.

When I first got my lathe I was struggling to get anything other than as you put it a record finish. Even after spending eons with every speed and feed rate available. I also spent considerable time grinding what I considered to be 'perfect' HSS tools – So much so that I convinced myself that the head stock bearings in the lathe were shot.

I asked a friend of mine who has been a pro for over 40 years could he come and cast his experienced eye over my useless defunct piece of scrap iron that had the audacity to be called a lathe.

He had a quick look at the bits of steel I had butchered then turned his attention to the tool bit. There was a pronounced 'Mmmmmmmmm" Did not say anything else but looked at me with slightly raised eyebrows in a somehow sympathetic way one would look at an injured puppy.

A few seconds, a few flicks of his wrist with tool at the grinder and back into the lathe it went at the correct height. The scrap iron of a machine was switched on and magically started to produce great swathes of swarf with a far deeper cut than I would have dreamed of taking. ………… The finish on the bar was fantastic. He went even deeper still and the swarf became streaming ribbons but still with a fantastic finish on the bar.

Then followed a lesson on tool grinding. (which I am still useless at) He also added that it would not be a good idea for me to take cuts as deep and as fast on regular basis with it being such a small machine. But he did so only to prove to me that there was nothing at all wrong with the headstock bearings and the machine was basically sound.

I was convinced that my grinding was correct and I had bought a lemon of a machine. ……………… Incorrectly.! ……….. And 40 plus years experience showed within a very short time how incorrect I was.

Nick

As mention by Jason, rebar has got to be one of the nastiest 'metals' to machine, and only useful for concrete.

Even welding the stuff would be a nightmare I would think, as who knows what the ingredients are.

Tried rebar once but consigned it to the 'Never Use Again' list.

Geoff – Sometimes I DO learn I would let you all know

falling off logs….I don't get it?

For idiot proof HSS tooling I can recommend the pre-formed HSS tools. They work well on steel and it ought to tell you once and for all whether your tools are ground correctly.

**LINK**

A bit more than blank toolbits and shaping your own but they just need touching up on a diamond hone to get them to cut well.

HTH

Jon

Like George I use a tangential tool holder for most of my work and I get a really good finish both turning and facing. Mine was from eccentric engineering and works very well.

At first I bought myself a selection of insert cutters thinking these would cater for all my needs having seen them in action in work but I just could not get the finish I wanted on aluminium and mild steel. I was limited to 2000rpm on the spindle of my lathe and after discussing my requirements with a insert supplier and trying a few different types it was concluded that at this spindle speed the inserts were not going to perform at their best. I subsequently sold my insert holders and ground a number of HSS tools. Knife tools both left and right hand are extremely useful!

Having said that, whilst machining the cast iron castings on the Stuart 7A a couple of the castings had very hard spots in them which quickly rendered my HSS tools useless. A borrowed an insert cutter which quickly made a perfect job of machining the castings so guess what…I have replaced the ones I sold

Gathering up some 1/4 square HSS from "home and workshop" and trawling the internet for guides on grinding lathe tools (which there are many!) has significantly improved the quality and accuracy of the parts I have made so far.