Official Luthiers Forum!
http://www.luthiersforum.com/forum/

End mills and router bits: interchangable?
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=22208		 Page 1 of 1
Author:  Dennis Leahy [ Fri May 01, 2009 11:02 am ]
Post subject:  End mills and router bits: interchangable?
Can end mills be used in a router/laminate trimmer just exactly the same as a router bit, or are they designed only for higher speed operations?

Check: American Carbide End Mills

Under $6 per bit (1/8" shank, 1/8" cutting diameter) looks pretty attractive for solid carbide.

Dennis
Author:  TonyKarol [ Fri May 01, 2009 11:05 am ]
Post subject:  Re: End mills and router bits: interchangable?
Most end mills are high speed steel, some are carbide. I use a 4 flute ball end 1/4 inch spiral end mill to do my truss rod slots, and trim headstocks to shpe using a template guide on hte router table Works for me. Until you try them, you will never know, but there is nothing wrong with using one.
Author:  Tai Fu [ Fri May 01, 2009 12:27 pm ]
Post subject:  Re: End mills and router bits: interchangable?
Most router spins way faster than milling machines anyways. I say use them, in fact they cut better than router bits and doesn't tear out as much. Only problem is that don't expect any of them to come with bearings so if you want to use templates you will need another method of guiding the cut.
Author:  Bob Garrish [ Fri May 01, 2009 12:38 pm ]
Post subject:  Re: End mills and router bits: interchangable?
Only the cheaper 'hardware store' end mills tend to be HSS now, you won't find a lot of HSS mills at any tooling dealers compared to carbide.

End mills work fine in anything that's made to use router bits. Mills tend to be solid where a lot of router bits are brazed. I've tried brazed router bits (even high-end ones) in the Fadal but they don't have any beam strength and they can't cut fast at all compared to a solid cutter (the shank will snap on a 1/2" brazed cutter at waaaay under half the speed you'd cut with a 1/2" mill!). If you don't need a bearing, dollar for dollar, 'router bits' are highway robbery compared to end mills.

End mills recommended for aluminum tend to have sharper edges and work better in wood than those that are specifically recommended for steel.
Author:  Dennis Leahy [ Fri May 01, 2009 1:49 pm ]
Post subject:  Re: End mills and router bits: interchangable?
Thanks Tony, Tai, and Bob!

I'm going to get some end mills. Looks like the ones at American Carbide are all downcut spiral.

Dennis
Author:  Link Van Cleave [ Fri May 01, 2009 3:14 pm ]
Post subject:  Re: End mills and router bits: interchangable?
Dennis,
Those bits that are in the link look fine. They also look like up cut to me.
I use 2 flute end mills all the time in a horizontal mortiser both carbide and high speed steel. (High speed steel is fine for wood but as Bob said hard to find. I prefer it because it is not as brittle.) It runs at 3,000 rpm. I also have a multi-router which is a fancy jig to hold a router. I have a speed controler that I use to run the speed down. Router speeds are a bit fast for larger end mills. However the smaller the bit the faster you want to turn it so with your trim router and those micro bits your speed will be fine. I personaly would use the 2 flute for the better chip clearing.
Link
Author:  John Watkins [ Fri May 01, 2009 3:24 pm ]
Post subject:  Re: End mills and router bits: interchangable?
I would advise against making any purchase decisions that are based around ambiguous terms such as "end mill". They are all, technically speaking, end mills.

Cutters that are made for metal-working will not work well at all in wood because they lack sufficient rake to be sharp enough. They are not intended to cut, but rather to shatter and clear.
Author:  Wayne Clark [ Fri May 01, 2009 3:28 pm ]
Post subject:  Re: End mills and router bits: interchangable?
I have purchased end mills from American Carbide for use in my router. No issues with the company and the bits work just fine in my router.
Author:  Dennis Leahy [ Fri May 01, 2009 3:29 pm ]
Post subject:  Re: End mills and router bits: interchangable?
Thanks, Link.

Yeah, I'm looking at upcut and typing downcut. Thanks for the tip on 2-flute vs. 4, as I would have probably ordered 4-flute thinking cleaner cut.

Dennis

p.s. Now, I'm also wondering if I can find a better price than $11 + shipping on a 1/8" ID; 1/4" OD collet adapter to run the 1/8" bits in a laminate trimmer. I guess I should have ordered one the last time I bought something at StewMac, but I didn't and now I hate to make that one item an order. There must be other sources for adapter collets.

John and Wayne, thanks, you and I were posting at the same time simultaneously together.

John, got a good source for carbide endmills with 1/8" to 1/4" shanks, that will be suitable for woodworking?
Author:  Link Van Cleave [ Fri May 01, 2009 4:17 pm ]
Post subject:  Re: End mills and router bits: interchangable?
Dennis,
That seems like a ok price. Seems to be the going rate for a collett adapter.


[quote]Cutters that are made for metal-working will not work well at all in wood because they lack sufficient rake to be sharp enough. They are not intended to cut, but rather to shatter and clear.[/quote

Joh,
I disagree. I have used metal cutting end mills for milling my woodwork for over 23 yrs. with perfectly fine results. I have used regular 2 flute end cutting end mills and also aluminum cutting ones. I use them in my routers and in a horizontal mortiser. They may not be designed for wood per say but in practice they work very well.
Link
Author:  Dave_E [ Fri May 01, 2009 4:57 pm ]
Post subject:  Re: End mills and router bits: interchangable?
I agree with John,

Stick to wood working bits, down cut for almost everything. They're available and they work in the Dremel type tools as well as trimmers (But you'll have to get a collett adaptor).

Dave
Author:  Dennis Leahy [ Fri May 01, 2009 5:51 pm ]
Post subject:  Re: End mills and router bits: interchangable?
Rod True clued me in to his source for adapter collets: Lee Valley, for $4.50 each.

With the knowledge gained that there is a difference between woodworking and metalworking engineering involved in the design of the end mills, it is probably wise to be cautious, to test the cutting performance on similar scrap before committing to cuts on instrument grade wood, to plan on multiple shallow passes rather than a "big bite", and to recognize that brittle chippy species (like Wenge) may really highlight the potential problems in using metalworking bits on wood.

Even knowing that, and somewhat based on the successes reported by some folks, I'll give them a try and see what I think. Some of the work I need to do will require several bits of various diameters, and if these bits work OK, the savings will add up.

Thanks!

Dennis
Author:  MRS [ Fri May 01, 2009 9:48 pm ]
Post subject:  Re: End mills and router bits: interchangable?
I have a couple that are solid carbide and i have used them with no problem.
Author:  Dennis Leahy [ Fri May 01, 2009 10:34 pm ]
Post subject:  Re: End mills and router bits: interchangable?
Todd Stock wrote:
The 1/32", 1/16", 3/32", and 1/8" CET bits cut anything I throw at them - I run the smaller ones at 54,000 rpm for inlay work, but they all cut cleanly at the low speed a laminate trimmer will give you. $5 each for the 2 flute cutters.

As for larger sizes of end mills, I used to use four flute mills for slot mortising...much smoother than miller style mortising bits and 1/4 the cost.

Thanks, Todd. Here's a link to CET, for anyone else on the hunt: CET end mills (sorted by price)

Dennis
Author:  Chris Paulick [ Sat May 02, 2009 12:05 am ]
Post subject:  Re: End mills and router bits: interchangable?
Carbide end mills are what carbide spiral bits are. Router bits are made to cut wood and come in 1/2' and 1/4" shanks. Where as mills come in different shanks and are usually use with the proper size collets. Two flute or 4 flute will determine your speed and feed when cutting metal. A 4 flute will cut twice as fast as a 2 flute. Go figure. I'd venture to say that a good mill is mroe precise then a router bit. Bottom line they just work fine on wood. But the HHS bits will burn up just as fast on wood. All those small bits you use for inlay are mills.
Author:  Tai Fu [ Sat May 02, 2009 12:44 am ]
Post subject:  Re: End mills and router bits: interchangable?
I used a small HSS cobalt end mill to cut slots in ebony for saddles, I never got any burns, and it cuts much better than router bits. If it starts to burn then the bit is dull.
Author:  John Watkins [ Sat May 02, 2009 8:29 am ]
Post subject:  Re: End mills and router bits: interchangable?
I'm sorry, Chris, but I have to disagree with just about everything you said.

Router bits come in all the same size shanks that end mills do, and four flute cutters have very different applications than two flute cutters. It really doesn't have anything to do with feed rate. Lastly, why would an end mill be more precise than a router bit?

This is like arguing that toothpaste is the best thing to wash your hair with.
Author:  Bob Garrish [ Sun May 03, 2009 2:13 pm ]
Post subject:  Re: End mills and router bits: interchangable?
I have to disagree with both of you :)

The reason to use a four flute cutter in most metals is a matter of feed rates. Your feed per tooth in steel is quite small, and your spindle speed has to be low to keep a proper edge speed, so you end up using a bunch of flutes to keep your feed rate up. In aluminum, where chip packing is the bigger problem, you generally use one or two-flute cutters except on finish passes.

So it is a matter of feed rates, but you can't necessarily feed twice as fast just because you've got more flutes. All cutting is a matter of balancing material hardness against chip packing to decide what'll cut best and then going as fast as you can without ruining the finish.
Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/