Carl Wilson
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Might just be optical illusion but looks like the piece you turned to check surface finish has a taper.
How are the spindle bearings adjusted? @grim_d @MrFluffy
Is levelling the lathe likely to improve the cut quality?
At the minute it is sat on blocks of hardwood across the two feet at either end so I can move it with forklift and paint it.
The only other thing I can do is get a 3MT test bar and chuck that in the reducing bush inside the taper
Just checked a piece of CrMoMight just be optical illusion but looks like the piece you turned to check surface finish has a taper.
The lathes accurate.
Perhaps it just doesn’t have the grunt, speed or rigidity for negative rake CNMG tooling at the minute.
Three phase 1.1kw so about 1.5hpWhat motor size have you got on it?
I concur with Richard regarding using the machines gearbox in tandem with the vfd. I do that with my Harrison M250. I fitted a 2 hp motor and I use the gearbox speed ranges and ramp the speed up or down.
I can do really slow screwcutting and set up the Dc injection braking to stop the motor quickly. This is almost as good as having a clutch at slow speeds when threading. Course the 140 has a clutch anyway.
My lathe does 34rpm at the bottom end.
If I increase the lathe speed to 1000rpm the bottom end will be 45RPM. That is more than slow enough to thread or power tap with.
A bigger motor + VFD definitely sounds like a good idea to me down the line.
1000RPM will help on finishing cuts with my negative tooling.
The Harrison 140 with the dual speed motor and the threading box with the three control knobs is the best lathe they ever made, in my opinion.
Yes this uses ISO 68 (Tellus 33 originally) in the headstock and saddle, ISO 220 (vitrea oil 72) in the norton gearboxOut of interest my M250 uses ISO 68 hydraulic oil in the headstock and threading box and VG220 gear oil in the saddle box.
The Harrison 140 with the dual speed motor and the threading box with the three control knobs is the best lathe they ever made, in my opinion. I wish I had one. Only thing I don't like about it is L00 spindle. I'm a camlock fan myself.