Eccentric Engineering T-blade parting tool: A+

Back in the workshop today after a lengthy hiatus and got to try out my shiny new T-section parting tool and holder from Eccentric Engineering on the Myford ML7. What a revelation. Best parting tool I have ever used.

I had planned to make a rear toolpost to hold the T-blade but due to various delays bought Eccentric's blade holder type SC that can be used either inverrted in the rear toolpost or right way up in the regular front toolpost.

Parted off 1" diameter bright mild steel bar like it was cutting through cheese. Ran it at 200rpm, one speed slower than normal turning speed. No chatter, no graunching, no getting hot and complaining, no regular withdrawal of the tool to clear swarf and cool the tip. No nothing really. Just wound straight in at a good crack the whole way.

Tried it both with a bit of soluable oil and without and did not seem to make any difference to the operation although I expect the oil might extend cutting edge life.

The secret is the T section blade. I bought the 2mm wide by 12mm deep blade and the vertical shank of the T is half a mm narrower than the cutting e edge, allowing clearance and not trapping swarf particles.

The swarf peeled off in beautiful curls with no little small chips to do any jamming. The swarf curls just roll out of that groove without hindrance. I think the top of the blade might be ever so slightly hollow ground so the swarf is curved and made narrower than the groove. Not sure on that though.

It was a stark contrast to my other conventional tapered blade parting tools, both front and rear, that still require a bit of care to avoid unpleasantness.

So excited about it I had to take a few pics.

Going in with nice ribbon coming out.

All the way in:

Those beautiful swarf coils that take themselves straight out of harm's way:

And from deep in the cut near the end:

The tool set up:

And a couple views showing the rather hard to see T profile blade:

I used it straight out of the box. Clamped the blade in as supplied with a 12 degree clearance angle on the end, which seems to give a nice sharp cutting edge. Centre height of the holder was spot on as can be seen by the absence of "tit" on the piece left in the lathe. And the blade was held dead vertical, unlike a cheap Chinese similar holder I threw in the scrap box after the first time I used it. (Came from a "reputable" supplier too!) Eccentric's "side mount" hoider absolutely minimises overhang too, which is a big help.

Very pleased. Well done Eccentric Engineering.

I will get around to finishing my rear toolpost one day and will probably mount this blade on it as a permanent fixture just swung out of the way when not in use. But in the meantime, anything up to 1" is no problem with the front toolpost.

I was going to test it on some 2" bar as the acid test to see if it can compete with my ancient Drummond and its rear toolpost but my ML7 fixed steady needs a bit of fettling to take the larger bar before it's ready to do this:

Could I do this with a front toolpost in the ML7? I'll let you know when I get there.

The other factor is that I just scored a brand new horizontal bandsaw for half price so I reckon my sphincter clenching days of parting off 2" are over for the most part. Bandsaw! Much dreamed of luxury that is!

Edited By Hopper on 17/03/2021 09:39:36

I got one of these T-shaped parting off blades from Chronos a few years ago, and it works well. I made a special holder for the blade with room for the wider part at the top.

Thor

So, are you using it "upside down" Hopper please?

No, I was using it "right way up" in the front tool post as shown in the first pics. That's why I was so surprised at its excellent performance. Usually on these small lathes I find the inverted parting tool on the rear toolpost works much better. I can't use inverted on the front toolpost on the Myford due to screw on chuck that could become an unwanted screw off chuck.

John,

Hopper’s second para: “I had planned to make a rear toolpost to hold the T-blade but due to various delays bought Eccentric's blade holder type SC that can be used either inverrted in the rear toolpost or right way up in the regular front toolpost.”

Aha!

I use the 1 mm a lot for small brass bar. I have the 2 mm too and will get around to getting the 1.6 eventually. I use them normal way up. I have several of the usual V shaped parting blades but never use them anymore. Carbide insert blade for larger diameter steel.

I bought the Chronos version as well and found it very good.

+1 for the Eccentric Engineering parting blade I struggled with parting off on my Myford S7 until I started to use a rear tool post and then with the addition of the EE blade I have never had any probs

H

Quote

A slight concave radius is ground along the top (bottom) of the cutting edge and this aids chip curl, assisting in swarf ejection from the cut.

An axial central groove in the top of the blade,similar to that on inserted carbide tips, tends to produce two streams of swarf, each narrower than the cut, so that it clears more easily rather than jamming.

If the E E parting blade works well in the front toolpost, that will solve problems for a lot of folk.

Inverted, in a back post, parting off should be a doddle.

Wonder if having Zero Top Rake helps reduce the risk of dig ins?

Howard