What is it? When and why do I use it?
Thanks in advance.
PS I looked in the documentation and couldn't find an explanation other than how to set it.
Need quick explaination of step over
- SIBUD
- Vectric Craftsman
- Posts: 228
- Joined: Sun Jan 06, 2013 8:32 pm
- Model of CNC Machine: ShopBot 18X24 Desktop
- Location: Nashville, IL
Need quick explaination of step over
Bud Meade
Nashville, IL
I don't own too many BMW motorcycles, I just have too little time.
Nashville, IL
I don't own too many BMW motorcycles, I just have too little time.
- zeeway
- Vectric Wizard
- Posts: 3157
- Joined: Thu Feb 11, 2010 9:24 pm
- Model of CNC Machine: Self-built
- Location: SC, USA
Re: Need quick explaination of step over
When doing 3D carving or pocket machining, your tool cuts the next pass offset sideways at a percentage of the diameter. For example on a .125 inch tool, at 9% stepover, the next pass moves over (9% x .125=) .01125 inches. So a one inch wide piece would require (1 /.01125=) 89 passes. The less the stepover, the finer the detail. From 8 to 10% is a good value for finish passes on 3D work. For rough passes, you could use 40 to 60%. Pocket machining with an end mill, I would use 30 to 40% stepover.
Angie
Angie
- Leo
- Vectric Wizard
- Posts: 4092
- Joined: Sat Jul 14, 2007 3:02 am
- Model of CNC Machine: 1300 x 1300 x 254 Chinese Made
- Location: East Freetown, Ma.
- Contact:
Re: Need quick explaination of step over
Angie nailed it on the 3D stuff.
On 3D - with a ball nosed tool - I will step over at 5% or so. Depending on the tool and the profile, I like to see .005 to .010.
If I was just doing a flat bottom pocket I would stepover at about 90%.
Figure this ---- The tool can cut a slot. That is 100%. Well with that in mind I want the best efficiency in time - so if the tool is capable of 100%, then with a small overlap in passes at 90% - that will be fine.
On 3D - with a ball nosed tool - I will step over at 5% or so. Depending on the tool and the profile, I like to see .005 to .010.
If I was just doing a flat bottom pocket I would stepover at about 90%.
Figure this ---- The tool can cut a slot. That is 100%. Well with that in mind I want the best efficiency in time - so if the tool is capable of 100%, then with a small overlap in passes at 90% - that will be fine.
Imagine the Possibilities of a Creative mind, combined with the functionality of CNC
- SIBUD
- Vectric Craftsman
- Posts: 228
- Joined: Sun Jan 06, 2013 8:32 pm
- Model of CNC Machine: ShopBot 18X24 Desktop
- Location: Nashville, IL
Re: Need quick explaination of step over
Thanks to you both. I think I understand it.
When using a V bit to carve letters, is step over an issue or should it be set to 0?
When using a V bit to carve letters, is step over an issue or should it be set to 0?
Bud Meade
Nashville, IL
I don't own too many BMW motorcycles, I just have too little time.
Nashville, IL
I don't own too many BMW motorcycles, I just have too little time.
- Leo
- Vectric Wizard
- Posts: 4092
- Joined: Sat Jul 14, 2007 3:02 am
- Model of CNC Machine: 1300 x 1300 x 254 Chinese Made
- Location: East Freetown, Ma.
- Contact:
Re: Need quick explaination of step over
zero step over on v-grooving - BUTSIBUD wrote:Thanks to you both. I think I understand it.
When using a V bit to carve letters, is step over an issue or should it be set to 0?
If you have a flat depth set - then yes there will be a step over amount. It will be small because you will be doing the step over based on the tip of the tool.
Step over is a sideways motion
Imagine the Possibilities of a Creative mind, combined with the functionality of CNC
-
- Vectric Wizard
- Posts: 4797
- Joined: Thu May 18, 2006 3:24 pm
- Model of CNC Machine: ShopBot
- Location: North Carolina
Re: Need quick explaination of step over
Hi Bud,
See if this helps:
If the v-carve is going to be cut with a single pass, then the Stepover values are not used.
If the v-carve is too deep and wide to be cut in a single pass, the depth for each pass is controlled by the Pass Depth you have set for the v-bit and the "Clearance Pass Stepover" controls how much horizontal movement takes place as the v-bit 'clears' the center material for that pass. This can be as coarse as your machine/bit/setup allows as it is just roughing out material which will all be removed when the toolpath completes.
If you have the Flat Depth option checked, the "Final Pass Stepover" controls how 'smooth' the flat bottom will be. The smaller the stepover, the smoother it will be however with a true v-bit (comes to a point) you will always see ridges. Also, the smaller the stepover, the longer the machining time. If you are using the Flat Depth option, it is always best to use an endmill to clear the flat areas and then the v-bit will only need to clear any flat areas where the endmill could not reach.
You can easily see the effects of different settings by calculating the toolpath, preview it and inspect the blue lines. These lines are where the very point of the v-bit will be traveling.
Tim
See if this helps:
If the v-carve is going to be cut with a single pass, then the Stepover values are not used.
If the v-carve is too deep and wide to be cut in a single pass, the depth for each pass is controlled by the Pass Depth you have set for the v-bit and the "Clearance Pass Stepover" controls how much horizontal movement takes place as the v-bit 'clears' the center material for that pass. This can be as coarse as your machine/bit/setup allows as it is just roughing out material which will all be removed when the toolpath completes.
If you have the Flat Depth option checked, the "Final Pass Stepover" controls how 'smooth' the flat bottom will be. The smaller the stepover, the smoother it will be however with a true v-bit (comes to a point) you will always see ridges. Also, the smaller the stepover, the longer the machining time. If you are using the Flat Depth option, it is always best to use an endmill to clear the flat areas and then the v-bit will only need to clear any flat areas where the endmill could not reach.
You can easily see the effects of different settings by calculating the toolpath, preview it and inspect the blue lines. These lines are where the very point of the v-bit will be traveling.
Tim
- SIBUD
- Vectric Craftsman
- Posts: 228
- Joined: Sun Jan 06, 2013 8:32 pm
- Model of CNC Machine: ShopBot 18X24 Desktop
- Location: Nashville, IL
Re: Need quick explaination of step over
Thanks Leo and Tim.
Your explanations make it perfectly clear.
I'm like a sponge, soaking up a lots of information.
Your explanations make it perfectly clear.
I'm like a sponge, soaking up a lots of information.
Bud Meade
Nashville, IL
I don't own too many BMW motorcycles, I just have too little time.
Nashville, IL
I don't own too many BMW motorcycles, I just have too little time.
- Leo
- Vectric Wizard
- Posts: 4092
- Joined: Sat Jul 14, 2007 3:02 am
- Model of CNC Machine: 1300 x 1300 x 254 Chinese Made
- Location: East Freetown, Ma.
- Contact:
Re: Need quick explaination of step over
Nothing wrong with sponges - I are one too.
Imagine the Possibilities of a Creative mind, combined with the functionality of CNC