Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Tjones14 on January 02, 2010, 04:49:45 AM

Title: router tooling
Post by: Tjones14 on January 02, 2010, 04:49:45 AM
Hi everyone,

I'm slowly working on putting together a mill/router for my workshop. I have many years of machining experience so I'm very familiar with the machining process, however, after watching a few of the artsoft videos on youtube a question popped to mind. I am planning on using a spindle rather than a standard router (I need the cnc speed control for metalworking) I believed that I would just be putting standard router bits into a spring holder and using those when I was working with wood.  However, it looked as though the machine that artsoft filmed cutting wood was using the mill tooling that I am used to from working in a production (metal) machine shop.  Please advise if I am seeing something incorrectly. 

Thank you,
T Jones
Title: Re: router tooling
Post by: Tweakie.CNC on January 02, 2010, 07:48:04 AM
The secret is in getting the cuttings out of the tool when routing wood (and plastic) otherwise the work is burned and possible tool damage occurs.

The four or more flutes of conventional milling tools often clog, so wood cutting tools with one or two flutes generally perform better because they don't suffer this problem so easily. Having said that, the conventional milling tools are generally much better quality and keep their sharpness better.

I have found (from others example) that a low pressure air jet, aimed at the tool, gets the cuttings out and enables multi-fluted tools to be used successfully. So the bottom line is try it and see.

Hope this helps.

Title: Re: router tooling
Post by: ger21 on January 02, 2010, 08:31:10 AM
There are spiral router bits that look like metal cutting endmills. Although many people do use metal cutting endmills to cut wood.

Title: Re: router tooling
Post by: Tweakie.CNC on January 02, 2010, 08:53:30 AM
To expand slightly on Gerry's reply without causing offense I trust.

The endmill definition may vary from country to country but here in the UK an endmill does not have the cutting surfaces on the tip extending completely across the whole face unlike a slotdrill which does.
This is an important difference as the endmill does not plunge feed as is often required with woodworking.

Title: Re: router tooling
Post by: Sam on January 02, 2010, 09:09:43 AM
Not sure exactly what video your referring to, but most carbide cutters can be used successfully on wood as well as metal.

WARNING: Rambling below....

 The thing about having a machine for both metal and wood is that the spindle speeds are so radically different for the two. The tooling may be the same, but the spindles are vastly different. The spindles that do cover a broader range cost a premium, and even then, they don't cover enough of the range to be really considered "dual purpose". When I think of speeds, I think 60-2500 rpm for metals, 12,000-30,000 for wood. Most people build their machine for either wood or metal, not both. You can cut metal with a high speed spindle or router for wood, but it has many drawbacks, and you shouldn't expect near the results you achieve with a milling machine. Some people have more than one spindle. If you make a simple attachment for a router, you now have a suitable secondary spindle for wood. The same goes for high speed engravers. Most of the wood guys have an attachment for those too. Also, keep in mind that if your going to be cutting metal, the rigidity of the machine needs to be far far far more stable, than for wood. Any flex at all, and you get broken cutters on the tips. After that happens....well, you've got years of machining experience to know what happens when using dull or broken cutters. This extra rigidity equates to a much higher price in the machine build.

I know I went into more than what you asked for, but you stated that you have years of machining experience, so naturally I'm thinking you want to achieve results close to what your used to with metal working machines. You also state your plans for a spindle, which tells me that your building, rather than retrofitting. You also state that you want to cut wood. This raised an eyebrow, and I felt some common misconceptions needed to be, at least, brought up.   With a bit (tons) of research and a little (a lot) care in design, you can achieve a machine capable of cutting both wood and metal, but it's not really possible to get both without some versatility. I'm not trying to dissuade you in any form or fashion, just a friendly "heads up" from my personal opinions. Take it with a grain of salt. When you start your build, keep us posted with pics and such. We feed on pics like a cow in a field. Can't get enough!
Title: Re: router tooling
Post by: Sam on January 02, 2010, 09:20:04 AM
Tweakie: That's indeed true on that particular style of cutter, however, there are also "center cutting" endmills that go across the entire face for plunging. Most of the carbide cutters are center cutting, at least the ones I'm used to having.
Title: Re: router tooling
Post by: Tweakie.CNC on January 02, 2010, 09:34:53 AM
Thanks Sam I didn't know that, I thought all endmills had the center hole.

Title: Re: router tooling
Post by: Tjones14 on January 03, 2010, 01:42:02 AM
thank you everyone, this was all great information.  I read stuff earlier but I didn't have a chance to reply at the time.

Sam - To tell you the truth, I have been working so hard on the engineering of the gantry/table/other non-spindle items that I hadn't though about the difference in RPM's necessary for the different material until you mentioned it.  I cannot tell you how glad I am that you brought that up.  It changes my plans, and I'm going back to the drawing board.

Since reading this today, I have enlisted the aid of one of the engineers at work to help me with the design.  so hopefully, I won't miss stuff like that anymore.  We'll see how things turn out.  I might end up making two smaller machines (one for wood and one for metal) rather than the larger machine that I had originally envisioned.  I don't really need a 6x3 table anyway. lol.
Title: Re: router tooling
Post by: Sam on January 03, 2010, 03:22:38 AM
Thank you for replying back. Glad to help out. I can tell you from my own experience, that I'm glad I started with a router build, and not a mill build first. That way, you find out the majority of the mistakes, and the "wish I woulda done it this way instead of that". I would rather have a second rate router than a second rate mill. Routers are more forgiving. Good Luck!!
Title: Re: router tooling
Post by: ger21 on January 03, 2010, 08:27:08 AM
When routing wood, unless you are using very small tooling (<.125"), 10,000-18,000 rpm's is all you need. With a 1/4" bit, you can cut at 300ipm at about 14,000 rpm.

Tweakie mentioned blowing the dust out of the cut to prevent burning. While that helps, and will extend tool life, there's no substitute for cutting fast. If you need an air jet to prevent burning, then you're cutting too slow.
Title: Re: router tooling
Post by: cncrailroad on January 26, 2010, 12:15:28 AM
The one thing that no one has mentioned is the mess!  Cutting metal vs cutting wood creates two different types of chips.  Metal requires a coolant system with some type of recovery system, where wood requires a dust collection system.

I have worked with both and when I purchased my router I made the decision to stay with wood, plastic, etc. anything that a dust collector will take care off.  After spending 17 years as a machinist I'm tired of the watery mess.

Good luck on your build, please post pictures, that's how we all learn.