What were these folks machining ?

My first thought was, due to the white dust and abrasion/rust on the machine guards, quartz but then I see hints of stingy chips on the lathe shot that looks more like plastic. Does anyone use a corrosive coolant on plastic ?

Or is it neither...any guesses ?



1997 cnc lathe



1997 cnc vmc

Could be they were simply machining more than one material.
Perhaps delrin or some sort of machinable wax, and then metal without cleaning in between?

Sean

Could be, but there are some photos I didn't include here that show an unusual amount of rust and missing paint inside the guards, for such relatively new machines (1997 Mazak's). The only other time I've seen that much corrosion on such late machines was the auction of Herazeous (sp?) Quartz Co. Besides alot of corrosion, Herazeous had to replace their Fadal spindles every 2 or 3 years due to all the abrasion and two shift use of top RPM.

Also, this company seemed to be set up for just one product, hence the one material theory. But who knows, they could have even bought the machines used with the abrasive material machinined by the previous owners...

I guess the bottom line is that I was hoping someone could point out a likely material match with the photos that might require an unusually corrosive coolant but where the material itself might not be very abrasive. Could be they just didn't care and used straight water for coolant but then the paint wouldn't have worn off...

[This message has been edited by D. Thomas (edited 08-06-2002).]

Ceramics, or glass-mica perhaps?

But would either of those produce the stringy chips in the lathe photo ?

I once got a great deal on a bunch of BP s that came out of a plant machining quartz, sticky white dust and corrorsion from using straight water as coolent. Lots of ware on those babies, all were for total rebuild.

The ultimate machining horror I've seen was in a division of Kennametal that machined carbide. All the manual lathes looked like their handwheels and other non painted parts were chrome plated...this from the carbide dust. If still in dust form it will wipe off but if it mixes with the least bit of hydraulic oil or general oil film, it becomes a nightmare to remove.

Don't know anything about the plastic material, but I used to run a job on a Nakamura CNC lathe that did in the paint job like that. They were 4130 planetary gear blanks, about 4 3/4" dia x 5" long, we turned one side down to about 1 5/8" for 4" of the overall length. Depth of cut was .250, with a .012-.015 feedrate at 400 sfpm, the chips were coming off so hot and fast that they would vaporize the coolant and it sounded like a continuous machine gun blast inside the cabinet. didn't take long for there to be very little paint on the inside of the machine.

Brian

D. Thomas...good question! Maybe jsut a crappy paint job? Have a couple Toyoda's that lost paint in chunks for about a year. The latest Haas was the worst though. We actually peeled some foot square sheets off the spindle nose and head. Coolant seemed to almost dissolve the paint in all cases. People that handle our coolant couldn't figure out why it was always "going bad". Ahhhhh, it's full of paint! Even our G&L's got to that point after 10-15 years of 20 hours a day use. It did take that long though. They use, or at least did use a really tough epoxy paint. Almost any finish will give up if you beat enough good sized 500 dgree chips against it.

Here's another photo of the VMC. Curious the rust at the bottom front edge of the guarding also..on such a new machine anyway.

I saw the machines in real life today. As it turns out the white areas are simply the remaining paint ! The chips are steel. Photos can be hard to judge sometimes I guess. I also found out how the lathe's entire left side sheet metal got so banged up....an unsupported rod extenting out the rear of the spindle pulled the bananna trick and tore up the guarding and knocked the Bijur auto lube off ! Besides the obvious saftey issue, not the kind of thing you want to do to a $90,000 lathe...