Fly cutter

[dennisa49]

I have been reading up on design and operation of fly cutters.
One cutting tool, either HSS or carbide.
Also have read where single fluted slot drills reduce vibration and chatter when compared to two or four flutes.
Does it follow that an insert tipped face milling cutter would function better as
an end mill (similar to a fly cutter action) with only one tip, when normally fitted with two?
Any thoughts please, I live in a small complex where a lot of noise is an undesirable consequence. The tipped cutter can be noisy when cutting steel.
Regards,
Dennis

 

[Wizard69]

I have been reading up on design and operation of fly cutters.

One cutting tool, either HSS or carbide.

Fly cutters can be very useful in delivering fine finishes once you learn to sharpen the cutter correctly.

Also have read where single fluted slot drills reduce vibration and chatter when compared to two or four flutes.

Does it follow that an insert tipped face milling cutter would function better as

an end mill (similar to a fly cutter action) with only one tip, when normally fitted with two?

A shell mill can give a surface finish matching a fly cutter if a single insert is used. Now functioning better is more subjective as the whole point of a shell mill with many cutting edges is eliminated if you pull all but one cutter from the head. So functioning better really comes down to expectation and frankly mill horse power.

Any thoughts please, I live in a small complex where a lot of noise is an undesirable consequence. The tipped cutter can be noisy when cutting steel.

Regards,

Dennis

Build a full enclosure. An enclosure designed to contain cutting noise has other positives including chip and cutting fluid containment. Such enclosures are often associated with CNC machines which I'm not sure you are into. However even a partial enclosure can do a lot for noise abatement. Further a single flute cutter might actually make a more disturbing noise that a multi flute cutter.

If noise abatement is a primary concern I'd do some experimenting. My guess is that the noise from smaller multi flute cutters running at higher spindle speeds would be easier to control than a fly cutter. Also drive train noise can be a big problem, one reason people go the belt drive route is to reduce machine noise that comes from gears in the drive train.

I guess what I'm saying is that if noise is a concern you need to look at the whole picture. No matter what you do there will be some noise generated. This means that you will need to contain it in some manner.

 

[Blogwitch]

From what I have found over the years and from a mentor who has long gone, the ideal shape for a flycutter tool is a largish round nose (quarter of a full circle).
I have found that because the round nose feeds in gently from the side and not reaching full depth cut until it is fully onto the job, mine are fairly quiet compared to the normal sharp pointed ones.
I always used to grind the round nose tool using an off hand grinder, but now, after seeing great results from a profile cutter on my lathe for many years, I have started to use them in my flycutters, and they give the same great results, deep cuts and mirror finishes.
The advantage of these is that once one area on the circumference of the tip gets worn, the tip can be rotated a little to give a new cutting edge. When it is dull all round, it still isn't done with, I rub the top face over a diamond lap and flatten them off, then the tips can be used for flycutting brass and other materials that don't require a top rake. This method is used for both the lathe cutters and the flycutters.

John

 

[goldstar31]

John gives good advice. However, I'm not into the carbide era and still use his suggestions about using hss or even gauge plate.
This reminds me because I still have tools- made from hss- which sweep face fastened to a face or even a catchplate and bolt my work on the saddle.

Clearly old fashioned but in the absence of a mill, that is where many quite competent model engineers did things.

Am I wrong? Well both Sparey and Westbury made their engines this way.

Thanks for the memory, John. Hopefully it might help as well.

Norman

 

[ShopShoe]

Blogwitch,

I have seen the tools you show before and I have been wondering about their performance on small, low-powered machines like mine.

I have experimented with some indexable tooling, but I put in more time working to fine-tune my HSS tool-grinding skills. (I can say that REALLY learning to grind tools to match the job is an incredibly productive exercise.) That said, I also like to experiment with other types of cutting tools just to make sure I keep an open mind.

I would say that I probably agree with some of the posters who have posted in-depth about indexable tooling and who also make sure that they generally are referring to larger machines, like 12-inch-swing lathes and bridgeport-sized mills. Viewing YouTube videos made by some of the well-known U.S. posters generally show very clean work with carbide indexables, but used on larger machines.

Bringing this post home, I have experimented with different tip radii on my machines on aluminum and have developed a feel for what works best for me, including with my flycutter, but I have also found that sometimes I just don't have enough horsepower to get the performance I would like.

--

Unrelated Add-On:

Regarding noise, I would think something that might be considered is whether one has conductive transmission. Is the machine isolated from its table or stand and is the stand isolated from transmitting noise through the floor or wall. The well-known industrial suppliers have isolating mounting pads, Insulating foot pads, all kinds of isolating materials in pads, grommets, etc.

--ShopShoe

 

[mcostello]

Light cuts might take longer but will be much quiter.

 

[Blogwitch]

Shop shoe,

I have to admit to having a smaller Bridgeport clone now, an 836, but even so, I have been using curved edge tooling in a flycutter for well over 30 years, mainly HSS that I ground up myself, and these were used on a small RF mill, not known for their power or rigidity, and I was obtaining mirror finishes even then.

I started to use the round tipped profile tools on my lathe most probably 6 or 7 years ago, maybe a little more, and noticed they gave super results. It didn't click for a long time about trying to use them with a flycutter until one day I tried it, and I got the same results on the mill as I did with the lathe. It was then I set my flycutter system up with three different sized toolholders, all using the same tip.

With my large mill, I have no trouble cutting to a depth of 2mm in non ferrous, half that in ferrous in one go. So in your case, I would expect them to take a cut of 0.5mm (20 thou) without any problems.
I do have a slowmo vid of a HSS tool in action, taking a rather deep cut, and if you look at the reflections as the tool comes over the job, you can see the mirror finish it leaves behind, the second half is a lot slower and shows the finish much better. I took this vid to see how the shape of the tool cut the material.

[ame]https://www.youtube.com/watch?v=FipAdIUr5OE[/ame]

John

 

[ShopShoe]

Thanks John

--Shopshoe