# Pm727m  and face milling



## Brad125 (Jun 12, 2020)

Hey fellas, i am in the market for a face mill for just squaring up parts. I am so lost on what "style" of face mill would be the best for this type of machine? Any suggestions? I want to stay economical, preferbly under 100$ right now.


----------



## GunsOfNavarone (Jun 12, 2020)

I have the same machine, I'm guessing that doesn't have much bearing other than staying under 2"? I have thought about it as well, but I read such horror stories with cheap import FACE MILLS. Interested in people chiming in here with their experiences...


----------



## DavidR8 (Jun 12, 2020)

There was a longish thread a while back on this subject... I'll see if I can find it.


----------



## Brad125 (Jun 12, 2020)

Yea i was looking into 2" face mills... but there is so many different ones. Being there is some flex in these machines, i wanted to see if anyone else tried one and what results they had.


----------



## jaek (Jun 12, 2020)

I have the G2861 and it's "ok". The surface finish isn't great but it works fine for squaring stuff up on my PM-727V. The Glacern 45 degree indexable mills look nice and from what I've read they should work better for facing (although not for cutting to a shoulder), but I haven't pulled the trigger yet. They also cost twice as much, so YMMV.


----------



## Brad125 (Jun 12, 2020)

I was looking at thoes g2861's. Seem to get good reviews, but i dont care for that style of insert. Of course, the inserts are cheap enough though.


----------



## mikey (Jun 12, 2020)

Is a fly cutter out of the question? It can square parts with the best of them and can even do stock reduction if you aren't in a major rush. Typically cheaper since it uses only one insert and no worries about getting multiple inserts aligned.


----------



## Brad125 (Jun 12, 2020)

No i dont like fly cutters, unless they would have an indexable cutter. But, thoes ones are outta my budget.


----------



## mikey (Jun 12, 2020)

If an inserted carbide flycutter is out of the budget then a decent face mill with multiple inserts will definitely be out of the budget.


----------



## Brad125 (Jun 12, 2020)

Sorry, but where did you find a carbide fly cutter. Id like to look at it. The only ones i found were expensive.


----------



## mikey (Jun 12, 2020)

I use the Tormach Superfly and a little Sherline single insert fly cutter (basically a 1-1/8" dia. single insert face mill) and both work well. There is also the B-52 flycutter and the Suburban Tools fly cutter. All will provide good finishes and all can do a surprising amount of stock reduction. Have a look.


----------



## Brad125 (Jun 12, 2020)

Thanks miley i will


----------



## Brad125 (Jun 12, 2020)

Mikey, the only one of thoes you mentioned ( the sherline single flute) is in my price range. I love the tormach flycutter but its just to much, especially of my occasional use of the thing.


----------



## Aukai (Jun 12, 2020)

If you have it you will use it, you will wish you had it if you need it.


----------



## Brad125 (Jun 12, 2020)

Exactly, i need alot of things lol. The interupted cuts of the sherline single flute cutter has me worried if it will make my Z axis walk down?


----------



## mikey (Jun 12, 2020)

Brad125 said:


> Mikey, the only one of thoes you mentioned ( the sherline single flute) is in my price range. I love the tormach flycutter but its just to much, especially of my occasional use of the thing.



Almost everything we do on the mill starts out as rough stock and has to be squared. There are essentially three ways to do this: fly cut it, face mill it or end mill it. Of these, you will find that a fly cutter, over the long term, will be the cheapest and in many cases, produces a better finish. 

Consider also that the Superfly can cut a 6" wide piece of work. Not many fly cutters can do this in one go, and in aluminum it can take at least a 0.070" deep cut and produce a decent finish while doing that 6" piece. Not too bad for what I consider a cheap tool. 

The Sherline flycutter will produce a superb finish if you have the speed. I haven't had any issues with Z-axis movement while using it. It, too, can hog off a surprising amount of material for a tool of this size. In addition, it can cut to a square shoulder so you can produce a ledge (the Superfly cannot do this). Of all the carbide fly cutters I have used, the Sherline flycutter produces the best finish. The main downside to it is its small size; it only cuts a 1-1/8" wide swath so you have to make multiple passes on larger parts but it will cut and finish quite well. I actually use it a lot more on my RF-31 than I do on the Sherline mill and if you must have a fly cutter on a budget and can accept its limited cutting width then this tool is not a bad choice.


----------



## Brad125 (Jun 12, 2020)

I am loving that tormach super fly? Ugh.... so much for a face mill. You guys are killing me.... how does it preform in steel? Vibrate like heck?


----------



## mikey (Jun 12, 2020)

Re the Superfly, if your speeds are good it cuts well and doesn't vibrate much. I do have a decent spindle, though.


----------



## Brad125 (Jun 12, 2020)

I have 1700or 1750 rpm max, is this enough rmp to utilize the super fly cutter?


----------



## mikey (Jun 12, 2020)

For steel, sure. Should do okay with aluminum, although the finish is better with more speed.


----------



## shooter123456 (Jun 12, 2020)

I tried one of those $25 ebay face mills from China and it is about what you would expect.  Does it work?  Yea sorta.  Does it work well? Ehhhhhhh.  It will remove material, but there is no way the inserts are at the same height.  The finish is fine, but you can clearly see it wobbling.  I wouldn't recommend, but for a $25 face mill, I am happy it makes a cut without exploding.  This is the only picture I can find of the one I got, but I would recommend a fly cutter as well.  A good face mill will be a bit more.


----------



## WobblyHand (Jun 12, 2020)

mikey said:


> The Sherline flycutter will produce a superb finish if you have the speed. I haven't had any issues with Z-axis movement while using it. It, too, can hog off a surprising amount of material for a tool of this size. In addition, it can cut to a square shoulder so you can produce a ledge (the Superfly cannot do this). Of all the carbide fly cutters I have used, the Sherline flycutter produces the best finish. The main downside to it is its small size; it only cuts a 1-1/8" wide swath so you have to make multiple passes on larger parts but it will cut and finish quite well. I actually use it a lot more on my RF-31 than I do on the Sherline mill and if you must have a fly cutter on a budget and can accept its limited cutting width then this tool is not a bad choice.


Is this the flycutter you are talking about?  https://www.sherline.com/product/7620-single-flute-insert-fly-cutter/


----------



## Brad125 (Jun 12, 2020)

WobblyHand said:


> Is this the flycutter you are talking about?  https://www.sherline.com/product/7620-single-flute-insert-fly-cutter/


Yes i think thats the o e he is talking about... atleast thats what came up when i researched it....


----------



## mikey (Jun 12, 2020)

I would suggest this one if you decide to try one. It has a straight shank that will go into a collet. The original Sherline fly cutter has a 1 Morse Taper and you would need an adapter to use it. 

This cutter, when used at high speeds around 2400 - 2800 rpm and with a slow feed, will produce a finish in aluminum that will be a near mirror finish; not quite, but amazingly good for a roughing cut! It has cut all machinable materials I've used it on with zero issues. There are a few tools that Sherline makes that are outstanding - this is one of them.


----------



## Brad125 (Jun 12, 2020)

mikey said:


> I would suggest this one if you decide to try one. It has a straight shank that will go into a collet. The original Sherline fly cutter has a 1 Morse Taper and you would need an adapter to use it.
> 
> This cutter, when used at high speeds around 2400 - 2800 rpm and with a slow feed, will produce a finish in aluminum that will be a near mirror finish; not quite, but amazingly good for a roughing cut! It has cut all machinable materials I've used it on with zero issues. There are a few tools that Sherline makes that are outstanding - this is one of them.



Yea thats the thing, my mill only goes to 1750rpm... i dont know how well it would work.


----------



## Brad125 (Jun 12, 2020)

And only having 1 cutter, im afraid its gunna beat the heck outta my spindle or hurt the r8 taper?


----------



## mikey (Jun 12, 2020)

Brad125 said:


> And only having 1 cutter, im afraid its gunna beat the heck outta my spindle or hurt the r8 taper?



No, it won't hurt the machine. Your machine is rated to take a 1" end mill or a 3" face mill. A little Sherline flycutter won't stress your 500# machine much at all. I take deep cuts with this tool on my little Sherline mill with no issues and my entire mill probably weighs less than the vise on your machine. I also use it on an RF-31 and it cuts extremely well, albeit in small bites. 

I don't only flycut with the Sherline tool. I use it like a single-flute face mill so it will do stock reduction and cut to shoulders. I often use it on steel and stainless steel for roughing and edge profiling because it will do what an end mill will do and outlast an end mill by a long shot. 

The inserts last a long time, at least in my hands. On aluminum, I can go the better part of a year before I have to index the cutter. In steel, the inserts don't last as long but I still get a lot of mileage out of them. I like this tool, a lot.


----------



## Brad125 (Jun 12, 2020)

So with the sherline tool, i can use it like and end mill also? Like run it along the out edge of a part to clean it up?


----------



## Brad125 (Jun 13, 2020)

Another question mikey, what size is the shank on the sherline fly cutter? Its just says straight shank, the description says nothing else.


----------



## mikey (Jun 13, 2020)

Brad125 said:


> So with the sherline tool, i can use it like and end mill also? Like run it along the out edge of a part to clean it up?



You can use it like you would use the end of an end mill. Since it has no flutes on the sides, no, you cannot run it on the edge to cut.

The shank of the tool is 1/2" od. It will fit in a 1/2" R8 or ER collet.


----------



## DavidR8 (Jun 13, 2020)

I believe it has a 1/2” shank 


Sent from my iPhone using Tapatalk


----------



## DavidR8 (Jun 13, 2020)

I have one on the way. 


Sent from my iPhone using Tapatalk


----------



## mikey (Jun 13, 2020)

DavidR8 said:


> I have one on the way.
> 
> 
> Sent from my iPhone using Tapatalk




Let us know how you like it, Dave.


----------



## DavidR8 (Jun 13, 2020)

mikey said:


> Let us know how you like it, Dave.



Will do, it’s for my knurler build 


Sent from my iPhone using Tapatalk


----------



## 7milesup (Jun 13, 2020)

Dangnabbit....   Mikey, you know how to spend my money, albeit wisely.  That Tormach Superfly looks awesome and I can now see myself having one.  I watched the NYC CNC video and it is incredible, although it sounds like a shield to contain chips would be in order.


----------



## tjb (Jun 13, 2020)

Mine's on the way, too.  Been itching to spend a little money.

Mike, you always come through!  Thanks.  I guess.

Regards


----------



## Brad125 (Jun 13, 2020)

Im still trying to decide, lol... i seen an Accurize 2" 5 flute face mill and its all one piece. It takes the APKT inserts also.


----------



## mikey (Jun 13, 2020)

7milesup said:


> Dangnabbit....   Mikey, you know how to spend my money, albeit wisely.  That Tormach Superfly looks awesome and I can now see myself having one.  I watched the NYC CNC video and it is incredible, although it sounds like a shield to contain chips would be in order.





tjb said:


> Mine's on the way, too.  Been itching to spend a little money.
> 
> Mike, you always come through!  Thanks.  I guess.
> 
> Regards



Guys, think about it. If you have to square a work piece, do you really want to gnaw away at it with an end mill like PacMan? Why do that when you can cut out to a 6" wide swath in one go and produce a much nicer surface finish that is as accurate as your tram? The Superfly will repay its cost in end mills, time and aggravation, trust me. On the other hand, if you often work with smaller work pieces or need to cut a ledge then the Sherline, being essentially a single insert face mill that costs all of $73.00, is a very good tool to own. 

Personally, I think you should have both flycutters. Come on, you know you want them ...


----------



## DavidR8 (Jun 13, 2020)

mikey said:


> Guys, think about it. If you have to square a work piece, do you really want to gnaw away at it with an end mill like PacMan? Why do that when you can cut out to a 6" wide swath in one go and produce a much nicer surface finish that is as accurate as your tram? The Superfly will repay its cost in end mills, time and aggravation, trust me. On the other hand, if you often work with smaller work pieces or need to cut a ledge then the Sherline, being essentially a single insert face mill that costs all of $73.00, is a very good tool to own.
> 
> Personally, I think you should have both flycutters. Come on, you know you want them ...



Don’t let me a bad influence but mine is on its way 


Sent from my iPhone using Tapatalk


----------



## parshal (Jun 13, 2020)

I bought this Accusize 3" a few months ago to surface a 12"x12" aluminum plate on my 833TV.  I've been pretty darned impressed although I've not tried some of the other, better, tools mentioned in this thread.


----------



## tjb (Jun 13, 2020)

mikey said:


> Guys, think about it. If you have to square a work piece, do you really want to gnaw away at it with an end mill like PacMan? Why do that when you can cut out to a 6" wide swath in one go and produce a much nicer surface finish that is as accurate as your tram? The Superfly will repay its cost in end mills, time and aggravation, trust me. On the other hand, if you often work with smaller work pieces or need to cut a ledge then the Sherline, being essentially a single insert face mill that costs all of $73.00, is a very good tool to own.
> 
> Personally, I think you should have both flycutters. Come on, you know you want them ...


Got some bad news, Mike.  I'm not going to be able to spend any money on a Superfly.  At least not until my homemade fly cutter breaks.  Here are some shots of one I made several months ago:







It has a 3/4" shank and can cut up to about 6".  I usually keep it set at about 4".  The set screw on the top allows me to adjust the angle of the cutting tip.  (That seemed like a nice feature to have, but I've never used it.  I set it once and never changed it.)  It cuts extremely well.  I've been bailing wheat straw all day and am worn out, but tomorrow I'll go down to the shop and post a picture of a piece of cold-rolled I recently faced with it.  It does a great job, so for at least the time being, I won't be in the market for a Superfly.  Sorry.

Call me crazy, but something tells me you'll come up with something else I can't live without.  Hurry up!  The suspense is killing me.

Regards,
Terry


----------



## springer (Jun 13, 2020)

Another vote for the tormach superfly. I used mine on my pm932 in both aluminum and steel. Superb finish on anything inside with it. I have a larger mill I'm rebuilding right now and contemplated getting a big ole face mill and talked myself out of it until the superfly let's me down.


----------



## Brad125 (Jun 13, 2020)

What about using these tools for the guys that dont have power feed, like me? Any suggestions?


----------



## mikey (Jun 13, 2020)

tjb said:


> Got some bad news, Mike.  I'm not going to be able to spend any money on a Superfly.  At least not until my homemade fly cutter breaks.  Here are some shots of one I made several months ago:
> 
> View attachment 327580
> View attachment 327581
> ...



That looks like an SCLCL tool holder, Terry. If so, then the insert geometry should cut okay when the tool is horizontal. If you alter the angle of the tool then it will cut with the nose radius and that will adversely affect the finish unless you really slow down your feed. In contrast, the Superfly's insert has a broad contact area with a positive rake geometry that is presented at a fixed but presumably optimal tool angle. Not sure how it compares to an SCLCL tool, though. 

As long as you have some kind of tool for surfacing accurately then that's what counts. As you say, I will get you some other way!


----------



## mikey (Jun 13, 2020)

Brad125 said:


> What about using these tools for the guys that dont have power feed, like me? Any suggestions?



Feed manually. Inserts like to take a bite and be moved along and you'll have to sort out what that feed rate is by looking at the chip and the finish being produced. I feed manually on my Sherline and can produce a finish that is very, very nice.


----------



## tjb (Jun 14, 2020)

mikey said:


> That looks like an SCLCL tool holder, Terry. If so, then the insert geometry should cut okay when the tool is horizontal. If you alter the angle of the tool then it will cut with the nose radius and that will adversely affect the finish unless you really slow down your feed. In contrast, the Superfly's insert has a broad contact area with a positive rake geometry that is presented at a fixed but presumably optimal tool angle. Not sure how it compares to an SCLCL tool, though.
> 
> As long as you have some kind of tool for surfacing accurately then that's what counts. As you say, I will get you some other way!


Okay, Mike.  You've prompted a question or two that might be beneficial to myself and others who might need an education on the features and use of fly cutters.  You are correct that it is an SCLCL tool holder with which I am using the following CCMT and CCGT inserts:



Here is a picture of the fly cutter, inserts and a piece of cold-rolled that I squared using the fly cutter:



Here are close-ups of the squared metal:




This block was an end piece that I played around with after making the following carriage stop:






All flat surfaces on the carriage stop were made using the same fly cutter.

Here's my question and the issue I have with using the fly cutter.  You will notice the 'profile' swirls on the squared piece that follow the contour of the arc on the fly cutter.  No surprise.  (Those marks were also on the carriage stop pieces, but I sanded those down, except for the contact surfaces.)  However, I have noticed that when I mill the piece from left to right, I get the exact pattern you see in the photos.  But if I mill from right to left, the leading edge looks the same but mirror image, plus the trailing edge has a very slight 'shadow' effect.  That is, the trailing edge IN THAT DIRECTION seems to be milling an additional microscopic amount on the piece - I'm guessing 1 or 2 tenths at the most.  My knee jerk has been that my spindle is ever so slightly out of tram.  I've even frightened myself into wondering if I'm putting too much torque on my spindle by using the fly cutter.  I've accommodated that by only doing final cuts in the left to right direction.  But your recommendation on the Tormach Superfly prompted me to do some investigating.  I watched some youtube videos on the Superfly and was somewhat surprised to see the same 'shadow' result - even on Tormach's own video.  None of the videos I saw commented on the observation, but it is very apparent when watching the videos.  Is this normal?  It makes sense to me that the wider the cutting area the more likely slight tramming would become apparent.  Right/wrong?

Would you think I could get better results if I removed my set screw so the holder would be flat?  I am milling something in the neighborhood of 4" at 800 - 1,000 RPM's at very slow feed rates.  Based on observations on this thread it seems to me I should be stepping up the RPM's perhaps significantly.  (Agree/disagree?)  Any other advice or observations?

All you other experts, chime in if you like.

Regards,
Terry


----------



## mikey (Jun 14, 2020)

I've also experienced the swirl or lack of a smooth mirror-like surface with fly cutters and have pondered why this is. In my mind, the answer is multifactorial, and since this is coming from MY mind it is naturally suspect. However, this is what I think.

Fly cutting is not a finishing process. The intent is to obtain a truly flat and accurate surface, which fly cutting does quite well. If you want a finely finished surface, buy a surface grinder or go at it by hand.
Tool geometry matters because like all machining processes, fly cutting produces cutting forces. Accordingly, we have to use the right insert in the right way. You are using a turning tool and twirling it around, which that insert was not designed to do. Does it work? Of course it does, but are the right edges or surfaces making contact so that the insert works as it should? This is why I suggested that angling your SCLCL tool might not be a good idea because you are then cutting with the nose radius and that greatly increases radial cutting forces and may produce unpredictable or suboptimal results. In contrast, the Superfly has a fixed geometry; you cannot alter the angle of the tool and the angle puts the insert at the desired geometry. The insert is commonly used in face mills so it is optimized to cut with the surface of the insert that makes contact with the work. The insert is a high positive rake insert that I think is intended to reduce tangential cutting forces, which is one reason why the Superfly works well on low HP mills. Bottom line on this is that the tool designers of the Superfly knew what they were doing. Even when taking deep cuts, the Superfly works. On light cuts, the user has to understand that there is a minimal effective cut and that is typically going to be the nose radius plus about a 0.005" or so. Too light a cut and the insert will deflect and you have chatter.
Tram is always an issue. I would guess that most mills are trammed well enough to function quite well but when fly cutting we are looking at the effect of minute amounts of tram being off. We're talking in the sub-thou range of off. So why does the pattern seem to change when we feed from different directions? I think this is the effect of climb vs conventional milling, and going in a climb direction will typically produce a better finish. I see this effect with my Superfly on my RF-31. I see less of an impact on my Sherline with the Sherline flycutter because that mill is trammed within an inch of its life but I still try to take finish cuts in a climb direction when finish matters.
Then there are centripetal forces and how they interact with cutting forces. This one is complicated and I still haven't figured out how to visualize how they interact. In my research, I haven't found anything to suggest anyone else knows, either. This is an important topic because it also applies to boring on the mill. I can bore and I can fly cut but do I honestly understand how the cutting forces are interacting? Nope, I don't. The reason this matters is because I think the finishes could be greatly improved with fly cutting if we could get a handle on this. Someday I hope to understand it, or at least hear it from someone who is a lot smarter than me.
A final note on why I think the Sherline fly cutter is an outstanding tool. As mentioned, it is essentially a singe insert tiny face mill. The insert is fixed and mounted in a solid chuck of steel. The insert is not hanging out there at the end of a flexing arm like the typical fly cutter is. Centripetal forces are there but they are minimal. Accordingly, you can take relatively huge cuts with this tool and it will cut well. Because the geometry is fixed and is so solidly supported, the finish is much better with this tool as opposed to more conventionally designed fly cutters. It will put a finish on aluminum that will frost your eyeballs, at least with the unaided eye. Under magnification, you will still see the radial marks of a typical insert but they are much finer than with most inserts. I may seem to make a big deal about this little Sherline tool but I have over 30 years of experience with it and have come to understand why and how it works. Sherline found a way to orient the insert so that it cuts well with one edge oriented vertically (so it can cut to a shoulder); it cuts with the side edge primarily and with light cuts, with the nose radius. However, since the nose radius is very nearly in line with the spindle and it has a mass of steel behind it, deflection is pretty well controlled and that allows a Sherline fly cutter to take lighter cuts and still be fairly accurate when doing so. 

Sherline finally woke up and made this tool with a straight shank. This allows us to hold it in a collet instead of a MT1 adapter. This is such a good idea that I'm sure it will sell much better as more people discover this tool. I used mine in a adapter and it worked well but of course, it never dawned on me to just turn the stupid shank down so it didn't have a taper ... Duh! Still, turning it down would have resulted in a much reduced shank diameter so I just decided to buy one with a straight 1/2" shank and will now be happy.

Okay, I'm sure I'll have other thoughts but off the top of my head, this is what I think.


----------



## Brad125 (Jun 14, 2020)

Does the sherline tool have a positive rake?


----------



## mikey (Jun 14, 2020)

No, the tool does not position the insert with positive rake. It uses CPMW 32.51 inserts that are commonly available. These inserts are typically flat on top with no chipbreaker. Like all inserted carbide fly cutters, this one needs some speed to work well. In steel, it will probably need to run at the top speed your mill can run at and will take a 0.015" deep cut to begin with. The 32.51 insert has a 0.016" nose radius so this minimal depth of cut is equal to the nose radius; it will cut better with a 0.020" deep cut. In aluminum, 0.020" depth of cut would be the ideal minimum cut at max speed.

EDIT: I should add that a 0.016" nose radius is already a big nose radius so going bigger in an attempt to achieve a better finish will work but it will also contribute to higher radial cutting forces so deflection will increase. You may not see this deflection in chatter but you will see it in the finish. I would stay with a 32.51 insert if you go with this tool. Also, at minimum, you can take a 0.008" deep cut. Going less may or may not work well. I've gone down to 0.004" deep cuts and got away with it but inserts don't like it when you cut too shallow due to large increases in radial cutting forces. Stay at about 0.008 - 0.010" minimum for finishing cuts and you'll probably be okay.


----------



## Buffalo21 (Jun 14, 2020)

I have one of the Grizzly G2861, while not a terrible face mill, it’s not a great one either. IMO the TPG inserts can work fine in a lathe, but marginal milling insert, they are weak, due to the 7 degree side angle, they chip very easily, are/can be reportedly rough on spindle bearings and finally surface finish can be quite poor. They are hardly text box on set up, very slight changes to speeds and feeds can change finish quality greatly. On mine the tool build quality is excellent, if it only worked as good as it looks.


----------



## Brad125 (Jun 14, 2020)

What about the shars 2" 75degree indexable facemill? Has a 15 degree lead angle? I am having a hard time figuring out if this will put more axial load or radial load on the SPINDLE....????


----------



## jwmelvin (Jun 14, 2020)

I have some single-insert end mills that use a TPG. Like buffalo21 says, they seem a little high impact on the machine. Why is the Sherline approach better? I know the inserts are different but they seem similar in the lack of positive rake.


----------



## jwmelvin (Jun 14, 2020)

Also. What about using one of these generic face mills with just a single insert, to avoid any issue of height variation between inserts?


----------



## tjb (Jun 14, 2020)

mikey said:


> I've also experienced the swirl or lack of a smooth mirror-like surface with fly cutters and have pondered why this is. In my mind, the answer is multifactorial, and since this is coming from MY mind it is naturally suspect. However, this is what I think.
> 
> Fly cutting is not a finishing process. The intent is to obtain a truly flat and accurate surface, which fly cutting does quite well. If you want a finely finished surface, buy a surface grinder or go at it by hand.
> Tool geometry matters because like all machining processes, fly cutting produces cutting forces. Accordingly, we have to use the right insert in the right way. You are using a turning tool and twirling it around, which that insert was not designed to do. Does it work? Of course it does, but are the right edges or surfaces making contact so that the insert works as it should? This is why I suggested that angling your SCLCL tool might not be a good idea because you are then cutting with the nose radius and that greatly increases radial cutting forces and may produce unpredictable or suboptimal results. In contrast, the Superfly has a fixed geometry; you cannot alter the angle of the tool and the angle puts the insert at the desired geometry. The insert is commonly used in face mills so it is optimized to cut with the surface of the insert that makes contact with the work. The insert is a high positive rake insert that I think is intended to reduce tangential cutting forces, which is one reason why the Superfly works well on low HP mills. Bottom line on this is that the tool designers of the Superfly knew what they were doing. Even when taking deep cuts, the Superfly works. On light cuts, the user has to understand that there is a minimal effective cut and that is typically going to be the nose radius plus about a 0.005" or so. Too light a cut and the insert will deflect and you have chatter.
> ...


Okay, thanks Mike.  Typically thorough response I hoped I'd hear from you.  I'll need to study your response in detail, but tonight my brain is just toast.  It's almost 9:00 PM my time, and I just got in from helping a friend RE-bale about a thousand bales of wheat straw that were bailed incorrectly - AND we were trying to beat a rain storm.  (What a job, but we won!)  I'll need to sleep on this, but I fully appreciate your superior knowledge on this subject.

Your first comment about fly cutting hits home with why I'm interested in picking your brain:  "_Fly cutting is not a finishing process. The intent is to obtain a truly flat and accurate surface, which fly cutting does quite well_..."  That observation removes quite a bit of uncertainty on my part.  I am, indeed, getting a flat surface (that's a good thing); and apparently, the finish that I'm getting is fairly consistent with results on the videos I've seen (that, too, is a good thing).  I need to study the rest of your response tomorrow.  There's a very good chance that you may yet convince me to fork over the dough and get a Superfly.  But not tonight.  See how easy it is to tempt neophytes to spend their money?

Regards, and thanks for your typically thorough response.  I'd be willing to bet I'm not the only reader who gets an education from your answer.

Regards,
Terry


----------



## mikey (Jun 14, 2020)

jwmelvin said:


> I have some single-insert end mills that use a TPG. Like buffalo21 says, they seem a little high impact on the machine. Why is the Sherline approach better? I know the inserts are different but they seem similar in the lack of positive rake.



I don't know if it is better. For all I know, it isn't. I just found this tool listed on MSC. 3" fly cutter with an R8 shank that uses TPG inserts. It is essentially a single insert face mill.


----------



## Aukai (Jun 14, 2020)

You guy's are late to the party, look Mikey's been here.


----------



## Aukai (Jun 15, 2020)

I have this insert, and a silver insert which is for what, it's not noted on the ziploc?


----------



## mikey (Jun 15, 2020)

The goldish one is for steels, the silver is for aluminum.


----------



## devils4ever (Jun 15, 2020)

Okay, mikey. You have me convinced to go for the Superfly cutter. 

I have the MicroMark HSS steel flycutter, but I haven't been happy with it. I can't get a good finish and I can only take baby cuts. It takes me forever to square up and dimension stock. I probably have the cutter ground incorrectly, but I feel I'll never be able to take decent DOC and feed rates with it. 

So, the Superfly will be okay on my PM25?


----------



## mikey (Jun 15, 2020)

I think it will work fine. This fly cutter is intended for use on low HP mills. I recall they tested it on the Tormach 440 model and it kicked butt. My RF-31 currently has only a 1HP Baldor motor on it and it can really hog off material. Granted, the Tormach is a 600# machine and mine is close to that so I'm not sure how a 300# mill will handle it but it cuts with so little force that I really think it should work fine for you ... I think. I know @higgite has one but I cannot recall which mill he has. Maybe he'll give us an opinion. 

Give it a try and let us know how it works out for you.


----------



## higgite (Jun 15, 2020)

Yeah, Mike tricked me into buying a Tormach Superfly before I knew that his mission in life, like mine, is to ruthlessly spend other people’s money. We have that common bond. Try it, it’s a blast.

But, to the topic at hand. I have an LMS 5500 (Sieg SX2.7) bench mill that weighs in at ~220 lbs. The Superfly works like a champ on it. When I first got it, I tested it to .035” DOC in 6061 and I’ve gone deeper with it since then but can’t quote the numbers offhand. When unleashed in all its glory, it will throw chips to the far end of the county in rapid succession. And leave a very good finish while doing it.

For the full story of Mike’s devious ploy to spend my money, see this thread.








						Tormach Superfly Cutter On 1hp Machine?
					

I only got one response for this question in the Tormach CNC subforum, so I'll try again here.  Tormach touts the Superfly as being ideal for machines under 3HP, but I don't see where they say how much under 3HP. My LMS manual bench mill (basically a SIEG SX2.7) has a 750 watt (1 HP) brushless...




					www.hobby-machinist.com
				




Bottom line is… buy one. You need it. It’s science. 

Tom


----------



## devils4ever (Jun 15, 2020)

Okay, if it's science, then I need to buy it! 

How about the inserts? Tormach sells them in units of 10 which may last me a lifetime. Plus, they're not cheap! A set of each costs more the the tool!

So, it's  SEHT1204AFFN-X83 for Aluminum and  SEHT1204AFSN-X45 for steel? Where can I get these at better prices that won't take months to get?


----------



## parshal (Jun 15, 2020)

So, which one is "better"?  The Tormach or Sherline?  I can't buy both just to see for myself!


----------



## higgite (Jun 15, 2020)

devils4ever said:


> Okay, if it's science, then I need to buy it!
> 
> How about the inserts? Tormach sells them in units of 10 which may last me a lifetime. Plus, they're not cheap! A set of each costs more the the tool!
> 
> So, it's  SEHT1204AFFN-X83 for Aluminum and  SEHT1204AFSN-X45 for steel? Where can I get these at better prices that won't take months to get?


I haven’t needed to buy any more inserts yet. The Superfly kit comes with 2 general purpose inserts and 2 polished inserts for aluminum. That’s 8 general purpose (a.k.a. steel) cutting edges and 8 aluminum cutting edges.

Tom


----------



## devils4ever (Jun 15, 2020)

Oh, I guess I misread their website. I thought they only gave you one of each. 

Did you buy directly from them?


----------



## higgite (Jun 15, 2020)

I need to correct myself. I bought my Superfly from LMS in 2016 for $118 and inserts were extra, not included.

Currently, LMS lists it the same way, no inserts, but for the same price as Tormach, but Tormach includes 4 inserts. LMS may have just not updated their description. They usually sell Tormach stuff at Tormach's list price. but I’d call to make sure they include inserts before I would buy it from them. The Tormach kit, directly from Tormach, says it includes 4 inserts.
“The TTS SuperFly Cutter includes: fly cutter body, tool bar, two general purpose carbide inserts, two polished carbide inserts for aluminum machining, insert Screw, wrench and anti-seize.”








						TTS™ SuperFly Cutter Kit
					

The TTS™ SuperFly Cutter includes: fly cutter body, tool bar, two general purpose carbide inserts, two polished carbide inserts for aluminum machining, insert Screw, wrench and anti-seize.




					tormach.com
				




Tom


----------



## devils4ever (Jun 15, 2020)

Yeah, I noticed the same thing. LMS doesn't include the inserts.

I'll just order directly from Tormach.

EDIT: grammar


----------



## mikey (Jun 15, 2020)

devils4ever said:


> Okay, if it's science, then I need to buy it!
> 
> How about the inserts? Tormach sells them in units of 10 which may last me a lifetime. Plus, they're not cheap! A set of each costs more the the tool!
> 
> So, it's  SEHT1204AFFN-X83 for Aluminum and  SEHT1204AFSN-X45 for steel? Where can I get these at better prices that won't take months to get?



I would buy the inserts on ebay. Buy one of each in boxes of 10 and in most hobby shops, that should last you the rest of your life.


----------



## mikey (Jun 15, 2020)

parshal said:


> So, which one is "better"?  The Tormach or Sherline?  I can't buy both just to see for myself!



Without knowing your machine and needs its hard to say but for most hobby shops I think the Superfly or similar fly cutter is the best choice. It will allow you to quickly surface and flatten a work piece up to 6" per pass and larger in multiple passes, and smaller work pieces just as well. You can bring a work piece close to dimensions with this tool too because it can hog off material, trust me. For smaller mills like most hobbyists own the Superfly is a good choice because it cuts with such low HP requirements and it will give you are pretty decent finish. For all these reasons, I think the Superfly or similar fly cutter is a good all around choice. Insert life is actually quite good; I've been using this fly cutter for several years now and am still on the same inserts I started with. Given that almost every work piece I've made since I bought it was squared with this thing, that's not a bad track record. 

I think the Sherline tool is a good choice for those of us who need a small tool that can cut ledges. This is an important capability in my opinion. It is also good for when you are squaring smaller work pieces and you don't need a big fly cutter whirling around. I choose it when I need to square a work piece that is an inch or two wide. The inserts have only two usable tips but they last quite a while in a hobby shop. The same insert will cut steels and aluminum, brass, plastic and can last for years when working with soft stuff. It will take a 0.05" deep cut in steel on a Sherline mill; it will go much deeper on a bigger mill. 

These tools are not the only ones out there and many folks make their own. I use these because they use inserts that have a good service life and they perform well for me.


----------



## parshal (Jun 15, 2020)

I've got an 833TV.  I ordered the Sherline after reading this thread.  I'm curious about it.  I've got the larger "fly cutter" I posted earlier in this this thread along with a smaller version.  Both of those will seriously remove some material.

The Superfly looks pretty interesting.  I may have to try that one, too.


----------



## mikey (Jun 15, 2020)

I have to correct something. The Superfly has a cutting diameter of 3", not 6". Not sure why my brain got stuck on 6".


----------



## Aukai (Jun 15, 2020)

TMB?


----------



## higgite (Jun 15, 2020)

mikey said:


> I have to correct something. The Superfly has a cutting diameter of 3", not 6". Not sure why my brain got stuck on 6".



I'm glad that wasn't a pop quiz. It slipped right past me.


Aukai said:


> TMB?


If that means what I think it means, that's getting too personal.   

Tom


----------



## Aukai (Jun 15, 2020)

Birthdays, not beers.....


----------



## higgite (Jun 15, 2020)

Aukai said:


> Birthdays, not beers.....


At our, er, Mike's age, that's even more too personal.

Tom


----------



## tjb (Jun 15, 2020)

higgite said:


> At our, er, Mike's age, that's even more too personal.
> 
> Tom


Don't know about Mike, but right about now, I'd rather have a beer than a birthday.


----------



## tjb (Jun 15, 2020)

mikey said:


> Without knowing your machine and needs its hard to say but for most hobby shops I think the Superfly or similar fly cutter is the best choice. It will allow you to quickly surface and flatten a work piece up to 6" per pass and larger in multiple passes, and smaller work pieces just as well. You can bring a work piece close to dimensions with this tool too because it can hog off material, trust me. For smaller mills like most hobbyists own the Superfly is a good choice because it cuts with such low HP requirements and it will give you are pretty decent finish. For all these reasons, I think the Superfly or similar fly cutter is a good all around choice. Insert life is actually quite good; I've been using this fly cutter for several years now and am still on the same inserts I started with. Given that almost every work piece I've made since I bought it was squared with this thing, that's not a bad track record.
> 
> I think the Sherline tool is a good choice for those of us who need a small tool that can cut ledges. This is an important capability in my opinion. It is also good for when you are squaring smaller work pieces and you don't need a big fly cutter whirling around. I choose it when I need to square a work piece that is an inch or two wide. The inserts have only two usable tips but they last quite a while in a hobby shop. The same insert will cut steels and aluminum, brass, plastic and can last for years when working with soft stuff. It will take a 0.05" deep cut in steel on a Sherline mill; it will go much deeper on a bigger mill.
> 
> These tools are not the only ones out there and many folks make their own. I use these because they use inserts that have a good service life and they perform well for me.


My Superfly is on the way.  Mike, you won.


----------



## mikey (Jun 15, 2020)

higgite said:


> At our, er, Mike's age, that's even more too personal.



What can I say, I are old.

I started shooting my recurve bow again recently and found that even my muscle memory has Alzheimer's!

The fact of the matter is that I'm often rushing to post here nowadays. I'll post something, then run off and do something that I'm usually late for, then come back and do it again or post between appointments. My brain is on overload. That's my story and I'm sticking to it.


----------



## mikey (Jun 15, 2020)

tjb said:


> Don't know about Mike, but right about now, I'd rather have a beer than a birthday.



I'll take the birthday ... not sure how many I have left!



tjb said:


> My Superfly is on the way.  Mike, you won.



I wasn't trying to, Terry, honest ...


----------



## tjb (Jun 15, 2020)

mikey said:


> I'll take the birthday ... not sure how many I have left!
> 
> 
> 
> I wasn't trying to, Terry, honest ...


So you can manage even when you're 'not trying'?  The mark of a true genius.


----------



## tjb (Jun 15, 2020)

mikey said:


> I'll take the birthday ... not sure how many I have left!


You can have both, if you want them.  Not sure how many of EITHER we have left.


----------



## Buffalo21 (Jun 15, 2020)

The daily double, your birthday and a beer.....


----------



## Rifleman1384 (Jun 15, 2020)

OK,  I just can't help it but with all this SuperFly business it's reminding me of early days turning wrenches at the Cadillac Dealership and the SuperFly Caddy back in the day.


----------



## devils4ever (Jun 23, 2020)

I got my *Superfly *in a few days ago and I had a chance to try it out. I needed to flatten a piece of 1018 steel about 0.9" wide by 9" long. It was cut off a much bigger piece and it had a slight bow in it with the ends higher than the middle. I clamped it in my Kurt 4" vise and took some shallow cuts about 0.003" deep. I was getting all kinds of chatter at the ends with a wave pattern generated that was both visual and physical. I was ready to start cursing it. But, I pushed ahead and kept cutting deeper until I got to the section that was clamped firmly in the vise. It was like a mirror. I realized that the ends of the bar were unsupported and causing the issue. So, I added a machinist jack at each end and tried again. It was awesome. Beautiful finish.

I'm still trying to learn feeds and speeds on this. I tried from about 600 RPMs to 1000 RPMs and feeds of 5 to 8 IPM. I want to try deeper cuts too. The deepest I tried was 0.005" So, what speeds, feeds, DOC, etc. would be appropriate for 1018 steel less than an inch wide?


----------



## tjb (Jun 23, 2020)

devils4ever said:


> I got my *Superfly *in a few days ago and I had a chance to try it out. I needed to flatten a piece of 1018 steel about 0.9" wide by 9" long. It was cut off a much bigger piece and it had a slight bow in it with the ends higher than the middle. I clamped it in my Kurt 4" vise and took some shallow cuts about 0.003" deep. I was getting all kinds of chatter at the ends with a wave pattern generated that was both visual and physical. I was ready to start cursing it. But, I pushed ahead and kept cutting deeper until I got to the section that was clamped firmly in the vise. It was like a mirror. I realized that the ends of the bar were unsupported and causing the issue. So, I added a machinist jack at each end and tried again. It was awesome. Beautiful finish.
> 
> I'm still trying to learn feeds and speeds on this. I tried from about 600 RPMs to 1000 RPMs and feeds of 5 to 8 IPM. I want to try deeper cuts too. The deepest I tried was 0.005" So, what speeds, feeds, DOC, etc. would be appropriate for 1018 steel less than an inch wide?
> 
> ...


Ditto!  Mine came in over the weekend, and I got a chance to play with it with a 4" wide piece of aluminum.  Photos don't do the finish justice.  I need to do a lot more experimenting with feeds and speeds, but I already know I love this tool!  MASTER MIKEY STRIKES AGAIN!!!!

Regards,
Terry


----------



## parshal (Jun 23, 2020)

I got the Sherline Fly Cutter and need to do a similar test to post, too!


----------



## Skowinski (Jun 23, 2020)

I haven't even broken down and ordered my PM mill yet, and already I see that I need a fly cutter.  Sheesh....


----------



## mikey (Jun 23, 2020)

devils4ever said:


> I'm still trying to learn feeds and speeds on this. I tried from about 600 RPMs to 1000 RPMs and feeds of 5 to 8 IPM. I want to try deeper cuts too. The deepest I tried was 0.005" So, what speeds, feeds, DOC, etc. would be appropriate for 1018 steel less than an inch wide?



Speeds are dependent on the material. Each material class will have a recommended cutting speed that is used to calculate RPM and the same calculation can be used to find a starting speed, whether you're turning or using a milling cutter like your fly cutter. There are tables for cutting speeds, given in SFM (surface feet per minute) all over the net and in reference texts. LMS has a popular one.

Find the material you are working with and look up the cutting speed for the tool you're using. For 1018 being cut with a carbide tool, CS is about 800 sfm. Now plug that CS into the formula: *RPM = CS X 3.82 / Diameter*, where CS is your cutting speed from the table, 3.82 is a constant and Diameter is the diameter of the cutter on the mill or the work piece on the lathe. In your case, the minimum diameter of your Superfly is 1.5" or so. Plugging in the values, RPM = 800 X 3.82 / 1.5 = 2,037 rpm. This same cut in aluminum would max out the speed of your mill. 

Note also that as the extension of your tool increases, the diameter increases and the speeds will accordingly slow down a bit.

As we know, carbide needs speed so you'll be running pretty fast. Note also that these speeds you calculate are estimates or a starting point; they are not written in stone. Try that speed and go up or down as your results dictate. If you get chatter, slow down. If you need a better finish, speed up. 

Feeds vary but carbide likes to cut a chip so don't dawdle with carbide. The tool should be constantly producing a chip. If the finish is too grainy, slow down. 

Note that speeds and feeds vary with depth of cut. The deeper you go, the slower your speeds and feeds need to be. You need to play with it but the Superfly and the Sherline fly cutter can seriously hog material. You need to set a depth of cut and speed and then see how fast you can feed to get the results and finish you need. Over time, you will learn how to adjust to the cut, which is the mark of skill.

Hope this helps. If it is not clear, sing out.


----------



## mikey (Jun 23, 2020)

I should add that a fly cutter is a relatively BIG cutter and when used properly, it is taking a big chip and slinging it out. This constitutes a significant danger to your eyes so be sure to wear safety glasses and keep your mouth closed! The Superfly in particular can throw a shower of chips a good distance and most of us who own this tool eventually make some kind of enclosure to reduce the mess. 

Along with chips will be your cutting oil/fluid. It can get messy but more importantly, it can get into your eyes. Safety first!

The other thing to note is that fly cutters will produce the best finish when climb cutting but results may depend on how deep you cut and the rigidity of your mill. Best idea is to rough in the conventional direction and finish in the climb direction; works well for me.


----------



## wrmiller (Jun 23, 2020)

mikey said:


> I should add that a fly cutter is a relatively BIG cutter and when used properly, it is taking a big chip and slinging it out. This constitutes a significant danger to your eyes so be sure to wear safety glasses and keep your mouth closed! The Superfly in particular can throw a shower of chips a good distance and most of us who own this tool eventually make some kind of enclosure to reduce the mess.
> 
> Along with chips will be your cutting oil/fluid. It can get messy but more importantly, it can get into your eyes. Safety first!
> 
> The other thing to note is that fly cutters will produce the best finish when climb cutting but results may depend on how deep you cut and the rigidity of your mill. Best idea is to rough in the conventional direction and finish in the climb direction; works well for me.



Ha! You should see the chips this thing can throw!


----------



## devils4ever (Jun 24, 2020)

mikey said:


> Speeds are dependent on the material. Each material class will have a recommended cutting speed that is used to calculate RPM and the same calculation can be used to find a starting speed, whether you're turning or using a milling cutter like your fly cutter. There are tables for cutting speeds, given in SFM (surface feet per minute) all over the net and in reference texts. LMS has a popular one.
> 
> Find the material you are working with and look up the cutting speed for the tool you're using. For 1018 being cut with a carbide tool, CS is about 800 sfm. Now plug that CS into the formula: *RPM = CS X 3.82 / Diameter*, where CS is your cutting speed from the table, 3.82 is a constant and Diameter is the diameter of the cutter on the mill or the work piece on the lathe. In your case, the minimum diameter of your Superfly is 1.5" or so. Plugging in the values, RPM = 800 X 3.82 / 1.5 = 2,037 rpm. This same cut in aluminum would max out the speed of your mill.



Thanks, mikey. The LMS table is a little confusing since it shows 800-885 FPM for lathe work for 1018 and 65-110 FPM for milling 1018. Unless I'm reading the tables wrong. Why would it be different?

Looking in my 25th edition Machinery's Handbook at "Table 11. Recommended Cutting Feeds and Speeds for Milling Plain Carbon and Alloy Steels", for 1018 steel, I see 800-1050 FPM (Opt.) for coated carbide end milling. That matches your value. Feed is 0.007"/tooth (Opt.). 

So, for calculating the feed rate: *fm = ft X number teeth X RPM* = 0.007"/tooth X 1 tooth X 2,037 RPM = 14.3 IPM. That seems a little high.


----------



## mikey (Jun 24, 2020)

Yeah, you're right. I looked at the numbers for turning, not milling, so sorry for the confusion but you get the idea of how the table and formula is used, right?

I should tell you that at this stage of the game, you should do the calculations and set the feeds and speeds but you have to keep in mind that the cutting speeds in the chart are for a depth of cut of 0.040" deep. If you cut less than that then your speed and feed can increase a little; if you cut deeper then you should slow down. There are no hard and fast numbers here. Start with the calculations but learn to respond to the cut.

The other thing you will find with inserted carbide fly cutters is that the insert needs adequate feed to cut well. Quite often, the response to a swirled finish is to slow down the feed but what usually happens is that you produce fine overlapping lines in the finish instead. This is because the insert is not being fed fast enough. Look at the width of the insert tip and you'll see that it is quite broad. In order to produce a clean finish, the Superfly needs enough feed rate to keep that tip cutting with minimal overlap. Try varying your speed and you'll see what I mean.

Remember also that all inserts require adequate depths of cut in order to reduce deflection from radial forces. On my mill, the Superfly insert cuts well at about 0.010" deep at a minimum. If I go shallower then finishes can be affected so I have to plan for this and make sure I have enough stock to allow adequate depths of cut.

My point is that calculations are only one part of the puzzle. They are not written in stone and with practice you will learn to respond to what the tool produces. Start with numbers but understand how the tool works so you can respond to what you see it produce and change things if the results are not what you want.


----------



## Brad125 (Jun 24, 2020)

Well i went againt reccomendations and bought a Accusize 1.250 "indexable endmill".  Only rhing i had laying around was a 3" piece of aluminum. I used the inserts that came with it designed for steel and it worked pretty good. Ill have to get the proper inserts for the cutter soon. There is a few swirl marks on it for what ever reason, but it pretty smooth. What do you guys think?


----------



## mikey (Jun 24, 2020)

Brad, if your tool gets it flat and accurate and you're happy with it then that is what matters. I suspect the tool can work better, though. I suggest a bit more depth of cut, speed and also see if you can increase feed a little bit. Use some WD-40 to lube it and see what happens.


----------



## Brad125 (Jun 24, 2020)

Mikey, i did use wd40, worked well. I only took a .005 cut because that piece of aluminum is for a project of mine. Id rather been closer to .030 depth of cut. But, i agree i think a deeper cut and the proper inserts would make a difference.


----------



## mikey (Jun 24, 2020)

Determine what the nose radius is on the inserts, then take a depth of cut at least a few thou deeper as a depth of cut and it will cut much cleaner and more accurately. It should also throw a shower of chips in a steady flow as you feed; get the feed right and the finish will clean right up. It always takes some time to get used to a new tool but congrats - you're on your way!


----------



## higgite (Jun 25, 2020)

Brad125 said:


> Well i went againt reccomendations and bought a Accusize 1.250 "indexable endmill".......


Brad,
I bought the same Accusize 1.25” indexable end mill back in early May and am very happy with it. It leaves what I would call a good finish on mild steel and a very good finish on 6061. I'm still playing around with feeds and speeds. As you know, it comes with inserts for steel, so I bought some Oscarbide bright finish inserts from Amazon (10 for $45) for use on aluminum and they work well. Mikey is right, deeper cuts will give you a better finish. And, he’s right again (I get tired of saying that. Mike, screw up once in awhile, will ya?) in that it cuts nicely to a 90 degree shoulder which my Superfly won’t do. Enjoy!

Tom


----------



## Brad125 (Jun 25, 2020)

Mikey the rose radius is .019ish , so i knew a .030 would be a good depth of cut, but this project i only had a few thousands to take off. I will get a piece of steel and try again eventually.


----------

