How to cut a chamfer on a job

Post general information and questions relating to Cut2D in this Forum.
Post Reply
sterob
Posts: 18
Joined: Sun Jun 28, 2015 10:12 am
Model of CNC Machine: X6-1500GT re-built with ESS and MB2
Location: Bunbury, Western Australia

How to cut a chamfer on a job

Post by sterob »

I need to cut out a small object out of plastic and I need a chamfer on the bottom of it.
No problem...I can cut it upside down and cut the chamfer first.

My question is what is the best way to position the 90° tool in order to cut eh chamfer. ( Chamfer is 45° )

My first thought was to just use the outer edge of the job as the centre of the tool and make incemental cuts dwn until teh correct sized chamfer was cut.
Would this work or is there a better way?

If I move the tool outwards and down, I would have to draw a perimeter around the job for the tool to follow.....?
Steve
Attachments
Chamfer.JPG
Chamfer2.JPG

ger21
Vectric Wizard
Posts: 1572
Joined: Sun Sep 16, 2007 2:59 pm
Model of CNC Machine: Custom DIY
Location: Shelby Township, MI, USA
Contact:

Re: How to cut a chamfer on a job

Post by ger21 »

My preference would be to offset the vector outward by 1/8", then cut a profile, on the line, with the depth being 1/8 + chamfer width.
Gerry - http://www.thecncwoodworker.com

sterob
Posts: 18
Joined: Sun Jun 28, 2015 10:12 am
Model of CNC Machine: X6-1500GT re-built with ESS and MB2
Location: Bunbury, Western Australia

Re: How to cut a chamfer on a job

Post by sterob »

Thanks Ger21...as per the 2nd pic?

ger21
Vectric Wizard
Posts: 1572
Joined: Sun Sep 16, 2007 2:59 pm
Model of CNC Machine: Custom DIY
Location: Shelby Township, MI, USA
Contact:

Re: How to cut a chamfer on a job

Post by ger21 »

yes
Gerry - http://www.thecncwoodworker.com

kstrauss
Vectric Craftsman
Posts: 188
Joined: Mon Apr 29, 2013 3:37 am
Model of CNC Machine: Tormach PCNC770
Location: Cobourg, ON, Canada

Re: How to cut a chamfer on a job

Post by kstrauss »

An easy way (rather than creating an offset path for every edge to be chamfered) is to setup the chamfer tool as having a smaller diameter than it actually is. For example, if you are using a 1/4-inch chamfer tool define it in your tool database as being 3/16 in diameter.

User avatar
mtylerfl
Vectric Wizard
Posts: 4814
Joined: Thu Jan 29, 2009 3:54 am
Model of CNC Machine: -CarveWright CNC -ShopBot Buddy PRSAlpha
Location: Brunswick, GA
Contact:

Re: How to cut a chamfer on a job

Post by mtylerfl »

Interesting alternative. Personally, I wouldn’t recommend that method - too much room for confusion. Better to layout the project correctly and keep the Tool Database specs matching actual bits used.
Michael Tyler

carvebuddy.com

facebook.com/carvebuddy

-CarveWright CNC
-ShopBot Buddy PRSAlpha CNC

User avatar
Martin Reid
Vectric Apprentice
Posts: 93
Joined: Wed May 18, 2016 6:00 pm
Model of CNC Machine: Shopbot
Location: Lancashire UK
Contact:

Re: How to cut a chamfer on a job

Post by Martin Reid »

Dear Steve

My two penn’orth is on option 2.

If the pieces are quite big then I may do the 'chamfer' after doing the profile cut - I get a really good finish and there is less work on the cutter as most of it is in the gap created with the profile cutter. If the pieces are small then I will do the chamfer before the profile cut so the pieces don't move. Also if there is some vCarving then I will do the chamfer while the cutter is in.

Doing the profile cut after doing a chamfer on the line (option 1) always leaves a quirk or raised arris that needs sanding.

Sincerely and in good faith
Martin
Attachments
Chamfer
Chamfer

sterob
Posts: 18
Joined: Sun Jun 28, 2015 10:12 am
Model of CNC Machine: X6-1500GT re-built with ESS and MB2
Location: Bunbury, Western Australia

Re: How to cut a chamfer on a job

Post by sterob »

@Martin
The job is quite small, so I think it would be easier to do the chamfer before the profile cut, as you say.
No VCarving. The job is a guide and a support for a charging connector, so it doesn't damage the device.
I suspected chamfering 'on the line' would leave some sort of artifact behind, but not a real problem.

I think offsetting the tool has too many avenues for math errors ( ok if I was doing lots but I only need to cut one )

The chamfer is only to allow the max surface area for gluing the guide in place.
Steve
Attachments
20180924_152909 (Small).jpg
Charging Guide Size.JPG

LittleGreyMan
Vectric Apprentice
Posts: 918
Joined: Fri May 15, 2015 1:10 pm
Model of CNC Machine: 3 axis small size machine
Location: France

Re: How to cut a chamfer on a job

Post by LittleGreyMan »

Steve,

To avoid cutting on the vector (your first drawing in your initial post), which does not give the best cutting condition (the linear cutting speed of the tip is 0), with a 90° V-Bit set these parameters for the 2D profile toolpath:
-machine vectors Outside/ right (or inside / left for an internal chamfer, not tested)
-set the allowance offset to - chamfer value. For example, for a 2mm chamfer (top view), set the allowance to -2
-set the cut depth to a value > chamfer value

The software will set the depth cut and the offset of the tooltip in order to get these values and cut as in your 2nd drawing. No need to do any math.

Tested on Aspire trial 9.5
Best regards

Didier

W7 - Aspire 8.517

sterob
Posts: 18
Joined: Sun Jun 28, 2015 10:12 am
Model of CNC Machine: X6-1500GT re-built with ESS and MB2
Location: Bunbury, Western Australia

Re: How to cut a chamfer on a job

Post by sterob »

LittleGreyMan wrote:Steve,

To avoid cutting on the vector (your first drawing in your initial post), which does not give the best cutting condition (the linear cutting speed of the tip is 0), with a 90° V-Bit set these parameters for the 2D profile toolpath:
-machine vectors Outside/ right (or inside / left for an internal chamfer, not tested)
-set the allowance offset to - chamfer value. For example, for a 2mm chamfer (top view), set the allowance to -2
-set the cut depth to a value > chamfer value

The software will set the depth cut and the offset of the tooltip in order to get these values and cut as in your 2nd drawing. No need to do any math.

Tested on Aspire trial 9.5
Cut2D will do that?
Thanks, I will check it out and have a play.

Post Reply