[mikejohn37]

I need to cut this wheel for a wooden geared clock from 1/4" plywood. (see pic?) So I need a bit less than or equal to 2.1mm or 3/32" (approx). A clean cut would be nice. What bit should I use and where can I get them please?Thanks in advance for the help.Mike

[daniellyall]

toolstoday O flute

[InMesh]

I thought you were joking they are a tool seller albeit a little expensive ,I have recently gone out on a limb for a 0.5 cutter a slow feed through rose wood and I was Impressed $12 fer 10 outa china these guys are getting good.

[daniellyall]

if you wont the good stuff with a long life you pay the money

[mikejohn37]

I tried to find a toolstoday O flute but I can only find one for aluminium. Would you mind linking to the page for me please or giving me a tool number. Sorry for the bother but I just can't find it. Mike

[daniellyall]

that will be fine or a upcut 2 flute coated cutter, coated cutters are more expensive but when you are finished with them you wipe them off and they last a long time

[RCaffin]

A 2 mm metal milling cutter with a DoC more than 6.25 mm is a bit long. Available, but treat with care.
Since you are cutting plywood, perhaps you should look at PreciseBits for their RCC08 router bits. They would suit. Spin them very fast: 20k to 60k!!!

Cheers
Roger

[Jon.N.CNC]

id either use a spiral down cut or a straight 2 flute. up cut will make for a rough top edge, you will still get a little furring of underside edge with downcut spiral but lesser of the two evils. hard to find either with a cutting edge of over 5mm in 2mm diameter tho.

[Jon.N.CNC]

A 2 mm metal milling cutter with a DoC more than 6.25 mm is a bit long. Available, but treat with care.
Since you are cutting plywood, perhaps you should look at PreciseBits for their RCC08 router bits. They would suit. Spin them very fast: 20k to 60k!!!

Cheers
Roger

20k+ on plywood? :s If your going 300ipm+ maybe

[daniellyall]

18000 to 21000 no problem depending on material, flutes, a upcut down cut compression spiral bit's are good for top and bottom edges

[Jon.N.CNC]

18000 to 21000 no problem depending on material, flutes, a upcut down cut compression spiral bit's are good for top and bottom edges

Yes at very fast feed. otherwise those speeds are ridiculous and a million miles away from recommended chip load for spirals especially. dull your bit in next to no time. Where are people getting these speeds from? the speed printed on the sides of your straight flute wood router bits dont apply to spiral tooling and barely apply to cnc.

never seen a 2mm compression spiral tho.

Always run your rpms at the lowest you can get away with, without it running lumpy, if you want your bits to last that is. 18k at 180ipm spiral in plywood say your only just going fast enough to stop the bit screaming and i personally wouldnt see the benefit of pushing a 2mm bit that fast, you would not be able to use a very deep doc, you can remove material faster at a slower speed with a deeper doc as heat transferal is better .

12k at 3.5-4m/min for cutting ply with a spiral.

[daniellyall]

from the sod that made the cutter's, just like you can run cutters at 60000 rpm ever seen a 60000 rpm machine there are a lot out there

[RCaffin]

On thinking about it, I have to agree. Trying to go 6+ mm DoC with a 2 mm cutter in one pass is not smart. Two passes (or 3), but with a high feed rate. Might even give a better surface finish.

I would like to hear a performance comparison of 'milling cutter' vs 'wood burr' too. I wonder whether there is really all that much difference between a wood burr and a notched roughing cutter - on wood.

Cheers
Roger

[daniellyall]

you only need to use ruffers with the hardwoods we can get Roger, high speed cutters are able to do a lot at a high speed it is what they are made for they are like $10 to $20 a mm starting at $30 for a 2 mm cutter. they last a long time as long as you look after them. plywood depending on if it is made from grade 1 timber you just go full wack, if its grade 3 well you have to go slower as the knots are hard as ****

[Jon.N.CNC]

On thinking about it, I have to agree. Trying to go 6+ mm DoC with a 2 mm cutter in one pass is not smart. Two passes (or 3), but with a high feed rate. Might even give a better surface finish.

I would like to hear a performance comparison of 'milling cutter' vs 'wood burr' too. I wonder whether there is really all that much difference between a wood burr and a notched roughing cutter - on wood.

Cheers
Roger

Lol 6mm doc. not exactly what i ment. 1.75mm to 2mm fine, not at 180 ipm tho, you will likely get 1mm doc max before you start over heating the bit and its dulling its tip doing more work than necessary.

better finish with more passes. best finish you can get in ply is with a full depth finishing pass. so not sure about your theory there. not that im saying thats possible with a 2mm bit in 6mm wood.

[RCaffin]

All very interesting.

I had better add that I have a machining centre, not a router and I have limited experience routing timber. I do a bit to make base boards and jigs for machining metal, mostly using very aged Australian hardwoods. For those who do not what these hardwoods are - you do NOT even attempt to machine them with HSS. They are not like pine and oregon etc.

I did try using MDF for a few jobs, but all I got was a lot of fluff. That is really crap stuff! Or maybe I was doing it all wrong.

Cheers
Roger

[Jon.N.CNC]

from the sod that made the cutter's, just like you can run cutters at 60000 rpm ever seen a 60000 rpm machine there are a lot out there

Maximum rpm is completely irrelevant unless you think your going to exceed it, you go by chip load... please do share the chip loads of these spirals you use at 20k+ and the feeds you use. 60000rpm great, completely irrelevant also as that is a completely different subject being that of engraving.

[Jon.N.CNC]

All very interesting.

I had better add that I have a machining centre, not a router and I have limited experience routing timber. I do a bit to make base boards and jigs for machining metal, mostly using very aged Australian hardwoods. For those who do not what these hardwoods are - you do NOT even attempt to machine them with HSS. They are not like pine and oregon etc.

I did try using MDF for a few jobs, but all I got was a lot of fluff. That is really crap stuff! Or maybe I was doing it all wrong.

Cheers
Roger

Mdf its very much down to the quality of the sheet. kronospan your general diy store sheet is useless if you want to do any more than straight contours through it, Medite is much better. Too many rpms with any wood, fiberboard will also contribute to a poor finish. best way i can descibe it is like a stretched cut is what you want if that makes sense.

HSS for wood? hss is becoming less available as its more expensive to make bits than it is with carbide so dont see many hss spirals anymore.

[daniellyall]

it all depends on the machine being used I have not had problems sticking a 2 mm bit cutting at full depth with a small step over or a small depth with full width you run it by what the chip looks like if it's dust slow down if it's a chunk speed up every type of woods needs a different speed, as roger said you cant use HSS with the hardwoods we get. MDF you just run to the grade and look at the chip or use your nose.

I use a chip load calculator

[bhurts]

Here you go. items in store on eBay!

This is where I buy all my small to medium sized endmills. Get both up and down spirals in 1/16 to start. These are good high quality USA carbide bits at incredible prices.

Ben