Seeking advice on suitable lathe

All of my CNC machines are Japanese Roland Machines. Designed to create high precision masters in lighter materials. Okay with aluminium and such like, but boring out stainless steel is a no no. I specifically use those as they can work directly from complex design packages using .stl and .obj files.

I take on board all the comments on suitable lathes. Whilst there are some big heavy lathes available out there for extremely low prices, often even cheaper than many mini lathes on offer, for my own circumstances and requirements for portability (within the workshop) I think a bench top mini lathe would be a more realistic option.

If you were willing to go up a few kg on weight, perhaps a 55 kg Chester DB7 (or similar lathes from Warco and no doubt others) would suit? They are more rigid than a mini-lathe but have quite short beds, but for your purposes that could be an advantage.

Brian

Edited By Brian G on 09/09/2019 12:58:57

Boring out to 20mm would really require a 3/4" drilled hole to start with. Have you thought of a bench mounted pillar drill to compliment a small lathe. I have a 7 x 12 mini lathe at home, and it struggles to drill 1/2" holes in mild steel, even in the low gear. It would be fine for the finish boring and parting off.

For stainless steel you could buy tubing which would save on material and drilling and use a jewlers mandrel to adjust the size to suit. I don't know in what form that the Damascus  steel comes in but that can be forged using a blank and punching a spike through and then using the mandrel to finish just finishing them on the lathe so any small lathe would do as long as the parts can be held on a mandrel to Finnish and polish.

David

Edited By David George 1 on 09/09/2019 15:38:00

Edited By David George 1 on 09/09/2019 15:38:44

I had thought of thick walled stainless tubing David. Whilst it does appear to be available, I am not sure how the variants with welded seams would actually machine. Certainly something to look at though.

I do have a bench mounted pillar drill 'Old Mart' and had considered trying a diamond coated core drill with the piece actually submerged under shallow water, which is the way I currently cut holes in glass and stone. Not done anything near the size to get a boring bit in there on a lathe afterwards though.

Damascus steel has a clearly defined pattern running through it, so any process other than machining would interfere with that pattern. A diamond core drill 'might' go through it to create the bore, but I guess there only one way to find that out. I would be interested on anyone's opinion on core drills with metal, especially if they have tried something similar themselves.

I did try a diamond coated holesaw a while back when someone wanted to cut thin wall stainless tube and avoid something with coarser teeth catching on the thin metal but doubt you will get anywhere fast with them in solid metal at the sort of sizes you are looking at. Easler to work up through twist drills 6, 8, 10, 12 and then boring bar.

Are you using a specific grade of stainless as some machine better than others, the Damascus will really depend on the grade or grades that have been fire welded together

The diamond core drills work best on hard surfaces Jason, but biggest core I've drilled was 5mm. There considerable more surface area to remove at 12mm or above.

I am specifically looking at Stainless 303 as that is recommended as one of the easily machinable variants.

Damascus composition alters not only by the materials used within it, but how the layers and thicknesses are intertwined to create a specific pattern when etched.. It varies from simple diagonal striped to more exotic patterns akin to leopard skin. It is that variance in pattern that currently makes it so popular as a jewellery material at the moment. It is possible to replicate the pattern in other materials by sculpting at the design stage for casting.

I use the diamond coated ones for work quite a bit upto 50mm on glass, stone and ceramics so know how they work, they seem to drag and clog on metal so not ideal.

An old lathe chuck mounted on the table of a pillar drill would hold the bar stock while the drilling was done. If the drill can be run slow enough for the larger drill sizes, they would cut much faster than a diamond core drill.

Unfortunately it's got to be done.................. I am going to 'sacrifice' an item of cutlery this week as a ready source of stainless... Give it a go with the 5mm core drill and also try cutting on the diamond bandsaw I have, just to get some feedback on how diamond performs with stainless.

Am off with the caravan for a couple of days now, so that a definite task for later in the week.

These were the photos I took of one cutting stainless tube

Thanks to everyone for their help and guidance on this topic.

So I have taken the plunge and purchased a virtually unused Clarke Lathe, which I'm picking up this coming weekend. It's compact enough to sit on one of my benches and movable at just over 40kgs. It was also bought at a great price, which is always a bonus.

Going to be a learning curve after my cnc mills where I just send the design to the mill and leave it to do its thing. Will have to get to grips with rotational speed, feed rates, types of cutter, etc .Really looking forward to exploring new ways of working though and exploring what a lathe can do.

No doubt I'll be on here soon with other questions, as you guys are a great source of help.