Port roughing

[DavidB]

Whats the best toolpath for roughing out a cylinder port from solid billet on a 5-axis?

[Guest SAIPEM]

David,

 

That will depend on the port.

 

What I normally do is establish vectors and create Workplanes from them and then rough as much as possible in 3-Axis.

 

I can usually get through one side with 2-3 Workplanes.

 

Believe it or not, with some ports, simply drilling intersecting holes is sufficient.

[Josh T™]

Depending on the port shape I like using Surf Rough Pocket with a few different views to rough the entire port. What type of port shape? Is it more of a straight forward intake/exhaust (GM, Ford, etc.) or is it something complex like a funky ruled/lofted surface?

[CJep]

David,

Like Saipem said sometimes the easiest way is to drill intersecting holes.

 

But I would like to add that you could also go into the roughing tab of the advanced multi axis toolpath and activate multi passes or depth cuts

[DavidB]

Then once roughed is flowline the go?

[mayday]

quote:

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Then once roughed is flowline the go

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That is more or less what the port toolpath is. Does it really require 5 axis? or just 3+2. I find the multi axis toolpaths give you much better control even if you only output in 3 or 4 axis

[Guest SAIPEM]

David,

 

By creating a chain or a simple line segment for tool vector control,

you can limit the amount of 5-Axis articulation and prevent shank collisions and clearance issues.

 

As long as your setup is sound, you'll be able to match cut your finish

paths from the intake and exhaust sides and you won't see the overlap.

 

Remember that you do NOT want a nice smooth surface for an intake

port. You want the port to create a bit of "turbulence" to facilitate

the fuel-air mixture for combustion. If the surface finish is too smooth,

the fuel will have a tendency to adhere to the port surface and prevent a proper mixture.

[Bob W.]

I would try intersecting holes first and then rough with the advanced multiaxis port toolpath. I would finish with the same toolpath as well. I like to tilt the tool through a curve progressing from start to finish. It changes the pivot location of the tool as it gets dooper into the port. Here is one that I did in the past, though it was in an existing port.

 

[mkd]

nice toolpath. scary close to the holder. eek

 

wish Haas would make a trunnion without the herky-jerky.

hijack-off