2D Compensation - Error

[rafael.sansao]

Hello,

Do you have problems with compensated 2D toolpaths (full radius)?

The NC code return the error on the machine and returns the message "Very large tool radius". (Heidenhain, Siemens, Mazatrol, Fanuc, etc.)

I believe that the problem can occur because the Powermill generates points very close. (Movement of only 0.001mm in X and 0.002mm in Y):

N175X-14.569Y-41.77 *

N180G01X-14.57Y-41772 *

I do not know what else to do to solve this problem. Maybe it's an internal Powermill problem.

can anybody help me? The ideal would be to run the NC on the machine (using any Post-processor)

Attached sample project.

Rafael

[CAMXPRESS]

Dear @rafael.sansao,

What is the tool diamater that U use for that toolpath?

CAMXPRESS

[rafael.sansao]

Hello,

Tool diameter is 16mm

Rafael

[rodrigooliveira.ttLGVPB]

Boa noite Sansão, voce conseguiu resolver este problema, pois estou passando pela mesma dificuldade

[rafael.sansao]

A compensação de raio completa é muito propensa a esse tipo de erros. Se você puder, utilize "desgaste".
Sobre este problema, ainda continuo com o mesmo, porém, criei uma maneira de verificar se a compensação 2D está boa ou ruim direto no Powermill

[O.C.]

When I have this issue, I start with making sure that CAM and machine control arc tolerances are the same, I had a case where they were not and that fixed the problem. If that isn't the issue, I add an arc with a 90deg linear move lead in and out. As a last option I move the toolpath start point away from any arcs to a straight line if possible.

I hope this helps.

[rodrigooliveira.ttLGVPB]

Aqui no momento eu estou utilizando a compensação por desgaste, mas em certas situações de acabamento a máquina me apresenta este erro de raio. Se você pudesse me apresentar esta maneira de verificar o programa com relação a estes erros eu ficaria muito agradecido. 

[Jaanyaar]

@rafael.sansao 

Did you find any solution to your problem?

[O.C.]

Hi @Jaanyaar,

 I have indeed ran into that problem and it can be very frustrating. A member of my team came up with a solution that is easy and seems to be pretty solid. When creating you lead in/out, make sure to add a straight line at 90 degrees from the start of the arc I generally use as long of a line as I can but usually 0.1mm seems to be enough to not error out.

I hope that helps.

[kevin.hammond3WX4X]

Remove the 8mm from the tool table, in powermill the tool diameter is taken in to account during the cycle calculation. It's my guess that the lead in and lead out amount do not allow for a moment of 8mm to actiavte the compensation.
Ps: if you need the 8mm rad comp in for a another reason, it is possible to have 2 lots of tool data for one tool in the tool table on some Heidenhain controls, i have seen it on Itnc 530 onwards. So if your tool number is T1, you could have second set of comp data set as T1.1.
Hope this helps in some way

[rafael.sansao]

I found a solution that works in most cases, however, the redistribution of toolpath points has to be set to "Redistribute". Does not work with arcs G2/G3.

[Jaanyaar]

Thanks! Without changing the default values for toleracne factor or...?

Don't you use M120 alongside?

[rafael.sansao]

I do not alter the tolerance factor values, and I do not use M120.

Instead, I have implemented a logic in the post-processor that removes points that are too close to each other, while respecting the toolpath tolerance. This has been working well.

[kevin.hammond3WX4X]

In the past i have found that in order for radius compensation to work at the machine  the toolpath must contain not only a lead in/out but an extended lead/in of an amount that exceeds the value in the tool table. 

We would have tool table set to zero for radius and have extended lead in/out of around 1mm, this allows you to have 1mm to use in the DR wear in the tool table, which I recall is 1mm max.

You do not need Radius of 8mm in the tool table for a 16mm tool as Pmill has already taken the tool radius into account, the tool path produced is from the tool centre.

Best regards Kev

[iamcdn79]

How did you implement a logic to remove the points in the PP?

[M_Hennig]

I looked at your project, for those types of shapes I would never dream of using a feature. I would use your exact tolerances and just pencil machine it, you will get many more true arcs.