Models for grinding HSS Lathe Tools

[Brento]

Wouldnt a thicker blade make a bigger cutting force as well though? I have to grind another cut off blade so i can maybe make the blade .100 thick? And i will make the cutting tip straight across not at an angle. Should i put a rake on the cutter? Anything else to help the profile? Of i gotta cut a part off and flip it over to clean it up then well thats what i have to do.

The tool post i have now i can only take 3/16 bits. I can fit a 1/4 in but then i have to grind alot off the top to get the bit on center. I am getting a new tool post set up made from Tom and he said he could fit 3/16 and i think a little bigger. I will do a little digging to see if i can find an adjustable parting blade like they have. I can only use hss i believe on this lathe so ill see how the adventure goes. Thanks for the help.

 

[Brento]

So i was at it again tonight the chatter was better looking today on the part then yesterday the chips i think look better as well.
I made a new blade up today that is .100 thick for maybe less flex.


I know the relief on both sides are not the same. My dads grinder doesnt have a rest to try and grind on so its all by hand. I had a small issue where it was cutting about .02 up the blade, so i took my dremel with a stone and dressed it to fix it up. I then rehoned that side and went back at it. This tool post is hard to set up on center so im not 100% sure if that is all of my problem still or not. I should hopefully have my new tool post soon and i will do more tests. I liked the finish on this cutter better then yesterdays.
Todays

Yesterdays

At this point i also have to take into consideration that i doubt i will be cutting and parting off stuff over a half inch as much? The stock is maybe around .600 so i have that going for me. I tried slowing the lathe down the slowest i can and but boy is the chattering loud. Not sure what else i can maybe do at this point.

 

[mikey]

Your tool looks a lot better and I'm not surprised it cuts better, too.

As for chatter, remember that if the tool chatters you need to slow the speed and/or increase the feed. If you are running at the slowest speed your lathe can run, increase the feed rate. Of course, chatter can also come from many other sources than just your cutting conditions (speed, feed). The lack of rigidity in a small lathe, not being dead on center height, tool not being precisely perpendicular to the work all come to mind.

Parting is a problem for a lot of folks. You just need to sort through all the possible causes and find what works best for your situation. Having a good tool really helps.

 

[Brento]

Thanks mikey i cant really push harder on the feed or due to the lathe rigidity. I can feel the vibration in the head stock and i dont want to stall out the spindle. Is there a cheating way to maybe get past part of the cut off tool. Like say if i made like a threading tool for example but gave it a nice radius and cut into the part or made a little slot and then used the parting tool?

 

[mikey]

Is it possible to rear mount a parting tool on your lathe? Does the cross slide have T-slots or can you adapt the cross slide to accept a rear mounted tool post? If so, that would be a really good option for you. A rear mounted parting tool post with a parting tool mounted upside down, with the tip set to center height, will part far better than from the front on a small lathe.

 

[Brento]

I have 2 t-slots on my compound so i could swing around and do that. My problem is the tool post block is mounted through a bolt and the tooling slot does not have alot of room to move. I can try that tonight and see what i can set up.

I also want to ask and say i was highly mis-informed i have m42 hss blanks and i always thought the m42 was for the amount of cobalt in the part. I found now that m42 is for stainless and high nickel parts. I ordered 10 bits of m2 which is recommended for steel, brass, and aluminum. I am still tempted to maybe make a pre parting tool cut off as i stated in my last post but i am not sure if that would help alot or not.

 

[Brento]

My qctp from tom is done and tge food news mikey is i can turn the parting tool upside down. Should i make a rake for the top of the cut off tool? Maybe like a 10 deg?

 

[mikey]

My qctp from tom is done and tge food news mikey is i can turn the parting tool upside down. Should i make a rake for the top of the cut off tool? Maybe like a 10 deg?

No, you just use your standard parting tool but mount it upside down. Be sure the tip of the tool is on center height and that the tool is precisely perpendicular to the work piece. Part by backing the cross feed handwheel out, pulling the tool into the part.

 

[mikey]

I have 2 t-slots on my compound so i could swing around and do that. My problem is the tool post block is mounted through a bolt and the tooling slot does not have alot of room to move. I can try that tonight and see what i can set up.

I also want to ask and say i was highly mis-informed i have m42 hss blanks and i always thought the m42 was for the amount of cobalt in the part. I found now that m42 is for stainless and high nickel parts. I ordered 10 bits of m2 which is recommended for steel, brass, and aluminum. I am still tempted to maybe make a pre parting tool cut off as i stated in my last post but i am not sure if that would help alot or not.

M42 is a HSS tool with 8% cobalt. It can be used for standard work but excels for cuts in materials that are either really abrasive or in high heat situations. Your lathe is not capable of generating excessive heat at the point of cut so a standard M2 bit will do for almost anything you're likely to encounter.

 

[Brento]

Ok well i ordered m2 bits. I had m42