# Face milling with a small mill.



## Ken from ontario

For the past 2 days I have been using the search function  here  on what tools to use for face milling Aluminum and mild steel, especially when the milling machine the tool goes onto, is a mini mill.
I found out a few important points and now I'll bring them up and ask you guys to please correct me in my findings :
1= with a 1/2 HP mill, It is best to use a smaller size indexable face mill.
2= the size of the indexable face mill should not be bigger than 1.5" you may get away  with a 2".
3= the best type of inserts for a small mill (which does not have a very ridgid mill head) is, TPG32.
4= the indexable face mill head should have at least 2 inserts but 3 is even easier on the machine, less vibration.
5=If possible,It's best to use a collet than an R8 EM holder , less chance of the tool vibrating .
6= Adjust your feed rate and RPM  to get a chatter free operation.
Am I missing any other important point? how about using compressed air for chip evacuation? or maybe using coolant(spray?),I do have the option to use a fly cutter but find it a bit too slow,overall I'm not comfortable using it but regardless of using that option,I still want to learn which indexable face mill is best for my mill. your comments as usual are important to me and very much appreciated.


----------



## ch2co

Ken,what do you mean by its is a 'Small Mill"?  What brand and model are you using?
I just have a bottom of the barrel  Grizzly 8689 mini mill that came to me used but at no cost when I bought a lathe.
I'm amazed at what I can do with the little thing IF I'm careful and take my time. I do want to move up several levels
at some time for a larger table more headspace more power and greater stability.  For facing I just use what came
with my mill, a fly cutter and have had good results. I do use lubricant when milling steel and just a few sprits
of WD40 at times with aluminum. I don't have a face mill so I don't know if I 'need' one.


----------



## TORQUIN

As far as size goes, first you have to decide if you need the entire face of the work piece to have a seamless cut across it, or if you can stand to have little ridges at the edges of where your smaller cutter was overlapping previous cuts. If you need seamless, you need a bigger cutter. Adjust your speed, feed and depth of cut for this. Your worry will be if you have the rigidity in the machine you are using, but most of the time you can compensate for this with the slower feed and smaller DOC.
While I have a Bridgeport, it is only 1hp, and when I need to face something big I use a big cutter. The biggest I normally use is a 6" with 10 inserts in it. I run it slow with slow feed and small depth of cut. I have had no problems getting a nice, seamless finish on the parts I had to face like this. It has not caused a problem with the mill of the parts.





I have a 10" cutter also, if I ever need to face something that big.

Chris


----------



## Ken from ontario

ch2co said:


> Ken,what do you mean by its is a 'Small Mill"?  What brand and model are you using?
> I just have a bottom of the barrel  Grizzly 8689 mini mill that came to me used but at no cost when I bought a lathe.
> I'm amazed at what I can do with the little thing IF I'm careful and take my time. I do want to move up several levels
> at some time for a larger table more headspace more power and greater stability.  For facing I just use what came
> with my mill, a fly cutter and have had good results. I do use lubricant when milling steel and just a few sprits
> of WD40 at times with aluminum. I don't have a face mill so I don't know if I 'need' one.


Hi CH2co, The mill I have is LMS 3960 mini mill,is has a brushless motor and higher torque than the classic motor , I'm quite happy with it and you're right it can handle quite a bit for it's size.
For facing Aluminum I usually use the largest end mill I have (7/8") but as you can imagine , it get tedious facing a let's say 3"x6" plate with such a small end mill (going back and forth ) , I thought an indexable end mill/ face mill could do that surface in a fraction of the time .
I have not tried my fly cutter with this mini mill yet.


----------



## Ken from ontario

Chris, now that's a nice size cutter. 
you mentioned if I could stand those ridges an end mill would leave,the truth is I can't stand them, and I get plenty of them ridges currently with my the end mill I use.
BTW, I would love to own a Bridgeport even if it came with a single horsepower.


----------



## mikey

I would use a flycutter, Ken. I have a Tormach Superfly and it works okay. I also have a Sherline inserted carbide flycutter that I use on my Sherline mill and my RF-31; it is only a bit over 1" OD so bigger pieces have overlap marks but if the mill is trammed well, they are visible but not palpable. Finish with that single insert is excellent; I get a near mirror finish in aluminum while running at max speed of 2800 rpm. It also cuts to a shoulder so I can make ledges with it. Because it holds only one insert, I don't have issues with getting other inserts to line up. I can take a 0.020" deep cut in steel without slowing the motor down at all. That little Sherline cutter is one of my most useful tools.


----------



## Ken from ontario

Mike, the fly cutter I have comes with 3 bits,2 of them are carbide, one is HSS,I'll give the HSS a try, I just have to grind the cutting edge and get it ready.
I'll let you know how it turns out.
Thanks.


----------



## Bob Korves

An ordinary cheap or shop made fly cutter with a sharp HSS lathe style tool will work beautifully doing light cuts in aluminum or mild steel on a light mill.


----------



## Ken from ontario

I guess I wasn't clear in my original post about what I'm trying to find out , I should not have mentioned  the option of using a fly cutter  since it has nothing to do with what I was asking, I'm sorry for causing the confusion.
Anyhow I figured it out myself and found out the answers to my questions right here on this site.

All I wanted to know was what was the biggest end mill I could use with a small mill, an end mill  bigger than the widest in my set which is a 7/8", I  am limited in choosing the size, can not go too big without sacrificing RPM or feed rate so 1.1/2" is the size I finally picked, I think 1.5" is  somewhere in the middle that I can be comfortable with .what I should have asked in my first post  was your  opinion on these  two types of indexable end mills:








They both are described as (1.1/2") end mills and both are capable of face milling but  which one  demands less torque for face milling? My search lead me to believe that the one on the left  with TPG32 inserts is more suitable for a less powerful mill because it only has 3 points touching the surface(needs less torque to operate)  and also less prone to create vibration than the one on the right with APKT inserts.


If you do have any opinion on these two end mills and don't mind sharing, please do so(I.E.  are they both equally capable of side milling?, or R8 vs straight shank in a collet?)I always enjoy reading about cutting tools in general but also respect your views and base many of my purchases on them .
Thank you all for your help so far.


----------



## T Bredehoft

I found one very similar to the one on the left, uses triangular inserts. Instead of a shank, has an R8 mount. My PM25 handles it nicely in steel and aluminum, I don't have the other to compare with, though, probably never will. I do not use it for side milling. Chuckle, that's what_ end_ mills are for.


----------



## higgite

Hi Ken,

As you probably know, the specs on your mill say 30mm (1.2”) is the max face milling capacity. Of course, that’s going to depend on DOC, feed rate, HP, ad infinitum, but I suggest you give LMS a call and ask to speak with Chris or Brandon. Both are very knowledgable about what their products are capable of doing and are more than willing to help.

I’m keeping an eye on this thread because I have been wondering the same thing as you about which style of face mill is “best” for what applications and if anybody knows, these guys do. I have a Super Fly that Mikey mentioned and it does a great job on my LMS 5500, but a guy can’t have too many tools.

Tom


----------



## Ken from ontario

higgite said:


> Hi Ken,
> 
> As you probably know, the specs on your mill say 30mm (1.2”) is the max face milling capacity. Of course, that’s going to depend on DOC, feed rate, HP, ad infinitum, but I suggest you give LMS a call and ask to speak with Chris or Brandon. Both are very knowledgable about what their products are capable of doing and are more than willing to help.
> 
> I’m keeping an eye on this thread because I have been wondering the same thing as you about which style of face mill is “best” for what applications and if anybody knows, these guys do. I have a Super Fly that Mikey mentioned and it does a great job on my LMS 5500, but a guy can’t have too many tools.
> 
> Tom



Tom,according to the specs I found on the site where I actually bought the mill from, the face mill capacity is 1.3/8"  so I'm going to give that 1.5" a try and see for myself,nothing beats the actual experience with the tool/machine.
Here's copy and paste of my Craftex CX612 specs. which is similar to LMS3960:


SPECIFICATIONS

Motor: 500 Watt, 110-V, 60Hz, Brushless
Drilling Capacity: 5/8" (16mm)
End Mill Capacity: 3/4 (20mm)
Face Mill Capacity: 1-3/8 (35mm)
Spindle Taper: R8
Head Tilt: + - 45°
Number of Spindle Speeds: Variable
Range of Spindle Speeds: 100 RPM - 2500 RPM
Table Size: 15-1/2" (390mm) x 3-5/8" (93mm)
Max. Table Longitudinal Travel: 8-3/4 (220mm)
Max. Table Cross Travel: 4 (100mm)
Maximum Spindle Travel: 7" (180mm)
Number of T-Slots: 3
Net Weight (approx): 50 Kg


----------



## Bob Korves

A mini mill is power limited as well as rigidity limited.  You will have better results if you spin a single cutter.  Multiple cutters multiply the load.  You need all the help you can get when trying for maximum performance.  A sharp tool will need less power than a dull one.  Ditto with a positive rake tool.  A 1" single insert or HSS tool is about all you can comfortably run with any real depth of cut.  Bigger diameters will require correspondingly shallower cuts, again the power and rigidity sets the maximum.  Running at the max possible loads also usually degrades the finish of the work.  Nothing will turn a mini mill into a 50 taper machine.  To paraphrase Dirty Harry "A man has to know his machines' limitations."


----------



## woodchucker

Bob Korves said:


> A mini mill is power limited as well as rigidity limited.  You will have better results if you spin a single cutter.  Multiple cutters multiply the load.  You need all the help you can get when trying for maximum performance.  A sharp tool will need less power than a dull one.  Ditto with a positive rake tool.  A 1" single insert or HSS tool is about all you can comfortably run with any real depth of cut.  Bigger diameters will require correspondingly shallower cuts, again the power and rigidity sets the maximum.  Running at the max possible loads also usually degrades the finish of the work.  Nothing will turn a mini mill into a 50 taper machine.  To paraphrase Dirty Harry "A man has to know his machines' limitations."



+1


----------



## Bob Korves

My 1300+ pound Millrite knee mill has a 1500 watt motor and I have just about zero interest in acquiring a face mill for it.  Fly cutters and normal end mills are perfectly adequate for that machine.


----------



## Bob Korves

The three things you can achieve with milling cutters are deep, wide, and feed.  Maximizing any one minimizes the others...


----------



## Ken from ontario

Bob Korves said:


> The three things you can achieve with milling cutters are deep, wide, and feed.  Maximizing any one minimizes the others...


Deleted.


----------



## Bob Korves

Ken from ontario said:


> Your comments(all of them) makes a lot of sense, based on you last one, 3 cutters should minimize the depth of cut and the feed rate, so would it be possible (within limits) to use the 1.5"/3 insert cutter but take shallower cuts at a slower feet rate?


Sure, Ken.  Those three cutters will be working quite lightly, like a flycutter, but with multiple inserts that can lead to worse finishes because the multiple cutters are not always mounted exactly identically on the head.  The inserts can also have slight variations between them.  Replacing a set of inserts is more expensive than a single cutter.  Some of the inserts for face mills are pretty expensive, and are used in multiples.  Below certain speeds and feeds, the finish can deteriorate.  Face mills are designed for hogging metal off a wider area.  If they cannot hog due to power limitations, then they might as well be replaced by a simple $10 or shop made flycutter that only has a single cutter and is easier to get a good surface finish with.  Some people take out some of the cutters from big face mills so they can make them work with a less powerful mill.  A single HSS cutter, once purchased for a few dollars, will last just about forever in a hobby shop with numerous regrindings possible, and with custom geometry just a bench grinder away.  It also will not become obsolete as some inserts do, making the head essentially scrap metal.  Just my opinion, and others will have different ideas...


----------



## Ken from ontario

Bob, your opinion is what I count on because it is based on experience, thank you ,I'll be looking for a single insert 1" or 3/4" end mill.
Thank you for taking the time to explain.
Ken.


----------



## higgite

Ken from ontario said:


> Tom,according to the specs I found on the site where I actually bought the mill from, the face mill capacity is 1.3/8"  so I'm going to give that 1.5" a try and see for myself,nothing beats the actual experience with the tool/machine.
> Here's copy and paste of my Craftex CX612 specs. which is similar to LMS3960:



Ken, I was commenting on your post #4 where you said your mill is an LMS 3960. I withdraw my suggestion to call LMS. They may not be too keen on commenting on a Craftex machine. Ha! 
Have you decided which insert style you're going to buy?

Tom


----------



## Ken from ontario

higgite said:


> Ken, I was commenting on your post #4 where you said your mill is an LMS 3960. I withdraw my suggestion to call LMS. They may not be too keen on commenting on a Craftex machine. Ha!
> Have you decided which insert style you're going to buy?
> 
> Tom


Tom, contacting LMS  to find out whether an 1.5" end mill could work with a 3960(identical to my Craftex) , would have been pointless since they already advertise a 2" indexable end mill as "compatible" with a 3960.lol.
http://littlemachineshop.com/products/product_view.php?ProductID=5427&category=
I have not decided on which end mill or what style insert  to buy yet, there are so many choices but the truth is , a 3/4"(fine tooth) roughing end mill could most likely do a better job than an indexable type.for facing and side milling, I just love my 1/2" roughing EM and use it often for many milling operations including facing although facing with it does get tedious on wider projects .


----------



## Bob Korves

Ken from ontario said:


> Bob, your opinion is what I count on because it is based on experience, thank you ,I'll be looking for a single insert 1" or 3/4" end mill.
> Thank you for taking the time to explain.
> Ken.


That will probably work well, Ken, and will give you some experience with that style tool with one your mill should be able to handle.  Still, watch out for oddball inserts, and it would be best if you can find one that has or can use relatively sharp edges, positive rake, or both.  I have experience with fly cutters but zero with face mills.  If I had a mill like a K&T or Cincinnati horizontal or vertical, a face mill would be high on my list, but I have no plans for that.  I have some solid HSS end mills in 1-1/4 and 1-1/2", and holders to fit them, but no plans to use them on my Millrite, which has way too little power, way too little rigidity, and too high of a minimum spindle speed (250 rpm) to use them.  Maybe on Delrin...?


----------



## bfd

all this size talk has me wondering if you are thinking of depth of cut you could use the largest face mill you can swing if you only take a .005" deep cut for a nice looking finish. I guess you need to  indicate what you are after. production, nice finish , fast stock removal. bill


----------



## Bob Korves

Ken from ontario said:


> Tom, contacting LMS  to find out whether an 1.5" end mill could work with a 3960(identical to my Craftex) , would have been pointless since they already advertise a 2" indexable end mill as "compatible" with a 3960.lol.
> http://littlemachineshop.com/products/product_view.php?ProductID=5427&category=
> I have not decided on which end mill or what style insert  to buy yet, there are so many choices but the truth is , a 3/4"(fine tooth) roughing end mill could most likely do a better job than an indexable type.for facing and side milling, I just love my 1/2" roughing EM and use it often for many milling operations including facing although facing with it does get tedious on wider projects .


Big end mills are expensive, so an insertable type might be a good choice, where you could replace just the insert instead of the entire end mill.  I have no experience with them.


----------



## Ken from ontario

bfd said:


> all this size talk has me wondering if you are thinking of depth of cut you could use the largest face mill you can swing if you only take a .005" deep cut for a nice looking finish. I guess you need to  indicate what you are after. production, nice finish , fast stock removal. bill


The whole point of going for a bigger end mill was to take off wider cuts in a single pass, ever since I got my mini mill I have learned to only take shallow cuts  like .020" max anyway.
The only time I've gone deeper than that was when I was milling a shoulder on a project using a roughing EM, that time I went 0.50" or about in each pass.
Nice finish is not my main objective ever.


----------



## Doubleeboy

I would look into the Tormach Superfly.  Its stupid expensive for what it is, but it works very well.  Save yourself a lot of money and buy the inserts on ebay, you could buy close to a whole pack of ten for what Tormach charges for a single insert.


----------



## Dabbler

An alternative for Very Wide cuts might be Suburban Tools fly cutter.  it's stupid expensive, but very rigid, and leaves a great finish.  it is for a standard 1" arbor, which is usually easy to find.


----------



## darkzero

A 6" vise is overkill for a RF45 style mill. A 4" is more appropiate for that size mill & IMO 5" max. I have a 5" GMT vise on my PM45 & it's slightly too big. Not enough Y axis travel to make use of the 5" full capacity. Better to save your money rather than getting something too big & most importantly the weight. I take my vise of the table quite often, a 6" is still light enough for me to be carried by hand but I'm glad I have a 5". I also have a 4" vise as well. I prefer the 5" though.

But those GMT 6" Premium vises are pretty nice. I'd love to have one but don't need one on my current mill. But if you plan on upgrading to a full size knee mill in the future than the 6" will be perfect.


Here's what the 5" looks like on my mill.




I couldn't even complete this cut without my bellows & DRO scale getting in the way. Not enough Y travel & the 5" vise is not even maxed out.




Here's what a 6" vise looks like on another PM45 (gt40's)
View attachment 253544


----------



## coherent

I have a fairly small mill and bought a set of inexpensive carbine indexable end mills from Shars that have R8 shanks. The set came with 1", 1-1/4" and 1-1/2". They aren't bad for surfacing and the finish is acceptable. I mostly cut aluminum though. I bought a bunch of Kennametal inserts off of ebay which provided better results than the ones they came with. If I remember right they were about $80 for the set of three.  I have seen some examples of the finish from the Tormach Superfly. About the best I've seen. Not sure what makes it so special, but it works well. Problem is the price which I just couldn't justify for my needs.


----------



## Ken from ontario

Thank you all for your views and comments, I did ask  for them and you guys didn't disappoint ,also thanks for taking the time to post links, pictures, etc. I learned quite a bit, it's always good to know what others are using , that superfly thing is not only out of my league it also out of my small mini mill's league,lol. I'd hate to spend good money on a tool just to find out it wouldn't work with my small mill.

Dark Zero, thanks for the pics,( you got  a great deal on those fly cutters,) you also asked if I wanted "a facemill for hogging material or for a nicer looking surface finish (less passes as opposed to multiple passes with smaller endmills) or a bit of both?"
I actually don't care much about nicer finish, maybe mainly for less passes than for hogging material but if I could get a little of both it would bet great. I found two candidates that fills my need, one is a smaller(1") version of the one with APKT inserts but it takes two and I hope having two inserts doesn't mean it's twice as hard on my mini mill , I also found a seller on ebay that sells a 3/4" shank  end mill  but the head is 1" with a single TPGB-2 insert,which is most suitable for a small mill.
I haven't decided which one to get:


----------



## higgite

Ken from ontario said:


> I found two candidates that fills my need, one is a smaller(1") version of the one with APKT inserts but it takes two and I hope having two inserts doesn't mean it's twice as hard on my mini mill , ......


Ken,

Could you use only one of the inserts for hogging and have the second insert available if you find that your mill can handle it, or maybe add the second insert for light finishing cuts? Just a thought.

Tom


----------



## Ken from ontario

Hmmm, that's not a bad idea to be honest, I'm sure you're talking about the end mill with APKT inserts,it does look like a more capable tool.


----------



## Bob Korves

Ken, the hogging metal removal rate is mostly a matter of power.  A very small end mill might be limited by feed rate, but with a mini mill you are probably limited by power and rigidity when using a 1/2" roughing end mill that is being used aggressively.  Beyond that, you can go narrow and deep or wide and shallow, but the motor and the machine rigidity will be the limit of how much metal you can remove each pass.  Also, through all options you need to make cuts to depths that do not eat cutters, there are optimum feed rates per tooth for all cutters.


----------



## Ken from ontario

Bob Korves said:


> there are optimum feed rates per tooth for all cutters.


Couldn't have said it better myself, I have been surprised a couple of times of the amount of torque this mini mill can produce, I know most of you think "weak" when you hear mini mill but this brushless motor is not comparable to the " classic" type that's known to bog down when used aggressively.
I think overall, I'm way too gentle with this machine maybe because I too think it's weak and should be babied but as I mentioned ,it is capable of more, how much more I'm still trying to find out as I'm getting to know it's limitations, based on what I've seen it it do and using the common sense you all provided in this thread, I think a 1" end mill with one or even two inserts is very workable with this mini mill,I will definitely need to find it's sweet spot as far as feed rate/depth of cut go but I am very optimistic about using the 1" .I just have to bite the bullet and get one to find out.lol.


----------



## coherent

I had a LMS that I converted to CNC and agree that the motors do well on these and torque wasn't an issue. They are great machines and I learned a lot since it was my first mill.
I later moved to a larger mill and realized very quickly how much difference a 80 pound mini mill is from a small mill weighing even a few hundred pounds. Like Bob mentioned the rigidness of the machine plays a huge factor. Good luck with your indexable end mill search.


----------



## Ken from ontario

I found a  a regular (non indexable)1" EM with 2 flute and 1/2" shank that will be a better fit for me,.
I asked Dave M on youtube after watching his face milling video and this was his comment about indexable EMs on small milling machines:
*I think a face mill is more a waste of money for surfacing. I've watched many videos of people test indicating the inserts trying to get them adjusted all the same height. Its impossible, one insert always ends up doing the cutting while another follows with a finishing cut. I think mini mills flex and vibrate to much for this type of cutter. I also don't see that great a finish with $80,000 CNC's. Watch some of my videos using a fly cutter. I get insane finishes with my latest DIY one. *


----------



## Ken from ontario

coherent said:


> I had a LMS that I converted to CNC and agree that the motors do well on these and torque wasn't an issue. They are great machines and I learned a lot since it was my first mill.
> I later moved to a larger mill and realized very quickly how much difference a 80 pound mini mill is from a small mill weighing even a few hundred pounds. Like Bob mentioned the rigidness of the machine plays a huge factor. Good luck with your indexable end mill search.


Yes ,Bob is the main reason I have stopped searching for tools that don't belong in my shop,he has saved me a few bucks and a lot of disappointment.


----------



## Ken from ontario

These are the two end mills I'm looking at for my mini mill, I 'd appreciate your thought on which one is is best,maybe neither or both?:



Bothe are 1", with  1/2" shank, can I plunge  cut with the 2 flute? it looks like a centering end mill .


----------



## willthedancer

If you get an APKT insert mill, you'll like it.

Sent from my Moto G Play using Tapatalk


----------



## Bob Korves

Ken from ontario said:


> These are the two end mills I'm looking at for my mini mill, I 'd appreciate your thought on which one is is best,maybe neither or both?:
> View attachment 228215
> View attachment 228216
> 
> Bothe are 1", with  1/2" shank, can I plunge  cut with the 2 flute? it looks like a centering end mill .


I would say neither.  Get an insertable end mill or two.  I actually have half a dozen or more of those cutters, bought in tool lots for cheap.  I must confess to not even trying them so far.  My mill has a low speed of 250 rpm and that is too fast for them unless you are cutting Delrin or UHMWPE, or maybe aluminum if you have the power and rigidity to keep taking big chips.  I am not in that big of a hurry, and value my machines and would like to keep them working, and not having them down for repairs.


----------



## Ken from ontario

Well that's all I needed to know, ,so they need low rpm and a lot of torque , didn't know that ,they do remind me of annular cutters in many ways.
Again.thank you Bob Korves.


----------



## Bob Korves

Ken from ontario said:


> Well that's all I needed to know, ,so they need low rpm and a lot of torque , didn't know that ,they do remind me of annular cutters in many ways.
> Again.thank you Bob Korves.


Actually, thinking about it more, and assuming 90 SFPM for mild steel, I get a speed of 360 rpm for a 1" HSS end mill.  So that is doable.  What I must have been thinking about is the 1-1/4 and 1-1/2" cutters I also have, also with no plans for using them.  The 1" two flute could work, and it would take no more power than a 2 insert insertable end mill, probably less, at least for cutting on the ends.  You could try it, but those are expensive cutters and are also expensive to sharpen, and a big chip will turn it mostly into scrap metal, though they can be reground if you can find somebody to do it at a decent price.  I think above about 3/4" it is time to look at insertable end mills.  A three or more flute end mill of 1" would also take a considerable amount of power to get it to make cuts having the correct chip load.  It it hard to hold some of that tooling in a collet without it coming loose and/or sucking into the work.  Adding a Weldon style end mill holder would probably take away all the headroom on your mill and more.  Thinking about that on a mini mill, which I have never personally used, just makes me shake my head sideways...


----------



## Ken from ontario

Actually Bob the 2 flute that you say might work is not that expensive ,it's only $32 CDN dollars which is around $24 USD, the 6 flute is about $40 USD, so price wise they are average but I'm not sure of their quality.


----------



## Bob Korves

Ken from ontario said:


> Actually Bob the 2 flute that you say might work is not that expensive ,it's only $32 CDN dollars which is around $24 USD, the 6 flute is about $40 USD, so price wise they are average but I'm not sure of their quality.


That is cheap, perhaps too cheap...  or perhaps a real bargain!


----------



## mikey

Bob Korves said:


> A three or more flute end mill of 1" would also take a considerable amount of power to get it to make cuts having the correct chip load.



I agree with Bob, Ken. If you lack the rigidity and power to take a cut with a decent chipload then there will be rubbing on the flutes of the cutter and that big end mill will get dull in a very short time. You can vary feed, you can vary speed and you can vary depth of cut but the closer you adhere to the chipload parameters the manufacturer lists for their cutter, the longer the tool will last. I would be hesitant to use a 1" multi-flute end mill on my RF-31 and its a 400# machine with a 1HP Baldor motor on it. I suspect a small bench top machine will not fare well with a cutter like this, regardless of how good a deal it is. 

Just my thoughts on this one.


----------



## Ken from ontario

mikey said:


> I agree with Bob, Ken. If you lack the rigidity and power to take a cut with a decent chipload then there will be rubbing on the flutes of the cutter and that big end mill will get dull in a very short time. You can vary feed, you can vary speed and you can vary depth of cut but the closer you adhere to the chipload parameters the manufacturer lists for their cutter, the longer the tool will last. I would be hesitant to use a 1" multi-flute end mill on my RF-31 and its a 400# machine with a 1HP Baldor motor on it. I suspect a small bench top machine will not fare well with a cutter like this, regardless of how good a deal it is.
> 
> Just my thoughts on this one.


What you and Bob are saying makes perfect sense, this  has been an eye opening thread for me and probably for a lot of others with smaller milling machines, we either listen to the logic behind what has been said or will soon have a collection of cutting tools  in perfect condition because we can't use them.
 I already have decided to start my search on smaller bits 3/4" max, I've used that size end mills and I know my machine can take it.
Thanks very much Mike.appreciate sharing your thoughts as always.


----------



## Downunder Bob

Ken from ontario said:


> For the past 2 days I have been using the search function  here  on what tools to use for face milling Aluminum and mild steel, especially when the milling machine the tool goes onto, is a mini mill.
> I found out a few important points and now I'll bring them up and ask you guys to please correct me in my findings :
> 1= with a 1/2 HP mill, It is best to use a smaller size indexable face mill.
> 2= the size of the indexable face mill should not be bigger than 1.5" you may get away  with a 2".
> 3= the best type of inserts for a small mill (which does not have a very ridgid mill head) is, TPG32.
> 4= the indexable face mill head should have at least 2 inserts but 3 is even easier on the machine, less vibration.
> 5=If possible,It's best to use a collet than an R8 EM holder , less chance of the tool vibrating .
> 6= Adjust your feed rate and RPM  to get a chatter free operation.
> Am I missing any other important point? how about using compressed air for chip evacuation? or maybe using coolant(spray?),I do have the option to use a fly cutter but find it a bit too slow,overall I'm not comfortable using it but regardless of using that option,I still want to learn which indexable face mill is best for my mill. your comments as usual are important to me and very much appreciated.



Ken I think you are suffering under a misconception, with cutters and power. The more cutting points on a cutter the more power you will need. With each different cutting approach the number of cutters actually cutting will vary. If plunge cutting with an end mill all points will be cutting, but when side cutting such as facing a plate only half of the cutting edges will be cutting if you are using the full width of the cutter.

 To reduce the power required we typically reduce the DOC and/or feed. eventually getting to the point where the tool is doing more rubbing than cutting. If you want to exceed the 1.5" face mill cutter then use a single point fly cutter, with this cutter you can face pretty much anything that will fit on the table of the machine. Set the dia. of the cutter to be somewhat larger than the piece you want to cut.

You can use HSS or carbide, but if using carbide make sure the grade is ok for intermittent cut. Be careful to reduce the RPM as you increase the dia of the cut. Also remember a sharp  HSS cutter will require a lower speed and less power than carbide. HSS tends to be better at very light cuts.

The major limitations of your small machine are power and rigidity, so it will be important to be mindful of the loss of power at the low end of your variable speed motor, and also to balance the cutter to help offset the lack of rigidity. Hope this helps.


----------



## Ken from ontario

Bobshobby, thanks for joining in and for your comment, throughout this  long thread we have covered a few of the  misconceptions you are talking about already,i.e.  3 point cutter vs 2 point or one, 3 point EMs being the least suitable for a mini mill  due to their lack of power and rigidity ,my original post was what I had gathered by reading other threads relating to indexable end mills  and their appropriate sizes for smaller /less powerful milling machines but the more seasoned members did put me on the right track but thank you again to reiterate the points for clarity.we are here to learn and I for one appreciate all the help I could get .


----------



## darkzero

Ken, when you are referring to the number of cutting points on a cutter, that is what is known as flutes. But keep in mind the number of flutes on an indexable cutter vs the number of flutes on an endmill is not really the same. For smaller than say .75" or so, you probably won't find an indexable endmill with more than 1 flute/insert. but let's just say that there was. The endmill will probably perform better cause it has a helix where the insert just has a single straight edge for each flute. Also at the end of the endmill, each flute has a longer very positive angle cutting surface than an insert which would just be a tip & dependent of the nose radius.

Not to discourage you but on a smaller size mill, you may just be better off with an endmill & not in such a large dia rather than an indexable endmill. On my larger benchtop mill, the largest endmill I use is 5/8" (but not for hogging). I can take deeper depths of cuts with a smaller dia endmill than I can with any of my indexable tooling. It may require more passes but in the end you still might be removing the large amount of material faster than an indexable. Also keep in mind with an indexable endmill & depending on it's geometry, you get some harsh beating similar to a flycutter so if you don't have a rigid machine, that will limit you as well.

Point is you can't always find an alternative for a good ol endmill. It may be that you just need to find the right type of endmill & I'm not sure if anyone talked about that yet. Try a 4 flute coarse roughing endmill for steel, so much more free cutting than a regular endmill for fast material removal. Or for aluminum try a 3 flute roughing endmill or even a high helix 3 flute. The high helix 3 flute endmills work great in aluminum.

What's interesting is that Stephan Gotteswinter even uses the 3 flute high helix endmills for roughing in steel. He also has an endmill shootout video.


----------



## Dabbler

just to add to darkzero's (which are right on!) comments, Stefan Gotteswinter tends to do very accurate work, and doesn't (usually) use indexable cutters on his mill.  He does use brazed on carbides from time to time.


----------



## darkzero

Dabbler said:


> just to add to darkzero's (which are right on!) comments, Stefan Gotteswinter tends to do very accurate work, and doesn't (usually) use indexable cutters on his mill.  He does use brazed on carbides from time to time.



That's exactly what I mean. I have the same style mill as Stefan. I was surprised at the size tooling he uses. He rarely uses big endmills or indexable cutters like you said. Even his choice of vise, he uses a small  tool makers vise where most of use are using big Kurt style vises! Because of him I'm starting to use 3/8" endmills more where before I used 1/2" the most.


----------



## pstemari

3/8" is a nice size for endmills in many respects.

As far as the Superfly goes, its big advantage are the inserts Tormach pairs with it.  The aluminum inserts are razor-sharp with lots of top rake. I'd guess 15 degrees of top rake on those inserts.  They can chip if you aren't careful, but generally they leave a mirror finish on 6061 aluminum and will take a surprising DOC. I don't have the cut parameters I was using on the Tormach 770 at the office makerspace handy, but I think I was running 0.010" DOC at 1000 sfpm and 0.002" chipload or thereabouts. On my Taig at home I keep the DOC at 0.002" when using a fly cutter.


----------



## Dabbler

Ken, I had a mill very much like yours until Christmas, when I upgraded to a larger one (I may write it up when I get it working).    I used 3/4" HSS 4 flute end mills for very light facing work (.010 DOC) and found it quite fast enough - and - it was quite fast to do a large surface.  I used a smaller face mill in Aluminum, but the finish was no where as good as using an end mill.


----------



## mikey

Ken from ontario said:


> For the past 2 days I have been using the search function  here  on what tools to use for face milling Aluminum and mild steel, especially when the milling machine the tool goes onto, is a mini mill.



Ken, let me play Devil's Advocate here for a minute. In your original post, you were looking for tooling to *face* aluminum and steel parts on a mini-mill. I assume by facing you are looking to produce a flat, smooth surface such as you would require when squaring a part at the start of the project. Is this still the goal or have you moved on to profiling?

Not to detract from the excellent discussion but I raise the question because if you're facing to square parts, end cutting with end mills are not the most efficient way to do that. Face mills will do it but your little mill is somewhat limited by the size you can use so, again, this is not the most efficient way to do the job.

If you are looking to face each surface so you can square it then the most efficient tool for that is a flycutter. It is not the only way, true, but it is the most efficient way and is likely to provide the best surface finish. If you are looking to face and size a part, a good flycutter will do this as well. Not only that, a flycutter requires the least amount of power for the surface area it cuts provided you are going for a facing cut instead of stock removal. 

As I re-read this thread tonight I sort of got lost in all the information and while all of it has been interesting and educational, I wonder if the goal hasn't been lost.


----------



## Ken from ontario

darkzero said:


> Ken,* when you are referring to the number of cutting points on a cutter, that is what is known as flutes.* But keep in mind the number of flutes on an indexable cutter vs the number of flutes on an endmill is not really the same. For smaller than say .75" or so, you probably won't find an indexable endmill with more than 1 flute/insert. but let's just say that there was. The endmill will probably perform better cause it has a helix where the insert just has a single straight edge for each flute. Also at the end of the endmill, each flute has a longer very positive angle cutting surface than an insert which would just be a tip & dependent of the nose radius.
> 
> Not to discourage you but* on a smaller size mill, you may just be better off with an endmill *& not in such a large dia rather than an indexable endmill. On my larger benchtop mill, the largest endmill I use is 5/8" (but not for hogging). I can take deeper depths of cuts with a smaller dia endmill than I can with any of my indexable tooling. It may require more passes but in the end you still might be removing the large amount of material faster than an indexable. Also keep in mind with an indexable endmill & depending on it's geometry, you get some harsh beating similar to a flycutter so if you don't have a rigid machine, that will limit you as well.
> 
> Point is you can't always find an alternative for a good ol endmill. It may be that you just need to find the right type of endmill & I'm not sure if anyone talked about that yet. Try a 4 flute coarse roughing endmill for steel, so much more free cutting than a regular endmill for fast material removal. Or for aluminum try a 3 flute roughing endmill or even a high helix 3 flute. The high helix 3 flute endmills work great in aluminum.
> 
> What's interesting is that Stephan Gotteswinter even uses the 3 flute high helix endmills for roughing in steel. He also has an endmill shootout video.


hi DZ, great post ,thanks for the links , I probably have watched them twice already but even today  I enjoyed watching his videos and reconfirm a points that already worked for me and my situation with a small mill.
 I referred to the number of cutting point as points and not flutes for one reason and that was to compare two specific (indexable)end mills and decide which type of inserts would require less power to do its job, one had two TPG inserts ,each with a cutting radius 1/32"  was doing the cutting and the other end mill had 3 APKT  which  the whole edge of the inserts would need to contact with the surface of the workpiece as oppose to the two points of the TPG inserts . saying two points versus three edges (I thought )would relay what I was imagining and inquiring about, better.

You and a few others correctly pointed"*on a smaller size mill, you may just be better off with an endmill" *which is the direction I'm looking at but for my face milling I'll go with 3/4" size to cover more surface in less time.


----------



## Ken from ontario

mikey said:


> Ken, let me play Devil's Advocate here for a minute. In your original post, you were looking for tooling to *face* aluminum and steel parts on a mini-mill. I assume by facing you are looking to produce a flat, smooth surface such as you would require when squaring a part at the start of the project. Is this still the goal or have you moved on to profiling?
> 
> Not to detract from the excellent discussion but I raise the question because if you're facing to square parts, end cutting with end mills are not the most efficient way to do that. Face mills will do it but your little mill is somewhat limited by the size you can use so, again, this is not the most efficient way to do the job.
> 
> If you are looking to face each surface so you can square it then the most efficient tool for that is a flycutter. It is not the only way, true, but it is the most efficient way and is likely to provide the best surface finish. If you are looking to face and size a part, a good flycutter will do this as well. Not only that, a flycutter requires the least amount of power for the surface area it cuts provided you are going for a facing cut instead of stock removal.
> 
> As I re-read this thread tonight I sort of got lost in all the information and while all of it has been interesting and educational, I wonder if the goal hasn't been lost.


Hi mike,I think this thread like many others I've seen,took a different direction for many good reasons but I , was looking for a cutting tool that was faster than my 1/2" roughing end mill to square parts, I never was after a nice finish, just to square up  stock I have mainly used my roughing end mill, remember mike I could only take no more than .020" DOC with each pass on mild steel,( bit more on Aluminum ) so I said to myself,wouldn't it be great if I could do the same thing but faster?
This thread as I said  made me learn what could actually would work  with a mini mill without spending money to find out , based on what I've learned and what I know with my mini mill, I finally bought two end mills, one is a 3/4"(fine tooth) roughing end mill like Dabbler was suggesting in post #53 , to be used in facing roughing,end milling, squaring parts etc.if I needed a better finish I do have a fly cutter and will use that or my 3/4"  regular 4 flute end mill, I tried this approach on a small piece of aluminum and I loved it.

My second purchase has not arrived yet but I kinda went against recommendations of the majority here and bought a 1" indexable end mill with two TPG222 inserts,3/4" shank, I have a good feeling it'll do just fine for light facing jobs, we'll see how it turns out.
I have come to the conclusion that end mills are my best friend as long as I have a small mill, I'm kind of resigned to the fact that I need to go slow and shallow  with this mill ,I do like my fly cutter but all I have used it for was for a nice finishing job  on a wider than usual stock,I normally don't need a nice finish and don't use wide stock so again,end mills have become my goto cutting tool.
Thank you again Mikey for all your help whether here or behind the scene with your pms and great advice.
Thank you all for contributions,thoughts and comments,  I can safely say my initial inquiry has been answered and I think I have made an informed decision based on what I've learned from this thread.two thumbs up to every one.


----------



## darkzero

Ken from ontario said:


> I referred to the number of cutting point as points and not flutes for one reason and that was to compare two specific (indexable)end mills and decide which type of inserts would require less power to do its job, one had two TPG inserts ,each with a cutting radius 1/32"  was doing the cutting and the other end mill had 3 APKT  which  the whole edge of the inserts would need to contact with the surface of the workpiece as oppose to the two points of the TPG inserts . saying two points versus three edges (I thought )would relay what I was imagining and inquiring about, better.



Although it doesn't matter since you made your purchase already but I just wanted to point out that APKT inserts also cut on the corner & not on a full edge. Pretty much all polygon shaped inserts are configured this way. Cutting on a full edge will be much more prone to chatter (like with a lathe form tool). A round insert would have the most contact but a circle is not a polygon.

Please be sure to let us know how it works out. I'm very curious as well.


----------



## Dabbler

HeyKen, one last word on your purchases.  Right after I sold it to him, they guy I sold my mill to bought an accusize facing mill in 2" and used it to face a 3/4" wide piece of hot rolled steel with the scale on.  It left a beautiful finish (I nail tested it).  He was only able to take a .010 cut with it, and I suspect it rattled the heck out of the machine.

So I predict that your 1" indexable end mill will work.  A note on saving wear on your machine, however.  Instead of the usual 2/3 engagement, try for 90% (to get less impact), and take shallow cuts (although each insert geometry needs a different minimum to work correctly - .004 is the bare minimum for any carbide at slow speeds).  Please let us know what you find, and pictures are always appreciated! [.010 is a great starting spot]


----------



## mirain33

I've been searching for a small face mill for my Clausing 8530. The largest collet I can use in the spindle is 1/2". Given that limitation can anyone suggest a source for a 1/2", straight shank, indexable face mill?
The smallest I've found is 3/4". 
Thanks


----------



## Ken from ontario

mirain33 said:


> I've been searching for a small face mill for my Clausing 8530. The largest collet I can use in the spindle is 1/2". Given that limitation can anyone suggest a source for a 1/2", straight shank, indexable face mill?
> The smallest I've found is 3/4".
> Thanks


Check out ebay,I found a few 1/2" all end mills with a single insert, here's one on Amazon:

Accusize - 1/2" 90 Deg Square Shoulder Indexable End Mill w/ APKT11T308 Inserts, #0056-0914
There's better description of this tool on Amazon .ca :

90° Cutting angle;Screw down insert;Radial rake angle: -10°;Axial rake angle: +7°
All types of square shoulder* face milling*, side milling and full slot milling (shaft end mills) of steels, alloyed steels, stainless and heat resistant steels, case irons and aluminum alloys.;
Fitted with 10° positive rectangular insert allow high depth of cut and feed per tooth
Uses APKT / APHW / APKR_APHT / APMT insert (sold separately);Cutting Diameter D: 1/2"
Shank d1: 1/2";OAL: 3-1/4";ap: 0.433";No of Insert: 1;Screw: M2.5 x 6.5;Insert: APKT11T308


----------



## Downunder Bob

Ken from ontario said:


> Bobshobby, thanks for joining in and for your comment, throughout this  long thread we have covered a few of the  misconceptions you are talking about already,i.e.  3 point cutter vs 2 point or one, 3 point EMs being the least suitable for a mini mill  due to their lack of power and rigidity ,my original post was what I had gathered by reading other threads relating to indexable end mills  and their appropriate sizes for smaller /less powerful milling machines but the more seasoned members did put me on the right track but thank you again to reiterate the points for clarity.we are here to learn and I for one appreciate all the help I could get .



Ken, back to your original question, you mentioned the max. dia. of a milling cutter on your small mill. If you use a single point cutter, aka a fly cutter, the only limit to dia is how big a cutter can you swing without hitting anything. The other factors you will need to consider if you have a variable speed motor rather than a gearbox do you lose much torque at low speeds, if so that could also limit the size. Also make an effort to balance the cutter so that the spinning out of balance does not cause wobble problems. make a large dia cutter head so as to act as a flywheel this will help with balance but also help with torque when cutting at low speeds. With a large dia cutter head you can drill a radial hole diametrically opposite to the cutter, and fit a bar without cutter to be used as a balance weight.


----------



## Ken from ontario

bobshobby said:


> make an effort to balance the cutter so that the spinning out of balance does not cause wobble problems. make a large dia cutter head so as to act as a flywheel this will help with balance but also help with torque when cutting at low speeds. With a large dia cutter head you can drill a radial hole diametrically opposite to the cutter, and fit a bar without cutter to be used as a balance weight.


That's one solution I never thought about , thank you for that.
I got my 1", 2 flute end mill the other day and used it on low and high RPMs  got acceptable performance, this mini mill doesn't loose much torque in lower RPMs which is a good thing but overall, I didn't like the finish I got with the 1" indexable end mill, the next size down I used was the 3/4" roughing end mill that worked absolutely great .


----------



## Richard Melloh

When I think, "small mill", I think a machine with a maximum .500" dia collet capacity. I am familiar with the challenges regarding this limitation.

My main mill is a Clausing 8532. It makes me a very good living. I use a cordless, variable speed, 1/2" drill motor with 5/8" socket drive for power feed on X and Y axis. It has DRO on the Y. The X axis is still true on 6" passes in my use range. I can fish for .0001". I have used this machine for two decades in this application.

For face milling plastic, aluminum, brass and bronze, I recommend using a 2" dia, HSS, shell mill on a 1/2 dia shank. For smaller parts, try a reduced shank (1/2"), HSS, six or eight flute mill, 3/4, 7/8 or 1" dia.  I get these mills from McMaster Carr, MSC, Enco and E-Bay.  Look for the best prices and sales. I am interested in index-able mills, but they are largely not designed for .500" dia collets. I have no use for the ones that are. They are too small.

My experience has taught me to stay away from any HSS Chinese mills of this type, very disappointing finish grinding is the reason. US, Polish and Spanish products are of good quality. If I see Niagara (US) products of the above range on E-Bay, I hoard them.

I recommend using metal specific cutting fluid for the best results on aluminum brass and bronze. It makes a world of difference compared to all other cutting fluids. Tap Magic made my life a lot simpler.

I use continuous high pressure air for cutting plastics, no fluids. I face mill 1.75" cross sections with a 2" dia shell mill all the time. I machine PEEK, which is very tough and does wear out HSS with poor cooling. Match feed speed to cooling capacity at all times. Slow feed rates down for partially worn mills. I always go as fast as I can. Time is more valuable than cutters.

For facing aluminum, brass and bronze, I use Tap Magic applied with a trimmed flux brush, a very tidy way to lube a mill. Pre-load the mill and part surface, then let another loaded brush drag across the mill while the pass is made. Mind you, my work is on the small scale.


----------



## Ken from ontario

Thank you Richard for your post and sharing your experience.
 You use  "2" dia, HSS, shell mill on a 1/2 dia shank" with your small milling machine ? I thought 1" Dia. was too big for my mill, I never tried any diameter bigger than that. your mill must be more powerful/ridgid than what I have.

Great point on tap magic, I use it regularly on Aluminum but I also use WD-40 as well ,both seem to work fine.


----------



## Splat

mirain33 said:


> I've been searching for a small face mill for my Clausing 8530. The largest collet I can use in the spindle is 1/2". Given that limitation can anyone suggest a source for a 1/2", straight shank, indexable face mill?
> The smallest I've found is 3/4".
> Thanks



I highly advise to NOT use collets to hold endmills. Using good collets on my 8520 you really gotta crank down on the endmill to prevent slipping. Since switching to endmill holders I've no longer had slipping. I found a Bison MT2 5/8" endmill holder, though that's really pushing the limits of this machine.


----------



## courierdog

Ken: There are many people writing their experience with Mills similar to your using the new and very inexpensive 
1 Set 90 Degree R8 FMB22 Straight Shank Arbor Face End Mill Cutter 4pcs APMT1604 Carbide Inserts Turning Tool delivered in Canada for less the $50CDN
When I bought my Mini Mill LMS 3960 there was no tooling capable of making more than a 0.75 inch cut and even that at only a few thou DOC. Now things have changed with the more precise and inexpensive Chinese tooling most of us can now afford to experiment.
However the Good Old Fashioned Fly-Cutter can be made in your own shop and using HSS or Crobalt Both can be sharpened on the bench grinder with ease.
My latest experiments are from and article for a very simple Single Facet Face Mill see the article https://www.hobby-machinist.com/threads/small-face-mill-using-tangential-cutter.82442/
Good Luck and Stay Safe I have a good friend who live in Peterborough. My sister use to live near there as well.


----------



## courierdog

Ken I found the article I was looking for on youTube with the small mini mill and the 50mm end/face mill 



I have looked at several similar articles and the tool holder works the quality of the carbide inserts seems to be the deciding factor as to the finish. More than on article checked the Run out on the tool holder and they were found to be of very good quality.
The biggest differences were the varying grade of the carbide inserts used after a lot of searching I found several different grades and recommendations for cutting different material stock. One type of insert is not suitable for all materials. So while the tooling can be delivered to Canada very inexpensively the inserts will take more research depending on your milling material requirements.
The nice thing I have found is I can use PayPal which provides me a more secure financial transaction.
Best of luck on your project.


----------



## Ken from ontario

Thanks for resurrecting this 3 year old thread, I have since learned a few things about my mini mill/lathe:
For  facing, I have been using a shop made fly-cutter and totally moved away from those indexable face/shell mills, it is my opinion that  the larger 1.5" to 2" face mills seem to do extremely well with larger/more rigid milling machines, if I owned a bigger more ridgid milling machine I would consider a 2" shell mill.
For material removal/profiling,  I use  2 or 3 flute good quality end mills no bigger than 1/2" Dia.
My shop time needs to be calming / soothing time and I've learned to achieve that by working within the limits of my machines.


----------



## courierdog

Ken:
I totally agree with you on the shop needing to be a place of calm and restful emotionally experience. I do not work well under pressure. This hobby is to be enjoyed and should provide a source of increasing knowledge which can be reflected in the things we work on or attempt to create. My latest thoughts are the creation of a larger fly-wheel based fly-cutter. I am working on a project the Acute Tool Sharpening System Kit from Eccentric Engineering. I am using it as both a learning process and a creation project.
There is no time limit and learning how to better use what I have while building the project as you say brings a very calming atmosphere to the shop. There are several minor milling processes required which I have been thinking could be done with a fly-cutter. Not the first tool that comes to mind, as the instructions call for an end mill. Now since it is not making a grove in metal only making a step into the side of the work piece. my mind keeps asking why not use a simple fly cutter. Slow yes, but I just said there is no time limit requirement. The Fly-Cutter similar to the simple concept found here https://www.hobby-machinist.com/threads/small-face-mill-using-tangential-cutter.82442/ It is not about the finish rather it is about the creation of a simple tool holder containing a simple HSS or Crobalt tool bit used to perform the milling operation.
This I Think is what you are striving for when you say the Shop should be a place of Calm. A place where simplicity rules the atmosphere.
Thanks for Listening 
Dave C


----------



## Dabbler

I agree that machining can be a calm and relaxing experience!  I love fly cutting, and I have very heavy machines...  It is a process where you can control the surface finish, the accuracy,  and on a well-trammed machine, leaves perfectly flat surfaces.


----------



## courierdog

I am working on the computer to design a Flywheel style Fly-Cutter.
I have two objectives
1. to produce flat smooth surface
2. to produce a precise corner for a step
While not totally exclusive the cutter face to achieve either case may require a different approach.
Typically a smooth surface requires a wide radius of the cutting edge while the sharp edge is a corner requires a sharp defined edge tooth cutter.
The simplest approach is a round tool bit for the smooth surface running at a tangential angle to the cutting surface
see the concept from https://www.hobby-machinist.com/threads/small-face-mill-using-tangential-cutter.82442/
The Sharp corner I would think would start from square stock tool bit this approach is most easily achieved using any of the conventional Fly-Cutter designs
My current challenge is to design one Disc or Flywheel which can hold either a round or square tool bit.
The basic concept must comply to the above article as it can be accomplished by most people
A square can hold either a Round or Square Tool bit stock.
While a simple 12 degree (facing the direction of the turn) drilled hole can accomplish the concept mentioned above.
The same approach using a square clamp would require the Flywheel to be cut at the desired radius and a 12 degree angled v cut into each side of the flywheel. When mated back together the two pieces would form the clamping square for either a round or square tool bit stock. The design concept is to turn the clamping square such that the tool bit is a tangential cutter capable of providing a square corner in any material it cuts on the edge.
It will also be quite capable of producing a good finish on both the vertical wall and the floor of the cut.
It will take some time mostly in coming up with the working angles as in this design once cut the angle is fixed and the design concept should be capable of using the standard Tangential Tool bit which in a lathe use a 12 degree by 12 degree cutting angle.
The typical grind is a nominal 30 degree. This provides a very strong and long lasting cutting surface and easily resharpened when the cutting edge requires resharpening. The other advantage to this concept is returning to the same cutting depth is a simple matter of adjusting the too protrusion from the Tool holder (Flywheel)
OK this is a very long winded explanation of the concept to bring the tangential Lathe tool approach to the Milling Platform.
The problem with the Mill is rotating the tool and we do not need any additional flying objects seeking more human blood to feed upon. More design work is required to minimize additional protrusions other than the cutting surface.
The thickness of the flywheel is to hide all or most of the tool bit
The diameter of the flywheel is to provide the designed radius.
IF there is anyone who can add to this concept you are more than welcome to add your comments as all ideas are welcome, as this is a hobby where we can share our ideas both good and not so good.
I wish I could draw what is in my head for the design concept then it would be much more clear for everyone to see and add their two cents to improve it for everyone else.
Thanks for Listening


----------

