Flycutter Project

[davec43]

I am spending a few hours making a flycutter I could buy for $15 on Ebay (no point going into that aspect).

My question is why am I getting the large burr on the bottom of the tool groove on the exit side. The feed direction is away from the column on all passes. The material is 1018 mild steel, diameter is 1.375, spindle RPM 1100, 4 flute endmill 5/16" diameter (cheap Grizzly model), DOC .005, feed should be 16" per minute but was hand fed and probably less than that say 8" per minute.

I am not real happy with the setup. It moved at one point. It could have used another clamp but had no room. I am trying to think of a different way to hold it but have not had any brilliant ideas yet.

The photo's should be self explanatory. I include a drawing of the design. I made a square corner because I don't have any tooling to make a radius.

[mechanicalmagic]

My question is why am I getting the large burr on the bottom of the tool groove on the exit side.

If you are speaking of the burr in fly..3.JPG, I would say, that's common for 1018 with a used cutter. I assume you are taking a .005" DOC for just the finish pass?

I am not real happy with the setup. It moved at one point. It could have used another clamp but had no room. I am trying to think of a different way to hold it but have not had any brilliant ideas yet.

If I was doing that job, I would use two "V" blocks in a Kurt vise, with a wrap of 1/16" soft Aluminum around the flycutter shank. Set the angle by eye or protractor.

Dave J.

[davec43]

Thanks Dave, I was talking about the burr in #3. There's not a lot of material choices in our small town.

The .005 DOC was what I did for all the passes with the 5/16 end mill, partly because of the setup, partly worried about flexing the small endmill. I like the two V-blocks in the vise better. It was easier to do the 15* this way but that's not a critical dimension.

The outside cut I used a 1/2" end mill and a DOC of .010.

[Bolsterman]

Is it possible your cutter is on the dull side?

Secondly, does the burr matter much, once you file it off?

[davec43]

The burr does not matter as you say. It matters if it is a result of improper technique or procedures. If that's as good as it gets with 1018, that's fine.

The endmill has seen little or no use, so should be sharp, but it's not an expensive endmill.

[LivingLegend]

Burrs are common with 1018.... especially if the cutter is getting on the dull side.

This is why they make deburring tools/knives and Cratex.

LL

[CarlD]

Your going to get burrs when you cut on any metal. Don't worry about them, just clean them off when done.

The only thing I see wrong is using the rotary table for the setup. As said before, you should use a vise and one or two V blocks. One would work but you still can't take a heavy cut even in a vise.

[seal killer]

Dave--

I have some of those Grizzly 4-flute, TiN coated end mills. They were the first ones I ever bought a couple years ago when I first began learning about milling.

Today, I have a BUNCH of American end mills both old and new. However, those Grizzly TiN end mills are still in my box and I still use them. Let me be the first to say that I have never really pushed one . . . maybe THAT is why they are still nice and sharp!

Additionally, just from a glance at your first picture, I wonder why you are using such a long end mill. A shorter one would provide more rigidity.

--Bill

[LivingLegend]

....I wonder why you are using such a long end mill. A shorter one would provide more rigidity.....l

Bill:

Nothing wrong with the end mill length being used.

Looks to be a around a 1/2" mill. Normal flute length would be around 1-1/4.

LL

[seal killer]

LL--

Got'cha.

My habit has been to use the shortest end mill that will do the job. It SEEMS to work, but then a longer one may have worked just as well.

Thanks.

--Bill

[LivingLegend]

Bill:

The shorter the flute length the less deflection.

Once upon a time, many years ago, I had to use a 1/4" cutter that had a flute length of almost 2".... And I only needed around 3/8" from the tip of the cutter to make the cut needed.

The reason for using such a long cutter? I had cut a groove in the bottom of a small pocket. It was the only way to get down to depth needed to cut the groove. Material was 8620 steel.

Had to take more than a couple of finish passes due to the cutter spring.


LL

[seal killer]

LL--

I understand. It was one of the first lessons I learned. Of course, I had to learn it the hard way.

Since then, I try to use the shortest end mill possible . . . until I get into that inevitable situation you so aptly described. However, I have no experience with a long end mill when working steel, as aluminum (and now, I suppose, bronze) are my primary materials.

I have a little experience with short end mills and 4140 and 1018. The 1018 cut like butter compared to the 4140.

--Bill