Having problems creating this 2 rail sweep

[marcrunner]

Having problems creating the top of this ring box. I have created the bottom, changing the center point of the the box half to a .25" flat area, in order to be able to machine this without any v bits or BN bits. Now having trouble wrapping my head around the top. I have the Aspire files if anyone can take a look, but was not able to post them here, due to their size. Happy to send them over. Thanks,
Marc






http://www.talkshopbot.com/forum/attachment.php?attachmentid=26597&stc=1

[marcrunner]

Have also searched to find out how to upload CRV files, and have seen others do so, but file size may be too large. Can anyone give insight as to how to accomplish this?

[Brady Watson]

Use WinZip or something @ max compression to compress the CRV3D and then post it. WinRAR @ max compression is smallest.

-B

[marcrunner]

Downloaded win rar. Shopbot says "Files not supported"
this compressed it to 27kb

[steve_g]

I use Google drive, others use DropBox. These services let you upload a file and just post a link. In my mind, way easier than trying to compress a file small enough to upload here on the forum…
SG

[Brady Watson]

Downloaded win rar. Shopbot says "Files not supported"
this compressed it to 27kb

Yeah sorry about that. I forgot this forum doesn't allow RAR. Just toggle it from RAR to ZIP and save it as a ZIP. Then upload it.

...or do what Steve mentions.

-B

[marcrunner]

http://www.talkshopbot.com/forum/attachment.php?attachmentid=26605&stc=1

[marcrunner]

http://www.talkshopbot.com/forum/attachment.php?attachmentid=26606&stc=1

[marcrunner]

I think I have it!

So the trouble I am having is with the box top file. I have created the 2 rail sweep for the 3d point on the box, setting the 3d model at a height of .3937, as well as setting the model at the uppermost portion of the modeling plane. I am pocketing the rest of the top of the box to the same depth as the model height, but can't seem to get them to line up with one another. AM I making any sense?

[Brady Watson]

Having problems creating the top of this ring box. ...in order to be able to machine this without any v bits or BN bits....

OK - thanks for the file.

First, I don't know what to tell you about machining a prismatic top/bottom without vee or ball bits. They are cheap, even HSS will work. Doing it any other way will be problematic on the CNC. You may be able to get what you want with the bandsaw or table saw. It is possible to do some funky offsets and get stair stepped cuts, but not smooth ones on those angles.

In regards to the 2RS, any time you have a negative 3D shape, your cross section needs to be a 3-sided 'chair' where the sides are straight walled down to, or say .005" below the lowest portion of the cross section. Otherwise you will have problems.

Does the attached pic help?

-B

[marcrunner]

Brady
Thanks, So for the box top, which I believe would be considered a positive 3d shape, I am asking the 2 rail sweep to machine down from tip to ridge at an angle on both sides, in order to make the shape. Shape height is .3937, and model has been placed at the top of material block. no problems there.

Next, I am asking the software to machine down to that same .3937 depth with a pocket labeled "Outside of ridge"
This is where, when previewed, the depth of the outside of ridge is deeper than the depth of the "3d model, even though I have asked to machine to the very same depth. Why the inconsistency with depths, when I am entering the same value for both?

Long story short, I want the depth of the pointed 3d shape to match the depth of the out side ridge, and they are different, but need to be the same. Thanks

[mezalick]

Since you have your Z from the top of the material, you are tell the machine to cut the 3-D component from the top down...
Next you are asking to cut a profile cut that will be .3937 down from the top.
This is why you are getting that lower outside edge.

Your model height is .3937
The sides of the model are .2632 tall
Your cut depth on the profile cut should be .1305

That should line up your edges,,,except..
The finish cut is set for the “use selected vectors”
Your .25” ball end bit will not go down deep enough to meet the .2632 level you are expecting.

I would create a flat component . 2632, set property to merge and use that outside vector to do the finish cutting.
You would not need the outside profile cut.

Here’s a file and some pictures.

Michael26675http://www.talkshopbot.com/forum/attachment.php?attachmentid=26676&stc=1http://www.talkshopbot.com/forum/attachment.php?attachmentid=26677&stc=1

[mezalick]

Here's a picture of what I get.
Michaelhttp://www.talkshopbot.com/forum/attachment.php?attachmentid=26678&stc=1

[marcrunner]

Thank You Michael !!!
Really appreciate this! I will take some time to go back over everything. Thank you to those who helped with file uploading as well.
Marc