I usually drill the hole before I bore the centre, or I used to before I had broaches and BFHA bit of a tweak with the cutting and relief angles would improve that a lot. What you can also do is turn a spigot to go into the bore,then drill a suitable sized hole half in the pulley,half in the spigot. Makes it a lot easier to get the keyway in as alot of material is removed before you start slotting
which is something I have not done in years! I even caught it on video!
I did tge same last week, I can't remember when I last broke one either. Whacked a carbide end mill in the chuck and soon had it sorted.I did a bit more on my ER32 chuck. I managed to break a centre drill
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They are for CNC, the major difference is that a CNC machine can push the edge in to the work a lot better than a manual lathe can, also try and get a bigger chip as the bigger the chip the more heat it takes away therefore the less coolant you lose and the more stable the part, better surface finish etc.
Are you using a HAAS ?
Lol, no, I’m using a 4x2’ Cnc router I built another 8 years ago. For most of that time it’s been cutting wood but just starting to switch it over to Ali u til I can get my small mill built.
Sorry i don't quite follow what you mean here? A big manual lathe can put as much if not more force through the power feeds...
Bull….Servo drives on most Commercial Cnc lathes will not match the same cutting force that a mechanically geared power feed on a comparable size conventional lathe will be capable of producing.
What scale mate??
1:5th MCD W5 Short course truck and RR5 buggy.
Drill round it with an annular bit/mag drill bit.
Yes a big lathe but most lathes are not big and most inserts are oversize for the manual type lathes, manual lathes are designed for HSS or Cobalt mix tools with a sharp edge, except brasses of course, so it will put more strain on the lead screws which are simple threads and not reciprocating ball lead screws designed for heavier loads, they simply are not designed for the blunt edge of a carbide insert.
Nice
I am referring to the lead screws they are simple collar nuts on a threaded shaft the wear increases 4 fold with a doubling of the load, it's fact based on data derived from manufacturers warranty and repair reports, your lathe may be ok, somebody else's will die a horrible nasty death, then of course there is the gearbox driving the lead screw which is taking as much heavier loading than design intent.
Could you blast it through with the stick welder ? have you use of a mag drill ? if you are in Northampton I could bring one to you
