cutting fiberglass

[MILL IT]

we are machining 1/2 thick fiberglass with diamond cutters. we have alot of machining to do and breaking them about 1/2 the way thru the part. the job is running about 5 hrs. does anyone have any idea on a good cutter that will standup. max dia can only be 1/2. thanks for anyone's help

[robk]

No experience with fiberglass machining, but Harvey has some cutters. Also they have 'em Belin

[maestro]

We have run quite a bit of this stuff. Hate it. We tried all kinds of carbide cutters and get pretty much the same result. Diamond coated probably the best but also the most expensive. This material is so abrasive it's not even funny. If you have as much millng as you say you do, you will just have to run the cutters for a set length of time, then change them out. I do not envy you for having to cut this stuff, and it makes such an awful mess. It's one of my least favorite materials to work with.

[bobw4c]

We stay away from fiberglass, but one of our woodworking tool suppliers has some cutters listed. Try Onsrud.com.

[R. Arizola]

You're on the right track with diamond. Diamond coated carbide is another option. Onsrud Cutter, Starlite Industries, or SP3 have good products intended specifically for composites. Tool life is never gonna be as good as with metallic materials due to the highly abrasive glass fibers, but negative rakes and speed and feed optimization can help.

[R. Arizola]

You're on the right track with diamond. Diamond coated carbide is another option. Onsrud Cutter, Starlite Industries, or SP3 have good products intended specifically for composites. Tool life is never gonna be as good as with metallic materials due to the highly abrasive glass fibers, but negative rakes and speed and feed optimization can help.

[crazy^millman]

Try the burr type bits for routers they do very well in Fiberglass. I would also run air on the tool keep your surface speed down and all will go good. I use to get about 45-60 hours out of our tools for roughing and they were just regular carbide tools. I also was doing 1/2 think G-10 sheets and also did some compostite rudders for a submarine as well with these cutters and they did good again rember the surface speed if it is too hight you are going ot burn the material and the cutters.

 

HTH

[MILL IT]

this is a awesome place. thanks for all the info. where else can you go to get this kind of help. thanks again

[billystein]

be aware,

make sure you take extra to clean your ways often while working with fiberglass. I have seen it plug oil injectors and destroy ways.

Also dispose of chips and dust. Don't blow it around if you can help it. very irritating to the skin and can hang around for years.

[wildcat99]

+1 to Onsrud, they can help you out with cutters.

 

There are a lot of factors that could be causing your cutters to break. Keep tool stickout to a minimum and make sure collets are not worn. Toolholders, tapers and collets should be as clean as possible.

 

I would check backlash on all axes, which should be at zero or close to it.

 

Also someone here once said to increase feedrate until the cutter breaks then back off 10%.

 

HTH

[GreggT]

Another thing you might consider depending on your machine, is to use tool life (FANUC 21i) and change the tool at at a certain torque value.

 

I've never seen this done or done it myself. My machine will do it? But it sounds like a possible option. If you have a tool changer and this feature?

[Joels]

I machine fiberglass once a month. I found fiberglass routers on a web page called http://national-tool.com. I purchased the 1/4 diameter router and so far i have doubled my production from 12 a hour to 24 a hour. i used to mill with endmills but they dont last long. The one router i used last time worked better and is ready for the next load.

[crazy^millman]

You can also get them diamond coated by coating compmaines as well and they will really kick some but then.

 

HTH