which end mill

[linkintiger]

i decided to buy end mill from mcmaster but they have 3 different materials :
solid carbide, high speed steel and cobalt steel which one will perform best?

[louieatienza]

Originally Posted by linkintiger i decided to buy end mill from mcmaster but they have 3 different materials : solid carbide, high speed steel and cobalt steel which one will perform best?

Depends on what material...

Before you buy them from McMaster, check out Kodiak Cutting Tools. I've been very happy with the quality and service. And Ive got a lot of good results using their carbide endmills for aluminum, especially their ZrN coated endmills....

HSS is sharper initially but wears faster. I don't think cobalt is used for aluminum except for roughing.

[fizzissist]

Originally Posted by linkintiger i decided to buy end mill from mcmaster but they have 3 different materials : solid carbide, high speed steel and cobalt steel which one will perform best?

If you don't KNOW what you need, stick with HSS. Stick with ruining cheap tools until you figure out what you're doing, and what you need.

[Superman]

Originally Posted by linkintiger i decided to buy end mill from mcmaster but they have 3 different materials : solid carbide, high speed steel and cobalt steel which one will perform best?

The material your cutter is made from depends upon :-
- what material is being cut
- how much is to be cut, or how fast do you want to remove material
- what your machine is capable of doing ( speeds, feeds, coolant, rigidity etc )
- tool holding method ( shrink holder is better than a collet holder which is way better than a drill chuck ), the better the holder, the longer tool life and better part finishes that can be achieved )
- how much you have to spend

HSS cutters are cheap, sharp edged, cut slowly, can take a deeper depth of cut, have a little give ( flex ) when cutting conditions vary( eg. the width of cut varies )

CBD cutters are $$$ (not cheap), stiffer, can snap easier, longer lasting than HSS, costs are high to resharpen, added coatings allow for cutting different types of materials, cuts 4X plus faster than HSS, better & more consistant surface finishes.

There are many factors to consider what to use, pick up a tool catalogue and look at the cutting data pages or technical pages - it'll blow you away. I've only just scatched the surface.

It is a big learning curve that can only be achieved by hands on

But when requesting info on what cutter would be best suited, always supply the material type that is to be cut, how much material is to be removed, the desired width and depth of each cut, if coolant or air is available to cool the cutter & remove swarf ( already cut waste ) & maximum spindle RPM of you machine ( too high an RPM can burn out your HSS cutters, too low an RPM and the CBD cutters will snap & not work their best )

PS nobody has yet mentioned the option of the number of cutting edges ( flutes ), 2 flutes going up to 5 or 6 flutes.

[louieatienza]

Originally Posted by Superman The material your cutter is made from depends upon :- - what material is being cut - how much is to be cut, or how fast do you want to remove material - what your machine is capable of doing ( speeds, feeds, coolant, rigidity etc ) - tool holding method ( shrink holder is better than a collet holder which is way better than a drill chuck ), the better the holder, the longer tool life and better part finishes that can be achieved ) - how much you have to spend HSS cutters are cheap, sharp edged, cut slowly, can take a deeper depth of cut, have a little give ( flex ) when cutting conditions vary( eg. the width of cut varies ) CBD cutters are $$$ (not cheap), stiffer, can snap easier, longer lasting than HSS, costs are high to resharpen, added coatings allow for cutting different types of materials, cuts 4X plus faster than HSS, better & more consistant surface finishes. There are many factors to consider what to use, pick up a tool catalogue and look at the cutting data pages or technical pages - it'll blow you away. I've only just scatched the surface. It is a big learning curve that can only be achieved by hands on But when requesting info on what cutter would be best suited, always supply the material type that is to be cut, how much material is to be removed, the desired width and depth of each cut, if coolant or air is available to cool the cutter & remove swarf ( already cut waste ) & maximum spindle RPM of you machine ( too high an RPM can burn out your HSS cutters, too low an RPM and the CBD cutters will snap & not work their best ) PS nobody has yet mentioned the option of the number of cutting edges ( flutes ), 2 flutes going up to 5 or 6 flutes.

There's a good point: Figure out exactly WHAT you want to cut, and that will most likely dictate what kind of endmill you will purchase.

Generally, the number of flutes is dictated by the hardness of the material you are cutting and the spindle speed. It helps to study the recommended speeds and feeds of bits from each manufacturer for the material being cut.

As for carbide endmills, they're really not much more than HSS if you look at the right places. But like stated above, you have to do some homework and experimentation to get good results.

You can only use the manufacturer's guidelines as a starting point. Since you are posting here in the DIY section I can only assume that you have a DIY machine. Thus, it's probably not as stiff or powerful or fast as a commercial VMC, and you'll have to adjust the numbers to suit your machine. The downside to this is that your endmills will havev a shorter expected life than the manufacturer's data indicates, but that is the tradeoff you'll have to make.

Whichever you choose, get the shortest bit that gets the job done. If your spindle won't take the entire shank, then have the shanks cut down. If you're pocketing, try to use bull endmills (endmills with small radii on the cutting tips) since they're less prone to break; but keep in mind you'll have to use the measurement between the radii to determine your stepover. Raising the workpiece via a spoilboard, clamp, or platform will increase your z axis ridgidity usually. Always use lubricant with aluminum, or you'll wear your endmills prematurely.

[linkintiger]

mostly wood pine or oak and sometimes poplar.

[louieatienza]

Originally Posted by linkintiger mostly wood pine or oak and sometimes poplar.

Then I would get wood router bits, not endmills. I would suggest carbide rather than HSS. Check out toolstoday.com, and request a free catalog. They stock the entire Amana line, and are very fast shippers. The prices are pretty good as well.

You will have to determine exactly what kind of routing operations you plan to do, and that will determine the types of bits you need. Luckily everything's categorized in the website.

I would also suggest for now, you buy exactly what you need for the job you need to do. It's very easy to get caught up with what you "think" you're going to need, only to end up with unused bits collecting dust! A lot of guys, including myself, use up-spiral bits, for its clean cutting and chip extraction; but most any wood router bit would work.

Some common bits to get would be a straight bit or spiral bit (for pocketing and profiling; 1/8", 1/4", and 1/2" are common), bullnose bit or tapered bit (for deep 3D work), v-bit (for v-carving). You can get a wide mortise bit for workpiece or spoilboard surfacing. You will also see that some bits are made specifically for softwoods or hardwoods as well.

You can really use any bit designed for hand-held or table-mounted router use. The Freud Diablo line sold at Home Depot gives great results, and they even have an up-spiral bit. Very fine ground polished edges as well... For example I use a 1/2" 2-flute long straight bit (2" flute length) for profile cutting guitar bodies, and I've cut basswood, alder, redwood, sapele, Honduras mahogany, quilt and birdseye maple, with clean cuts.

[linkintiger]

great info louie one more question what bit will you recommend for half-round edges like in the half pipe? or something similar to colonial casing?

[louieatienza]

Originally Posted by linkintiger great info louie one more question what bit will you recommend for half-round edges like in the half pipe? or something similar to colonial casing?

For half rounds, they make roundover bits in different sizes. The handheld versions have ball bearing pilots. Amana sells a round over groove bit that would work great for cnc (no pilot) and it would trim the edge as well.

For colonial casing, you could probably use a raised panel bit to achieve the profile. Amana makes insert raised panel bits that would work. If you have to match an exact profile they can make a custom insert, though they're not cheap!

Note that many router bits made specifically for CNC have open flute design, meaning they are not anti-kickback and you should not use them in a handheld (or even table mounted) router...

Another bit to consider: if you do a lot of mortising work, or dados/grooves, you might want to consider a down-spiral bit (especially cross-grain in oak ply) or even a mortise compression spiral.

[linkintiger]

ok thx fot the info

[solodex2151]

For wood, you will want the following based on application:

General - 1/4" and 1/8" spiral flute endmills. There are 2 types, downspiral and upspiral. Upspiral will leave a nice bottom surface and help to eject chips out of the cut. Use it for dados, rabbets, pockets, and anywhere you need a crisp bottom edge. Downspiral helps hold the piece down and will leave a nice top surface. Use for thin sheet stock and profile milling.

Sign making - V-Carve bits produce nice crisp lettering. You can generally get different degrees of angle, though 60 and 90 degree bits are all you probably need. Bigger bits sometimes have a flat bottom for more pronounced lettering.

Wood Carving and decorations - Round nose bits (also sometimes called Ball-Nose bits) are used for finish passes when carving 3D designs in wood. They can be used for reeding, fluting, veining, grooving and general ornamentation where a round bottom groove is desired.

I offer some starter packs in each application for wood at CNC Bits for Wood : Fine Line Automation. MLCS Router Bits and Woodworking Products is another good place for router bits.

In regards to roundover bits and other edge bits, they do work well on the CNC, but normally I will do that operation by hand with a hand held router. With the bearing guides it's pretty much fool proof and I actually save some time. It takes me just as long to change the bit out and rehome the Z-Axis for a round over bit as it does for me to take the hand held router and do the edges myself. Add in that I don't have to rehome the endmill for the next set of parts and you can do the edge work while the machine is doing the next batch of parts and you have some real time savings. I am not advising against doing it with the CNC, just saying to consider whether or not an operation is worthwhile on the CNC.

Regards,

Nate

[linkintiger]

yeah i saw that upspiral always leave a small chips of wood onthe edges on top of the cut but it never happens when i use 2 flute straight router bit.