Thread: Poor finish with my finishing tool.

Thanks dave, is the 5/16 on its own strong enough for deep cuts.

That one I posted up was only 1/4 tool and taking 2mm deep cuts and I would have no problem pushing it deeper. This tool sort of shears it off, not putting a lot of strain on the tool. So the 5/16 tool is plenty.

Dave

I forgot to mention that I use a left handed version of this tool for facing and it works great as well.

Dave

dave, just read your response about not using back rake, which also allows the tool to be continually sharpened with out loosing height.
the back rake angle is the main reason i never bothered to use hss without the angled holder.
have a curio about the side cutting edge, due to not using back rake, does that edge point slightly downwards towards the tip when grinding the side cutting edge angle, due to the tool tip now being in a lower section of the side rake slope,
or when grinding, should the side cutting edge angle be ground before the side rake.

I have a draw full of HSS tools that I inherited from the old man. They are mostly 1/2 inch. I have some others that are about 16mm as well. These are what I use and have become used to using. I would not be used to using anything smaller. In fact I find it easier to grind larger tool bits even though there is more material to grind away, they are easier to hold.

Simon

Cheers for posting that Dave. I'll make one and see how it goes.

Re the coolant question from a couple of pages back - thats actually mixed stronger than reccomended. The bottle says to mix 5% coolant with 95% water and its mixed closer to 10% and 90%

Re the radius - I often screw up this bit, and my hone isnt appropriate for lathe bits (its one of those diamond ones full of holes - unsuitable for anything under 25mm wide)...so i'll probably play more with a radius when I get a decent oil stone.

Brendan

When you rub your fingers under the coolant stream are they slippery or do they feel slightly dry.
Not knowing the brand or type of coolant you are using does make it hard to comment,but normally Solubile Oil when mixed looks a lot like milk.

This stuff is green, and tends to stay that way when in use. It went milky when it picked up oil that was in the swarf tray from when I overfilled my spindle.

I'll stick up the details in a couple of weeks...going on hols now.

Originally Posted by lather

dave, just read your response about not using back rake, which also allows the tool to be continually sharpened with out loosing height.
the back rake angle is the main reason i never bothered to use hss without the angled holder.
have a curio about the side cutting edge, due to not using back rake, does that edge point slightly downwards towards the tip when grinding the side cutting edge angle, due to the tool tip now being in a lower section of the side rake slope,
or when grinding, should the side cutting edge angle be ground before the side rake.

Hi,
I grind the side clearance, then the tip angle/front clearance and then the side rake last. When I grind the side rake I have the wheel square to the front edge.

Dave

Dave, thanks for the tips, this has definitely been the best help of all the info that i read on the net.
Just tested on a 40mm bar, without honing or a radius.
it worked great.
the cuts were smooth and didn't get the scratchy surface probably due to the tool trying to dig in.
even a light cut at 300 rpm had a much better finish compared to the the diamond tool holders finish run at the slowest speed.
will sharpen another tool, to use one for finishing and the other for deep cuts.
I understand now that the manuals are to be used as a rough guide, "A very rough guide" considering there is no back rake on this tool.
Rough to me is a few degrees here or there.

Cheers,
Merry Christmas to all.

will have more fun today,my poor mans dro arrived, the next tool project will be a universal tool platform for sharpening the HSS on the grinder.
my home made drill sharpener works great, it,s roughly based on the Tormek_DBS-22_Drill_Bit_Sharpening_Attachment.

these are sold pre ground LATHE CUTTING TOOL SET 8pc PRO GROUND 5/16" Sq HSS | eBay

Thanks to all who contributed to the thread. Glad to see many people have benefited from everyones ideas as I have. I look forward to applying the new information I have gained from you guys in the new year. Can't wait to spend some quality time grinding up a kick ar..se finishing tool.

I'm going camping for 5 days from tomorrow so I will catch up with you all in the new year.

Have a safe Christmas to all.

Cheers,

Originally Posted by lather

Dave, thanks for the tips, this has definitely been the best help of all the info that i read on the net.
Just tested on a 40mm bar, without honing or a radius.
it worked great.
the cuts were smooth and didn't get the scratchy surface probably due to the tool trying to dig in.
even a light cut at 300 rpm had a much better finish compared to the the diamond tool holders finish run at the slowest speed.
will sharpen another tool, to use one for finishing and the other for deep cuts.
I understand now that the manuals are to be used as a rough guide, "A very rough guide" considering there is no back rake on this tool.
Rough to me is a few degrees here or there.

Cheers,
Merry Christmas to all.

will have more fun today,my poor mans dro arrived, the next tool project will be a universal tool platform for sharpening the HSS on the grinder.
my home made drill sharpener works great, it,s roughly based on the Tormek_DBS-22_Drill_Bit_Sharpening_Attachment.

No problem and thanks, great to hear your getting good results and is working good for you. Sometimes what works for one person doesn't always work for another. I have been using this type of tool for around 20 years and it worked good for taking big cuts on the Hercus as well, with out straining it too much.
I up the speed for finishing cuts but just did that test at 200rpm as the lathe was set on that. The only thing you have to watch using it dry at higher speeds is the tool getting hot and the edge going off before finishing the cut, but coolant even sprayed on by hand will help that.
Now your using this tool you can now see how I got the finish on those cylinder squares.

That DRO will make life easy, don't forget to post up about the install etc. With this tool you will now be able to do finer cuts than the DRO can read.

Dave

Originally Posted by simonl

Thanks to all who contributed to the thread. Glad to see many people have benefited from everyones ideas as I have. I look forward to applying the new information I have gained from you guys in the new year. Can't wait to spend some quality time grinding up a kick ar..se finishing tool.

I'm going camping for 5 days from tomorrow so I will catch up with you all in the new year.

Have a safe Christmas to all.

Cheers,

I hope you have a great time and will catch up with you in the new year.

Dave