Machining stand up letters in graphite?

[nickelback]

I need to know what type of cutter is best to use when machining letters in graphite. The letter are standing up .03 high and are .02 wide by .07 high. Does anyone have experience in maching standing letters in grafdite. It is for an electrode to burn a cavity in an injection mold.

 

Thank you

[Rekd™]

Diamond coated carbide holds up pretty well.

 

'Rekd

[Scott Sizemore]

We have made a lot of electrodes like that. Diamond tooling is for sure the best but, you will become limited in the smaller sizes of cutters.

[Accu-Molder]

+1 to diamond coated harvey tool company will coat there end mills if you need small cutters Ive got .010 .080 reach coated I think its around $12 above the cost of tool does vary with quantity

[Midwest]

+1 on the diamond coated

 

I just finished a trode and burn a few days ago. I went down to a .012 dia cutter.

 

The picture is on the FTP site if you want to see a picture called (1088 Blue Sky Insert.jpg)

 

I tried the hpphoto.com site but they removed the option.

[Teh Bear without Brains kinda idiot]

I engrave letters (stand-upping ) in everyday manner on copper and graphite .

Y prefer not cutters but end-mills .

End mills 3,1,0.5 and 0.3 mm thats what I use (coated Tia and not coated ) .

And my max speed is 8000 rpm ,but this is not a big deal

End mills are better then cutters because if a cutter has angle even 5 degrees for very small letters it is sometime enough to take of halh of

letter height and with end mill you will have no problems

 

And I do not have .

[Midwest]

Testing Photo Bucket.com for pictures since hpphoto quit working.

 

picture

 

picture way to big changed to a link. Have to try and resize picture.

[Mark Lovelace]

I have found carbide end mills to be sufficient for graphite, though they do wear out. If this were a production piece, diamond would be the way to go, but for just a one-off mold, graphite should be okay. The best thing I've found is actually to use carbide-tipped wood-working bits (router bits) if you can find the right size). They are lots cheaper than solid carbide, and they are not spirals. For some reason, this seems to improve cutter life. Of course, for the small size you are looking for, you probably won't find anything like what I'm talking about.

[moldmaker10]

I typically use a 1/32 dia. cutter with a TICN coating. Works well and is cheap since it is a standard size, also the limitation of my machine RPM's I use a speed multiplier with a 7:1 ratio. The biggest problem I've noticed machining letters with this size end mill is the distance between letters is usally too small so I will make 2 electrodes for one logo and omit every other letter. Works great for me.

[Jimmy Wakeford from Barefoot CNC]

+1.2.3 to everybody.

Just wanted to say NickelBack one of the coolest new bands since Zepplin.

 

Jimmy teh Dazed and Confused.

[Teh Bear without Brains kinda idiot]

In my place letters 1 mm (0.04)in size and even less is a usual thing ,so the end mill 0.3 mm is my permanent tool for this .

I use it a lot and it lasts a lot if you know how to use it (in copper for 8000rpm 70 mm/min take -off 0.05 mm for noncoated end mill 2 flutes )

Naturally I use other mills for roughing .

Many times I need to change a bit geometry for 0.3 to make space for mill ,but it is a little thing .

I made engraving on cylinder without 4-th axes (only indexing head ) and some other crazy engavings and a lot of logo`s and I try to stay away from cutters ,only end mills and I always have some spare mills for this case .

 

Winnie teh true type font