Feeds and speeds for a newbie

[spork]

I built a paramotor, and now want to build propellers for it. I've designed a propeller, and have been using Cut3D to make the toolpath file. I plan to do a test-run out of MDF and only then move to birch for the final propeller.

I have a 1/2" ball-nose high-speed steel bit with two straight flutes. I've been having a bit of trouble figuring out the appropriate feeds and speeds for this project. Can someone point me toward a spread-sheet or calculator that will get me to a good starting point?

I need to figure out spindle speed, feed speed, cut depth, stepover, etc.

Thanks!

[dlcw]

Rick, Welcome to the forum.

If you do a forum search for feed rates, spindle speeds,, etc. you will find lots of threads on this topic. The only definitive answer, as with anything CNC, is it depends. Search around and I suspect you will find exactly what you are looking for.

[spork]

Rick, Welcome to the forum.

If you do a forum search for feed rates, spindle speeds,, etc. you will find lots of threads on this topic. The only definitive answer, as with anything CNC, is it depends. Search around and I suspect you will find exactly what you are looking for.

Will do. I did a search on "feeds and speed" and didn't find what I was looking for, but I will give it a better try.

Thanks.

[supertigre]

www.onsrud.com/xdoc/FeedSpeeds

everything you ever wanted to know about feeds, speeds, and chiploads.

[spork]

www.onsrud.com/xdoc/FeedSpeeds

everything you ever wanted to know about feeds, speeds, and chiploads.

Thanks very much! Someone else gave me the same tip today. I'm going to study this over the break.

At a glance, it looks like I have to figure out what series my cutting tool is. It's a 1/2" ball end, 2 flute, HSS bit. Any tips would be great. Otherwise I'll do more poking around.

Thanks again.

[curtiss]

What type of software did you use to design the propeller ? What sites do you fly without a motor ?

I would suppose you would have to "flip it" to cut both sides.

[spork]

What type of software did you use to design the propeller ?

I'm an aero engineer. I designed the prop based on some very basic principles and a little bit of airfoil research. A buddy and I recently built a 17 foot propeller for a wind powered vehicle, and I chose to use the same airfoil for my PPG prop (but of course a very different planform, diameter, and twist profile.

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I then wrote a program that produced an ASCII STL mesh that describes the blade. And I had a friend design the hub on some CAD program (not sure which).


What sites do you fly without a motor ?

When I fly without the motor I usually fly at the coast in Pacifica, California. For mountain flying I tend to go to Dunlap (near Fresno).

http://www.talkshopbot.com/forum/attachment.php?attachmentid=13950&stc=1&d=1324614997


I would suppose you would have to "flip it" to cut both sides.

Yes. And I think I'll make extensive use of tabs (in Cut3D) to keep from doing lots of unnecessary cutting. I'll make top tool-path and a bottom tool-path. The top tool-path will have tabs that keep the tool from cutting all the way to the bottom as it passes the leading edge. It only has to cut just pass the leading edge - and vice-versa for the bottom.