02-19-2015, 06:19 PM
The C10-13-16 are very nice lathes, but if you have your druthers (and your shop floor can take it), go for a model H - you can see one one youtube (not in action, sadly) if you search "mighty Holbrook" - they DO need 415v x 50Hz/480v x 60Hz though, as they are quite demanding (10HP) on power... they have the threading trips/stops, leadscrew reverse "on-the-fly" etc, which the model C doesn't - although I'm working on that! A model H is probably the only lathe that could turn my head, the machine shop at work may have to get rid of one soon, too...
The 1024 is also a cut above the average, even for English toolroom lathes, I suspect you're going to love it!
For my C13 I had to hack a 415v-in VFD to fool it into thinking it had the right supply when it was really getting 240v single phase (actually pretty simple when you know how) as the 3-speed motor is 415v only - no way to rewire it for 240 for less than the price of the lathe(!) - and is part of the Holbrook experience :)
Once hacked and installed, I have 2RPM - 2500RPM available. a combination of the lathe's 12 speeds (3 speed motor x 2 speed clutch n' brake box x 8:1 backgear) and a 5-85Hz VFD, from the original 22 - 1500RPM - the ultralow speed is useful for things like milling with a toolpost-mounted spindle (although it can "cog" a bit), the highest speeds for small work in aluminium.
Should you be as daft as me and use the VFD at very low frequencies (30Hz and below particularly), it's worth fitting an external fan to the motor for cooling, espacially if you're loading it much - if I remember right, airflow through a fan is proportional to the square of the speed, so at half speed it's only getting a quarter the cooling air - in my case, at 5Hz it's getting a hundredth... recipe for an escape of Magic Smoke from the motor! I recently struck lucky in the skip at work, Papst 10-inch cooling fans replaced as preventative maintenance in standby equipment that's used twice a year for half an hour to make sure it still works... 2011 date codes on them, and about 3-4 hours runtime total! A bit of adaptation's required though because they're metric, the fixings are on a 254mm diameter circle, not 10" like the Holbrook's motor... ;)
ANyway, enough of me digressing (it's the medicinal alcohol, probably), best of luck with the S&B, senda PM if you want any hints and tips :)
The 1024 is also a cut above the average, even for English toolroom lathes, I suspect you're going to love it!
For my C13 I had to hack a 415v-in VFD to fool it into thinking it had the right supply when it was really getting 240v single phase (actually pretty simple when you know how) as the 3-speed motor is 415v only - no way to rewire it for 240 for less than the price of the lathe(!) - and is part of the Holbrook experience :)
Once hacked and installed, I have 2RPM - 2500RPM available. a combination of the lathe's 12 speeds (3 speed motor x 2 speed clutch n' brake box x 8:1 backgear) and a 5-85Hz VFD, from the original 22 - 1500RPM - the ultralow speed is useful for things like milling with a toolpost-mounted spindle (although it can "cog" a bit), the highest speeds for small work in aluminium.
Should you be as daft as me and use the VFD at very low frequencies (30Hz and below particularly), it's worth fitting an external fan to the motor for cooling, espacially if you're loading it much - if I remember right, airflow through a fan is proportional to the square of the speed, so at half speed it's only getting a quarter the cooling air - in my case, at 5Hz it's getting a hundredth... recipe for an escape of Magic Smoke from the motor! I recently struck lucky in the skip at work, Papst 10-inch cooling fans replaced as preventative maintenance in standby equipment that's used twice a year for half an hour to make sure it still works... 2011 date codes on them, and about 3-4 hours runtime total! A bit of adaptation's required though because they're metric, the fixings are on a 254mm diameter circle, not 10" like the Holbrook's motor... ;)
ANyway, enough of me digressing (it's the medicinal alcohol, probably), best of luck with the S&B, senda PM if you want any hints and tips :)
Rules are for the obedience of fools, and the guidance of wise men...
(Douglas Bader)
(Douglas Bader)