[magicniner]

Is there something wrong with the rotary toolpath I posted? It did the double undercut......

BurrMan,
I think your suggested solution will work I'm getting to grips with Base Point settings but the help is written by someone who knew what it did, how and why for someone who knew what it did, how and why ;-)
Regards & Thanks,
Nick

[BurrMan]

Hey Raf,
The stock is not moved. It's loaded in the machine at those axis points. Anywhere where the axis is broken by the model will use a new feature with the axis set to allow the part cut.

So from your screenshot, 3 features. 2 with the same. The low lobe would have it's own base point set. Then use the start and end points in the rotary feature to only cut those areas.

[magicniner]

BurrMan
Maybe I'm not understanding the axis points.
Is there a way to under cut by using the main journals in my post as the rotation point or will the stock physically have to be moved on the forth axis to make the Rod journal smaller?
Am I missing something here?

Thanks
RAF

Set Base Point on a line where it passes through solid for the section you're machining to avoid voids in your tool paths,

- Nick

BurrMan,
I'm yust generating decent paths for the concave compound curve sedtion of the beavertail after a rough test worked but was, predictably, rough ;-)
Cheers!
Nick

[BurrMan]

BurrMan,
I think your suggested solution will work I'm getting to grips with Base Point settings but the help is written by someone who knew what it did, how and why for someone who knew what it did, how and why ;-)
Regards & Thanks,
Nick

SO the second picture in this post here:

http://www.cnczone.com/forums/bobcad...ml#post1361184

Will show you exactly whats going on. Notice the toolpath is being generated from the basepoint in the center, which wont let the tool "undercut". If the base point is set at the little cylinders center, then it can compute all the way around, and moves in the "y" plane accordingly with the z.... Setting the base point doesn't change where the stock is chucked up (That's done in the machine setup), so the actual rotation axis is still the original set, the toolpath is just calced from the new, needed one.

The help system has "1 sentence"????

We use the rotary toolpath.

[magicniner]

BurrMan,
I've just realised that the beavertail needs to be split into 3 sections with three different base points.
Many thanks for taking the time to help with this, it's much appreciated, I think perhaps Base Points warrant their own instructional video from Al to augment the Help entry ;-)
Regards,
Nick

Paths generated image attached

[RAF.]

Hey Raf,
The stock is not moved. It's loaded in the machine at those axis points. Anywhere where the axis is broken by the model will use a new feature with the axis set to allow the part cut.

So from your screenshot, 3 features. 2 with the same. The low lobe would have it's own base point set. Then use the start and end points in the rotary feature to only cut those areas.

EXTRA EXTRA READ ALL ABOUT IT

So the caped Man flies in again and SAVES THE DAY
Seems to work great just did it with a single cut but it looks good

Thanks BurrMan

[magicniner]

Update - on close inspection the paths generated on the thin end of my beavertail have a slight "figure eight" cross section so I'm still at a point where Rotary isn't going to do the job :-(

[magicniner]

Rotary is an advertised function of 4-Axis Standard on the promotional flyer.

[BurrMan]

Update - on close inspection the paths generated on the thin end of my beavertail have a slight "figure eight" cross section so I'm still at a point where Rotary isn't going to do the job :-(

Not really sure what that means. Maybe you should get a personal look with Al where he can log on to your system to see whats wrong.

[magicniner]

Not really sure what that means. Maybe you should get a personal look with Al where he can log on to your system to see whats wrong.

BurrMan,
It's just on the thin section - images attached. To get rid of the distortion I have to move the Base Point outside the model at one side or the other and then BC ignores chunks of stock again, the thicker sections have decent paths and I can have a decent path on one side or the other of the thin section with associated lumps of stock hanging around the opposite side.
Al's been at a big show all week so I suspect he's got a lot to catch up with before he'll have chance to look at this,
Regards,
Nick

[BurrMan]

Yeah, that looks ugly Nick. Hard to tell from the screengrab, but it looks like the axis is kicking in as "not centered enough" to allow the full rotation. May have to break that small area again?

Be sure you are selecting the "entrie model" for each feature, and not just parts.

Also, with 3d solids, the entity summary to get the center line can have included whats called "bounds data", which can give you a false centerline that would cause the axis rotation to be slightly off like that. The way to get it surely centered would be to extract the edges of the model and hide the solid, then entity summary just the edges. These will give the accuracy for an exact centerline.

Since your model is proprietary, will have to wait for Al, but he should be able to get it sorted with you. Hang in there a bit more.

[aldepoalo]

Please grant me some time to look into this. Yes 4axis standard offers rotary tootpath, but there are limitations. No I do not think the toolpath is designed for off center cutting as it isn't a true 4axis. It isn't just a swap axis, an is generated based on the surfaces, but the axis of rotation plays a large role. Not to say you can't cut off center....

So when I get back to the office I 'll have a look and respond with a video and answers....

As a 4 axis pro customer you would have more options for rough and axis of rotation plays less of a role. With that said 3d roughing, index to the other side, 3d rough and then 4axis footpath for finish work the faster and more standard approach for this type of work.

Next week I 'll take a deeper look and hopefully fill in the gaps.

[magicniner]

What you remember is that the rotary toolpath is a finishing strategy, which has a step down, although, because it's a finish strategy, when you add steps, it adds steps to the entire toolpath, so it will add steps "up" from zero plane, equal to the down steps, so you cant really rough out these types of parts with it.

I really look forward to seeing solutions to the problems not already covered by BurrMan in this thread, to be honest I'll be very happy if I have to hand chisel and file it to rough shape first but can just get a finishing path that's right ;-)
I'd be happier if we had started with finishing and later dealt in detail with the problems for which solutions had already been posited, but I realise that a start to finish treatment will help better others in the future,
Regards,
- Nick