creating toolpath for a simple impella

[mortzs]

Hi, I am new to this forum so please excuse me if this has already been answered.

 

I am trying to machine a simple 2 blade helical impella on a 3 +1 machine. I have tried various options on our X4 software, we have the 5-axis add on. But when I do the simulation it either gouges or machine straight though part of it on the simulation. The final component is to be machined from inconel so I cannot afford heavy cuts. Any advice would be greatly appreciated.

 

The original model was drawn using inventor put that seemed difficult to handle, I then redrew it in solidworks saving as an iges file and that seems to help a little, I can now seperate surfaces. I just dont seem to be able to get it to do what I want. If it helps I could post an image or the file.

 

Cheers Chris M

[William Grizwald]

First, have you machined impellers before? Do you have a strategy that you'd like to implement for the process?

 

A few things to consider: many impellers have blade faces (suction/pressure) that are not developable (not simple ruled surfaces when "unrolled"). The test is can the tool be tangential to the surface along the length of the tool at some angle?. Flank milling will not be suitable on those surfaces.

 

The best plan is to write down the steps you need then approach it with cam.

 

--

Bill

[mortzs]

Hi thanks for the reply.

 

No I have not machined impellers before, it is simply to be used for stirring/mixing so at the stage nothing is fixed.

 

My problem is I can draw it, see it, bocken it down to individual faces and independantly pick these faces. However any of the routines i have tried take out some or all of the blades i think with the flank of the tool. The only routine i can get to work is the 4 axis rotary however there is no simple means to rough out and it does plunges which take out the tool (final piece to be machined out of incone).

 

You mention unrolling, i looked at one of the sample files "roll die" and that would do it so I generated what I thought would be the 2d geometry and imputed the paramters however this does not work either. Can i unroll the solid model?

 

Sorry for all the questions but this is seriously doing my head in now!!!! I bought the software from my buget expecting work to pay for the training 1 year on and still waiting, everything else seems logical!!

 

Cheers

 

Chris M

[John Summers]

I'd like to take a look at the part. Maybe I can help. There are several different approaches, depending on the part. Unroll only works for a very special kind of impeller.

[William Grizwald]

Hi Chris,

 

When I said unroll, I meant for surface analysis only. Meaning: the surface could be "unrolled" to a planer surface. You would not machine it unrolled as a roll die. If it's like you say for stirring perhaps you could tweak the surfaces to allow flank milling which is much cheaper to manufacture than point milling or approximated flank milling.

 

Don't get too frustrated with this project. Impeller machining done properly is a niche industry. It's not something many folks pick up right away. I did them for 2 years straight and each one was different. Depending on the design of the impeller there are specific metheds that work best. Up till recently the only cam system uniquely designed for this work as a "canned" sequence costs >$100k.

 

Could you post just a picture of the part? Rather than try to find the magic buttons of the cam system (which is never a good idea), as I said you need to define how you want to machine it first.

 

--

Bill

[KalCam]

I have had a strange event machining a impeller. The vanes were extremely pointed for some reason. Using cut depths for light cuts for the thin points on top worked fine but the same toolpath totaly wiped out the vanes if I tried to avoid machining the top of the vane done by the previous operation. So I adjusted the cut depth above the part and no problem, just some redundant passes.

 

Not sure if that helps with your situation as this impeller had draft and was just using surface contour toolpath.

[Tyler Robertson]

When you backplot, do you have the 4th axis simulation turned on?

 

Posting part would be big help - you're new, so there is an have an FTP address you can upload to. Instructions are linked at the top

 

otherwise send me the part [email protected]

 

and I'll take a look at it

[mortzs]

Hi thank you all for your help, i have tried the ftp site but cannot conect to it, i will see if i can attach it to a web page?

[mortzs]

I have just tried my works PC and i still cannot connect to the ftp site having followed the instructions???

[Jayson Kramer]

Does your work block FTP's I have been seeing this more and more not sire why.

 

Have you tried useing internet explore?

[mortzs]

Hi i have tried at first from home using explorer (then updated it) and firefox. Than at work.

At home my ISP is SKY so unless there is issues ther i dont know, i will try my daughters MAC in a bit.

 

Cheers

 

Chrtis