What kind, brand and where do you buy your end mills?

[rlb]

Forgive me if this has been discussed--I did a quick search but didn't find what I was looking for.

 

I'm new to milling (other than some crude experiments with a Proxxon rotary tool in a drill press type holder), and I'm trying to get my information in order before spending any more on bits/mills

 

It seems that a 2-flute end mill is good for wood, upcut or downcut I'm not sure, but thinking downcut may be better.   I'm not sure how much this matters.  Some don't say whether they are up or down cut.  I'm looking for good quality, smooth finish, minimal tear-out.

 

What do you recommend, and who do you get them from?  Any other useful info that I should know about end mills?

 

Thanks,

Ron

 

 

[wefalck]

What do you mean by up-cut resp. down-cut?

[TBlack]

I'd second wefalck's question and further ask what sizes are we talking about.

Tom

[rlb]

I'm talking 1/4" or 1/8" shank size, 1/16" to 1/4" cutting size.

 

See below.

 

This image refers to "router" bits, but I have seen the terminology when talking about end mills as well (not even sure what, if any, difference there is between the two).

 

 

Ron

Edited February 9 by rlb

[Jaager]

I am having a difficult time imagining where I would need to make any of the three cuts in wood.

For an outside shape, a sanding drum -slower, but more forgiving.

A slitting/slotting blade for a thru channel

A burr for short. 

The tip of a 22⁰ twist drill for a rabbet-  but in hind sight, I think a chisel would have been wiser - much slower - but wiser.

 

In any case, I would want to get the wood shaving out.  If doing that affects the edge or surface, I would use a different tool. 

For wood - slow and shallow?

[Toolmaker]

Terminology has to be learnt and even then can remain confusing when we are writing explanations from different countries.

 

Not all milling cutters can be used to “plunge” cut. In the UK the different types of cutters regarding this issue were known as “end mills” and “slot mills”

What is the differences between a Slot Drill and an End Mill? A slot drill is a mixture of a drill and an end mill meaning it can plunge in like a drill then slot across like an end mill. Conversely, an end mill will primarily cut laterally and horizontally. 

If you want your cutters to be able to “plunge cut” make sure you buy the right sort.

 

Another relevant term is climb/conventional milling. Whether your cutters have right or left hand flutes it will be the direction of travel that dictates whether you are climb milling or conventional milling.  This terminology is also known as “up” milling and “down” milling depending where you learn your trade.

There is plenty of internet explanation for the different methods. If your milling for a living it’s worth knowing but for hobby milling taking very small cuts on wood it is really not important.

 

Member No Idea has discussed milling cutters on his build log and I think his advice is as good as you will ever need. 
 

Good luck with your milling

cheers

Paul

 

Edited February 9 by Toolmaker

[rlb]

Paul, thank you for referring me to "No Idea"'s build log.  That is exactly the type of milling that I need to do.  I just want to make sure I buy the right type and quality of end mill bit.

 

Here is a sketch of some of the cuts.  Yes, Jaeger, all can be done with a chisel (and I have made them all more than a few times!), but with so many to be done, learning to do these with a milling machine will save me much time.

 

Ron

Edited February 9 by rlb

[wefalck]

I am coming more from the metal side, where the terms conventional and climb-milling are used.

 

As toolmaker has pointed out there are end-mills that have one cutting edge that cuts over the centre, these are the ones that can be used for 'plunging' into material (like you do for a drill). Other end-mill can only be used for side-milling.

 

The only end-mills I have ever come across in practice that do 'down-cut' are certain single-lip carbide cutters. Everything else I have encountered transports the cut material upwards. I am not quite sure for what application the 'down-cut' single-lip carbide cutters were meant for - I got them by accident.

 

When milling in wood, it is important to have a cutter with a lot of room for chips, which is why router bits typically have only two lips. Three- to four-(or more) lip cutters are for metal. You also want a cutter with a steep spiral to lift the chips quickly out of the slot. 

 

The ubiquituous two-lip carbide end-mills with 1/8" or 1/4" shaft are probably good for most wood applications, if run fast enough.

[Toolmaker]

Ron,

Great explanation there from wefalck. I’m always grateful that he can be bothered to do the hard work of explaining things fully.

Mark (No Idea) would also advocate 2 flute cutters for easier chip removal and he would likely suggest this site for cutters;

 

https://cnc-plus.de/en/End-Mills-266/

 

For you, being in the US, you should just look for a stateside supplier of quality tools. I tend to use good quality metal cutting tools and having a Sherline miniature mill I am able to run the cutters at multiple 000’s of rpm. If the machine is rigid and the cutters are running true, you can’t go too quick with wood. Guhring is the make I use generally but I have also bought generic cutters from Amazon.

 

The beauty of using sharp tools on wood, whether machines or hand chisels, is that you are not creating dust and you can get a better finish against using sanding methods.

 

btw, a standard end mill is suitable for all those examples you have shown.

Edited February 9 by Toolmaker

[wefalck]

Unlike toolmaker it seems, I am a mere self-taught amateur ...

[Toolmaker]

37 minutes ago, wefalck said:

Unlike toolmaker it seems, I am a mere self-taught amateur ...

Maybe, but it’s a long time past that I did much serious practical work, and there is not much “mere” about either your advice or your machining output. I always enjoy reading your posts.

[rlb]

Thanks so much, wefalck, and Toolmaker, for providing some guidance to a beginner.  I have messaged with No Idea, and between all of you, I think you have given me the info I was seeking.  

 

For anyone following along, the key points for square end cutters for use in wood, as I have learned are:

     If unspecified most cutters are upcut, which is better for this use.

     2 flute cutters are best, with fishtail ends (vs flat ends) even better.

     High rpm's are important.

     Uncoated, carbide cutters are fine.

       

 

Thanks again,

Ron

Edited February 10 by rlb

[wefalck]

This is now a bit of thread-drift, but coming back to those down-cut carbide cutters: I got them by accident among a bunch of up-cut ones in a lot - some production industries (circuit-board manufacturers, aerospace, etc.) change their cutting tools regularly in order to avoid spoiled parts and unscheduled down-times. Such tools are still good enough for our puposes because they have been changed before they become dull. Such lots appear frequently on ebay. The shank diametres are usually imperial, i.e. 1/4", 3/16", and 1/8".

 

The best use in my workshop for the down-cut ones is as very stiff boring-bars on the lathe, preferably in through-holes. They work on any kind of material a shipmodeller is likely to encounter. They would also work for side-milling or milling of rabbets or basically anything, where the chips can be thrown out sideways easily.

 

However, the up-cut bits are much more versatile in any case and I would only look for them.

[Toolmaker]

It’s only slight drift as we are still on milling cutters. You are showing your experience now, using milling cutters as stationary tools, as in your boring bar.
When turning small aluminium parts (usually optical instrument housings) we would often plunge with a slot mill and then finish bore with the same tool. No tool change required. Years later they developed specific tools for this.

 

Here is another instance using a stationary milling cutter. I am trimming Syren cannon wheels to remove the char and to true from the centre hole. The parts are just pushed onto a tapered wooden mandrel and fed down past the cutter.

 

Edited February 10 by Toolmaker

[wefalck]

Yep, a milling machine can be used for turning as well. For amateurs, military field-use or on board of small ships in history, combination machines were developed (see www.lathes.co.uk) that could do turning, boring, and milling with little or no change of set-up. With modern CNC-machines the distinction between these operations also has faded away, as the work-piece would be chucked onto driven axes and then driven or stationary tools applied.

 

Another example for this 'relativity' is that lathe boring-bars can be used in a boring-head on a milling-machine ...

 

For the moment I am well kitted-out, but I used to be always on the look-out on ebay for lots of such carbide tools discarded by industry. There are small traders who buy them off industrial companies in bulk and then sell them in amateur-sized lots. You may get good cutters for less than 1 EUR/USD/GBP per piece. OK, wood can dull cutters quickly, but they usually lasted me for years.

[Mike Y]

If in doubt - a set of Proxxon mills that are included with their MF70 mill is a great start. No problems in any kind of wood, very clean cut, can do plunge cuts as well. No burning, charring, they cut like butter.

Do not use them in your rotary tool freehand though, as they would dig into the wood and jump away from you.

 

Part number NO27116

https://proxxon-us-shop.com/products/milling-cutters

[No Idea]

9 hours ago, Toolmaker said:

It’s only slight drift as we are still on milling cutters. You are showing your experience now, using milling cutters as stationary tools, as in your boring bar.
When turning small aluminium parts (usually optical instrument housings) we would often plunge with a slot mill and then finish bore with the same tool. No tool change required. Years later they developed specific tools for this.

 

Here is another instance using a stationary milling cutter. I am trimming Syren cannon wheels to remove the char and to true from the centre hole. The parts are just pushed onto a tapered wooden mandrel and fed down past the cutter.

 

That is class work mate and the experience shines through

 

[No Idea]

2 hours ago, Mike Y said:

If in doubt - a set of Proxxon mills that are included with their MF70 mill is a great start. No problems in any kind of wood, very clean cut, can do plunge cuts as well. No burning, charring, they cut like butter.

Do not use them in your rotary tool freehand though, as they would dig into the wood and jump away from you.

 

Part number NO27116

https://proxxon-us-shop.com/products/milling-cutters

Hi Mike - These are simply over priced 2 flute fish tail end mills that can be bought for a fraction of the price elsewhere.  You are right though that they really are great for the job that we do and most importantly get the chips out quickly.