Router bits. ( Aluminium veneer )

[ynneb]

I am having trouble finding a router bit that will do what I need.

I am routing 12mm customwood. On each side of the custom wood is a veneer of 1mm aluminium. I have bought a 12mm straight bit that also has a round cutting bit at the end.

What I am finding is when I do a plunge cut, it cuts the aluminium but a small disk is kept under the bit. This resuts in the cut smoking its way through its cycle.

I have tried to put ramping moves into the cutting code but it has only limited succes.

I have seen cutting bits that drill through the work with a v at the end. Normally this would be ok but there are time in the cut that I only have to route half way through the work. I dont have tool changer capabilities.

Does anyone know of a bit that would do what I want.

[InventIt]

Would a sacrificial board under the work piece your cutting help to prevent the laminate from pushing out? You know, cut through your work piece and a few mm into the board underneath.

[turmite]

ynneb what kind of bit are you using? Endmill or wood router bit? If you have a spoilboard as previously posted a center cutting endmill should take the cut all the way through.

Mike

[ynneb]

Yes guys I do use a sacrificial board underneath. The problem is more that the bit cuts out a something like a coin that then sits under the router bit while it travels in an x or y direction. This "coin" clogs up the tip and causes the bit to burn its way along the cutting path. I need a bit that will plunge and not cut a "coin" . It needs to be able to disintegrate the aluminum while plunging.

[Ken_Shea]

Benny,
If you can, try a ramp cut into the material at about 2 degrees.

I am not sure of your controllers options but this may be a solution.

Ken

[ynneb]

Thanks Ken I will try ramping 2 degrees and report the results.

Nup still havnt read all that PDF.

To all those who dont know what ramping is, It is the back and forwards movement of the Z axis as it lowers the router. So you can imagine a lot of back and forward movement over a 20mm run going down 15mm @ 2degrees. I only leanrt about ramping a few days ago myself.

[turmite]

ynneb the "coin" is the reason I think you need to change bits.
It sounds like to me you are using a two flute wood bit that is not a center cut and it will leave a ring or coin if you will.
Mike

[ynneb]

I just thought Id make a picture of what ramping is. sorry for the poor quality, that is the only way i can make this gif fit.

[kong]

The gif is a little tricky to work out, but I think you got it. There is a good example of ramping over on Swedes website
http://www.5bears.com/cnc26.htm towards the bottom of the page.

[ynneb]

He He, Yes Kong the gif as it is in small version is strange. I dont know what happened with the upload. But if you push the gif and see it bigger it works ok.

[garagefela]

Hey Ben,
This may help with the problem of producing a coin and doing damage to the workpeice and also the cutting tool.

Lets say you want to go all the way through the full thickness of your board, I will assume 10 mm MDF with 1 mm aluminium on both sides.
Z0 is the top surface of the aluminium, X0,Y0 is the starting point just for this little excercise.

Choose a place clear of the actual finish size/wall, rapid to X0,Y0,Z3 and feed to Z1 then feed by ramping to Z-2 X30 then plunge Z-10 then another ramp movement back to the starting point X0 Z-13 you are now free to mill to desired finish size. These Z and X movements are only suggested sizes for this excersize ( X might need to be longer)

Doing this has benefited from producing no coins but has only wasted minimal time by not ramping through most of the MDF where it is not needed. IE ramp alum, plunge MDF.

This will work with a cutter designed for end cutting, if you are using a cutter that will not end cut you will have to ramp all the way through the thickness of the board ( or just push it through the MDF anyway)

Hope this helps M

[garagefela]

Ben,
I found this router bit which you may find helpful for cutting laminated products, it appears that during normal cutting it will lift the bottom laminate and push down the top laminate, very usefull if you find the cutter is lifting the top laminate off.

Although its a bit dear, if its needed, its needed

Its on E bay number is 2397639840 , I have no idea how to do a link, help me for your sake!!!!

Cheers M