MadModder

The Shop => Tools => Topic started by: mattinker on March 06, 2012, 01:52:38 PM

Title: Speeds and feeds
Post by: mattinker on March 06, 2012, 01:52:38 PM

Hi,

I had a speeds and feeds chart that came from a model engineers web site. Unfortunately, I've lost it. I know that I can work it out with surface feet per minute, but this chart was in RPMs for a given diameter in different metals. I had one for drilling, (which I still have) one for milling (two and four flute) and one for turning. With my selective memory which only retains unusable information, I don't remember speeds and feeds. My charts were great I had filled in the metric diameters by hand and with a bit of trial and error, things worked well! Has anybody got or could point me to a set of charts that would cover my needs? I've heard that Starret published one, but I've been all over the web and I still haven't found what I need!

Regards, Matthew

Title: Re: Speeds and feeds
Post by: steam oil on March 07, 2012, 12:13:30 AM

Hi
I found this web site hope it helps

http://www.daycounter.com/Calculators/GCode/Feed-Rate-Calculator.phtml

Brian

Title: Re: Speeds and feeds
Post by: mattinker on March 07, 2012, 02:31:03 AM

Thank you for your reply, your link is interesting, there are other very worthwhile calculators besides the feeds and speeds on there.


What I'm looking for is a paper chart that I can look at and not have to use my grubby mitts on a calculator! I'm a dirt magnet, as soon as I get in to my workshop, my hands are dirty, swarf and calculators don't get on very well!

Regards, Matthew

Title: Re: Speeds and feeds
Post by: Lew_Merrick_PE on March 07, 2012, 02:01:56 PM

Matthew,

Back in the day (you know, when pet dinosaurs were still playful...) I could eyeball a cutter and know it was right for the cut.  You use it or you lose it, and I lost it years ago (sometime before aspirin becoming my drug of choice).  So, what I have done is to make a printable spreadsheet matrix that: (A) provides me spindle RPM's based on the (4:4:2) pulley set-up; (B) closest to optimum RPM for HSS and carbide endmill diameters vs. my most common set of materials; and (C) closest to optimum RPM for drilling (HSS only) vs. my most common set of materials.  I print that out on card stock, laminate it in CrystalSeal, and have it posted right next to my mill (with a couple of spares stored in a reasonably convenient drawer).

My version of it was created using the OpenOffice Calc spreadsheet.  It was created specifically for my mill's pulley set.  Basically, I created: a matrix of spindle speeds by pulley configuration (A/B/C/D:1/2/3/4:A/B) on one worksheet; a list of cutter RPM's for specific SFM speeds by type of cutter (HSS or carbide) on another worksheet; and then filled in the closest match in a matrix  in another part of that (cutter speed->RPM) worksheet.  I then copied the RPM to Pulley Configuration data into a third workbook with the cutter speed to RPM data by material below the Pulley Configuration data and formatted it all to nicely print out on an 8.5 X 11 (inches) sheet.

Does that suggest a solution?

Title: Re: Speeds and feeds
Post by: mattinker on March 07, 2012, 06:09:11 PM

Thank you,

 I was begining to think along those lines, I just thought that maybe somebody had a convenient chart already made. The most annoying thing is that I had a perfectly good chart that suited me and I lost it!

Regards, Matthew

Title: Re: Speeds and feeds
Post by: Lew_Merrick_PE on March 08, 2012, 10:52:55 AM

Matthew,

I will have to figure out which CD (yes, it's that old) I have the "source code" for my system hidden on.  It was done using OpenOffice Calc (which is free software).  You would have to "edit in" your spindle speeds (possibly re-creating the pulley-step chart data).  I will not have time to get to it until at least next the end of next week (call it 16-18 March) as I am in the middle of doing a rather major project drawing and model data release.

On the other hand, it probably took me an hour to create the "master" that I use.  It should not take you much longer than that -- and then you have a chart customized to your preferences.  ???

Title: Re: Speeds and feeds
Post by: dvbydt on March 08, 2012, 05:05:05 PM

Not offering this as the ultimate answer, but it should get you a starting point. There are too many variables in the home workshop to get a definitive answer but cutting speed is what burns out tools.

(http://i757.photobucket.com/albums/xx213/dvbydt/Engineering/CuttingSpeeds.jpg)

Ian

Title: Re: Speeds and feeds
Post by: mattinker on March 08, 2012, 05:35:03 PM

Lew_Merrick_PE and Ian thank you both!

Ian's chart will be just right, all I need is a guide, which is what it is. I've not done enough machining to remember speeds, once I have an approximate speed, the feed is not too difficult.

Thanks again, regards, Matthew.