Cuttoff off 3/4" "cane" shaft of .1" wall thickness 1

[JustinM]

I have a fiberglass reinforced epoxy shaft that I need to cut. It is Cuttoff off 3/4" diameter with .1" wall thickness.
I have believe that abrasive tooling is best for this. I plan on using a

http://www.toolbarn.com/product/milwaukee/6180-20/

Cut-off machine with an abrasive blade.
What blade materials do you recommend? Is this the right aproach? I need about +/- .125" and little to no delamination.

Am I on the righ track here???
Thanks,
Justin

 

[GBor]

We used a diamond-tipped blade for similar materials. Are you only cutting 1, or is this a production line? You may also want to stick something inside the hollow portion and, it possible, stick that inside another pipe. Cut slowly and you should come out with a pretty clean edge.

 

[JustinM]

We are doing a production line. I am planning on designing support for both sides of the cut. One concept is to mount it into a pin for support.

How many teeth on your blade?

 

[GBor]

It has been a while, so I don't recall. Sorry...

 

[Compositepro]

That saw will work but it will be a very rough cut. I posted this in another thread on cutting composite tubes:

1. Use a high-speed abrasive cut-off blade.

2. Support both sides of the cut so the pieces cannot move during cutting. Peeling-out the last fibers to be cut is very common if you don't do this.

3. Avoid generating too much heat during the cut. This depends a lot on the resin's heat resistance. If the resin softens and degrades at low temperature it will be difficult to get a neat cut. Water cooling may be required but be aware that wet carbon dust on metal is very corrosive to the metal (galvanic corrosion).

4. Rotate the tube while cutting very lightly into the surface. This minimizes the temperature reached at the cut. It also directs the cuting forces tangetial to the surface. With a straight through cutting action there will be times when the cutting forces are directed out from the surface and this causes peeling.

How do you do what I describe? Put an abrasive blade in a table saw, use the fence to control your cut length, and use
a piece of wood on your slide to push the tube until it touches the blade. Then rotate the tube as you slowly push it into the blade. The blade only needs to advance through the wall thickness but you can push it further to polish the cut on the side of the blade (you will cut into the wood too, but only on the first cut). Remember to hold onto the tube on both sides of the cut.

You will generate a lot of heat cutting fiberglass. If you are doing high volume cutting you must use water cooling.

 

[PanelGuy]

100% agree with Pro.

Rotating during the cut avoids fiber splitting on the exit.

Support is good, but an outside support helps keep the round.

A good abbrasive blade is best, you want to grind glass not cut it. A toothed bade with fracture the composite and cause well..you know.

A water coolant flood is great. May not need it.

Personally, I would put a fixture on an old surface grinder and use a thin abrasive blade. The wide angle of attack should help avoid the splitting and they usually have coolant.

Another way that is not addressed here that is excellent is just cutting it off with a lathe. You are probably better to just spin the shaft and get a full round cut. I used to do a ton of precision rod stock this way.

 

[MandrelMan]

Compositepro has several good points, including number 3 which dicusses resin heat resistance. Try using a ceramic endmill if you decide on a production volume.