I have gained a great deal from the “ZONE” over the past 1½ yrs and would like give back a little to the members. I’m currently writing a small program that calculates various values that seem to be used while machining. Not knowing actually any of the formulas I began searching, and it appears that speed and feed are the most requested. Below is a list of what it can do so far along with the formulas that I used. If any of the formulas are incorrect please let me know so they can be corrected and any other function (along with formulas) that would be useful in the “hobby shop”. Keep in mind that I am self taught in VB and that my skills are limited.

Current Functions:

*Spindle Speed: speed = (cs)*3.82 / d
CS = the sfpm of the material
D = diameter of the cutting tool
There is also a chart that can be edited for the different material CS values.


*Feed Rate: feed = (chip load) * (# of flutes) * (spindle RPM)

*Fractional to Decimal converter: (for those of us that need it)

There is a database associated with the program so adding things as far as like drill sizes,Tap drills etc wouldn’t be hard to incorporate into the program. As I stated, I’m open to suggestions as far as what else would be nice to have, but I might not be able to accomplish all that is requested.

are you wrighting this as a program you cam down load

my communications software has a pretty good calculator i use multi DNC v 7.0 build 28

yes, this will be a free downloadable program.

thats good you can never have to many calculators

COOL! :)
And... maybe add some formula's to calculate the machine itself?

thumbs up!

Brunow,
Looking at the attachment it would be fairly easy to do...just need to get one part of program up and de-bugged before adding any additional features
thanks for the file

now that's some good news to start the day with! :)

I have added a converter to go from decimal to fraction (in 64th). I was searching last night for some reference material for the suggested sfpm of various metals, didn’t find exactly what I was looking for, does anyone know of a web site that offers a chart or should I just get the latest “machinist handbook”? I would like to populate the database with some of the more common metals, aluminum, mild steel, tool steel, brass, stainless etc. for both “HSS” and “Carbide” tooling. While testing the application I did notice that placing a high “sfpm” say 400 and using a .250 tool resulted in a suggested RPM of 6112. Most mills “Hobby Class” don’t turn this fast, so is how is this overcome in the shop? Crank the RPM as high as you can and let’r rip?
Thanks in advance

Here is a screen shot of what it looks like so far, let me know what you think
http://www.cnczone.com/gallery/data/500/medium/screenshot.JPG

:cool: No idea how you do it. But it looks kinda cool!
Nice idea adding some value converter to it. decimal - fraction. Maybe add inch - mm allso? :banana: (http://www.digitaldutch.com/unitconverter/index.htm)

Brunow,
I will be adding a “metric” option to the program once I get the “inch system” going or I might just re-write (copy and paste…lol) a whole new program. Seeing how you are in Belgium, when it comes to machining formulas do you use the “inch” or “metric” system and do you have any links to the metric formulas?

I have been work on a couple of issues the software has (1) rounding on the "decimal to fraction" (2) storing the data for recommended speeds. I currently have the decimal to fraction set to calc. 64th but there is a problem
if you enter and decimal between .008 and .023 it will show 1/64" working on that, the other problem is I would like this to be a small application, currently the data for material speeds is store in a database (which you can edit) the only thing is it makes for a large program and supports files that need to be loaded on the host computer..I will post an .exe as soon as I get these ironed out.

I'm not sure a user would require a converter from decimal to fraction.

I imagine it is quite hard to write code to make a fullproof converter for all decimals.

Perhaps a dropdown window of the more common ones is all that is required.

I would like to start by saying "thank you for contributing". I can always use a calculator (be nice if one had everything you needed). A converter for fractions would be nice for those brain fart days. Can never have to many functions. Again thanks.

This is quite cool, and I've been working on a 'shop calculator' of sorts as well. We've got different interests though, it seems. I'm starting off with a right angle calculator and adding similar features like sine bar buildups and also speeds and feeds. If you're looking for things to add, a right angle triangle calc would be an excellent addition. I know I'm not alone in that I'd prefer to use a program over trigonometry.

As it is now, it looks really nice, I especially like the table of suggested speeds. Keep up the good work!

Why not simply look in the Machinists Handbook? From what I see, these are only guess's. This program does not take into account the type of coating on the tools, TIcn, Tinal, etc. A true machinist does not need a "program" to find out all this information. Example... carbide at 300 SFPM in low carbon steel? See what you get at 700 SFPM at .090 DOC
Steve

Hope you have not given up on this. Please post status of your project.
Thanks a million.

Here is a screen shot of what it looks like so far, let me know what you think
http://www.cnczone.com/gallery/data/500/medium/screenshot.JPG

Where`s the down load?
:confused:

Why not simply look in the Machinists Handbook? From what I see, these are only guess's. This program does not take into account the type of coating on the tools, TIcn, Tinal, etc. A true machinist does not need a "program" to find out all this information. Example... carbide at 300 SFPM in low carbon steel? See what you get at 700 SFPM at .090 DOC
Steve

This place is full of non machinists that don't own the handbook. They do spend money on parts and pieces to build machines and some buy machines.
Just because this is a machinist forum doesn't mean you have to be a machinist to get something out of it. I think his program is a great tool for the rest of us non machinist dummies that don't own a handbook or have years of school and experience machining stuff. I think we probably fall in the hobby group... :)

BUMP!

Anxiously awaiting a download link!

RLC,

Any progress?

While testing the application I did notice that placing a high “sfpm” say 400 and using a .250 tool resulted in a suggested RPM of 6112. Most mills “Hobby Class” don’t turn this fast, so is how is this overcome in the shop? Crank the RPM as high as you can and let’r rip?
Thanks in advance

I'd say add an entry for the user to provide the highest RPM their machine can do. If its slower than the calculated RPM then figure out what fraction of that speed the machine can do and multiply the IPM by the same amout.

Example, a hobby machine can do 4,000 RPM and the calculated RPM is 6,000 so the hobby machine can only cut 2/3 as fast as recommended. Multiply the calculated IPM by 2/3 and use the lower numbers as the recommendation.

Come to think of it, a lot of machines can achieve high RPMs (24,000 here) but can't achieve high IPM. My stepper setup can't really go more than 70 IPM in air and isn't rigid enough to cut heavy. I average 40 IPM in MDF which cutting 1/8 deep or less as things start to wobble and shake if I go any faster. Might want to add something about limiting IPM for different materials as well.

From what I've seen a lot of shop monitors aren't really high resolution so you might not have a lot of screen real-estate to work with but, if you can fit it in, it might be good to show both the unadjusted calculated values and the values adjusted to the person's machine in the same window (though not vital I would think).