W1 turning with HSS

[Jyman]

Hey everyone,

I am trying to make a 14.5 degree gear hob cutter out of W1 steel and was trying to turn it with a HSS cutter. But it only cut one of the five sections of the W1 before it just rounded over the point, and even after grinding the HSS again it round it for a second time.

Did I just hit a bad spot on the W1 or is my HSS cutter shaped wrong?

 

[gbritnell]

Hi Jyman,
I use H.S. tooling for most everything I cut, lathe and mill. I cut W-1 drill rod all the time and have no trouble. I would say that probably your turning speed is too fast. H.S. steel is quite uniform so I doubt that you hit any impurities in the material. I would also use some type of cutting oil also.
gbritnell

 

[Jyman]

Thanks for the information,

But I didn't think I was turning it that fast, it was spinning at 550 rpm on a 1 inch bar. And I had some cutting fluid but not a lot.

 

[napoleonb]

It could be possible that you've accidentally work-hardened your piece in the process of turning it by choosing a wrong speed or feed and warming up the workpiece. Using coolant can in some instances harden your heated up workpiece. I didn’t’ know what hit me when I had this problem until a teacher of mine started laughing and explained. Once it is hardened you can’t seem to get past it with HSS tooling, quickly dulling your tool. Try annealing it and start over.

:edit: this can be the result of a dull tool or improper center height which leads to a lot of friction even when correctly speeds and feeds are used

 

[toolznthings]

You are in the lower range of 180 sfm on W1, but I like to go with what I know works from experience. I would slow down my rpm a little on my first cuts at the 1" diameter and see how that works. Experiment with rpm and feed rates. Make sure your tool is ground correctly. Hope this helps. As George said, HSS tools should work fine.

Brian

 

[Jyman]

Ya I know it's a little on the slow side, but my only options for speeds is 550ish or 970ish and the 180sfm falls right between them.

I will try what everyone suggested, thanks for everyone's input.

 

[SmithDoor]

Using W1 or 01 for cutting tools use less than 30 CFM with lot of oil coolant.
I have use this type O1 and W1 but will dull faster than HSS. This why the machine tools from 1900 ran very slow.


Dave

Hey everyone,

I am trying to make a 14.5 degree gear hob cutter out of W1 steel and was trying to turn it with a HSS cutter. But it only cut one of the five sections of the W1 before it just rounded over the point, and even after grinding the HSS again it round it for a second time.

Did I just hit a bad spot on the W1 or is my HSS cutter shaped wrong?

 

[mc_n_g]

I made this one a while back. Slower speeds and plenty of cutting fluid.
Take your time. Everything needs to be SHARP with your HSS tool. My tool was cutting on all three sides at once. Peeling off uniform curls while adding cutting fluid.

 

[Jyman]

That's a nice looking cutter, how well did it cut for you?

I managed to get the turning and machining done on my cutter, all I have left to do is heat treat it and sharpen it.

View attachment ImageUploadedByModel Engines1453656765.326902.jpgView attachment ImageUploadedByModel Engines1453656780.109301.jpg

 

[mc_n_g]

Your cutter looks good. Make sure to leave about .005" at least for grinding the tooth cutting surface. You will need to clean and grind the front of the teeth to give you a sharp cutting face. If you have the ability and the grinding stone, lightly touch up the sides of the teeth. When you use the cutter use the exact center of the tooth for your location. Do not try to cut everything in one pass. Use plenty of cutting fluid.
Mine worked well on aluminum and HDPE plastic. Overall I was very happy with how the gears turned out.
Be patient. You will have horrible burrs on the exit side of the gear.
The zoom in shows the gear is not a smooth surface. It will wear in. It is an approximate involute form based upon short facets or segments from all the indexing.

 

[Jyman]

The gears look great, I don't mind a little clean up after.