Flywheel Fly Cutter for a Mini Mill Concept

[courierdog]

I am looking at the building a Flywheel based - Fly Cutter.
A few basic criteria are essential.

1. I want to use a common HSS Square tool Bit.
2. Use a standard R8 FMB22 arbor which fits the majority of Mini Mills

Using the Tangential Concept.
The Bit will extend out of the bottom of the flywheel
Angled centre to the out side by 12 degrees
Angled bottom to top by 12 degrees
I want to clamp the square tool bit using a split piece similar to the method used by the Diamond Tool Holder.
I have discussed this with Gary Sneesby of Eccentric Engineering, at length.
Gary suggested I start with what he has used in the past.
Gary’s idea is to use the Diamond Tool Holder in a secondary Jig and form the Fly cutter in that matter.
While the concept does work.
I feel the design has a lot of excess momentum whirling around waiting to fly off and seriously incurs someone.
A Mill is as another wise person has already stated a machine tool looking to cause great bodily harm.


I would like to find someone who can draw what I have in my head (I have ZERO CAD experience )
With proper drawings I may be able to construct a flywheel with the tool bit mounted using part of the flywheel cut and milled to hold the tool in place.
The final assembly can be then turned on a lathe to minimize the Momentum of the assembly.
To finally balance the flywheel holes can be drilled to compensate for the one side off balance.
It will only be a reasonable balance as the tool bit will wear causing loss of material.


If the design can be drawn out correctly my idea is some amateurs may be more willing to attempt the building of it.
Most commercial Fly Cutters I have used do not inspire me with confidence for an amateur Machinist to use.
The big advantage of the Tangential cutter especially for the beginner is he/she only has to learn one simple jig supported sharpening (grinding) process.
With the Diamond Tool holder covering almost 90% of normal beginning lathe work
Coupled with a Flywheel based Diamond Tool Holder for the Mill the initial work with a mill can begun simply and I believe provide a safer work environment for the beginner.
This allow a new amateur machinist to actually make and use a tool that will be simple to maintain allowing them to have confidence in their abilities such as simple sharpening and straight forward lathe turnings and the beginning of facing with the mill.


I hope you can grasp what I am attempting to get across.
If Not I am will to discuss at length the concept further.
If anyone who has CAD abilities and who is willing to work with me I would very much appreciate it.


Thanks for Listening.


The following are the photos Gary Sneesby of Eccentric Engineering sent to me.
The purpose is to illustrate the Tangential Flywheel Fly Cutter concept.
I would like drawing (CAD) assistance to create a stand alone Flywheel Fly Cutter.
As the majority of Mini Mills used by Amateur Machinists I suggest an R8 Arbor as the Mill Holding Tool insert.
An R8 FMB22 as an example as the tool holder for the Flywheel


Gary Sneesby has a professional grade Mill as he is a Machinist by trade.
There are however many mounting that can be used and my concept is to use something most Amateur Machinist can obtain or have in their tool box that will work on their machine.
The other reason for using the R8 based Mill mounting tool is with one screw the Flywheel can be separated from the mounting and only the Flywheel needs to stored when not in use.

1/4 inch Square HSS or Crobalt tool bits are a simple and basic tool bit every machine shop should have.


#1


#2


#3


#4


#5

[NortonDommi]

I wasn't aware that Gary had built this. I have had the bit move slightly on heavy interrupted cuts on the lathe though. The large mass would make for a smooth cut due to inertia and kinetic energy. Mass is good.

[courierdog]

You are a lot closer (Physically) to Gary than I am in Edmonton.
I bought my first Diamond Tool Holder from Bay Comm, per the recommendation of Rudy Kouhoupt. Since I have purchased a matching set and another one so I have qty 2 sets. I also have the FoR tool. I am struggling with the Acute Sharpening System. Living in Canada is officially Metric, but purchasing real metric machine tools like Tapping Drills and Reamers is a but challenging.
Gary and I have had several discussions on the Tangential Fly Cutter, as a matching tool for the DTH. As a Starting point, for newbies.
Having a tool which can be used with simplicity of sharpening and maintenance. will increase the confidence in the new comer.
So I am looking for someone to assist me to put the project to Paper as it were (CAD) so construction can begin.

[greenie]

Before you even start on the fly cutter, find out if the hi/low gears in the head of the mini-mill are plastic, if they are plastic, you will soon mash them with a fly cutter and need to change them, don't bother asking how I know.

If the gears are plastic, you just better go buy the ally ones and replace the plastic crap, then once you've done that, then you can start to think about making a fly cutter for your mini-mill. :-)

[courierdog]

My Mill is the Little Machine Shop HiTorque 3960 High Torque Mini Mill no plastic gears in this machine.

[NortonDommi]

i bought some Eccentric Engineering tangential cutters years ago. Gary sent the order but the bank hadn't processed the payment and I got a 'phone call about two weeks after receiving them! Really nice guy. I use the tangential tools for the majority of external work and have found that sharpening against a cup wheel is better than the periphery of a standard wheel.
The couple of times the bit has moved I was admittedly taxing hard.
We have been officially metrickery here since 1969 and although getting some things in Imperial is getting harder tooling and steel is available in both Metric and Imperial everywhere but big shed stores and lumber stores.
I can recommend https://www.voelkel-shop.com/en/voelkel.html for taps. I am in love with their serial taps. I can buy locally or get them within a week over the interweb. Worth looking at if you have trouble finding what you want.

[CanBeDone]

If anyone who has CAD abilities and who is willing to work with me I would very much appreciate it.

The tangential cutter is an excellent idea, and I intend to build myself one once I have figured out how to overcome its inherent flaw: the toolbit is held by a single screw, and whenever I tried a single screw to hold my toolbit, whatever its design, the bit slipped during use, messing up my setup, and I ruined my work piece. Not again.
If you still want to go that route, your easiest way to do that is to get hold of a screw of appropriate size and turn its shaft into a R8 mandril, and give its head a slot to hold your existing tangential tool holder, so that it looks somewhat close to this:

and as a 2D drawing

Since the toolbit is not vertical to its axis of rotation, the risk of slipping out of its slot is much reduced, and the four screws holding the 6mm bit hold it much firmer than a single screw ever could. The dimensions on my drawing refer to my own machine. With its MT4 taper and 1.5 kW motor, it is somewhat stronger and bigger than yours, but otherwise very much the same design. When I built this flycutter many years ago, I wasn't aware of the tangential cutter, and thus its cutting edge is of the conventional design, with two faces to be ground.

When I bought my milling machine, it came with a face mill using four brazed carbide cutters - easy to replace and easy to sharpen, Just as I like it. But it is still two faces that need sharpening. Over the years I learned how to sharpen them, and how to mount them in the facemill, so that I can obtain an (almost) as-polished surface. It looks like this:

I came also into possession of a large screw, with a head more than 80mm wide. It has been turned down to something close to another facemill, with the head ready to accept 5 cutters. And there it languishes . . .

Clearly, a tangential cutter is not present, yet. What needs to be done here is to copy the angles from my attempt at making a less slippery tangential tool onto this facemill and then study the consequences - such as what setup is needed to cut the slots at the proper angles. So if you can keep me motivated . . .
From your side, I need to know what operating system you use so that we can exchange 3D files, what the maximum diameter is you care to use (i.e. how much torque does your machine produce?) And if you want a as-polished surface, your rpm's cannot be at the bottom of the range, i.e. your flycutter is size limited by the power (and stiffness!) of your machine, and your setup.

[courierdog]

Thanks everyone for the inspiring suggestions.
Let me start again.
the purpose of this exercise is to present the tool bit to the work piece in the exact same orientation and manner as the Diamond Tool Holder holds and presents the tool bit to a rotating piece in a lathe. A rotating tool on the mill in my mental view, or proposed view, is a static view of the instant of contact. My Purpose for this approach is Simply to enable a newbie to start work using his lathe and his Mill with HSS Tool bits which can be resharpened simply and as often as required by a newbie with the aid of the. same jig as used to sharpen the tool bit as used in the Diamond Tool Holder.
This simplified tool bit profile and its cutting ability enable a simple approach to this Hobby of Machining with a minimal investment in equipment, tooling and enables again the newbie to sharpen and maintain the cutting tooling as required.
The Tangential Tool as used in the Diamond Tool Holder uses the entire end of the tool bit rather than a side or an edge of the tool bit.
It is this concept I want to recreate as a basic cutting tool holder specifically for the Mill.
My base machine is a modest Little Machine Shop High Torque 3960 Mini Mill which is a custom SEIG X2 mini mill.
It has a solid, rigid Column.
I have in my past in our lab used the expensive Lathes and Mills. Since Retiring I now own a Mini Lathe LMS 3560 and a LMS 3960 Mini Mill.
So I live on a fixed income, where cost is a real concern.
I want to avoid Carbide Tooling that initially is cheap but you have to repeatedly purchase new inserts, Like the proverbial Gillette Razor the company makes the real money on selling the replacement blades.
A standard 1/4 inch HSS tool bit costs a nominal $7 for a piece 2.5 inch long. This will last a long time if used in the Tangential cutting mode such as the Diamond Tool Holder.
With your assistance my hope is we can bring a similar tool to the Milling side of the house.
What I require is someone who has access to CAD and is willing to lend his assistance to craft a set of drawings from which the concept can become a real possibility.
Thanks for your understanding and patience with an old man and his dreams.

[CanBeDone]

Thanks everyone for the inspiring suggestions.
Let me start again.
the purpose of this exercise is to present the tool bit to the work piece in the exact same orientation and manner as the Diamond Tool Holder holds and presents the tool bit to a rotating piece in a lathe. A rotating tool on the mill in my mental view, or proposed view, is a static view of the instant of contact. My Purpose for this approach is Simply to enable a newbie to start work using his lathe and his Mill with HSS Tool bits which can be resharpened simply and as often as required by a newbie with the aid of the. same jig as used to sharpen the tool bit as used in the Diamond Tool Holder.
This simplified tool bit profile and its cutting ability enable a simple approach to this Hobby of Machining with a minimal investment in equipment, tooling and enables again the newbie to sharpen and maintain the cutting tooling as required.
The Tangential Tool as used in the Diamond Tool Holder uses the entire end of the tool bit rather than a side or an edge of the tool bit.
It is this concept I want to recreate as a basic cutting tool holder specifically for the Mill.
My base machine is a modest Little Machine Shop High Torque 3960 Mini Mill which is a custom SEIG X2 mini mill.
It has a solid, rigid Column.
I have in my past in our lab used the expensive Lathes and Mills. Since Retiring I now own a Mini Lathe LMS 3560 and a LMS 3960 Mini Mill.
So I live on a fixed income, where cost is a real concern.
I want to avoid Carbide Tooling that initially is cheap but you have to repeatedly purchase new inserts, Like the proverbial Gillette Razor the company makes the real money on selling the replacement blades.
A standard 1/4 inch HSS tool bit costs a nominal $7 for a piece 2.5 inch long. This will last a long time if used in the Tangential cutting mode such as the Diamond Tool Holder.
With your assistance my hope is we can bring a similar tool to the Milling side of the house.
What I require is someone who has access to CAD and is willing to lend his assistance to craft a set of drawings from which the concept can become a real possibility.
Thanks for your understanding and patience with an old man and his dreams.

Exactly, that is the goal. Yours, and mine too.
Now, let's talk about the path to get there. I have sketched in my previous post two possible paths that can be taken.
The easy way out, and that is why I mentioned it first, is to give Gary's toolholder a rotating base, along the lines Gary himself has suggested. Since my ZAY7045FG is stronger than your High Torque 3960, Gary's suggestion would not work for me at all, as the holding power of a single bolt is not good enough for my cutting forces. Thus, I am not particularly interested in taking this route. I have shown my version of a flycutter going this route just to show that by changing some angles, the risk of the toolbit escaping from the tool holder can be reduced, making the whole tool safer to use at high rpm's. And high rpm's is, I have learned through long experience, the sine qua non of producing a near mirror finish surface on my mill.
On the other hand, if you are willing to build jigs to enable milling at other angles than just 90 degrees, you can discard Gary's toolholder, and its inherent weaknesses, but still keep his toolbit, its sharpening jig, etc. In other words, you keep the advantages that a tangential tool has, while ditching Gary's toolholder, and the holding power limitations it has. This is the second route I have suggested in my previous post. It is also the route I prefer to take.
I have already built about half of the jigs needed, and have a good idea of what else I'll need to build to complete the job. This means I am at the right junction where someone else's input can only improve the overall package, and that is where you, courierdog, come in, with your concerns about manufacturability and cost.
The limiting factor for doing it on this website is that I do not know how to make a 3D drawing readable in three dimensions on this website, the upload of an stl file failed. File Size limitations? No facilities to display stl files? gif might be another format capable of handling three dimensions on a two dimension screen. Does anybody know of software to convert stl into gif that runs on linux?
Unless this communication obstacle can be removed, we will have to leave this website and communicate via e-mail.

[courierdog]

I copied the screen image to my reply. Is this what I am looking at.
CanBeDone: I used FreeCAD to open your STI file. Please explain what I am looking at. as I am at absolute ZERO on learning any CAD system. I do not know how to rotate the drawing to see what I may be looking at.
However that in it self is a start. Thanks