Need to Machine a STL Part

[macduff]

Happy New Year Everyone!

I have a STL file and would like to produce a part that I can machine. I'm thinking of using the SLA process because of its accuracy and the material will be hard so I can machine it.

Any thoughts or comments?

Thanks,

Colin Fitzpatrick (aka Macduff)
Mechanical Designer
Solidworks 2010 SP 5.0
Dell T5500 Windows 7 Pro (64-bit)
Xeon CPU 2.53 GHz 6.00 GB of RAM
nVida Quadro 4000 2 GB
3D Connexion-SpaceExplorer

 

[ctopher]

Hi Colin,
Depends on the complexity of the part and what it's used for.
If a production part, and you want rapid prototyping, you may want to go with SLS or something better, or injection molded.
If steel or alum, can you have it machined?

Chris
SolidWorks 11
ctopher's home
SolidWorks Legion

 

[CorBlimeyLimey]

If you are asking for recommendations of which RP process and material to use, a bit more information would be helpful;

Size and shape?
End use?
Type of machining you will be doing?

 

[macduff]

Let me add this comment:
Currently we have Alum castings and are in production. The program is very old and will undergo redesign early this year. The problem I have the CAD file I have is a STL and cannot verify if the correct revision. So I would to make a RP part for machining to prove the tol paths before going to a hardtool casting.

Colin Fitzpatrick (aka Macduff)
Mechanical Designer
Solidworks 2010 SP 5.0
Dell T5500 Windows 7 Pro (64-bit)
Xeon CPU 2.53 GHz 6.00 GB of RAM
nVida Quadro 4000 2 GB
3D Connexion-SpaceExplorer

 

[Updraft]

Macduff,

The SLA/STL file is faceted. If you plan to send this part to a CAM program for machining such as with a CNC mill you will unnecessarily be giving yourself grief. Basically, the STL files are suitable for the SLA and other additive rapid prototyping processes, but they are a pita for machining.

For machining you are so much better off sending a Parasolid or ACIS file.

- - -Updraft

 

[macduff]

The CNC program is done. The only file in existence that I can find is a STL file. If can prove the STl is the correct revision, I'll spend the time to create a solid model for my redesign. I need to prove the potato chip geometry because it fits on the exterior leading edge on a B777.

See attached images


Colin Fitzpatrick (aka Macduff)
Mechanical Designer
Solidworks 2010 SP 5.0
Dell T5500 Windows 7 Pro (64-bit)
Xeon CPU 2.53 GHz 6.00 GB of RAM
nVida Quadro 4000 2 GB
3D Connexion-SpaceExplorer

 

[Updraft]

Macduff,

Thanks for the additional info. If I understand everything you have two file: an STL version of the part and a CNC file to make the part. Apparently the CNC file is the current geometry and you want to compare the STL file to it.

Have you checked into the options available in the CAM package? We use FeatureCam and it has some ability to compare solids. It also has the ability to export an STL file (unfortunately that is the only type of solid file format it exports). If your CAM system can export an STL file you might be able to compare it to the existing STL within SWX.

- - -Updraft

 

[kellnerp]

I am not sure how this relates to CAD, but machining SLA is tricky. It is very brittle and wants to grab the tool. One screw up and you ruin the part.

Use FDM, it is much stronger and you can get it in wax. It won't be as smooth, but these are castings, right?

Why don't you just have the existing part scanned at a service bureau? Then you can do the comparison on the computer.

TOP
CSWP, BSSE

http://www.engtran.com

http://www.niswug.org

http://www.linkedin.com/in/engineeringtransport

Phenom IIx6 1100T = 8GB = FX1400 = XP64SP2 = SW2009SP3
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[macduff]

Thank you so much for everyones help! I think I'm leaning towards a FDM part. It will be much cheaper part to prove the contour.

Colin Fitzpatrick (aka Macduff)
Mechanical Designer
Solidworks 2010 SP 5.0
Dell T5500 Windows 7 Pro (64-bit)
Xeon CPU 2.53 GHz 6.00 GB of RAM
nVida Quadro 4000 2 GB
3D Connexion-SpaceExplorer

 

[GRF]

You might want to check out polyjet. I have gotten prototypes using these types of rapid prototype parts faster and less expensive than FDM. They are also more accurate. They build up in smaller layers. Their big selling point is the higher resolution in the technology.

 

[ctopher]

Colin,
These people do a good job.

http://www.solidconcepts.com/materials-fused-deposition-modeling.html

I have used these materials, they work well.
If you care about color, have it mixed with the material, not surface dyed.
If it's dyed, it will come off with machining and sanding.

Chris
SolidWorks 11
ctopher's home
SolidWorks Legion

 

[macduff]

Thanks Chris. We use them a lot for our products. The overall changes in technology is overwhelming

Colin Fitzpatrick (aka Macduff)
Mechanical Designer
Solidworks 2010 SP 5.0
Dell T5500 Windows 7 Pro (64-bit)
Xeon CPU 2.53 GHz 6.00 GB of RAM
nVida Quadro 4000 2 GB
3D Connexion-SpaceExplorer

 

[loki3000]

STL file is made from a lot of triangles, not surfaces. it is not good for machining.
you can convert it to a solid file (with curvy surfaces) with geomagic studio, catia, nx...

 

[mterm]

Colin,

You can convert the stl on import to a solid or surface model by changing the option in the open dialogue window.

Hope this helps,
Mark

 

[CorBlimeyLimey]

Lots of good info at

http://www.dezignstuff.com/blog/?p=398

 

[macduff]

Thanks so much for all tips amigos!


Colin Fitzpatrick (aka Macduff)
Mechanical Designer
Solidworks 2010 SP 5.0
Dell T5500 Windows 7 Pro (64-bit)
Xeon CPU 2.53 GHz 6.00 GB of RAM
nVida Quadro 4000 2 GB
3D Connexion-SpaceExplorer