Models for grinding HSS Lathe Tools

[Brento]

Yesterday i finished my last internal radius tool. Have to get a picture when im back home but now to try and hone it. I am not sure how i am going to do it.

 

[Brento]

Picture as promised

 

[Watchwatch]

Advice for grinding a finishing fly cutter bit? I’m looking to flatten aluminum fixture plates.

A vertical shear bit looks promising.


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[ttabbal]

Advice for grinding a finishing fly cutter bit? I’m looking to flatten aluminum fixture plates.

A vertical shear bit looks promising.


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I use a left hand square tool for most fly cutting. It works great.

 

[Z2V]

Like @ttabbal , I also use a left hand turning tool.

 

[Watchwatch]

How did you grind the square tool? Mikeys general use square bit which is 15 degree all around?


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[ttabbal]

How did you grind the square tool? Mikeys general use square bit which is 15 degree all around?


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Yes. Nothing real special, and it works great.

 

[devils4ever]

For a 60 degree threading tool, I assume I would just keep the 15 degree clearance angles and leave a flat top?

 

[ttabbal]

For a 60 degree threading tool, I assume I would just keep the 15 degree clearance angles and leave a flat top?

Yes. I mark the 60 degree point where I want it on the tool, then keeping the table at 15 degrees, grind the point. So I get the clearance angle needed, but it keeps the top flat and the grind is simple.

 

[devils4ever]

I have to give a major kudos to mikey. Thanks to his instruction and guidance, I'm getting better and better at getting my HSS lathe tools ground correctly. I can take much bigger DOC now on my lathe and I get long spiral chips coming off the tool which I never did before. I'm sure they are not perfect, but they are a major improvement of what I was getting previously.

With my newly completed belt grinder, I can fix my previous attempts quickly. It's easy to regrind the tool with a coarse belt something that my bench grinder would have takes 10X -20X longer. I'm using very fine belts now (600, 1200 grit) to give the HSS a nice polish. I still use the diamond hones to touch up things, but I have to admit, I'm not that good with them. Holding the hones flat on the faces can be tricky especially the front and top faces.

One thing I noted is that using the 600 and 1200 grit belts overheats the HSS much quicker than the coarse and medium belts. This seems counterintuitive. When using these belts, a light touch is required with frequent dipping in water.

In any case, a big thanks to mikey!