BobCAD 3D Core help

[skimann20]

MMOE, all your fixes worked. I still see a micro break when I'm zoomed out but when I drill down I don't see any of them so it's of no concern to me. I was almost wondering if they are there so you can see where "end of lines" are to make connecting lines just that much easier for end points?

So I can say that BobCAD is sooooo user friendly. I can draw skis in this program in about 2-3minutes without issue. Thank you for the suggestion to get this program. a few follow up questions.

I've attached my ski base file to this thread. It has a reduction in the side to account for the base width. looks great in bob and via cad. however when I generate the tool path in Bobcam it doesn't follow the side of the ski, only the tips tails (it does connect at the tip, mid section, and tail of the reduced area but that's it; It almost looks like it is trying to make the curve more smooth and not have two radiuses). Can someone verify if it does the same on their BobCAM? (base outline)

Second question, I've drawn the ski core dimension in ViaCAD as MMOE demonstrated. supper easy, thank you. however when I import it into bobCAD it doesn't come in as a solid and I can't generate a tool path with the file. I can import one of the "2D models" in the z/x axis just fine and pull it out in the y but then I'm profiling more than I need to. (Core Profile) Am I missing something here? does it have to do how I'm exporting out of ViaCAD?

Once I get these two items figured out I'll have 51% of this stuff figured out... then it's all down hill from there. :-)

Please let me know if you need screen shots of any the bobCad stuff. Cheers.

[mmoe]

To send a solid to Bobcad from ViaCAD, I'd use either a STEP (or STP) file or IGES file. STEP files don't really have any settings and they always import nicely to BobCAD, so I'd suggest you start there. If you want to try an IGES, I find the "Jama" version (option in the exporter) tends to be the most compatible with Bobcad. STEP files just tend to be very compatible all around, so would be my first recommendation. In ViaCAD, go to "File>>>Export..." which will bring up the export window settings. Then select "STEP" format and save the file. You can then either "Merge" the geometry into a new Bobcad file or open it directly with Bobcad. I prefer to use the "Merge" method, then I save the file as a .BBCD file once the geometry has been merged. Just a personal preference and either way will work. I do recommend saving it as a .BBCD file ASAP whether you merge the geometry in or open the geometry directly.

It's a bit late for me for checking files, but I'll try to remember to have a look tomorrow. It would be good if you post your .BBCD file so that we can see the toolpath that you've created as well. Just save it as a .BBCD, then create a ZIP file in order to post it here.

[skimann20]

So I tried the import of the solid as an IGES file and it worked great! Thank you. should I export all my ViaCAD this way? (2D and 3d)

I tried the 2D base with the same import and i still got the strange following of the side walls. *note: I drew a new ski thinking it was something with the way a drew it up. so it is not the same shape that I attached yesterday, it is slightly different but the same concept. I've attached the BOBCAD/CAM file, see below. please let me know if you need any additional information.

[mmoe]

So I tried the import of the solid as an IGES file and it worked great! Thank you. should I export all my ViaCAD this way? (2D and 3d)

I tried the 2D base with the same import and i still got the strange following of the side walls. *note: I drew a new ski thinking it was something with the way a drew it up. so it is not the same shape that I attached yesterday, it is slightly different but the same concept. I've attached the BOBCAD/CAM file, see below. please let me know if you need any additional information.

I keep them as Viacad format files, and then export them as needed. If the file is just lines (2d), I save them as DXF files and merge them in with the solids if necessary.

The file looks good to me other than one thing. The tool appears to be offset to the inside of the line instead of the outside of the line. I'm not sure if that's what you're asking about, but the green toolpath lines are not going to be the same as the lines you drew since the tool gets offset by half the width of the tool. You have it set so the offset (compensation) is to the "right", but that's putting the toolpath on the wrong side of the lines. You can right click on "geometry" in your CAM tree and click on "reverse direction". Then re-calculate the toolpath and see if that fixes your problem. Otherwise, I might not be following what you're looking at.

[skimann20]

Interesting. When I look at it in bob CAD the green line stays on the outside of the red line (which I want) in the tips and tails area. then when the tool steps down to cut the side walls of the ski it is on the outside of the red line then goes down toward the middle of the ski and wile traveling it almost becomes even with the red line then when it get to the "middle" point of the ski its back on the out side of the line and then when it travels back to the tail section it crosses the red line then when it gets to the tail it's back on the out side of the red line. Is that what you see? I would think that the green should stay on the outside of the red line the entire way around not just pay attention to the tip/midpoint/tail section of the ski?

post #17 in this shows what I was seeing back in the day and I'm still seeing it.

[jrmach]

I am with mmoe on this.
Here is your file back the way I like doing this type of tool path.I use contours.Let me know if that looks right and whether you want help learning them.

[skimann20]

hello Jrmach,
I can't open the file because "it was saved with a newer version of bobcat" I have V24. Can you re-save with an older version?

[mmoe]

I forgot you are on V24. In V26, I get the following. The first image is what it opens as, with the toolpath on the inside of the lines. The second image is after I "recalculate" the toolpath. It turned out that I did no have to change direction of the geometry, it was already correct. I did have to recalculate though. Unfortunately, my V24 is still on my old computer, and I can't access it. It will be hard for me to trouble shoot since it's generally correct at my end. I've been intending to deactivate it and install it on my laptop, but have not got around to it as it's a bit of a project to get the old computer running again. As jrmach suggests, you can take the geometry, select it all and then create a "contour" from it, which may make a difference for you.

[skimann20]

yes. the drawling on the right is what i want it to look like, mine looks just like mine but the long sides don't match up. I wonder if its just a glitch that it displays the tool path wonkey. I'll look into creating a "contour", that does't ring a bell to me. maybe worth just looking at the G-CODE to see if it matches up.

[BurrMan]

Ski,
Go to preferences-settings part and on the display tab, slide the "wireframe quality" slider up really high and select apply, then check the "wonky".....

This is called the display "mesh angle"... The display is chopping up the view of the geometry to something less than accurate....

It's just a display thing, and doesn't affect the geometry or toolpath in any way...

[skimann20]

Ski,
Go to preferences-settings part and on the display tab, slide the "wireframe quality" slider up really high and select apply, then check the "wonky".....

This is called the display "mesh angle"... The display is chopping up the view of the geometry to something less than accurate....

It's just a display thing, and doesn't affect the geometry or toolpath in any way...

unbelievable... that was it. thanks for all the help BurrMan and mmoe.

[skimann20]

okay next issue. can some one tell me why the corners are rounded, I want it to be sharp (which I selected)? I've attached file for viewing. I'm wondering if this has always done this and now that I know what the heck is going on I've finally picked up on it. (note it still post at G20, i just change this in Mach 3 when it imports, low on my priority list)

[BurrMan]

can some one tell me why the corners are rounded

Sorry, cant figure out what you are referring too.... Can you clarify it a bit more?

[skimann20]

look at the tool path in the corners. instead of taking a right angle turn its take a radius turn, thus cutting the the hard angle of the corner to a rounded edge. For this layup, that is very bad. I verified with "squares" and "triangles" in the same CAD drawling and the tooling path does a "hard turn" not a radius turn (tried all the other corner turns on these shapes and it allows them all). So it has to do something with the ski part. when I get to the corner section of CAM i've tried all the options and it still only does a radius turn unlike like triangle and square parts. (does that make sense, if not I'll take a screen shot.)

[BurrMan]

Are you talking about the z level finish job?

Although the toolpath looks "rounded", the tool is round also and it will make a square edge with that type of movement... The 3d toolpath z level finish wont be reading "lines" so to speak, it is just traveling arounf the surfaces....

If you extract the edges and use profile operations, there will be options to have the tool pass "straight by" all the edges and then continue down the others....

I may still be unclear on what you are looking for... Also, just as a reminder, you are running V24?

[skimann20]

this is cutting is only in the X/Y profile, no Z is top of table, V24 being used.
Okay BurrMan, so i've been wrapping my head around this "Although the toolpath looks "rounded", the tool is round also and it will make a square edge with that type of movement..." this finally makes sense to me, I think. I guess the question is why is it rounded when I select sharp for corner profile. see square image below that has the sharp movement. does that make sense?

[BurrMan]

It's a function of a "3d" toolpath and a difference of a "2d" profile op..... I think if you look in the 3d features there is no "make sharp" option......

You could probably "force" a toolpath like that using boundaries and different selections.......

[mmoe]

Generally speaking, you'd want to use the "round" option for outside corners anyways. It will run smoother through the corner and produce just as sharp of a corner if the machine is set up right. Even for inside corners, where I know I'm going to have some degree of radius, I often draw the interior corner with an ever-so-slightly larger interior radius than the bit I plan to use unless there is a tolerance I have to meet for customer specs. It's subtle, but it is a tad bit smoother through the interior corners that way as well. I don't find there is any practical difference between a 1.75mm radius and a 1.5875mm radius on an interior corner, but it does reduce the dwell in the corner and they come out a bit nicer with the slightly larger radius IMHO.

[jrmach]

"I often draw the interior corner with an ever-so-slightly larger interior radius than the bit I plan to use unless there is a tolerance I have to meet for customer specs. It's subtle, but it is a tad bit smoother through the interior corners that way as well."

B I N G O,,,,I have not heard anyone ever mention that.I have done that all along as I know the ill effects of tight corners.Manual machine enough years and you'll get that.

[skimann20]

Hey Gang, Digging this one up again. I thought post #50 fixed my issue. well the gremlin is back. in the pic you can see the tool path follows the bottom line perfectly but the top line you can see that it drifts away from the line in the top left and actually gets too close at the apex.

the perplexing part is that when I drew the shape, the bottom line is a mirror image of the bottom line. so i don't believe its a formatting issue.

thoughts?
~Brad