24-03-2014, 05:47 PM
Hi,
Having worked with lathes for the last 50 years all I've usually had to do is pull levers and press buttons to let the lathe do its job. Restoring this Lorch is proving very interesting to me as I start to understand the various options it affords me over other lathes I've previously operated.
Thanks for asking Alan D; actually on this Lorch it has the standard heavy duty lead-screw with drive picked up by the half nuts this driving in sliding mode only (along the bed) both forward and reverse; unlike other lathes though this lead-screw does not provide power feed for facing (across the bed).
There is a second shaft this not being a second lead-screw it being merely a plain drive shaft but with a full length key-way. The drive from this shaft is picked up by a worm gear having a securely located key. This second shaft is quite ingenious in that the worm then imparts drive to a phosphor bronze gear which is common to one half of a cone clutch the cone being phosphor bronze but the socket is steel. If you look at the apron controls you will see a large steel knob; above this is an indent giving three positions. The large knob on a left hand thread when rotated engages the clutch this then imparts drive via an intermediate gear on a swinging arm providing drive to either sliding or facing modes; using the outer indents automatically locks out the main lead-screw allowing drive to be picked up via the plain drive shaft; the center indent is neutral allowing the lead-screw to be used. Very clever indeed and the cone clutch is "sensitive" allowing it to slip at a pre-set torque for jobs I presume such as tapping? I've never had a lathe with this arrangement before and when I bought the lathe it was a puzzle to me because the sensitive facing mode was not working and I thought there was possible damage ahead once I started to investigate? Only by completely stripping the drive did it all become clear to me. At that time it was most strange to me to have a lathe with two sliding drives?
I will indeed add more pictures as work progresses Nick; I've spent all day today just re-assembling the saddle and apron and I'm delighted to now have these in position once again on the bed as seen in the picture below. All modes are now working so the lathe now provides two sliding modes via Lead-screw and drive shaft and facing mode via drive shaft. I've still got to install the top slide but this is already fully restored so won't be a big job; Once the carriage is completely installed I can then turn my attentions to the lead-screw and drive shaft installing both these; this will hopefully allow me to take decent pictures which I'll be happy to post.
It's difficult to explain in text the three drive modes; it was impossible when I bought the lathe to even understand what the controls on the apron were for because as I say the facing mode was not working which complicated matters. I'm pleased I did decide to do a full restoration because now I fully understand how all the controls work; I'll need to experiment with the clutch though because I cannot find any details about this particular Lorch model on the web.
The restoration moved forward quite a lot today; the carriage was one of the largest assemblies to sort out; I'm sure I'm in for more work as I move onto the head-stock and tail-stock but the hard work is now well behind me in fact I'm pleased to see my bench once again?
Kind regards, Col.
Having worked with lathes for the last 50 years all I've usually had to do is pull levers and press buttons to let the lathe do its job. Restoring this Lorch is proving very interesting to me as I start to understand the various options it affords me over other lathes I've previously operated.
Thanks for asking Alan D; actually on this Lorch it has the standard heavy duty lead-screw with drive picked up by the half nuts this driving in sliding mode only (along the bed) both forward and reverse; unlike other lathes though this lead-screw does not provide power feed for facing (across the bed).
There is a second shaft this not being a second lead-screw it being merely a plain drive shaft but with a full length key-way. The drive from this shaft is picked up by a worm gear having a securely located key. This second shaft is quite ingenious in that the worm then imparts drive to a phosphor bronze gear which is common to one half of a cone clutch the cone being phosphor bronze but the socket is steel. If you look at the apron controls you will see a large steel knob; above this is an indent giving three positions. The large knob on a left hand thread when rotated engages the clutch this then imparts drive via an intermediate gear on a swinging arm providing drive to either sliding or facing modes; using the outer indents automatically locks out the main lead-screw allowing drive to be picked up via the plain drive shaft; the center indent is neutral allowing the lead-screw to be used. Very clever indeed and the cone clutch is "sensitive" allowing it to slip at a pre-set torque for jobs I presume such as tapping? I've never had a lathe with this arrangement before and when I bought the lathe it was a puzzle to me because the sensitive facing mode was not working and I thought there was possible damage ahead once I started to investigate? Only by completely stripping the drive did it all become clear to me. At that time it was most strange to me to have a lathe with two sliding drives?
I will indeed add more pictures as work progresses Nick; I've spent all day today just re-assembling the saddle and apron and I'm delighted to now have these in position once again on the bed as seen in the picture below. All modes are now working so the lathe now provides two sliding modes via Lead-screw and drive shaft and facing mode via drive shaft. I've still got to install the top slide but this is already fully restored so won't be a big job; Once the carriage is completely installed I can then turn my attentions to the lead-screw and drive shaft installing both these; this will hopefully allow me to take decent pictures which I'll be happy to post.
It's difficult to explain in text the three drive modes; it was impossible when I bought the lathe to even understand what the controls on the apron were for because as I say the facing mode was not working which complicated matters. I'm pleased I did decide to do a full restoration because now I fully understand how all the controls work; I'll need to experiment with the clutch though because I cannot find any details about this particular Lorch model on the web.
The restoration moved forward quite a lot today; the carriage was one of the largest assemblies to sort out; I'm sure I'm in for more work as I move onto the head-stock and tail-stock but the hard work is now well behind me in fact I'm pleased to see my bench once again?
Kind regards, Col.
Happiness is a wreck of a cabinet to restore.
