Post by catgate on Oct 4, 2005 20:29:18 GMT
I sent him my cheque on 31st May and he confirmed it was cleared on 9th June. I received the lathe about 25th August.
After getting the lathe, and cleaning it, I started to change the motor, from the 5hp 3ph.one it came with to a 3hp (which is what was fitted to the original Triumphs when they first saw light of day) single phase one that I had “in stock”.. Having been a 3ph set up it was going to be necessary to doctor the coolant pump, and add some capacitors, to run it on normal 240v supply. So, I took the top off the pump motor to see if it was star or delta wound. As I lifted the lid there emanated the dreaded smell of fried motor. There was lots of melted insulation too. Fortunately I had a coolant pump, off the lathe I had just scrapped, which I had already “modified”. However there had to be mountings, rewirings and switchings devised to utilise that.
After this I thought I would prepare the way for the fitting of the replacement half nut (when it finally arrived) by removing the broken portion of stem left up the hole in the apron front. This necessitated taking the top off the screw cutting gearbox to disconnect both the lead screw and the splined shaft, in order to slide them out through the bracket cast into the tailstock end of the bed.
I eventually dropped the apron down and got it onto the bench. The removal of the broken stem was no big problem, a slight tap with a punch and out it came. Which was more than could be said of the mass of nylon “swarf” mangled up in amongst the apron gears. One piece of this had been wound into a position where it had “unlocked” the interlocking mechanism, that prevents turning and screw cutting “simultaneously”. This looked like the root cause of the breakage. The lathe must have been tearing large lumps off a piece of nylon, working towards the tail stock, when a large piece of swarf had worked its way up into the interlock mechanism and allowed the half nut to fall, because the detent spring was very tired. The half nut stem must have broken, and because the apron was travelling towards the tail stock the half nut was able to “get out”. Had it happened whilst travelling the opposite way things could have been much worse.
During the installation of the 3hp 1ph motor it was necessary to rejig the reverse switch wiring. This switch is situated at the back of the head casting (beyond the clutch bell crank etc.) and is operated by a lever and rod . This lever is in front of the clutch/operating lever, and the rod on which it is mounted runs through the tubular clutch/operating rod. I discovered, when I first dared to fire the machine up, that movement of the clutch lever caused disturbance with the motor because the inner rod was binding within the outer tubular rod and was switching out the “Run” capacitor. Another reaming, honing, filing session ensued. The result was far from satisfactory, but at least the interference was minimised and enabled the clutch lever to be moved without causing distress to the motor.
As previously reported the promised “replacement” half nut never materialised from the vendor, and so I was thinking about putting my little Atlas lathe to some pain in the making of another one. In the end I realised it was not really up to the job and so enlisted the aid of a local engineer, who “repaired” the old one rather than “remake” a new one.
After fitting this part and its attendants bits, and reassembling the shafts and gearbox, I could now put power to the motor and run the lathe in both directions. I could also face, and turn and screwcut, at least in theory.
(to be continued)
After getting the lathe, and cleaning it, I started to change the motor, from the 5hp 3ph.one it came with to a 3hp (which is what was fitted to the original Triumphs when they first saw light of day) single phase one that I had “in stock”.. Having been a 3ph set up it was going to be necessary to doctor the coolant pump, and add some capacitors, to run it on normal 240v supply. So, I took the top off the pump motor to see if it was star or delta wound. As I lifted the lid there emanated the dreaded smell of fried motor. There was lots of melted insulation too. Fortunately I had a coolant pump, off the lathe I had just scrapped, which I had already “modified”. However there had to be mountings, rewirings and switchings devised to utilise that.
After this I thought I would prepare the way for the fitting of the replacement half nut (when it finally arrived) by removing the broken portion of stem left up the hole in the apron front. This necessitated taking the top off the screw cutting gearbox to disconnect both the lead screw and the splined shaft, in order to slide them out through the bracket cast into the tailstock end of the bed.
I eventually dropped the apron down and got it onto the bench. The removal of the broken stem was no big problem, a slight tap with a punch and out it came. Which was more than could be said of the mass of nylon “swarf” mangled up in amongst the apron gears. One piece of this had been wound into a position where it had “unlocked” the interlocking mechanism, that prevents turning and screw cutting “simultaneously”. This looked like the root cause of the breakage. The lathe must have been tearing large lumps off a piece of nylon, working towards the tail stock, when a large piece of swarf had worked its way up into the interlock mechanism and allowed the half nut to fall, because the detent spring was very tired. The half nut stem must have broken, and because the apron was travelling towards the tail stock the half nut was able to “get out”. Had it happened whilst travelling the opposite way things could have been much worse.
During the installation of the 3hp 1ph motor it was necessary to rejig the reverse switch wiring. This switch is situated at the back of the head casting (beyond the clutch bell crank etc.) and is operated by a lever and rod . This lever is in front of the clutch/operating lever, and the rod on which it is mounted runs through the tubular clutch/operating rod. I discovered, when I first dared to fire the machine up, that movement of the clutch lever caused disturbance with the motor because the inner rod was binding within the outer tubular rod and was switching out the “Run” capacitor. Another reaming, honing, filing session ensued. The result was far from satisfactory, but at least the interference was minimised and enabled the clutch lever to be moved without causing distress to the motor.
As previously reported the promised “replacement” half nut never materialised from the vendor, and so I was thinking about putting my little Atlas lathe to some pain in the making of another one. In the end I realised it was not really up to the job and so enlisted the aid of a local engineer, who “repaired” the old one rather than “remake” a new one.
After fitting this part and its attendants bits, and reassembling the shafts and gearbox, I could now put power to the motor and run the lathe in both directions. I could also face, and turn and screwcut, at least in theory.
(to be continued)
