Spherical Radius /Need Help

[Getter-Done]

I m trying to put a radius on the end of a handle bar Nub that goes on a Motor cycle.
My radius is Spherical because / the Side veiw of 1.420 Dia part is 1.290 long.
The radius starts at .290 at the end of the part( It is 1.420 Dia for 1 inch) then .290 at the end is a radius.
If you are looking at the front view (Diameter) O.D. dim. is 1.420 then the radius stops at .875 the center is flat in that .875 circle and has a countersunk hole. here is a link to the part Left Handlebar Weight Suzuki VS800 Intruder 1998 | eBay
I have set my Z start point away from the part .41 then .75 radius (That got it Close instead of .875 at the end it is .1145)then move those numbers up and down an can't get it right
Any Idea's

Thanks

[KenFoulks]

What kind of tool are you using? What values are you using for your cutter comp? Please post a few lines of G-code.

[Getter-Done]

Thanks I figured it out today.
With help from my Instructor.
The Diminsions I was given was not (Totally) Correct.
With that being say /My Radius figured to be 0.300.

Which was 0.331 with Cutter Comp in the code

My code that worked was as follows

T303
G 54;
G50 S1200;
G96 S300 M03;
G00 X 1.47;
Z 0.05;
G71 P101 Q102 U0 W0 D0.005 F0.006;
N101 G00 X0.758;
G01 Z0;
N102 G03 X1.42 Z-0.331 R0.331;
G00 X1.47 Z0.05;
M30;

I still have an Issue with my RPM & SFM & Feed rate when I turned the Diameter of the piece down.

The stock is Stainless Steel (dont know what kind )
It is 1.750 dia to be turned down to 1.420.
I never could get it to curl off right.


I tried all different RPMs /feeds & SFM,s and depth of cuts .015 down to .005.

I guess I will have to buy a Machinist Calc Pro calculator.

I got real close with Info from MHB
but it still left real small grooves in the surface
The bit seem to be sharp.
Any Suggestions?

Thanks again

[Getter-Done]

Thanks Ken I posted the Code in the Thread

[KenFoulks]

Any Suggestions?

Need much more information, especially the type of material. Stainless has many varieties. Answer these questions:
Material: (303, 304...)
Work-holding: Good (hydraulic, bored soft jaws) Bad (Manual, close diameter hard jaws)
Machine: (SL-20, 30)
Tool: (CNMG, VNMG, DNMG)
Insert Grade: (4225, 4015...)
Insert Size/Radius: (432. 431, 532...)

Assuming the first selection of each, try 130 SFM, .085 DOC, .012 IPM

[Getter-Done]

Thank you for your time

1st Question : This stainless is Very Magnetic
2nd Ques : Regular 3 jaw chuck with Chuck key
3rd Question : it is a HAAS toolroom lathe SL 6 or 9 not real sure I can Find Out.
the rest of it I'm Guessing
I think 432 on on Radius
The bit holders are black in Color and made of very (hardnend) material.

I check today about more accurrate info

Thanks

[KenFoulks]

400 series stainless steels are the only stainless steels that are magnetic. Based on your problem, it does not have sulphur in it, which improves machinability. This rules out 416, leaving 410, 420, 430, 431, and 440. These materials have an average surface speed recommendation of 75 to 90 SFM. Assuming you have the smallest tool room lathe, the TL-1, it has a 7.5hp 1800RPM spindle. The most torque is available at about 50-400 RPM. Try these cutting parameters:
75-90 SFM (160-200RPM at 1.75" dia, 200-240 at 1.42" dia)
.035-.07 DOC (adjust this up from.035 to be more efficient)
.012 IPM (Adjust down if you have to, to not stall spindle)

Good Luck

[Getter-Done]

Thanks Ken

My biggest Problem was the DOC. Is was taking .015 cuts.
When you suggest .085 that turned on the (light bulb).
I was taking to light of cuts.

the Stainless Steel was 17-4 PH

Here is the code that worked

T303;
G54;
G50 S2000;
G96 S300 M03;
G00 X1.825;
G00 Z0.15;
G71 P101 Q102 U0 W0 D0.1 F0.015;
N101 G00 X1.42;
G01 X1.42 Z-1.325;
N102 G01 X1.825;
G00 X1.825 Z0.15;
M30;

[KenFoulks]

Always take a DOC bigger than the radius of the tool.

[Getter-Done]

That is good to Know
I can remember That

Thanks