Cam turning

[gunda]

Hi all
Does anyone has any suggestion on how to turn a cam or ellipse (viewed from the XY plane) controlling the X value in accordance to the position of the C axis on an Okuma LB4000/2000EX with P200 control?
Thanks

[budgieW]

Something like this

http://www.youtube.com/watch?v=Enze_8LlCgc]LB4000EX MY x750 - YouTube

[gunda]

Exactly!
I've only seen it on videos but I can't put it to work. How is this programmed?

[Tancuda]

I'm pretty sure you need a software for it, but only my opinion !!

I would love to try this on my LB4000ex too.

[underthetire]

I saw it done on a standard Cadet once. Our old app engineer wrote a macro for it years ago. Needed user task II i believe. Way beyond my programming ability.

[OkumaWiz]

Cams can also be cut using the old G88 threading function. I typically use this to do oil ring grooves, but with the right calculations and RPM it can cut cams too since it syncs axis drives with spindle rotation.

X and Z coordinates can be used on each line and large feedrates to allow for cam diameter variations per revolution. RPM is limited since axis feed per rev is pretty intense, but as long as you stay below the rapid rate, you can do some amazing things.

Best regards,

[fordav11]

I believe Okuma has 'cam turning' as an option?

[OkumaWiz]

Yes, they make cam lathes that have been used to make automotive pistons (they are not round) Those machines are a specialized animal with special slides and turrets and special software that can learn and compensate for following error. VERY high tech and $$$! They made TM-APT cam software that went with it. RPM's were in the thousands and accuracy was in the microns. You could produce a piston skirt with a changing lobe amount and taper at the same time.

But I don 't think this post was about that. Your standard lathe has some "camming" ability using G88.

Best regards,

[gunrights]

Yes, they make cam lathes that have been used to make automotive pistons (they are not round) Those machines are a specialized animal with special slides and turrets and special software that can learn and compensate for following error. VERY high tech and $$$! They made TM-APT cam software that went with it. RPM's were in the thousands and accuracy was in the microns. You could produce a piston skirt with a changing lobe amount and taper at the same time.

But I don 't think this post was about that. Your standard lathe has some "camming" ability using G88.

Best regards,

You are correct about automotive piston. They are not only oval but they are also barrel shaped. The tolerances we generally hold at the highest point of barrel diameter are +- 7 microns. We use specially designed machines because even the specially designed Okuma cannot get us the 23 sec. cycle time that we need.

[gunda]

How exactly is the G88 used to define the exact geometry of the turned part?
I think the LB4000 as shown on the video is using some control of the C, X and Z axis but I didn't find any function to do the job in the manual of P200L. How could it be achieved with a macro?

[budgieW]

Yes XZC is the answer

[MCR-B II]

For cams LU 15 V1 CAM or V8 CAM lathes are suitable.