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Trouble With BobCad

toolnuts

Cast Iron
Joined
Sep 27, 2009
Location
washington
Hello all,

I have been having some trouble with Bobcad V29, and maybe you could help me.

I designed, in Bobcad, a plate that was drilled and countersunk.

It had three countersunk holes that were all the same. I ran the refresh
the geometry, and calculate the tool paths. Then I ran the simulation and
the part was exactly as I wanted, so I saved it.

Later I decided that I wanted a plate that had only two countersunk holes. I
opened the three hole version and deleted the middle hole, ran the refresh
the geometry, and calculate the tool paths. When I ran the simulation I found
that the countersink had gone twice as deep. I checked the strategy and
nothing had changed from the three hole version.

I went back and re-opened the three hole version, and ran the simulation, and
all was well. So I ran the refresh the geometry, and calculate the tool paths,
and ran the simulation again and this time the countersink was to deep like the
two hole version.

Anyone have an idea what's going on???


Thanks for any help or insights.

Best Regards,

Paul Hoffman
 
I was able to get the same results on the two hole version as the three hole
version by changing the countersink depth from +.150 to a -.015.

jrmach: you need to re-read my post more carefully. I didn't use the correct
Bobcad terminology, the corrected forms would be "Update all Geometries" and
"Compute all tool Paths".

So the Update all Geometries is throwing an accumulated error of .150+.015 = .165".
I don't know where that comes from - maybe they have a software bug.

I tried starting over on all the strategies, but with the same problem.

Paul Hoffman
 
Hi Paul,
I've observed BobCAM losing the top of feature/bottom of feature references when unrelated geometry changes.

Also been sent for a loop a few times by my own inconsistent modeling of spot/chamfer/countersink tools - similar tools but where one is modeled with a point and the other a flat, where for reasons I haven't figured out, BobCAM will change the selected tool on it own, e.g. from the pointed to the flat bottom chamfer tool. If I don't catch it, BobCAM will calculate Z based on the wrong tool, with a similar result.
 
Hi All,

I tried another experiment, I brought in the 3 hole version, made no changes to the model,
updated the geometry, and computed tool paths - I got the same over cut problem with the
chamfer as I did with the 2 hole version.

So I thought that I should try the same routine again, (updated the geometry, and computed tool paths)
to see if it over-cut more than on the first go-around, but no, it was the same amount error -
no change.

Paul
 
OK,I downloaded the Demo,,,I see no problem with what you say,,BUT,with out a file that is giving you problems,or a re-creation at least of the tool path,,, ???????????????????

Glad to help you,,file please
 
The ZIP File

OK,I downloaded the Demo,,,I see no problem with what you say,,BUT,with out a file that is giving you problems,or a re-creation at least of the tool path,,, ???????????????????

Glad to help you,,file please

Hi Jrmach,

I sent you a private message requesting your email address so I can send you the file.

Paul Hoffman
[email protected]
 
So I believe follow up helps the Forum community,that way when search is used,an answer to a question is there

I got his file

The short answer is not quite setting up the software as intended

"Terminology" is king,,,got to understand the words as intended by the software

Issues with "top of stock",,,,,,"top of feature",,,,,,,,and "origin of machine set-up"

and when removing geometry,,the intended way of "re-computing tool path"

Awaiting a call from OP,,will go over his file with him

not a "BOB BASHING" thing here folks,,works fine

The You Tube video's for 27,28,29 should all help people in these areas
 
Here is a little more information on this topic.

1) If you update your geometry for a drill feature the depth settings will change unless you do the following...


use cutting conditioins.jpg

You need to un check the use cutting conditions check box. Do this will keep the user defined depth settings.


Otherwise re selected geometry is run though a level of logic that resets values you changed yourself.

When saving drill features, or using copy and past I would follow this same workflow. Just un check the use cutting conditions check box....
 








 
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