2d Contour with tabs

[valdiorn]

Hi there. I'm a recent convert to SolidWorks and I'm trying to use HSM Express as my CAM package. I've been trying to set up a milling operation for what I believe should be a very straight forward task, but I've been unable to get the behaviour I want.

To put a long story short; I'm preparing to mill a two sided piece, and I'm trying to set up a contour operation that would cut the outline of a main part, but leaving several tabs to retain the cutout fixed inside the stock. To illustrate my problem, I have attached a very simple part that exemplifies the problem I'm having. Please keep in mind this is not the part I'm actually trying to mill, it is a simplified part that should illustrate the problem.

What I want to do is to contour the cylindrical part out of the stock, but leaving the two tabs in place, but I've been unable to come up with a path that does this.

To give you a bit more background, the "full" problem I'm trying to solve is to mill the contour of a guitar body, represented in my example by the cylindrical solid, from a large rectangular stock, but leaving tabs/bridges to keep the body fixed, as the stock will be fixed down at the edges and I don't want the cut out piece to go flying across the room. Since HSMWorks/HSM Express doesn't seem to support tabs, I'm trying to manually model them, and then trying to prevent HSM Express from milling them away.

An example of the result I want to achieve would be something like this

If you can assist it would be greatly appreciated.

Best regards - Valdemar.

[aewrmc]

Like the image below?

[valdiorn]

Yes that's pretty much what I want to achieve.

Could you share with me what you did to get this toolpath?

Many thanks - Valdemar.

[aewrmc]

You need to create a containment/boundary for the tool path to work with. I just used a large circle in the example. Hope this helps.

[valdiorn]

Thank you. I will try this as soon as I get home tonight.

Are you using a 2d contour operation or is this a different type of operation? Because I'm not sure how I tell HSMExpress to respect the boundaries of both the cylinder and the tabs. Whenever I select the cylinder's edge, it would always try and cut out the entire cylinder, cutting through the tabs.

[valdiorn]

I've spent another 2 hours trying to get this to work. No matter how I try to set it up I can't get HSMExpress to cut out the cylinder but respect the tabs.

I get what you're saying about the Stock Contour, that's a good point to make sure the tabs stay attached to the stock, but I just can't seem to come up with a toolpath that follows the edge of the cylinder *and* the tabs; it always wants to cut through one or the other... or both.

[daniel_lyall]

https://community.osbeehives.com/t/solidworks-tabs-creation-method/232 is your best better or change over to useing Fusion 360 what has them.

[valdiorn]

Thank you Daniel. Unfortunately that video doesn't really show any toolpaths being generated, but I believe the point of the exercise was to create that contour in the middle of the part. Then you could generate two toolpaths at different depths, one that follows the rectanglular shape, and one that includes the tabs.

I don't really find this a satisfactory solution as it requires modifying the geometry of my part, and also doesn't lend itself to just any geometry; it's not a very portable solution.

I think I'm at a loss here, I'm going to experiment with some other CAM packages now as this just doesn't seem to be inside the scope of what HSMWorks can do without resorting to convoluted workarounds, which is unbelievable because I thought something as simple as "follow this contour, but don't hit this part" would be a basic capability. It's a shame because I like the rest of the workflow very much.

Thank you everyone who helped, aewrmc if you do have the chance, I would love to know how you generated that toolpath you posted a screenshot of 🙂

[daniel_lyall]

I don't use HSM express but the selection in HSM and Fusion is usely pick the toolpath click in it again and edit it that way like what is here https://www.youtube.com/watch?v=ATs4rsI_TPc

[valdiorn]

Yeah that video shows exactly what I need to do, now if I could only do the same in Solidworks... 🙂

[daniel_lyall]

this is about all that I can find that may help               

  https://www.youtube.com/watch?v=H7zPDiZZesE&list=PLjUJwQJKr2zdsehaHeWLfa1Po7I-yxtPv

And Lars has some here https://www.youtube.com/watch?v=0Xdfz2lelvM&list=PL40d7srwyc_PV1SvoyhP6F3VRapTY64T9   

 I am surprised the selection does not work the same.

I will have to dig into the manual my self

[aewrmc]

I'm using Inventor HSM with the adaptive clearing cycle (3D), the yellow is the stock contour, the green is the boundary selection (top edge of the cylinder) with a 10mm offset. No other geometry is required to be drawn unless you need it.

Image bellow is the simulation.

Hope this helps.