cnc porting cylinder heads

[Katech Inc.]

Who on the forum is porting cylinder heads using Mastercam?

[cadcam]

I am in the middle of helping a ustomer with this.

What are you useing for digitizing and makeing your surfaces of the point cloud at this time?

 

[ 02-15-2002, 07:47 PM: Message edited by: cadcam ]

[Katech Inc.]

We don't do enough different port shapes to justify the software and digitizing equipment so we had a supplier digitize and surface for us. They used Raindrop Geomagic to do the surfacing. It does a great job but it creates a patchwork surface. Very clean and perfect edge matching but Flow5ax in Mastercam has to have the surfaces form a row. ie: mating edges (and its surface patch) must go the entire length of the port or each patch must circle around the port like a stripe.

 

They were able to reduce the number of patches to 2 for the intake, 2 for the exhaust and 4 for the chamber. This works but we are running into other problems with Mastercam in full 5-axis motion with gouging/fishtailing. I like to explain it as the software only calculating its current tangent point in its travel, not caring that it might be gouging on the other side of the tool. With digitized data this presents a problem because of very small deviations in the surface smoothness. The tool tangent point carries the whole tool into the variation overcutting. You may be familiar with this already.

 

We are working with CNC software directly on it and they are very helpful and are making progress on addressing some of the issues but I am hoping some other users out there might be familiar with the problems and have worked out some other solutions.

 

Have you gotten far enough to actually create tool path and if so is it with simultaneous 5-axis motion? These problems go away with 3-axis motion, they are aware of where the entire tool is relative to the surface.

[cadcam]

quote:

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Raindrop Geomagic

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Bassaclly what i am useing but its call Revquick but the main software is the same company.

But we are able to make a single sirface using this. Analized picture of port

 

And acutlly have done some 5axis porting.

For a few all ready. geting started on the LS1 now.

 

Oh by the way vary tough road with this.

 

[ 02-16-2002, 03:34 PM: Message edited by: cadcam ]

[Guest CNC Apps Guy 1]

Are you creating a Flowline toolpath then using Focus 5Ax C-Hook to direct the motion of your shank?

[Katech Inc.]

We have been cutting heads in 5-axis for a while now. Even with the problems I have mentioned above (gouging which equates to distorting the port shape slightly) the heads are good and we can ship product.

 

With this inquiry I am trying to discern whether others are having the same problems or perhaps have come up with solutions. I would like to cut our port more accurately.

 

Cadcam: Try downloading Camaix's 5-Axis Multi-Surface software that checks for gouging. It does not repair the toolpath in an acceptable manner for us but it does quantify how many times you violate the surface. In our case it is extremely high, meaning the entire port by a couple tenths to a thou or so.

 

Use that to determine if you are cutting what you think you are. Or take a few points from the program and place your tool and see if it is popping out of your surface.

 

These problems do go away if you use physical touch probe scanning and the stylus is the size of your cutting tool. Then you can cut with your tool center on the surface. Our surface was white light scanned and represents the actual surface. The problems also go away if you are cutting in 3-axis with 4/5th positioning only.

 

James Meyette: Yes, we are cutting with flow5ax and then focusing with the c-hook.

 

Are you guys running into the same problems or not?

[cadcam]

quote:

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Are you guys running into the same problems or not?

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At this time I will say yes.

I will actually keep you updated if you like.

We are in the middle of some changes to see if this can get better.

[Katech Inc.]

So then, you are cutting in 5-axis and your surface is the actual surface (not created from touch probe center data)? If so, you are having a problem. Like I said, it isn't horrible, but it isn't good. When I said a thou, maybe its more like 0.002-0.003? and its variation over the port is bound to catch up to you(us) eventually.

 

If mastercam in 5-axis could look at the whole tool relative to the surface like it does in 3-axis and just drive right over small holes it won't fit in, then the problems go away and we only have to play around with tool containment. That isn't easy either but at least we have some control over it.

[Guest CNC Apps Guy 1]

The guys I know that are porting heads actually probe the head on their Boston Digital 5 Axis machine with a stylus that is the same diameter as the tool. Visually the parts are phenomenal(sp?) but I don't know if there are the gouges you are speaking of. All I know is that one particular guy that comes to mind, runs these heads and is Number One in the world in a certain high profile NHRA class.

[Katech Inc.]

Visually, I am happy with the port with exception of a little fishtailing around the guide in the exhaust. We are working on that one but all else is fine.

 

The gouging is not visible...it is only causing small variations in the port shape and size (only a couple thou/side).

 

Who is the porter you are refering to? Are they in CA or elsewhere? I might know them is why I ask.

[Guest CNC Apps Guy 1]

They are in California. Ontario, California to be precise.

 

Have you been talking to Brian S. at CNC? He's very knowledgeable in 5 Axis Applications.

[Katech Inc.]

Brian is the man. He has been very helpful and they have done a lot for us.

 

I am really on the forum to see if other people have come up with other solutions on their own. Not many people doing this with Mastercam from what I can tell.

[barbill]

Hi guys,

Can't you create the port surfaces in Mastercam??

As I have just started a course in Mastercam...but have done and still do Cylinder Head porting in Unigraphics very successfully.

 

Steve

CAD/CAM Programmer

[cadcam]

Barbill, we can create the surfaces . but not a single port surface.

Can you create this as a single from the digitized data?

[INVNO1]

If I create flowline curves alung a sigle surface port at .05 distace and split a surface horizontal and make an edge curve for me to follow a when recreating a swept surface I end up with wrinkles along port when trying to re make a single surface, is their a smoothing option in version 10 I dont know about.

[Guest CNC Apps Guy 1]

Ok I have to ask, why are you splitting the

single surface?

[crazy^millman]

Have you looked at the filter settings for the operation? What do the surfaces look like? Is this on a 5 axis machine or a 5 axis indexer set-up. Is this 3 axis machines? Have you tried a different toolpath and got the same results?

 

Welcome to the Forum.

 

HTH

[Torr Man]

Hi Guys

 

Go to www.centroidcnc.com that have a complete machine set up for porting cylinder heads. They use their own digitizer but the use Mastercam to do the cutting. They have a video on the site which is quite interesting

[MACHINEMASTERG]

that centroid setup is sweet

[Mic]

This setup has worked very well for me on some tube appliaction I've done. Design a new single patch surface witch is bigger than the ones you like to cut. Create an advanced multiaxis toolpath using this surface. Use the scanned surfaces for checking and make the retract along the surface normal. The tilting you can control very nicely with a tilt curve.

 

This way you get a smooth toolpath because of the single patch surface but it compensates to the scanned surfaces.

[TomHemphill]

Maybe I'm missing the question but we create single surfaces from centerline digitized data all the time using the Centroid setup

We start with the centerline surface then create offset surfaces the radius of the probe and smooth it from there(We can cut from the centerline surfs also using neg stock to leave)

We use mostly Flow 5x and adv 5x to cut with

We find we are actually able to improve the port with Mastercam beyond the hand ground copy

[Moldmaker74]

Holy old post dig up! Anyways thought I would throw it out there that we also make 5 Axis Cylinder Head Machining centers at Optipro. I haven't been able to program any heads yet because the control probes the original part and makes its own program based on the shape. I might get some junk heads and give it a try at some point.