Problem- Raduis O.D. Groove

[peelmachining]

I have a job to program.
A raduis groove, diameter 17mm 4mm deep at Z-35.00.

I have a 5mm rad and a 3mm rad grooving tool available.

I have not attempted this before any help get you kudos

Thank you
John

[Geof]

I think you are missing some information. You give diameter 14mm; is this the groove diameter, or the diameter of the bottom of the groove?

A picture would be helpful.

[txcncman]

Is center at Z-35.000?

Basics are plunge groove tool at groove center line to depth leaving something for clean up (0.002 diameter) then back up and interpolate one side of the groove to center line and depth then back up and interpolate the other side to center line and depth.

Do you need an example?

[peelmachining]

Yes Please, an example would be great.
thank you Txcncman.
John

[txcncman]

I program for lathe off of the tool edge, not center of radius. The following is in inches, not millimeters.

G0 X0.9
G0 Z-1.437
G1 X0.3563 F0.002
G0 X0.9
G0 Z-1.3976
G1 X0.4331
G2 X0.3543 Z-1.437 R0.0394
G0 X0.9
G0 Z-1.4764
G1 X0.4331
G3 X0.3543 Z-1.437 R0.0394
G0 X0.9

[peelmachining]

o.k. thanks I will give it a shot. The part that confuses me is how to allow for the smaller tool radius to get the actual radius right. or is it trail and error?
John.

[txcncman]

Ok. In this case, you are cutting a 5mm wide groove with a 3mm wide tool, both full radius. Radius of groove is 2.5mm. Radius of tool is 1.5mm. Subtract one from the other equals 1mm. Note in the example, the tool will make an arc of 0.0394 (1mm). Look at the screen shot carefully.

Any other questions?

[fordav11]

Originally Posted by peelmachining I have a job to program. A raduis groove, diameter 17mm 4mm deep at Z-35.00. I have a 5mm rad and a 3mm rad grooving tool available.

how wide is the groove? and what radius do you want at the top of the groove (or chamfer?) and what radius at the bottom? I use radius grooving tools a lot to machine radius grooves. just make the tool interpolate any arc you need as long as the tool has a smaller rad than your groove.

It just occurred to me that you might mean a large curved groove that doesn't have any straight sides where the radius is much larger than the depth? and maybe you mean the radius has a curve that is diameter 17mm? i.e. the radius is 8.5?
In that case you'll need to use some software to generate the proper code.

I can post the code here if you give more details about the X diameter, radius of the groove and the width and at least one Z position to some specific point like the start or the middle. Z-35.0 and all of your other info is just too vague to know exactly what you want

[peelmachining]

Hi
I cant work out how to delete this post after editing it I discovered the "quote"
Button , but I cant find a delete post yet.

Regards John

[peelmachining]

Originally Posted by fordav11 It just occurred to me that you might mean a large curved groove that doesn't have any straight sides where the radius is much larger than the depth? and maybe you mean the radius has a curve that is diameter 17mm? i.e. the radius is 8.5? In that case you'll need to use some software to generate the proper code.

Yes that is more the shape. O.D. spline 44.22mm bottom of groove 36.22mm rad 8.5mm.

txcncman came up with an acceptable answer Thank you and kudos.

I just made some minor adjustments after first cut most likely because the tool is hand ground tool steel.
I am going to add a carbide rougher now so I don't spend all day regrinding.
Regards John

[fordav11]

well like I said it's not that simple.

Here's the code for a 5mm rad tool where the start of the groove in Z is -35.0.......

G0 Z-37.773
X45.0
G1 X44.22 F0.25
X39.514 Z-39.242
G2 X36.22 Z-42.211 R3.5
G2 X39.514 Z-45.181 R3.5
G1 X44.22 Z-46.649
X45.0
G0 X200.0 Z200.0

etc

[fordav11]

Originally Posted by peelmachining Hi I cant work out how to delete this post after editing it I discovered the "quote" Button , but I cant find a delete post yet. Regards John

there is no delete option. you can edit existing posts but after about 24 hrs its locked. This is quite sad as most board software when configured correctly will always allow editing your own posts and deleting them for any period of time set in the configuration (usually no limit is set). This software (vBulletin) doesn't appear to be set up properly or simply doesn't allow it. I asked the admins to look into it and change it, still waiting for a result..... :/