View Full Version : Fixed Angle Head Pros & Cons

06-12-2009, 04:34 PM
We are looking at purchasing a 90 deg fixed angle head. Can someone please tell me the pros & cons of usiong one of these. how about feeds & speeds etc. We are wanting to cut internal square splines/key ways. Thanks for your input.

06-12-2009, 05:14 PM
The big question is, will the head fit within the confines of the hole, and how deep is the key feature (vertical length)? You'll also need a rotary table to index the part for spline cutting.

I've only run my angle head on a few jobs, and its a bit like learning to hold a pencil between your toes and learn to write with it. You gots to be real careful-like :D

06-12-2009, 05:24 PM
Thanks HuFlungDung, we have a rotary, the one we're looking at will fit the bore & it's an extended length one which will cover the length. I'm wondering about heat build up from the gear set, rigidity, feeds, speeds, DOC, cutter/spindle torque values so one doesn't shred the gears.

06-13-2009, 10:59 AM
I would tend to judge the sturdiness of the whole thing by the stop stud, or whatever you call the anti-rotation device that engages the stop block on your machine spindle. Any bit of play in that connection is going to result in some degree of slew slop at the tool. I used a shop made stop block on my Haas, which I made with a few thousandths clearance for an easy fit on tool change. That works fine for running a speeder.

But for the angle head, that clearance turned out to be problematic, so I added a setscrew lock to the stop block. The operator has to tighten (or loosen) this set screw against the stud when the tool in installed (or removed).

Then, with that issue resolved, there is still the matter of the overhung tool length from the machine spindle bearings which lessens the sturdiness just as you would expect. The drawbar pressure should be good and high to keep the tool seated, too.

So in use, I think you have to be quite conservative with feeds and depth of cut until you can assess the machining performance of the new tooling.

06-14-2009, 05:18 PM
Firstly make sure your anti-rotation pin is 180 degrees opposite cutter, and it must there be 0.010" inference with the bottom of the anti-rotation block & pin, when head is pull-back by draw-bar mechanism into, the spindle it act as a support. For this reason I would not recommend heads with spring loaded anti-rotation pins.
The cutting data will be reduced, but this is only to be expected due to length of overhang. I personal I have always use ‘Centreline’ for any angle heads I needed.

06-15-2009, 11:41 AM
Thanks Guys, that's some stuff I haven't thought of. One thing I'm worried about is exceeding the max torque of the head. I found a few online calculators (Kennametal, Iscar & Sandvik) that will give you the torque at the cutter spindle. But I would like to get the formulas so I can build a spreadsheet to do what if scenarios. I found a book, Advanced Metalcutting Calculators & Engineering Formulas for Metalcutting, CD and Book Combo
Edmund Isakov, Published: June, 2005.

We're trying to find a faster way to produce the internal slots/key way than using a shaper to produce it.