[rajanish]

hi
can anyone suggest me how to remove chips from workpiece during cutting by technique of vacuum sucking by some vacuum nozzle??
thanks

[ImanCarrot]

I use a venturi type extraction system. It works by forcing presurised air down a nozzle: this in turn creates a vacuum at the nozzle entrance. However, I do Diamond Machining and the swarf/ chips are extremely fine... my finish cuts are typicaly 0.002mm deep.

[rajanish]

hi thanks you
actually i am also working on diamond turning..i wanted to remove chips from the work zone..i tried few methods for that particular work piece to remove chips, but i couldnot...i want to try this vacuum sucking method...thanks for the suggestion...

[ImanCarrot]

Wow! someone else who's doing Diamond Turning!!! Hi There

Are you machining Aluminium? if so I assume that the swarf comes of in a big long silvery thread?

The trouble I find with swarf extraction is that you can get it started, but it always clogs up eventualy.. even using the veturi system.

Incidentaly, I find that coolant positioining is important to force the swarf away from the tool.

When machining plastics I have a larg diameter extraction system from Air Cleaning Systems here in the UK, it needs cleaning abot once a week.

Oh, Diamond Machiners are notorious for taking their machines to bits and tinkering with them... be careful if you leave the enclosures off when machining Aluminium as the swarf conducts electricity and can short out boards etc.

Anyways! nice to meet you

[rajanish]

i am not machining aluminum. we machine brittle materials like silicon. and now i am trying to machine a new optical material and i found problems regarding the chips, so i am finding proper method.
anyway nice meeting you too...

[ImanCarrot]

I have also machined brittle materials like Silicon, Germanium, Zinc Sulphide and Zinc Selenide etc.

I assume that the problem you're having is a poor finish?

The stuff I check to ensure a good finish are:

Tool Top Rake= -25 degrees (this is vital).

Coolant pointing upwards (beneath the tool).

Tool has to be a Natural Diamond (synthetic are no good).

The material I cut has to be mono- crystalline, polly crystalline cuts badly.

Vibration, vibration, vibration.

You've probably checked all these, but thought I'd mention it

[rajanish]

hi iman,
could you please provide more info on venture type extraction system..
thanx

[RICHARD ZASTROW]

rajanish, You might look into the Vortec site. www.vortec.com Look at the Vortec and Paxton product lines for good information. I do not sell, represent or have any interest in Vortec/Paxton. I did use a vacuum method for chip removal in the past.

[rajanish]

hi richard
thanx for the suggestion...i'll check out that site..i tried vacuum sucking but it was not efficient..so i am looking for better performance..my chips are very fine and its very difficult to remove from the machined surface...causing damage to the surface if i try to remove offline..

[sc brian]

Coming into this thread two years late...

Rajinesh, search for articles published by LLNL for machining KDP...they lead the world at this art. There is an entire process published on the web

Regarding chip extraction during diamond turning:

I am typically frustrated by clogging of the extractor. Anyone have any good ideas?

[fizzissist]

I worked for a record company R&D section and one problem with cutting laquers (for records....anyone remember them?) is picking up the chip at the beginning of the cut so it doesn't wrap around the cutting stylus and make a mess of things, if not just going up in flames. You don't want to "drop the chip" during cutting either.

The trick is getting the nozzle close enough to the stylus, but not so close that the vacuum noise is "heard" on the disc. .. With a really good quality system, you can hear the noise in very quiet passages with the gain up.

We used 1/4" aluminum tubing, bent and formed and cut the nose just right, and the chip went down the tube into the chip jar just fine.

Thinking of this gave me the idea to do the same thing with this problem, but if clogging powder is the glitch, then do a reverse spray mist thing....turn on the vacuum, then turn on a slight spay of water (injected into the nozzle instead of outside the nozzle) to flush the powder going down the tube?

....Just thinkin' out loud...

[sc brian]

As long as we are discussing diamond machining of metals and crystals, I would like solicit opinions on environmentally and health safe coolants for this work, in particular for metals like aluminum and copper

Historically we have all used odlorless mineral spirits, mineral oils, kerosene, naptha, etc., but these will eventually kill you if you breathe enough and if you vent it outside then you will have environmental problems. Or if you are really lucky they will just catch fire.

Anyone have any good ideas? Anyone try vegetable oil? Anyone try water soluble mist coolants? Pros? Cons?

And if you have a magic potion, where do you get it and how do you clean it off of the work when done?

The coolant needs to allow for a good surface finish, allow for the surface to be thoroughly cleaned, and not be dangerous. I am all ears.

[tech-trans]

We have had a long history of success building complete custom vacuum systems which collect chips (and other materials) during machining phases. We have collected chips from deep galleys of aluminum cylinder heads for Ford, other programs have included removing finite carbon fibers and ti from aircraft skins thus removing hazardous materials from the environment.

Thank you,
Kris Walker
Tech-Trans Unlimited Corp.
http://www.tt-uc.com

[najdub]

I am looking for a source to purchase clear lexan vacuum fittings possibly with some sort of a brush end to mount as close to the machined part and cutting tool. Does anybody know a supplier that specializes in this sort of thing?? I have a powerful vacuum system and have problems concentrating the vacuum to the cutting tool and prevent migration of the dust to the equipment and operator. The equipment used is a engine lathe 36"x 120" between centers. The workpiece is 25"OD x21"ID x38" long. Both ID and OD is done with a boring bar. Material is Fiberglas. Tooling is PCD with .079 max. depth of cut generating a lot of dust.

[underthetire]

Depends on the material. I know a lot of our diamond turning is done with alcohol. But most of the parts would fit on top of a straight pin, and can't be contaminated with anything.