. In the end I chose desired angles and stepped around the shape using a single dimension which worked but felt really clumsy and prone to error.

FWIW, this is for a puzzle of sorts I'm going to make for my grandson's third grade class. Each student gets a single shape to decorate as they wish and then all come together on backboard. The theme being something along the lines of "many yet one".

I didn't anticipate Grandpa would get stumped right out of the chute, so I guess we both get to learn something!

Thanks again.

garylmast
Vectric Wizard
Posts: 1042
Joined: Fri Oct 23, 2009 4:03 pm
Location: Sandy, Utah

### Re: Help with Geometry

Here's another way.

Gary
Attachments

carbidetooth
Vectric Apprentice
Posts: 52
Joined: Mon Apr 09, 2018 8:01 am
Model of CNC Machine: ShopSabre Pro 408

### Re: Help with Geometry

And thank you Gary. Yet another bit of Vectric Wisdom. "Polar" array is new to me. Is that a "circular" array by a different name?

highpockets
Vectric Wizard
Posts: 2948
Joined: Tue Jan 06, 2015 4:04 pm
Model of CNC Machine: PDJ Pilot Pro

### Re: Help with Geometry

Sounds like a great project!

Remember to allow for the diameter of the bit you choose to cutout each piece or the puzzle won't fit together correctly.

If you're using a laser to cutout the piece then ignore the above....
John
Maker of Chips

garylmast
Vectric Wizard
Posts: 1042
Joined: Fri Oct 23, 2009 4:03 pm
Location: Sandy, Utah

### Re: Help with Geometry

Yes, it's the circular copy. Once you do the copies, you'll still have to move them to connect the ends. Once you get the hang of it, it should just seconds to do.

Gary
Attachments

carbidetooth
Vectric Apprentice
Posts: 52
Joined: Mon Apr 09, 2018 8:01 am
Model of CNC Machine: ShopSabre Pro 408

### Re: Help with Geometry

One other aspect of this I could use some help on. All MDF so no grain orientation, I'll cut the shapes separate from the "big picture" pocket they'll fit into, so no tool clearance concerns. I'm thinking clearances between pieces perhaps .030 for easy assembly and disassembly, but that's a guess on my part. If anyone has done similar perhaps you can advise what works well.

Thanks again.

Vectric Apprentice
Posts: 843
Joined: Sat Jul 27, 2013 10:08 pm
Model of CNC Machine: AXYZ 4008

### Re: Help with Geometry

One thing to remember is that all the "inside corners" will be cut rounded. You should use the fillet tool to radius all the outer corners (or all corners for completeness) so they nest in with the rounded inside corners.

See attached file. Knowing that I'll cut this shape with a 1/4" router bit I used a fillet with 1/8" radius on all corners. I didn't need to do the three "inside" corners as you get a fillet for free when cutting them. But! I did fillet them just in case I decide to use a smaller than 1/4" bit (say 6mm, 3/16", or 1/8").

Steven
Attachments
tessellation.crv
Created with VCarve version 9.519

BrianM
Vectric Staff
Posts: 1960
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Location: Redditch U.K
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### Re: Help with Geometry

mtylerfl wrote:Hi Peter,

I made a quickie video (less than 3 minutes long) of one way how to create a shape like what you are working with. The shape can be varied easily via how you alter the original triangle shape that it is based upon.

https://www.screencast.com/t/wZ2uRMWZiie
Michael,

That is a very impresive and consise answer to the question, Adze that identifies the practicalities of actualy cutting it. Teamwork at its best! I love this forum

Brian
Brian Moran
Chairman
Vectric Ltd.

FixitMike
Vectric Wizard
Posts: 1597
Joined: Sun Apr 17, 2011 5:21 am
Model of CNC Machine: Shark Pro Plus (extensively modified)
Location: Renton, WA USA

### Re: Help with Geometry

And yet another method.
Good judgement comes from experience.

tomgardiner
Vectric Wizard
Posts: 387
Joined: Thu Oct 02, 2014 1:49 pm
Model of CNC Machine: FMT Patriot 4 x8

### Re: Help with Geometry

I love reading through the variety of solutions. Maybe this should be a weekly event. One drawing problem per week.

WNC_Ed
Vectric Craftsman
Posts: 266
Joined: Fri Dec 07, 2018 5:56 pm
Model of CNC Machine: Shark HD4 AXYZ 4010
Location: Western North Carolina - Heart of the Smokies

### Re: Help with Geometry

Wow, that poor cat got skinned over and over
The Vectric software is pretty dang amazing but what puts the software over the top is the users on the forum.
I learn something on here just about every day.
Thank you all!
Maker of sawdust