cad for superimpose creation or solid models for geometry removal

[lucadileta]

Hello everyone,

I would like to ask you a problem that I have in creating a model of a drum cam. for a project of a cinematism I and my colleagues have created a cinematism through a drum cam. the problem we have encountered is that with the cads we have it is not possible to realize a model of the above cam correctly. Specifically we used solidworks 2016, the camtrax program and the new features "sweep cut" of nx 11 that allows for very simple path also to have intersecting cutting profiles. the problem is that none of these roads went along proved to be accurate. geometry has been verified with matlab is always different from a small but not negligible quantity.
At the end of all I believe that the only way is to create the model with a software that allows to reproduce the geometry by means of a cut for envelope that follows the process of milling the cam but sincerely I do not know

is anyone aware of such software? Maybe that also allows you to have intersecting cutting profiles?

thanks to all in advance

♪

 

[marcof]

Hello everyone,

I would like to ask you a problem that I have in creating a model of a drum cam. for a project of a cinematism I and my colleagues have created a cinematism through a drum cam. the problem we have encountered is that with the cads we have it is not possible to realize a model of the above cam correctly. Specifically we used solidworks 2016, the camtrax program and the new features "sweep cut" of nx 11 that allows for very simple path also to have intersecting cutting profiles. the problem is that none of these roads went along proved to be accurate. geometry has been verified with matlab is always different from a small but not negligible quantity.
At the end of all I believe that the only way is to create the model with a software that allows to reproduce the geometry by means of a cut for envelope that follows the process of milling the cam but sincerely I do not know

is anyone aware of such software? Maybe that also allows you to have intersecting cutting profiles?

thanks to all in advance

♪

Oh, you didn't even put an image in all this papel. and how should we do to guess what is the form of the dig you have to do in the cam?

with solidworks:
1 - Have you tried the function of digging with sweep using instead of profile 2d directly a solid that represents the shape of the cutter that will be used?
2 - Have you tried to create through surfaces the shape of the excavation and to remove it from the solid?

I have wrong something, because if solidworks has limitations on the surfaces (but I'm sure your cam can be done) it certainly has no nx so it's just about finding the right method to create the correct geometry.

There is to say that here on cad3d at the time we tried to make a helical excavation on a cylinder as it was created by a candle mill, using various cads, and the results were at least ambiguous and apparently no one came to the end correctly.

 

[lucadileta]

Oh, you didn't even put an image in all this papel. and how should we do to guess what is the form of the dig you have to do in the cam?

Hello marcof

Sure you are right, now I put the cam development file in pdf. I will try to be as precise as possible.

the execution of the cam takes place through a milling in which the drum rotates and the head of the candle mill oscillates compared to a certain center of rotation (see in pdf). the problem is precisely the oscillation that is not reproducible with any cad.

in the end we opted, as you hypothesized, in a sweep of the throat on 4 guide profiles made with matlab (an elliptical correction of the profiles was made). the result is acceptable but has a big limitation, i.e. you cannot carry out self-intersecting profiles. the sweep cut function of nx 11 allows it but only for very simple geometries and cmqe not for the splines.

I hope I've been a little clear

 

[ceschi1959]

Hello marcof

Sure you are right, now I put the cam development file in pdf. I will try to be as precise as possible.

the execution of the cam takes place through a milling in which the drum rotates and the head of the candle mill oscillates compared to a certain center of rotation (see in pdf). the problem is precisely the oscillation that is not reproducible with any cad.

in the end we opted, as you hypothesized, in a sweep of the throat on 4 guide profiles made with matlab (an elliptical correction of the profiles was made). the result is acceptable but has a big limitation, i.e. you cannot carry out self-intersecting profiles. the sweep cut function of nx 11 allows it but only for very simple geometries and cmqe not for the splines.

I hope I've been a little clear

I tried the volume swept of nx11 and it gives me uncommon results, I opened a pr to gtac for this.
If you put a step with the path and the tool I see to give us an eye.

Hi.

 

[lucadileta]

I tried the volume swept of nx11 and it gives me uncommon results, I opened a pr to gtac for this.
If you put a step with the path and the tool I see to give us an eye.

hi baskets, the step file I do not have because in the end as soon as we saw that the cut sweep does not work on self-intersecting splines all the advantage of using nx came less, also because the loft of the straight section of the tool on 4 guide curves make it all fall nx would have been great for the issue of the self-intersecting cut but coming without this factor loses any interest. If I can access the company's server, I can post tests with nx 8.5 with which we have also noticed errors on the generation of radial offsets starting from the splines of the driving curves.

Thank you very much in advance

p.s. attached put the text file of the tool coordinates.
diameter utenslie 28.04 mm
external cylinder radius 122 mm
height of the cylinder 72 mm

 

[ceschi1959]

with solidworks:
1 - Have you tried the function of digging with sweep using instead of profile 2d directly a solid that represents the shape of the cutter that will be used?

hello marcof, can you tell me a link on youtube where can I see this function of sw?

Thank you.

 

[MassiVonWeizen]

the function is always the cut with sweep only that instead of a profile you select a body http://help.solidworks.com/2014/italian/solidworks/sldworks/hidd_dve_feat_sweep.htmHere is a video https://www.youtube.com/watch?v=alkp4su5248

 

[lucadileta]

the function is always the cut with sweep only that instead of a profile you select a body http://help.solidworks.com/2014/italian/solidworks/sldworks/hidd_dve_feat_sweep.htmHere is a video https://www.youtube.com/watch?v=alkp4su5248

hi massive! putroppo this function is not useful to my case because the mill oscillates compared to a defined point while with this sw function remains fixed on the axis of the cylinder to work and generates an incorrect profile.

 

[MassiVonWeizen]

My answer is the question of baskets.

 

[lucadileta]

My answer is the question of baskets.

I understood, it was just to say that I had already tried with that function.

 

[ceschi1959]

My answer is the question of baskets.

Thanks :finger:

 

[ceschi1959]

thanks to the film I managed to make the sweep with sw student edition 2017 that uses my son to the polimi and I noticed that it is not correct.
in the image that I attach I have highlighted a flat island that must not be there, try to believe.

 

[lucadileta]

thanks to the film I managed to make the sweep with sw student edition 2017 that uses my son to the polimi and I noticed that it is not correct.
in the image that I attach I have highlighted a flat island that must not be there, try to believe.

I agree with the fact that it is wrong, moreover it is not possible to choose to maintain the trajectory of the tool or a certain inclination of the axis of the milling in relation to the profile.

 

[lucadileta]

thanks to the film I managed to make the sweep with sw student edition 2017 that uses my son to the polimi and I noticed that it is not correct.
in the image that I attach I have highlighted a flat island that must not be there, try to believe.

Hi baskets, I attach the file of the generation of the cam through tool path, maybe it explains better. It was done with nx 8.5.