2 flute for 4 flute mill for aluminum??

[Sean Bowf]

2 flute for 4 flute mill for aluminum?? I don't own a mill yet, and it will be a little while before I get one...but going to need to use my drill press or the lathe to bowl out head buttons until I do get one.

I have been buying cheap carbide cutters for my lathe. How long will HSS last cutting aluminum?? Is the carbide overkill?? If the carbide is the right way to go, which one should I be getting?? I think I have seen C2, C5, and I don't know how many others...

Thanks in advance for the help,

Sean

 

[Chris Wood]

well sean i am not my father but i would bet he would say a 4 flute.. smoother cut.

as for carbide, i would say YES. one thing i learned yrs ago.. cheap is cheap for a reason.. in some applications hss works but if you can afford carbide or something better it will last longer and work better for you in the long rund

 

[Sean Bowf]

Thanks Chris.

Sean

 

[jetpack]

Hi Sean, if you're not using a cnc just a manual lathe you'll find the HSS will be the way to go becaus you're working a bowl shape with the head buttons and will require quite a bit of clearance and carbide will tend to chip out doing that, or not have a sharp enough cutting edge/rpms to leave a decent finish. A bench stone can also be used to final dress a HSS or touch up without having to go to the grinder again and possibly loose your shape.

Milling aluminum requires quite a bit of coolant for a decent finish, two flute or four. Four flutes always tend to weld chips when climb milling for me even with plenty of coolant. Better off using a two flute at a good rpm and conventional mill for size and finish.

If there is a ragged nicked finish when side milling move your depth and take another pass without taking any more to remove the ridges. Not a good idea to use the same cutter for steel and aluminum also, so choose a new one or a regrind. Regrinds dont do well btw also with aluminum because of the changes in flute depths and cutting angles.

 

[steve wood]

for head buttons use plain high speed, ball end, 2 flute. they will probably last you for life. for nova's i use a 5 mm carbide,cause that's all i could find in 5 mm. for general aluminum the best mill i have ever used is the accupro 3 flute,carbide, zirconium coated, that msc sells. the finish looks like it came off a cnc, and the aluminum doesn't weld to the cutter,like it does with all the rest(never use a tin coated for aluminum,if you don't have to,it acts like glue to aluminum).for aluminum just use wd-40 or wal-mart stuff,it's the best.and always climb mill for best finish, if your machine can do it without grabbing

 

[glenng]

2 flute for 4 flute mill for aluminum?? I don't own a mill yet, and it will be a little while before I get one...but going to need to use my drill press or the lathe to bowl out head buttons until I do get one.

I have been buying cheap carbide cutters for my lathe. How long will HSS last cutting aluminum?? Is the carbide overkill?? If the carbide is the right way to go, which one should I be getting?? I think I have seen C2, C5, and I don't know how many others...

Thanks in advance for the help,

Sean

Sean, Don't even think of using a drill press-use the lathe. A-9 is a good cutting fluid for alum. and hi speed steel works fine-slow the machine rpm down to about 80. If you're just starting out in machining a good book to have is the Starrett handbook for student machinists-covers all the basics-tool grinding,threading,milling, knurling-etc.

Good Luck,

Glenn

 

[Sean Bowf]

Sean, Don't even think of using a drill press-use the lathe. A-9 is a good cutting fluid for alum. and hi speed steel works fine-slow the machine rpm down to about 80. If you're just starting out in machining a good book to have is the Starrett handbook for student machinists-covers all the basics-tool grinding,threading,milling, knurling-etc.

Good Luck,

Glenn

80 RPM?? Really?? I would have figured it would be a lot higher than that from watching milling machine video on youtube..

I will check into the book Glenn. I was thinking of taking a class at one of the local colleges on milling before I took the step of buying a mill.

Sean

 

[glenng]

Sean, Don't even think of using a drill press-use the lathe. A-9 is a good cutting fluid for alum. and hi speed steel works fine-slow the machine rpm down to about 80. If you're just starting out in machining a good book to have is the Starrett handbook for student machinists-covers all the basics-tool grinding,threading,milling, knurling-etc.

Good Luck,

Glenn

80 RPM?? Really?? I would have figured it would be a lot higher than that from watching milling machine video on youtube..

Sean

Sean, Rigid numerical control machines operate at very high spindle speeds-lightweight manual machines require much lower speeds. Can't say that I ever met anybody that learned to machine watching you tube.

Take a piece of scrap alum. try it at 80 rpm and then at 1500 rpm.

Glenn

 

[Sean Bowf]

Thanks for the heads up Glenn...I would have probably gone at it a lot faster than that...heh.

Sean

 

[Hydro Junkie]

I have to agree on the three flute and DW-40. I've been told to go with high RPMs, even with my Sherline mill by several experienced machinists. To see the 80 RPM recommenddation is a real surprise to me. My mill has so little power at low RPMs due to it's age that I dont' think it would even cut at that speed. I've been running my mill wide open to cut aluminum due to that reason, though it only spins up to maybe 2500 rpm, if I remember right.

DO NOT USE A DRILL AS A MILL!!!!!!!!!!!!!!!! The difference between a mill and a drill is the bearings. A drill has bearings that are designed for only a vertical load while the mill has bearings designed for both a side and vertical load. Using a drill as a mill can damage the drill's bearings and possibly more in the spindle assembly

 

[Sean Bowf]

I will keep it off the drill presss... As an FYI, for now, it will pretty much be a plunge cut. I ordered a 3/8ths inch ball mill to use to make the little heads for the .18 engines to learn the whole process....then go from there.

Later I might be interested in tearing down my .21 CMB LS to see if there is anything I "think" I can do to make it better...

Sean

 

[Hydro Junkie]

Did you go with the carbide or HSS? All the endmills I've bought are carbide, which just means I can't sharpen them. I do have some HSS that get used every so often. I haven't been able to see any real diffence in the cut or finish as of yet.

 

[jetpack]

Sounds fun to try.

Another thing to try out is either center drill to your depth, or center drill and tap drill your plug hole first to clear out for the center of the cutter. It could help with holding size but not necessarily chatter.

Plunge cutting with a ball end mill will always result in mixed results depending mostly on length of the cutter. They are not designed very well for plunge cutting even though they are ground to a centerless point they will always flex or not want to stay on center when doing so.

To stay away from chatter go slow on RPM's and heavy on feed, and back off as soon as you reach your stop, or practice watching for your chips to clear up off the cutter and the finish cleans up and back off. Try to do this as close to one revolution as you can.

You usually only have one split second between ending the cut and where the chatter starts so try to hit it close like a reflex action.

A three flute cutter would be the way to go for this because it has more stability than a two flute, and a four flute is asking for trouble because its basically a two flute with twice the chance of chatter.

 

[Sean Bowf]

I ordered a carbide from Ebay HJ.

Jetpack, I was thinking of center drilling the head, then bowling it, then tapping it. I figured this would save me some trouble with the tap. I did not know there was a problem with plunging with a ball mill.

I have not picked up the tap yet...I will need to figure out the threading of a glow plug. I am pretty sure I have seen the question asked on this forum before, just need to see if I can find it. EDIT...found it... 1/4 by 32

Sean

 

[TERMINATOR]

I will keep it off the drill presss... As an FYI, for now, it will pretty much be a plunge cut. I ordered a 3/8ths inch ball mill to use to make the little heads for the .18 engines to learn the whole process....then go from there.

Later I might be interested in tearing down my .21 CMB LS to see if there is anything I "think" I can do to make it better...

Sean

if the head button is going to be replaced and it is not a turbo version , ill buy it sean before it meets the lathe..lmk

tk

 

[Jerry Wyss]

​

I ordered a carbide from Ebay HJ.

Jetpack, I was thinking of center drilling the head, then bowling it, then tapping it. I figured this would save me some trouble with the tap. I did not know there was a problem with plunging with a ball mill.

I have not picked up the tap yet...I will need to figure out the threading of a glow plug. I am pretty sure I have seen the question asked on this forum before, just need to see if I can find it. EDIT...found it... 1/4 by 32

Sean

Quite a challenge making head buttons, very tedious and time consuming work from scratch. I've made a couple

dozen from round stock but later on I down loaded the <emachineshop.com> 3D design program free online.

Since I mostly dealt with 21 size buttons I designed up a "blank model" that had the three rounded segments with

dimensions in the ballpark. They made the blanks up for me for for about $13 a piece and I worked them from there on my lathe.

Ball end mills I have found are not the total answer for the bowl shape. My better performing bowl shapes have a

more pronounced radius "shoulder" next to the glowplug than the ball would give me. A 3/16 to 1/4 square tool

had to be shaped to give that "bowl roof" a shoulder. I used the Mac O/B button as a guide to shape the tool.

Plug face depth was a learning curve I went thru before I discovered that anything deeper than .130" wasn't going

to light up very well. Most of mine are between .118" to .122" from the squish face to the plug face and nothing over

.18cc in volume for a 21 O/B.

I use the tail stock to bore the plug hole and also use it with the 1/4-32 tap. With the tap the tail stock is not tightened down. I can slide it back and forth while rotating the chuck head by hand. It works much in the same manner as if you were using a tap wrench,, go in a few threads pushing on the tail stock and pull on it slightly to back it out, all by rotating the head by hand.

Theres alot of other stuff to cypher too,, all while trying not to screw up!

 

[Sean Bowf]

Jerry, by "shoulder" next to the plug, do you mean a flat area?? So instead of being totally round, it was rounded up to the squish, but had a flat area near the plug??

Not sure what is it called, but I have seen a gizmo that would allow you to mount an item in it, then spin the item. This is what I had thought of doing with larger buttons. Then I could put the ball mill in it a little off center plunge it in, then spin the button. This would give me a donut shape, then I would just need to flatten out the bottom where the plug goes in. Is this profile you are talking about??

I saw a pic of someone with a tap in a lathe. It made no sense to me because i figured as soon as anything was turned on it would yank the button out of the chuck. It makes sense now...thanks.

Sean

 

[Jerry Wyss]

Jerry, by "shoulder" next to the plug, do you mean a flat area?? So instead of being totally round, it was rounded up to the squish, but had a flat area near the plug??

Not sure what is it called, but I have seen a gizmo that would allow you to mount an item in it, then spin the item. This is what I had thought of doing with larger buttons. Then I could put the ball mill in it a little off center plunge it in, then spin the button. This would give me a donut shape, then I would just need to flatten out the bottom where the plug goes in. Is this profile you are talking about??

I saw a pic of someone with a tap in a lathe. It made no sense to me because i figured as soon as anything was turned on it would yank the button out of the chuck. It makes sense now...thanks.

Sean

Yes you could go off center with the ball end but on a

cheaper lathe how you going to do that. It would take

a re-adjustment of the tail stock and you would have to

find center again. I don't have anything on the tool post

that would hold a ball end,, maybe that's the way to go.

Considering all that, you will be holding parts of the

button with the 3 jaw. The hold can let go under aggressive

cutting and can perdy much send you back to

square one.

A collet is the best way to hold a button in the lathe but the

thru the bore quick release type are made for larger

lathes. If there was another fixture to hold the collets in a

3 jaw I haven't found it,, but that would be a great fix.

 

[steve wood]

Jerry, by "shoulder" next to the plug, do you mean a flat area?? So instead of being totally round, it was rounded up to the squish, but had a flat area near the plug??

Not sure what is it called, but I have seen a gizmo that would allow you to mount an item in it, then spin the item. This is what I had thought of doing with larger buttons. Then I could put the ball mill in it a little off center plunge it in, then spin the button. This would give me a donut shape, then I would just need to flatten out the bottom where the plug goes in. Is this profile you are talking about??

I saw a pic of someone with a tap in a lathe. It made no sense to me because i figured as soon as anything was turned on it would yank the button out of the chuck. It makes sense now...thanks.

Sean

Yes you could go off center with the ball end but on a cheaper lathe how you going to do that. It would take

a re-adjustment of the tail stock and you would have to find center again. I don't have anything on the tool post

that would hold a ball end,, maybe that's the way to go. Considering all that, you will be holding parts of the

button with the 3 jaw. The hold can let go under aggressive cutting and can perdy much send you back to

square one.

A collet is the best way to hold a button in the lathe but the thru the bore quick release type are made for larger

lathes. If there was another fixture to hold the collets in a 3 jaw I haven't found it,, but that would be a great fix.

you hold the ball end mill in the same toolholder as you would a turning tool. drill and tap the hole first. you can power tap down to a 8-32 with no problem. then use the ball mill to make your bowl, make sure the mill is on center. once you have the bowl end done part off to length +. i have a piece of 3/4 brass i threaded to 1/4 32, i chuck up, then screw the button on to it,to turn the back side. you can also use this to mod head buttons

 

[Jerry Wyss]

On the subject of the "shoulder",, if you draw a circle and take the width of the plug face off the top of

the circle. You will see whats going on there with the shoulder were talking about. It becomes more

dramatic the smaller the ball is and will result in a greater loss in "plunge" the smaller it is.

With larger buttons this may not be much of a problem.