- Joined
- Dec 19, 2018
- Messages
- 125
Gathered some data and would like to share this with those of you whom don't have the spindle tach or a means to calculate IPM feedrates with the optional power feed. Calculating speed and IPM feeds is a good way to ensure good tool life. It's just as easy to burn out a tool from too high RPM's or too low feedrates as it is with excessive feeds vs RPM"s . I started by using a simple Sharpie marker to divide my variable rpm dial into 16 segments as shown in the pics below (15 segments for my power feed, see my note below). I then tested the RPM's using my Pyle laser RPM meter. Keep in mind these are not exact rpm readings but they will at least get you close when you calculate SFM based upon your material and tool configuration. I entered all the rpm's into an Excel page and took a screenshot. (I have both the std gears, and the optional 5000 rpm gears as reflected in the chart) These numbers should work on most all the hitorque variable speed mills. It won't be exact but it will be way better than "guessing". If you already have the digital RPM readout your one step ahead of the game, I already had my RPM meter and just don't see the value in spending another $130 on a rpm guage in my situation.
Pic of my spindle RPM dial :
Pic of my power feed dial:
**NOTE: Disregard that last 2 sharpie dots on the dial. My max IPM feedrate is reached at position #15
**NOTE: "Pos #1" in the chart represents the FIRST Sharpie dot, not the number "1" on the dial. I do not get any feed rpm from the "1" position on the dial)
Screenshot of the Excel rpm data:
Lastly the link to the easy to use LMS speed and feed caculator:
https://littlemachineshop.com/mobile/speeds_feeds.php
Pic of my spindle RPM dial :
Pic of my power feed dial:
**NOTE: Disregard that last 2 sharpie dots on the dial. My max IPM feedrate is reached at position #15
**NOTE: "Pos #1" in the chart represents the FIRST Sharpie dot, not the number "1" on the dial. I do not get any feed rpm from the "1" position on the dial)
Screenshot of the Excel rpm data:
Lastly the link to the easy to use LMS speed and feed caculator:
https://littlemachineshop.com/mobile/speeds_feeds.php
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