Helical Interoplation (Spiral Cut)

[kjm30]

I have been trying to learn how to do a Helical Interpolation or Spiral cut on Fanuc Fadal 4020 OiM and BobCad Cam. But really havent had some time to study.

Currently normally I drill an 1 1/4 opening in Grey Casing. Then pocketing it after would make it look messy. I need to do a finish pass in spiral perhaps it will clean up the roughing cut.

Was wondering if anyone knows how to program a helical interpolation.
Heres the info.
(everything in Inches)
Grey Cast Iron
Maybe 0.02 Finish Pass
The Tool diameter is 1.0 inches
The length of the insert on the tool is 0.4 but the total length of tool holder is long enough to do the job. When it makes spiral cut it has to be 0.4 in height so 6 times in circular?
The exact measure of finished hole is 1.94 hence 2" Split Flange. Roughing Cut will end at 1.92 along with finish pass being 0.02. So I only need to do one pass of helical Interoplation cleaning up.
The Depth is 2.4.

This forum has been extremely helpful, even more than our machines companies. Keep it up.

[glenthemann]

helical and spiral are totally different, spiral would be for a tapererd hole, or for finishing the bottom of a hole.

What you have to do is program a Z move along with your G02/03 and that will give you the helical motion you desire. However you do know that this would leave a "spiral" marking the hole way up your hole right?

However you say that pocketing after you do the drilling makes it look messy? I assume you mean you are roughing out the rest with pocketing and then you want to finish it with the helical interpolation? Sounds to me like your problem really lies in your pocketing

Hope I was of some help somehow

[mactec54]

Hi kjm30

This is all you need to do,This has a .1 step down per cut around your hole if you want a different step down, speed & feed send me a PM & I can do it for you

[kjm30]

Thanks everyone for the help.

glen; I understand the spiral cut might leave a spiral mark. Thought it would be worth a try. The best way would be just to get a certain size indexable drill to do the job. It too expensive to have all indexable drills for all (split flange, NPT, and o'ring Boss hole sizes however the boss will be ok due to reamer being used to clean up the hole.)

mac; I will study on it some more and try out the program.
Thanks again

[mactec54]

Hi kjm30
You will be amazed how well the program works I use them all the time for roughing out holes

[leggazoid]

I thought all the OiM controls had built in macros for this and other things.

O9170 Outside frame milling
O9171 Inside frame milling
O9172 Pocket frame milling
O9173 Face milling
O9174 Outside circle milling
O9176 Inside circle milling
O9177 Pocket circle milling
O9179 Slot milling
O9180 Row pattern drilling
O9190 Rectangular frame drilling
O9280 Bolt-hole circle drilling

check your control for these programs.

[mactec54]

Hi leggazoid
None of those macros will do what he wants to do, even if his control does have them

[kjm30]

Originally Posted by mactec54 Hi leggazoid None of those macros will do what he wants to do, even if his control does have them

I believe mac is correct. Macro pocketing will only do a circular cut to the specific diameter then move downward and do the same thing until it reaches to the bottom. There will be circular markings at every finished cutting path.

[glenthemann]

in any case with an endmill youre gonna get lines.. unless of course you can find a super extended endmill, though im not sure they make them 2.4+ deep.

Best bet for a good finish would be to bore the hole, though im not sure if that control has a boring canned cycle.

you know more than any of us about the part, and the requirements and its application. You must determine if the hole is critical, doing the circular pocketing leaving lines at every depth may be perfectly admissible for the product, or it may not be. Like I said I dont see any way to avoid the lines other than using a boring tool, but those have to be set up perfectly with the orientation of the spindle for the macro to perform the operation correctly.

I wish I knew the control so I could give you some more help

[DIFF OVER]

Originally Posted by glenthemann helical and spiral are totally different.

WTF.
A helix is a spiral. You can create a helix or spiral with any two axis.

http://www.bing.com/Dictionary/searc...al&FORM=DTPDIA

[glenthemann]

Originally Posted by DIFF OVER WTF. A helix is a spiral. You can create a helix or spiral with any two axis. http://www.bing.com/Dictionary/searc...al&FORM=DTPDIA

I apologize for my wording, in my first post I was confused and got thinking about an actual spiral path in the xy plane with constant upward motion in z, ie, in taper thread milling, vs what you are talking about.