4th axis rotary cam slots

[Smit]

Gentlemen,

I need to mill cam slots in a tube, which I don't do very often. Actually, I've never done it before. I think I have the parameters set correctly, and it looks good in backplot. But when I verify it the model does not look correct. If somebody with more 4th axis contouring experience could check it out and provide feedback and/or advice I'd be very appreciative.

 

The model is in the FTP site, MC9_files directory under the name ROTARY_CAM_SLOTS.MC9

 

I'm using Mastercam 9.1 MR0105.

 

Thanks!

[Guest]

ok dont see any replies so am gona try to help you out. havent done this in mcam either so blind leading blind (careful).

the file is in the ftp site, mc9ROTARY_CAM_SLOTS DS.MC9

added an op for you to look at, note the rotary axis box and parameters.

ok pro's, jump in any time.

 

doug

[5 AX]

I think everything looks good. I do not see any problems in verify.

[Smit]

Thanks for the replies. Doug, that toolpath did look better than what I had. It was actually cutting with the rotary. I'll give that a try.

 

5 AX, the problem in verify is that it appears in my toolpath that the cutter was cutting a 2D slot rather than a slot with the rotary. If you go to the front view and look at the splines, they should be offset from top to bottom because of the difference in diameters. In my toolpath they weren't.

 

My dealer recommends either a Rolldie or swarf toolpath. I couldn't get either of those to work satisfactorily. The swarf didn't look bad, but I'll have entry problems.

[Reece L Gibson]

If you are wanting to follow the upper and lower contour, the path you have will not work(do not know how critical you need it).I made a ruled surface between the upper and lower contour.Is that what you are wanting? Dealer is right, Rolldie, and 5 ax swarf.I will look at later when I get time.

[5 AX]

My bad. I took another look and did it with 5 axis swarf. I checked the 4 axis tab and used and entry and exit curve. I will send you what I have done. Hope this helps.

[Lathe-Mill]

what about unrolling the geometry, then apply a toolpath to that geometry, and use rotary with rool option on the diameter where the slot is on.? hth

[John Summers]

ROLLLDIE was specifically designed to deal with slots (and rolldies, of course). The SLOT option in ROLLDIE works from the slot centerline, and offsets either side from that. SWARF would work from the walls, which would be difficult to model, but worse, would not end up quite parallel after machining, so a pin or follower wouldn't fit right. Worst-case for slots is when you get a solid model of a slot and have to reconstruct the centerline. I prefer to work from unrolled geometry, but ROLLDIE has an option to handle rollled geometry.

[Lathe-Mill]

HUMMM....what is rolldie?

where it is?

[5 AX]

It is a C-HOOK.

[Smit]

Thanks for the replies, guys.

 

Mr. Summers modified my geometry and returned it to me. Since there seems to be some confusion on how to use the rolldie in this application I've placed the file in the ftp site, mc9_files directory under the name of ROLLDIE_EX_FROM_JS.MC9

 

The level 1 stuff is original geometry, so it's easier to visualize the desired slots.

 

Once again, thanks for the support!

[John Summers]

Thanks, Smit, I probably should have posted it.

[Lathe-Mill]

hello, now that i know there is another way to make cams lots (probably better that what i do).

could some one please explain to me how to use the rolldie chook?

i also do cam slots often , I uploaded a file to the .mc9 folder on the ftp, it's call 0022541-26

you will be able to see what i do, again perhaps the chook is the best way to go.thanx for your help.

[John Summers]

Lathe-mill,

See SLOT.MC9. Again, the biggest difficulty is re-constructing the slot centerline. That's much easier to do unrolled. Use the SLOT and AUT REVERSE options in ROLLDIE.

[Lathe-Mill]

John, did you created that geometry or unrolled the slot?

and once you have the 2d or flat geometry, do you create a center line then use it as chain?.

sorry for these questions, might sound silly but i will like to use what is easier and accurate. thanx.

also, what about cutter comp?....188 +/- .0005

[John Summers]

I unrolled the slot on a 1.499 diameter. You must use the same diameter in the ROLLDIE toolpath as you use for UNROLL. If you want a roughing toolpath, declare a narrower slot. I wouldn't use cutter comp.

Yes, I created the centerline from the unrolled edge curves, and used it as a chain. You only need to drive it in one direction when you use the auto reverse.

[ak762]

John, I tried to repeat steps at SLOT.MC9

quote:

---

I unrolled the slot on a 1.499 diameter

---

but don't get same geometry as at UNROLLED EDGE CURVES level

 

Could you explain by steps how you unrolled geometry from EDGE CURVES level

And

I tried to visualise contour_3D OP and Roll_die OP

seems Roll_die OP much quickly but strange for me

different geometry produce same slot?

[John Summers]

ak762,

Unroll LV 2 to LV 3. Unroll parameters are:

OPERATION Unroll

ROTATE ABOUT X axis

DIRECTION CW

ROTARY DIA. 1.499

ANGLE TOL. 1.0

TYPE Lines

POSITIONING -90

Resulting geometry should look like 2 lines at Z=0. The CL is a line between these 2 lines on LV 4. UNROLL takes geom. on ROTARY DIA. and puts it a Z=0. ROLL takes data at Z=0 and puts it on the rotary diameter. Other depths are positioned accordingly.

If you use CW, -90, unrolled geometry will appear where you probably want it. Angle tolerance of 0.1 is too tight. I usually change it to 1.0. If you select the wrong axis, the relults will look funny (and be incorrect).

Unfortunately, ROLLDIE doesn't display an unrolled toolpath when you select unrolled geometry. You get a rolled toolpath, so it's hard to compare it to the unrolled geometry you just selected. If you have rolled geometry also, compare the toolpath with that.

The bottom line is that ROLLDIE can produce slots with parallel sides. If you use 3d toolpaths and axis substitution, the slot may be similar, but not exactly right.