Struggling with an awful o-ring groove

[bd41612]

On 1/30/2022 at 1:04 PM, cncappsjames said:

Get the CS Contour and Orbital Milling option on your machine while you're at it then you can basically scrape it.

 

Google "Hale Milling". A certain machine tool builder likes to say it is their own proprietary function blah, blah, blah... (bovine excrement) it may be their name that is proprietary, but the function has been around for YEARS! I've been recommending the function for certain applications since the early 2000's. No telling how long before that it was created. 

James beat me to it. You could have a large rugged tool to reach down that wall and do the hale milling. One advantage is that it can generate a better sealing surface because there is no cross hatching witness marks where leakage can occur. It's going to be a pricy option, but if it works...

[cruzila]

Garr end mills and other brands all have different grinds. They do this to try to stand apart. My experience with standard Garr is they have no wear landing and are chatter prone. I've programmed cuts and made an endmill change and it goes from working well to not at all. What about dynamic milling? Might work to get the engagement to eliminate chatter.

[JB7280]

On 1/31/2022 at 7:37 PM, byte said:

.125 is a long way from .050, I would just scale your formula back till you are turning very slow, then work your way up, if needed..

How do u calculate your feeds and speeds? What I would do was make a table with formulas in google sheets and i would input my tool parameters there..

You're saying basically make a table to keep track of the different things I try to cut this feature, so I have a record or works the best?  

 

I usually start with HSM advisor or Harvey's MAP.  Of course, with this feature/tool, those don't apply so much.  I can do a little in sheets/excel....but I'll be honest, I'm not great with it.   

[Bob W.]

One thing I have done in the past with long cutters is take a high feed approach (sort of).  I'd rough with a 3/32" tool (3/16" shank) and .030 corner radius at .005-.008" depth cuts so the cut was low on the radius, then come back and finish with a nice sharp end mill.  Ideally it would be a HSS end mill with a carbide shank, but not sure that even exists, LOL!  I would have definitely no quoted this.  Jame's hale milling idea is a winner if that is available on your machine.  Anytime I have long stickout tools I have much better luck with shallow cuts with a bull mill going fast.

Another idea is an offset end mill.

[Guest]

I use a spread sheet with formulas built into it to calculate things like RPM based on tool diameter or feedrate based on number of teeth or feedrate per tooth.

Then you can further define columns for scenarios where you have extra long stickout and document and record the results, so you will always gain data on how you solved the issue the last time and can somewhat duplicate that..

In excel you can just define some simple formulas on cells

 

Mill f_s chart.zip

Lathe f_s Chart.zip

if you use google sheets online its free and you can download it into excel format, so its a portable solution

[JB7280]

3 hours ago, byte said:

I use a spread sheet with formulas built into it to calculate things like RPM based on tool diameter or feedrate based on number of teeth or feedrate per tooth.

Then you can further define columns for scenarios where you have extra long stickout and document and record the results, so you will always gain data on how you solved the issue the last time and can somewhat duplicate that..

In excel you can just define some simple formulas on cells

 

Mill f_s chart.zip

Lathe f_s Chart.zip

if you use google sheets online its free and you can download it into excel format, so its a portable solution

That's a pretty awesome spreadsheet.  I like that it adjusts the chipload according to the tool diameter.  Unfortunately I'm not nearly skilled enough with excel/sheets to add the stickout column, but perhaps I would be able to look at how you did this one, and reverse engineer it a little after collecting some real data.

 

Thought you should know, it seems that row 2 might be broken.  When changing the diameter, it doesn't change the RTF or CLPT columns.

[JB7280]

On 1/30/2022 at 1:04 PM, cncappsjames said:

Get the CS Contour and Orbital Milling option on your machine while you're at it then you can basically scrape it.

 

Google "Hale Milling". A certain machine tool builder likes to say it is their own proprietary function blah, blah, blah... (bovine excrement) it may be their name that is proprietary, but the function has been around for YEARS! I've been recommending the function for certain applications since the early 2000's. No telling how long before that it was created. 

 

On 2/1/2022 at 10:37 AM, bd41612 said:

James beat me to it. You could have a large rugged tool to reach down that wall and do the hale milling. One advantage is that it can generate a better sealing surface because there is no cross hatching witness marks where leakage can occur. It's going to be a pricy option, but if it works...

After some youtubing, I get how the process works, basically a shaper, that can do contours.  But I'm having a hard time picturing if you'd be able to make the tool geometry in such a way that it could round corners?  I have an area where it would need to turn a .383 rad (based on an arc along the middle of the slot)

[crazy^millman]

49 minutes ago, JB7280 said:

 

After some youtubing, I get how the process works, basically a shaper, that can do contours.  But I'm having a hard time picturing if you'd be able to make the tool geometry in such a way that it could round corners?  I have an area where it would need to turn a .383 rad (based on an arc along the middle of the slot)

Now you thinking the problem is that it has to be made with that radius clearance on the back of the tool like a Face Grooving tool is made. I work it would be not very strong.

[JB7280]

30 minutes ago, crazy^millman said:

Now you thinking the problem is that it has to be made with that radius clearance on the back of the tool like a Face Grooving tool is made. I work it would be not very strong.

I could still see the process being a huge benefit for the long, straight stretches, then maybe another, weaker shaping tool for those corners, or even use the painful endmill method for only those small areas.  Even still I really like the hale milling/orbital milling idea and it's definitely something I'm going to look into once we're going and a deadline isn't such an issue.

[Guest]

On 2/5/2022 at 8:35 AM, JB7280 said:

That's a pretty awesome spreadsheet.  I like that it adjusts the chipload according to the tool diameter.  Unfortunately I'm not nearly skilled enough with excel/sheets to add the stickout column, but perhaps I would be able to look at how you did this one, and reverse engineer it a little after collecting some real data.

It is pretty straightforward,

A1 is the first cell in a spreadsheet

B1 is the second cell

Then in Cell C1 you could make a formula to add the first two cells and display the result

after checking the green check mark you can see the result

[GoetzInd]

We have some machine with Cs axis and normal direction control (Hale machining function). It is ideal for this.

Mike 

[JB7280]

On 2/8/2022 at 10:26 AM, GoetzInd said:

We have some machine with Cs axis and normal direction control (Hale machining function). It is ideal for this.

Mike 

I've asked someone from Matsuura about this.  We'll have to get it working for now with an endmill, but I think this will be the best long term solution.