Circular? Spiral?

[fourwheeler]

I am trying to cut a simple stack of circles like the following pic;

But after the cutting procedure I get these cuts in the side of the circles...what have I not set properly? Does this have to do with the spiral toolpath I am using? Should I be doing it a different way?

[Andre' B]

Is there a little box you can check to have it do a finish pass?

[fourwheeler]

Is there a little box you can check to have it do a finish pass?

Not that I can find...oh and this is using BobCAD V21 if that helps.

[Andre' B]

Not that I can find...oh and this is using BobCAD V21 if that helps.

It would if I used BobCAD, I am using MasterCAM and it has a helical boring tool path I use a lot and if you want a flat bottom you need to check the make a cleanup pass box.

Your part looks like the tool is just spiraling in until it hits the small diameter and then stopping.

You should be able to add a simple 2D contur path around the circle after the spiral path to get rid of the rest of the material.

[SBC Cycle]

Can you post the .cad file (you must zip it to upload to the forum). Or the G-Code and maybe someone can spot the error.

[fourwheeler]

I think I have attached a zip file with the G-code in it if anyone cares to take a look.

[BurrMan]

Looking for the BobCad "CAD" file there fourwheeler.

[SBC Cycle]

It would if I used BobCAD, I am using MasterCAM and it has a helical boring tool path I use a lot and if you want a flat bottom you need to check the make a cleanup pass box.

Your part looks like the tool is just spiraling in until it hits the small diameter and then stopping.

You should be able to add a simple 2D contur path around the circle after the spiral path to get rid of the rest of the material.

Looking at your code, I think Andre hit it right on the head. Nice intuition! Rough the material out of the way with the spiral, finish up with one or two circular passes to finish to size.

I don't have my V21 with me here at home but it would look similar to this graphic. The green is the spiral, it stops "RIGHT AT" the finish diameter and goes no further. The highlighted entity is the finish arc move to make the boss circular.

[fourwheeler]

Thanks for the help guys I was out of town today so I will try to find the finishing pass part of the software tomorrow.

[fourwheeler]

Ok after doing some looking the only place I can see the ability to do a finishing pass is by using the "spiral pocket" feature but that will not work as all I am trying to do is cut the outside of the features not pocket them.

[moldmker]

You're discovering the weaknesses of v21.

Several ways of dealing with roughing and finishing stock but they all require more work on your end.

As mentioned before, the easiest way is add profile cuts to the end of your existing program. Profile each boss diameter separately. You will need to define the depth of each in the Profile dialog box.

Or you could use Spiral Pocket features to do it all, but again you will need a separate pocket feature for each depth. Select inner boss diameter and outer stock diameter so they are both highlighted (oh...and they must also be on the same Z-level) and then select Spiral Pocket.
The tool path will be contained between the 2 dias.
But you don't have the option of starting at the stock dia. and working towards the boss dia.
I tend to use Horizontal Pocket to get the most efficient paths and then Profile after.

Or you could manually offset each boss diameter several times and link them together to form a chain then use Cut Auto. (lots of extra work that only pays off if your doing enough parts to return the time with the quicker path)

v23 is better with toolpaths in this area.

[fourwheeler]

It is just beyond me that after you specify the size and shape of the boss that v21 doesn't automatically finish the cut on it's own. The software knows where the cut should be made so why doesn't it finish the cut on it's own? You say V23 is better with tool path calculations?