Lathe questions

[Jeff]

I was watching a youtube clip the other day and saw one with a CNC where they used compressed air as a coolant. I was using a friends lathe recently taking a finishing cut and the swarf was building up, so grabbed an air hose and blew onto the tool. This removed the swarf building up on the tip which looked like it was scratching the finish on the part.

Is this bad? The coolant pump on said friends lathe was broken so I had not been using coolant anyway. Does swarf buildup affect surface finish?





Jeff

[Blknight.aus]

depends on how and what you're cutting.

simple answer,

Yes.

[Bigbjorn]

Sometimes you will get a build up of swarf welding onto the tip, particularly aluminium workpieces. Yes, it will affect finish. An oil can or spray bottle of kerosene squirted onto the tip from time to time usually stops build-up. Don't set the swarf tray on fire! I have also seen plenty of machinists use a scriber to pick at the build-up whilst the machine is running. Please don't do this unless you are in a suit or armour, and likewise, with long chipping material, don't try to remove a birds nest of long swarf from around the job or chuck whilst the machine is running. Good way to lose a finger or two or get grabbed and dragged in to the machine.

[Jeff]

I am mostly turning 5000 or 7000 series aluminium.

I sometimes pull the birds nest of swarf away with a tent peg, but shudder at the thought of using my fingers.

A friend often turns magnesium as he makes Manx Norton replica brake drums, and often has swarf fires under his lathe.

Jeff

[Hall]

Remember as a apprentice the other apprentice did some serious damage to a hand. Dropped the swarf hook into the swarf on the floor next to the head stock. Went to retrieve it and the swarf pick up around the chuck. I had to clean up. You can get spray cans of cutting fluids. These are better as they not flammable. Always found tool steel best for non ferrous metals as you can get a much sharper edge than carbide.
Cheers Hall

[marko66]

Hi All


Apparently the waste from bio diesel is also a good lubricant


Regards Mark

[snowbound]

Hi All


Apparently the waste from bio diesel is also a good lubricant


Regards Mark

Don't use it in the bedroom!

[Jeff]

I bolted some wheels together and had to take a skim off the edges. Initially I used what I thought was slow speed and a carbide tip, but it chattered like a very chattery thing, so I changed to HSS and ran it about 25 rpm and it cut beautifully.





Jeff

[Jeff]

More questions. I may be able to pick up a lathe, but it has been neglected and abandoned (indoors) for a few years. The bed, cross slide and chuck have quite a bit of surface rust on them and some gears are missing from the feed. I have not run it, as the oil level was low, but it has had little use and was looked after before being 'abandoned' when the tradesmen were moved elsewhere.

How rusty is too rusty?

Are gears and other bits available or interchangeable between brands?

Jeff

[JDNSW]

More questions. I may be able to pick up a lathe, but it has been neglected and abandoned (indoors) for a few years. The bed, cross slide and chuck have quite a bit of surface rust on them and some gears are missing from the feed. I have not run it, as the oil level was low, but it has had little use and was looked after before being 'abandoned' when the tradesmen were moved elsewhere.

How rusty is too rusty?

How long is a piece of string? As long as the precision mating surfaces are not pitted enough that they do not slide smoothly, should be OK after the rust is removed. Be very careful removing rust to not remove any metal. Other than on mating surfaces, the rust will only be cosmetic.

Are gears and other bits available or interchangeable between brands?

Jeff

Whether bits are available new will depend on the brand. If it is a popular brand, ebay is a likely source. Parts are unlikely to be interchangeable unless one brand is a copy of another (which happens quite a bit, but knowing this is not likely to be easy unless you have an informant who is experienced on both!)

Hope this helps,

John