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drmico60
02-08-2011, 10:06 AM
There do not seem to have been many developments in flycutter design over the years and I thought that this unconventional approach might be of interest to others.
It uses a tangential tool mounting and this seems to be advantageous in allowing a much greater depth of cut and a better surface finish.
There are more details here:
http://mikesworkshop.weebly.com/tangential-tool-flycutter.html
I would appreciate any comments especially with regard to why tangential tools seem to allow a much greater depth of cut than radial tooling.
Mike

DICKEYBIRD
02-08-2011, 12:49 PM
That's a great tool Mike; wish I'd thunk of it!:D

I made a tangential tool that works great in my lathe so I can see how it'd work very well for a flycutter. Clever idea on the stop screw as well.

Cheers,
Milton

ps: Great website too!

dneufell
02-08-2011, 12:49 PM
Mike! Very nice website......Thank you.....Dean

Pherdie
02-08-2011, 01:17 PM
Nice tool, Mike, and a good detailed drawing too.

Also, fine job on the website. I particularly liked the mod on your 4X6 bandsaw for swarf control, very clever!

Stu
02-08-2011, 01:56 PM
Nice, well thought out design there Mike. How did the tip of the cutter do with the interrupted cut on your test piece?

Stu

Alistair Hosie
02-08-2011, 03:43 PM
Man that was worth watching well done for sharing.Alistair

rohart
02-08-2011, 09:24 PM
Well, I'm not convinced that the geometry of the flycutter is anything to do with it. In my opinion the ability of this cutter to do a lot of work is down to the general heavy build of the tool.

I built a flycutter of roughly the same proportions, but the cutter bits are parallel to the axis. I used it in my lathe - having no mill at the time. The cutter would stop my (small) lathe dead if the cuts were too deep. No chatter - just very smooth work if the DOC and the feedrate were small enough for the lathe to keep going.

Paul Alciatore
02-09-2011, 03:45 AM
Interesting fly cutter and very interesting web site.

drmico60
02-09-2011, 09:23 AM
Nice, well thought out design there Mike. How did the tip of the cutter do with the interrupted cut on your test piece?

Stu

The tangential tool tip showed no sign of damage in any of the tests I have made despite the interrupted nature of the cut. I think part of the reason is that the tool tip is better supported when used in the tangential mode. The tool tip shown in the photo on my website had in fact been used for many tests.
Mike

DFMiller
02-09-2011, 10:52 AM
Mike,
Interesting idea. I imagine the large mass sure helps make it work so well.
I really enjoyed your website. I like the tap holder chuck.
Thanks
Dave

rmuell01
02-09-2011, 12:45 PM
real good idea that I will copy.

Nice documentation on your web site. I'd really like to see larger versions of your .jpg's as clickables.:o

Rob

Forrest Addy
02-09-2011, 01:27 PM
Nice variation but instead of that clunky screw I would clamp the tool with a wedge pulled in with a screw from the top. Also the angle on the plate makes a sweep likely run over accumulations of chips and mash them into the freshly cut surface.

Heavier cut? How heavy a cut could you expect using a fly cutter with a skinny shank - especially when held in an R8 spindle? I'm guessing 0.020 DOC about 0.005" feed per rev. Running 80 ft min for mild steel and sweeping a 2" radius that's about 76 RPM x 0.005" = about 3/8 IPM.

Nope. Nice tool design, well executed, but not a game changer. It is a flycutter and fly cutters are not productive. You use them as a last resort when multi-tooth cutters are not available in the right diameter or unsuitable for some reason.

rmuell01
02-09-2011, 02:40 PM
Nope. Nice tool design, well executed, but not a game changer. It is a flycutter and fly cutters are not productive. You use them as a last resort when multi-tooth cutters are not available in the right diameter or unsuitable for some reason.

A fly cutter seems to be a better tool for me with my 8520 clausing. a multi-tooth cutter might be to heavy for my light mill.

Rob

Forrest Addy
02-09-2011, 09:51 PM
A fly cutter seems to be a better tool for me with my 8520 clausing. a multi-tooth cutter might be to heavy for my light mill.

Rob

Which is where "...unsuitable for some reason" is intended to apply.

Bill Pace
02-09-2011, 10:03 PM
To each his own, I guess - I LOVE a fly cutter and the almost mirror finish I can get.

Mike Burdick
02-09-2011, 10:38 PM
Mike,

That's a GREAT idea! One of the main concerns of the home shop machinist is to find relative inexpensive tooling to accomplish their projects. You did that!

Too bad you didn't write this up for HMS. Thanks for sharing and I'm definitely going to include it in my tool collection!

drmico60
02-10-2011, 08:30 AM
Nice variation but instead of that clunky screw I would clamp the tool with a wedge pulled in with a screw from the top. Also the angle on the plate makes a sweep likely run over accumulations of chips and mash them into the freshly cut surface.

Heavier cut? How heavy a cut could you expect using a fly cutter with a skinny shank - especially when held in an R8 spindle? I'm guessing 0.020 DOC about 0.005" feed per rev. Running 80 ft min for mild steel and sweeping a 2" radius that's about 76 RPM x 0.005" = about 3/8 IPM.

Nope. Nice tool design, well executed, but not a game changer. It is a flycutter and fly cutters are not productive. You use them as a last resort when multi-tooth cutters are not available in the right diameter or unsuitable for some reason.

I like the elegant suggestion to use a wedge to clamp the tool.

With regard to depth of cut what you say is perfectly true in a production environment. I am only a hobbyist with a small X1 mill driven by a 150W motor. With a conventional flycutter I was limited to cuts of circa 0.1mm. With the tangential tool flycutter I can take cuts of 0.4mm. To me that is a 4 fold increase in productivity.

What intrigues me is why tangential tooling, in both the lathe and now on the mill, permits heavier cuts to be taken than is possible with conventional radial tooling.

Mike

lbhsbz
02-10-2011, 12:21 PM
I think it's the weight, and therefor rigidity of the setup that makes the most difference. The china store bought ones are too small to deal with anything I think. Here's a 5" unit I whipped up to resurface an intake manifold....uses 3/8 lathe bits, and the bit is a light interference fit into the body, also have 2 s
1/4-28 set screws to secure the bit. I was amazed at the improvement i'n performance and finish. I plan on cutting it for 3 more tools, so I'll have 4 total....like a face mill.

http://img.photobucket.com/albums/v201/machschnelGTI/0f62e00c.jpg


Only changes to next will be to press/weld in the shank, instead of machining it down from the stock diameter.

rohart
02-10-2011, 06:01 PM
Yes, come on. This sounds like magic, of which there isn't any.

If the set up is heavy and rigid, the angle of the root of the bit can have no effect. By definition, the cutting edge is being held rigidly.

If it's not rigid enough, it's not rigid enough.

Seems quite straightforward to me. Make a heavy rigid flycutter, with short tool bits mounted in holes parallel to the axis, and ground to sensible cutter profiles. Locking screws, or cotters, as long as they're substantial. Best is to force the tool bit against the bore in the same direction the cutting forces will take it. Don't let the cutting forces push the tool against the clamp.

The heavier the flycutter, the less substantial the shank needs to be. The inertia of the heavy tool will take care of the shock loading.

DICKEYBIRD
02-10-2011, 07:57 PM
Yabbut ya'll detractors of the tangential cutter need to make one and use it a while on your lathe. Can't speak for the flycutter 'cuz I haven't made one yet.

I can't argue the technical aspects of the actual chip flow & cut dynamics but: (A) They do cut very well, perhaps only because it's so easy to get a truly sharp cutting edge and (B) Because it's so easy to get a truly sharp cutting edge....over & over again.:) Far easier than trying to maintain all the correct angles on a conventionally ground tool. I dread stopping during a project to do a major re-sharpen on a standard tool but a major regrind & hone job on a tangential bit takes maybe 2 minutes tops.

drmico60
04-13-2011, 08:17 AM
I have added a short note to my web page on tangential tool flycutter, regarding the design aspects, see:
http://mikesworkshop.weebly.com/tangential-tool-flycutter.html
I hope this helps anyone thinking of making one.
Mike