end mills?

[ramos96]

Hi all,

I would like to get some suggestions of end mills that I should buy? I bought the full kit but not the premium so I didn't get any end mills.I would like to start with CNCing into wood first and then work into engraving on metal surfaces.

Humbly,
Roo

[edwardrford]

My suggestion to anyone asking the question of "what endmill should I buy?" is pretty simple:

Buy an 1/8" 2 flute endmill.

This might seem like it's being over simplified, but here is my rational:

When I started into CNC several years ago I was paralyzed by the endmill decision. There are so many out there and there isn't much information suitable for a beginner. It's very intimidating: number of flutes, coating, speeds/feeds, etc). So I spent months and months (literally) researching what I needed to buy and trying to learn as much as I could about these mysterious tools. In the end, I just bit the bullet and ordered one, mostly out of frustration. "Just jump!" is what I thought.

Limiting yourself to one endmill is a constraint, and although the connotation of the word is somewhat negative, I like to think of constraints as something helpful! Constraints keep you grounded and don't allow you to get sidetracked with unnecessary action items. Constraints are good in my book. They let you focus on what's important by not giving you so many choices. For instance, when you are designing something to cut, instead of focusing on what bit you will use, you can instead focus on the design of the part, with your trusty 1/8" end mill as the constraint, you will have to focus your design to accommodate.

With an 1/8" 2 flute (center cutting) endmill, you can machine all the plastic and wood you want, and will do a nice job staying cool and clearing chips. Get a HSS (High speed steel) and save yourself some money. You might want to buy 2 or 3, just so you have extras.

Once you're comfortable using the machine, and you can see for yourself where another size/type of endmill would be more beneficial, that would be a good time to branch out and try a few other types.

I started the wiki page a while back: http://www.shapeoko.com/wiki/index.php/End_mills. It's by no means an all encompassing list, but it's a good place to start.


-Edward

[daveczrn]

Like Edward said. There really are so many choices for end mills its overwhelming for a beginner. If your cutting wood and plastic your feeds will be higher. You will need a little room for chip clearing so the 2 flute mill will be good. As well the high speed steel is a good thing because it has some give where it may not break right away if you program something wrong.

Good luck.

[AndrewR]

This should get you started. I ordered a similar one from Drill Bit City a few months back and it's met all of my needs so far.

http://www.ebay.com/itm/MICRO-MACHINING-KIT-10-NEW-CARBIDE-ENDMILLS-METRIC-/380469360194?pt=LH_DefaultDomain_0&hash=item5895bdb642

[levlandau2]

Yes, what AndrewR said above. A great set of bits at a good price. They are hard to break too and have withstood many errors on my part and have even milled aluminum.

[T4b]

http://lcamtuf.coredump.cx/gcnc/#2
Scroll down to 2.2 (can't link it directly).
It's a really nice guide, if you have the time, read it in it's entirety.

Edit: Although you need to keep in mind that some of the advice this guys gives is specific to his interests - namely small, accurate parts for which he mills moulds out of relatively easy to mill prototyping-material.

[Improbable Construct]

That is a nice guide!
Thanks for the link T4b.

[ramos96]

Thanks all!! I just finished my build yesterday
I clocked in right about 15 hours lol, but I was really slow and methodical in my assembly. Unfortunately I'm on my way to Ghana and cant play any more till I return in a month or so, but it gives good reading time. I will post up pics and videos in the buildlog when I return as there were a few things from the instructions I found missing.

Humbly,
Roo

[typomaniac]

Hey all : )

thank you very much for this thread where i learned a lot (which is now more than nothing but still very little ; ).

Unfortunately customs and shipping from the states to germany is very expensive and i recently lost a package
with no insurance so i wanted to take a look at german sources.

I was not able to translate some of the terms because i am new to cnc (e.g. »flutes«I guess it is »Schneiden«). I found a source with end mills and would like to ask, if someone can help me and identify the right mills (like the set or the recommended Buy an 1/8" 2 flute endmill)
The link is: http://www.sorotec.de/shop/index.php/ca ... aeser.html
I think it is the »2-Schneider (Flach)« or the »2-Schneider (Fisch)« but there seems to be no hss option.

What i also do not know is which size i should get. The recommendation is 1/8" 2-flute end mill but 1/8" is only the shaft size if i understood this correctly?

thanks a lot,

Andre

[cvoinescu]

I would say that the one mill you must have is a 1/8" (3.175mm) square-end center-cut two-flute end mill made of solid carbide. In this case, 3.175mm refers to both the shank diameter (which is the most common by far for small tools used for CNC) and the diameter of the cutting part. Center-cut means that the center of the mill can cut too, so you can lower the mill into the material straight down, like a drilling bit. Non-center-cut mills need to enter the material sideways, at an angle, so it's simpler to avoid them. Solid carbide is tougher and harder wearing than HSS, and, at this small size, not more expensive. Just forget HSS and go for carbide. In addition to that, there are special coatings that make the bit even harder wearing, or help with lubrication. For wood and plastics, uncoated carbide is cheaper and perfectly fine. From the site you linked to, this is one such end mill (but bear in mind that I don't know German: I used Google Translate and it looks like the right thing).

Depending on what you want to do, you may want to get one or two smaller mills too (e.g. 1mm -- it will still have a 3.175mm shank). You don't need many sizes; I think 1mm and 3.175mm cover a lot of ground. If you plan to mill smooth, rounded shapes you also want a ball-nose mill (3.175mm if you make large things, something smaller for small things with lots of detail). If you want to mill a lot of aluminium, plan on getting a specialized, coated bit, which will cut better and last much longer than uncoated carbide. For faster milling in wood, a 4-flute 3.175mm bit is useful.

An excellent guide is the guerrilla guide to CNC machining, mold making, and resin casting. Also, Improbable Construct shared valuable insight about end mills on this forum, so look for his posts.