Deburring threads

[jeff]

Lathe question...

 

I am just curious to see how others do this.

We do it the old-fashioned way,after the program ends,switch to manual,start the spindle,and use a file to deburr the sharp edges of the threads on the face of the part and at the point of undercut.

 

How do you guys do this,is there a faster way that I have not seen in my 15 yrs of cnc machining???

Maybe create a sub that calls up a different tool and somehow deburr?

I'm sure that production shops don't manually deburr every part before it's taken out of the chuck.

Maybe have a minimum wage guy that sits at a bench grinder with a wire wheel???

[J Coulston]

I run the finish tool back over the thread, if it pushes the lead thread then I run the thread again, just one pass full depth. A few extra seconds on the machine saves the PIA deburring the thread later and eliminates a saftey issue.

[B747US]

It all depends on the quantity and the size of the product, this may help for higher quantity and relatively small items.

 

http://www.aaceng.com/deburr.htm?source=Overture

[jeff]

Degmc, we use those full profile inserts,they do a great job of deburring the tops of the thread.

But still have a burr at the beginning of the thread with a chamfer,and at the end with the undercut.

J Coulston, I'll have my guys run it twice and see what happens.

Thx all.

[chip]

I've used the same thread tool. After running the threads, I have the tool go back and chamfer the front. If matl' permits. If your running inconel or heat treated matl'. I'd probably use another tool. I always try to have as much done in the machine as possible.

 

[Philcott]

Jeff,

 

quote:

---

I run the finish tool back over the thread, if it pushes the lead thread then I run the thread again, just one pass full depth. A few extra seconds on the machine saves the PIA deburring the thread later and eliminates a saftey issue.

---

This is what I do as well to almost all my threads. I will also, sometimes, put in a couple lines at the end of my program (before part-off) that will surn on the spindle to allow a quick deburr with a cratex stick of emery cloth. This is what I put in and run in single block.

 

M00 (SINGLE BLOCK AND DOOR OPEN)

M3 G97 S1500 (POLISH THREADS)

M00 (CLOSE DOOR FOR PART OFF)

 

Also, depending on the job, we use a bench grinder that can be brought to the work area that has a scotch brite wheel on it. Does a great job on threads.

 

Phil

[CR]

I also use the full profile insert

(Like the NTC from Kennametal each insert is for a specific TPI)

they take care the deburring on the crest of the thread

I run the final tool again (just to deburr the fist and last lead of the thread)and re-run the threading cycle at full depth

[CR]

Don't forget the infeed angle some times that help to control the burr direction

 

I prefer use the multiple threading cycle

(G76 or G71 on okumas)

Fanuc has six kinds of infeed-angle 80, 60, 55, 30, 29, and 0

Okuma has only 3 infeed patterns cut on front face of the thread, zig-zag and rear face of the thread

 

Some times I rough the thread relif, run the threading cycle, finish the thread relif, run finish profile and re-run the thread cycle at full depth you add a few second to the cycle time but the deburring goes away.

[LackyCam]

I use single point inserts – all the time unless necessary.

1. Rough +.01 on OD

2. Thread

3. Finish OD to major dia. cut front and back chamfer

4. Repeat thread only one pass full depth (two passes for stainless steel)

This action pushes burr in thread direction on back chamfer and kick out burr in opposite direction on front chamfer.

Than here is secret:

Cut back chamfer first not OD in tapered motion approach back chamfer and recut back chamfer.

(Second threading op caused burr to be kicked out in threading direction) than pull up change to G41 and cut OD and front chamfer coming from opposite direction (in Z+ Direction).over same path as before.

This action cuts burr on front chamfer.

I NEVER deburr threads, touch it up little bit with gray scotch brite it’s all it takes to get burrless thread.