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racerbear02
09-11-2014, 03:12 PM
Another couple of newbie questions I am faraid

Are there any timbers that should be avoided in regards to routing ease and finish?

Also, is it possible to simulate fretwork with a CNC router? if so what sort of tooling and would it need to be roughr out with a large diameter tool first?

Thanks in advance

EddyCurrent
09-11-2014, 10:23 PM
Another couple of newbie questions I am faraid

Are there any timbers that should be avoided in regards to routing ease and finish?

Also, is it possible to simulate fretwork with a CNC router? if so what sort of tooling and would it need to be roughr out with a large diameter tool first?

Thanks in advance

Oak can be a problem with long splinters coming off, especially if you route against the grain. It's similar for any coarse grained wood or where the grain changes direction, tearout is always a danger.

With fretwork it implies cutting right through the work, so I use the smallest end mills I can easily find such as 1mm diameter. e.g. http://www.ebay.co.uk/itm/10pcs-1-1mm-Carbide-End-Mill-Engraving-Bits-Great-Replacements-for-CNC-Machine-/271659219689?pt=UK_BOI_Metalworking_Milling_Weldin g_Metalworking_Supplies_ET&hash=item3f4026bae9
It leaves a 0.5 mm radius in corners that can be left or cleaned up with a suitable hand tool such as a knife. You can take a roughing cut first with a larger cutter, leaving a 'roughing clearance' of about 0.5mm, then take a finishing pass with the small cutter preferably full depth.

Boyan Silyavski
10-11-2014, 01:55 AM
There is no wood that can resist sharp carbide bit at the proper feeds and speeds and using a technique exactly for it. Its art .

Fretwork is difficult. Meaning that needs planning. What Eddy says is one way. Depending on thickness desired, material and size there are other ways:

-use V bit and route the design leaving 1mm of material bellow. Flip and surface or just sand it.
-use waste board and screw the material where possible
-use very thin double sided sheet tape.
-mount 2-5w laser diode and just burn it if thin veneer
-make your DIY Swivel Drag Knife Cutter

racerbear02
10-11-2014, 08:20 AM
Thanks for the replies gentlemen, very helpful.

Of course round here there is an abundance of oak. typical. !!

Eddy, I guess those 1mm tools you listed are quite fragile, hence being sold in packs of 10

What sort of feeds and speeds and depth of cut would they work best at in hardwood? and what would be their life expectancy, assuming not broken first ?

silyavski, I had not considered that as an option at all, on 10mm thick it would give quite an undercut which might not be what I am looking for aesthetically though, but I shall explore the idea.

Thanks again

racerbear02
10-11-2014, 08:26 AM
Thanks for the replies gentlemen, very helpful.

Of course round here there is an abundance of oak. typical. !!

Eddy, I guess those 1mm tools you listed are quite fragile, hence being sold in packs of 10

What sort of feeds and speeds and depth of cut would they work best at in hardwood? and what would be their life expectancy, assuming not broken first ?

silyavski, I had not considered that as an option at all, on 10mm thick it would give quite an undercut which might not be what I am looking for aesthetically though, but I shall explore the idea.

Thanks again

Boyan Silyavski
10-11-2014, 11:48 AM
Hi,

Tool life depends most of all on deflection and tooth engagement. All else is just a way to achieve these 2 or a result of it is achieved properly or not .

Hence, rigidity of the machine, setup, speeds and so ...

Basically small tools/3-6mm/ at 16000rpm and 60 IPM is a good starting point at depth 1 diameter. Though i tend to go 18000 for hard woods and lower the feed if the bit is thinner than 3mm

luke11cnc
27-01-2015, 08:01 PM
I find ash wraps it's self around the cutter
I cut oak and 20000rpm and at 1800mm/min and a cut of around 3mm with a 6mm bit

James