Model Engine Maker

Help! => Tooling Review => Topic started by: sshire on March 26, 2016, 11:46:10 AM

Title: Help needed from MEM
Post by: sshire on March 26, 2016, 11:46:10 AM
I need some input.
I have the Machinist Calc Pro 2 app for my iPhone. It is identical in usage to the "handheld" version but $45 cheaper.
Very useful BUT...
In facing ops, any D. O. C. of less than .04" returns 0 for the RPM. My finish pass with a face mill is usually less than .04.
I called them and was asked to submit a bug report. Here's the reply. Any comments would help to get them to fix this.
Thanks

Reply

Thank you Stan,
 
I have submitted your findings to our Product Development team for review. They said the reason for the limited depth was that we did not have data to support the parameters and any further information you might have would be greatly appreciated.
Title: Re: Help needed from MEM
Post by: Stuart on March 26, 2016, 02:03:29 PM
Stan

Looks like they cannot be bothered

I use FSWizard app for the iPad ( I have the lite app because it's free ) tight git that I am and it will accept DOC for face mills smaller than you have quoted

Ok it's not as elegant as the app you have bit crude but it works


Sorry cannot help any more

Stuart
Title: Re: Help needed from MEM
Post by: sshire on March 26, 2016, 03:27:24 PM
Thanks. I'm looking for some explanations as to why I'd possibly want to take a finish pass of less than 40 thou.
I do know that a finish pass of .025-.03 with my 2" and 4" face mills results in a mirror finish.
Title: Re: Help needed from MEM
Post by: AOG on March 26, 2016, 03:36:22 PM
Stan that's easy enough. On my old minimill 40 thousands was a roughing cut. For a finishing cut while face milling I generally used 5 thousands. For fly cutting it was 2-3 thousands. The final sumerized answer is that smaller machines need to use lighter finishing cuts due to lack of rigidity. Not everyone has a Bridgeport.

Tony
Title: Re: Help needed from MEM
Post by: b.lindsey on March 26, 2016, 04:27:02 PM
Stan,

I am behind the times but I  have the Machinist Calc Pro. If you will give me your input values would be interesting to see what the handheld calculation comes up with. If it returns an RPM value other than zero, then that might give you some ammunition, like why the handheld works and the phone app doesn't.

Bill
Title: Re: Help needed from MEM
Post by: sshire on March 26, 2016, 04:51:30 PM
Bill
Diameter 4"
Material 6061
Operation Face milling
Tool Carbide
D.O.C.  .025
Title: Re: Help needed from MEM
Post by: Stuart on March 26, 2016, 04:59:32 PM
Stan
For comparison to Bill's result

Fswizard give 1118 rpm and 1128 mm/min

For your figures in 6061

Stuart
Title: Re: Help needed from MEM
Post by: b.lindsey on March 26, 2016, 05:01:41 PM
Well, unfortunately I can't be of any help...those calculations are the new ones added to the Pro 2 version. Guess its time for an upgrade  :(

Bill
Title: Re: Help needed from MEM
Post by: Dave Otto on March 26, 2016, 10:17:50 PM
GWizard gives a range of 1169 RPM @ 12.4 IPM to 1375 RPM @ 66.5 IPM

The DOC really doesn't matter as long as your tooling can handle it. If I plug in different DOC's the RPM stays the same (it's all about the material and surface speed). What changes the RPM and feed rate in the above numbers is where the conservative or aggressive slider is set. The way that I see it is if your app will give you an RPM and feed rate for a .04" DOC then it would be the same for a .004" DOC.

Dave
Title: Re: Help needed from MEM
Post by: kvom on March 26, 2016, 10:49:37 PM
I have a 4" 4-insert face mill for the Bridgeport.  I run it at 2000 rpm and take very small DOC for just prepping metal surfaces, usually .01" or less.  Same for any materials.
Title: Re: Help needed from MEM
Post by: John S on March 27, 2016, 02:06:38 AM
GWizard gives a range of 1169 RPM @ 12.4 IPM to 1375 RPM @ 66.5 IPM



Dave

?? so go 206 revs faster but move 54.1 in/ min faster ??
Title: Re: Help needed from MEM
Post by: Dave Otto on March 27, 2016, 02:27:08 AM
I thought that was kind of strange too; I guess the aggressive setting doesn't take into account that you just might want a nice surface finish on your part.  :lolb: The type of inserts that you are using would also influence the surface finish. I went back and changed the radial engagement to 75% and it dropped to 43 IPM which seems more reasonable. I have run my face mill at work at 60-80 iPM in some materials and have had good results.

Dave