Cutting 6mm Dia Glassfiber Disks - Tips & Ideas

[beho86]

Hello,
I am working on a project, and I need to cut ~ 6 mm dia disks, and 3~4 mm thickness. The material is a composite made out of layered glassfiber. I am cutting those samples out of a 5 x 5 in composite.

My question is what is the best, accurate, and affordable way to cut those samples?

I tried to use a punch through the panel, but it gave me a destroyed disk. I have a custom made hallow cutter to cut the disks, but the tip bended with only 2 ~3 samples prepared.

I was thinking about using a hole saw, but I couldn't find a 1/4 in dia cutter, as I need the disks to have well refined edges. Any tips or ideas?

 

[Q_Goest]

Most plastics including reinforced materials are commonly machined just like metals on lathes, mills, etc... This is a lathe cut part.

 

[beho86]

so, probably the only way is to use a CNC mill, but it is going to waste a lot of materials. Thanks for the suggestion Q_Goest

 

[DickL]

You might try a wood plug cutter. These work in a drill press and are used to cut round plugs from a board. 1/4 in. is a common size. Fiberglass can usually be worked with wood cutting tools. Plug cutters are cheap, so give it a try.

 

[jgeating]

Yeah, the wood plug sounds good, as long as your setup is very rigid. I'm assuming you won't have a center drill because you want an entire disc, so you'll have to find a way to mount the plug cutter.

Also don't underestimate making an oversize cut by hand and then sanding it to the desired radius. It will take a little finesse, but it is the cheapest way, and if it meets your tolerances/specs, there's no reason not too.

Lastly, a cnc mill will give you the best results, and you could potentially lose the least amount of material depending on what end-of mill you use.

What is the thickness of th 5*5 sheet you have and what are your tolerances?

 

[DickL]

Plug cutters mount in a standard drill press chuck, same as a drill. They do not have a center hole, although some have a centering pin, which I think retracts as you drill. Once you've run the plug cutter, you cut the plug free from the block with a saw (band saws work good for this, also hand saws). Cut the plug a little longer than needed and then sand to final length.

You can buy one at Home Depot or Loews, shouldn't need to go to a high end or specialty store.

 

[beho86]

I was thinking about using plug cutters, but It will probably waste the same amount if I were to mill the disk using 1/8 end mill. don't the disk gets stuck inside the plug cutter?
I will try to use the cnc mill tomorrow and see.
The thickness of the 5 x 5 in blocks is about 4 mm. refining the disk by hand will take a lot of time, as I will be cutting more than 50 disk. Thanks guys

 

[pantaz]

For that material, abrasive water jet will give you the best surface finish.

 

[Topher925]

Is this FR4 or a similar material? If so the best option is to used a carbide (or better) tool at high speed.

Actually, the very best option is to use a water jet like stated above.

 

[beho86]

Water jet will be expensive for my work. It's similar to FR4, but it has several layers. I will be trying a plug cutter tomorrow, and I hope it works. it should be probably the fastest.

 

[Skrambles]

You could try using a jigsaw if you don't need the cuts to be very precise.

 

[beho86]

Thanks a lot guys. I used a wood plug cutter, and it worked like a charm. thx