Importing tolerance for CAD tools

Verifun · 2012-07-06 01:58:08

Hi,

This one I discussed with an AE weeks ago, so here it goes:

When you import a CAD tool via ToolManager, the tolerances under which the models are brought are hardcoded in the SW. For this reason, cutting inserts for example are much tesselated and that's also why we have accuracy problems with imported inserts now.

What if you allow the user to define the tolerance during the importing, in the import dialog? Today the guys can decide if the component is an acessory, a holder or an insert right? An extra column to define the tesselation tolerance for that component could be helpful...

CAD models are usually more detailed and poses more memory comsumption, so using a generalist tolerance can work fine for holders but no so well for inserts and cutters, but maybe too tight for holders/extensions and too loose for inserts...

As holders/extensions are bigger and far more detailed than inserts (And thus requires more memory), a hardcoded tolerance may lead Vericut to use extra memory where we don't need...

By setting the importing tolerance we could have a way to improve the verification performance, even tighting up the tolerance for inserts.

A common scenario we use with our machine simulation software, WFL CrashGuard Studio:

0.5mm for holders and 0.01mm for inserts. The insert model sizes are not seriously affected by this tiny tolerance because they are sually small compared to the tool holders, the final effect is more facets only in the radius region... the other surfaces are usually flat and the number of triangles remains the same... however the quality of the simulation in the cutting area and the cut stock increases significantly... as well as geometric accuracy of the cut stock...

On the other hand, as we set up a holder tolerance of 0.5mm, the memory consumption drops significantly... this is because the software allows us to set different tolerances for each component...

CGTech could make even more interesting for the user if they create variables in the vericut.bat to define default values for each component type:

Something like this:

CGTECH_DEFAULT_TESSELATION_TOL_HOLDER=0.5
CGTECH_DEFAULT_TESSELATION_TOL_INSERT=0.01
CGTECH_DEFAULT_TESSELATION_TOL_ACESSORY=0.5

If for an specific tool assembly the user don't want to use the default values he could manually overwrite the values in the import dialog...

JM2C

MustaphaC · 2012-07-09 15:18:50

Just a small comment about "the tolerances under which the models are brought are hardcoded in the SW", this is not true. CAD Model import uses "â€œModel Toleranceâ€ in VERICUT Properties.

Verifun · 2012-07-14 21:23:39

MustaphaC wrote:

Just a small comment about "the tolerances under which the models are brought are hardcoded in the SW", this is not true. CAD Model import uses "â€œModel Toleranceâ€ in VERICUT Properties.

Mustapha,

I just tested and your statement above is very accurate - And for this very reason a functionality to define independent tolerances for each component during CAD tool importing makes sense.

I used a tight tolerance to confirm your point and the insert came with a very smooth nose radius, but the importing time was 4x higher and the whole simulation was slow... :cry:

If we could define a small tolerance only for inserts and use a bigger one (Maybe the default value defined in the â€œModel Toleranceâ€ in VERICUT Properties?) for holders and fixtures... I think this would help with the current accuracy problems concerning imported inserts... imported inserts are currently useless for finishing in turning, boring and milling IMHO...

JM2C,

Daniel

MustaphaC · 2012-07-16 07:18:47

Daniel, I entered an SCR (Software Change Request) on your behalf to have tolerances for inserts and holders...
In the mean time here are two tips you can do:
1- To get an accurate cutting with inserts do not use the insert as is but use the cutting face definition, that is the most accurate you can get as VERICUT takes the original 3D curves to define the cutting face
2- Import the insert only with a tight tolerance to a new assembly, change the tolerance to a bigger value, import the holders only and use the "Append To Tool" function to append it to the insert previously imported. That will not affect importing time as you will be importing the some amount of models.

Verifun · 2012-07-16 10:23:29

Mustapha!

First off, thank you for the SCR!

Some remarks:

Tip #1 - Ok, we already use this so I think we're fine then...

Tip #2 - Thanks! I'll keep this in mind!

Best,

VERICUT Users' Forum

#1 2012-07-06 01:58:08

Importing tolerance for CAD tools

#2 2012-07-09 15:18:50

Re: Importing tolerance for CAD tools

#3 2012-07-14 21:23:39

Re: Importing tolerance for CAD tools

#4 2012-07-16 07:18:47

Re: Importing tolerance for CAD tools

#5 2012-07-16 10:23:29

Re: Importing tolerance for CAD tools

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