E-Bait ER20 Chucks and ATC Grooves

Has anyone had any luck cutting the ATC grooves into the E-Bait ER20 chucks? I bought 20 of them before I built an ATC, and now need to put the grooves in, but my first attempt was a miserable failure. Tapering the top of the shank was easy, but the groove turned our to be much more difficult than expected. HSS does not cut well - seems too hard. So, I ground a custom cemented carbide lathe tool, but it broke half-way through. Any ideas how I can get this done? I'm tempted to try doing it on the mill, using a carbide slitting saw and circular interpolation, then just do the bevel as a second-op on the lathe, but I don't know if that would work well or not.

Any ideas?

Regards,
Ray L.

No rotary table?

Quote:

---

Originally Posted by BAMCNC.COM

No rotary table?

---

Yeah, that would work as well, providing the carbide saw was up to the task. Do you think it would be? I have little experience cutting hard stuff - I work almost exclusively in aluminum.

Regards,
Ray L.

I grooved all of my old non-ATC tools in the Tormach's spindle using this tool.

T10012 Parting Tool with Carbide Insert

The critical dimension is the distance from the flat that contacts the spindle face to the top of the groove. And even that can vary by about 0.005" since the ATC has some movement built into it. The chamfer angles aren't as critical.

Here's my code, which is written for the Vertical Lathe configuration. You can use the code, or just pick the feeds and speeds out of it. The usual disclaimers apply.

Code:

---

%
(Add ATC Groove)
(DATE: 05/21/12 TIME: 19:19)
(PROGRAMMED BY: FREDERIC SCOTT)
(MACHINE: TORMACH 1100 VERTICAL LATHE)
(MATERIAL TYPE: 1018 STEEL)
(BLANK SIZE: FINISHED TTS TOOL)
(ORIGIN: 1.815" FROM SPINDLE FACE.)
(NOTES: )
 
(******START TOOLING LIST******)
( T0404 @GLANZ CUTOFF )
(*******END TOOLING LIST*******)

N00020 G90 G94 G40 G18 G80
N00030 G20( Inch)
N00040 (Postprocessor Rev14, 9April09: MyMachTurn14)
N00050 (*************Lathe Grooving*************)
N00060 (Workpiece diameter: 1.5 in)
N00070 (Workpiece length: 3.185 in)
N00080 (Tool Zmin, Zmax: -1.518 in, 0.541 in)
N00090 (Tool Xmin, Xmax: 1.153 in, 1.9 in)
N00100 M6 T0404 (MSG, Waiting on tool T4)
N00110 (*************@Custom  l0.35, Ti0.07795, Re0.00498,

Ia0.09374, Ph0 *************)
N00120 (Tool Zmin, Zmax: -1.518 in, 0.541 in)
N00130 (Tool Xmin, Xmax: 1.153 in, 1.9 in)
N00140 G48 S220 G41 D01 (max rpm for CSS mode)
N00150 G96 S864 M3 (CSS mode with surface speed)
N00160 G0 X1.7 Z0.54057
N00170 Z-1.51751
N00180 X1.90004
N00190 X1.70004
N00200 G95 M8 (feed/rev)
N00210 G1 X1.50004 F0.004
N00220 X1.49666
N00230 X1.4867 Z-1.51253
N00240 X1.48596 Z-1.51223
N00250 X1.48516 Z-1.51196
N00260 X1.4843 Z-1.51173
N00270 X1.4834 Z-1.51155
N00280 X1.48248 Z-1.51141
N00290 X1.48152 Z-1.51131
N00300 X1.48056 Z-1.51126
N00310 X1.153
N00320 G0 X1.70004
N00330 Z-1.47448
N00340 G1 X1.50004
N00350 X1.4945
N00360 X1.36944 Z-1.51058
N00370 X1.3688 Z-1.51076
N00380 X1.36796 Z-1.51094
N00390 X1.36734 Z-1.51104
N00400 X1.36672 Z-1.51112
N00410 X1.3661 Z-1.51119
N00420 X1.36546 Z-1.51123
N00430 X1.36482 Z-1.51125
N00440 X1.153
N00450 G0 X1.90004
N00460 M5 M9
N00470 M30 G40 G80 G90 G94 G97 S1000
%

---

Fred,

That looks like a good approach - I wish I had one of those on-hand. May have to order one. I'm going to have a go with the slitting say, and see how that does. I'll do it on the holder I've already buggered, so if it doesn't work, no real harm done. If it doesn't work, I'll order one of those parting tools. I've wanted one for a while anyway.

Gotta get this out of the way, so I can start getting the shop ready for the new mill to show up in a couple weeks...

Regards,
Ray L.

Please let us know how it goes. I have a nice little carbide slitting saw that I bought on a garage sale once, would be perfect for this - if it worked.

I thought I had a carbide saw, but it turned out to be HSS. I tried it anyway, and pretty much ruined it. So, I ordered the carbide insert parting tool Fred recommended.

Regards,
Ray L.

For me the Iscar Do-grip insert parting tool works really well. The same insert works as well on SS as it does in aluminum. One of the reasons I like the Do-Grip is the cutting tip geometry in which the chip is narrower than the slot being cut.
http://i72.photobucket.com/albums/i1...DoGripChip.jpg

Here is the Do-Grip insert tool parting off a 3.8” diameter aluminum part in my lathe. Note the excellent surface finish in the parted part.

http://i72.photobucket.com/albums/i1...arting-off.gif

Also:

[ame=http://www.youtube.com/watch?v=L3jjr30-mG0]ISCAR DO-GRIP - YouTube[/ame]

Wow! That is impressive!

I also add:

Looking at the geometry of the parting insert and the resulting chip it can be seen that the chip has a "broken back" or bent spine that causes the chip to be narrower than the slot. The idea of the "broken back" was suggested by George H. Thomas in the chapter "On Parting-off" from "The Model Engineers Workshop Manual" ISBN 1-85761-000-8. http://terrificshare.com/search/%7B7...E20A397%7D.htm Thomas suggested that grinding a 140 degree vee (similar to the DO-Grip) into the end of a HSS parting tool would do the same. Thomas writes: "The chip produced by these tools is of a vee formation which is free within the width of the slot and tends to curl out in continuous form instead of being retained as a collection of short chips or tight spirals; furthermore, the surface finish is, in general, much superior to that obtained with the conventional blades."

http://i72.photobucket.com/albums/i1...DoGripChip.jpg

Don,

Can you give the details of which Iscar Do-grip insert parting tool you are using? Part number for holder and inserts. Also where did you purchase it.

Many thanks,
Jeff

Iscar DoGrip DGFH-26-2 blade Insert DGN 2202J IC328 coating held in a KDK 1010 insert cutoff bar. Sadly KDK is no longer in business and I don’t believe there is a Chicom clone bar to replace the KDK 1010. I purchased the Iscar blade and inserts from R.L. Stephens Tool. Machine Tools, Cutting Tools, Cordinate Measuring - RL Stephens Tool and Equipment

Don

Don,

Thanks for the information - I'm getting one.

Jeff