Hi,
Over the last couple of days I've managed a couple of short sessions in the garage which on the whole has been nothing but frustration. Due to our prolonged winter I've forgotten what its like to potter around so have had to start from scratch.
The Clarke lathe was carried into the garage to clear bench space in the workshop so it wasn't set up for service and the tooling was scattered around.
First job though was to cut the cast iron blank into two lengths. This wouldn't be a problem using the big Startrite Volant bandsaw? I had been using the bandsaw to cut some flat steel but this steel was very tough and killed the blade so I installed a new blade only for the new blade to refuse cutting the steel; I ended up cutting this flat steel using the hacksaw.
The cast iron blank was very carefully marked at the cutting point and as the blank was only just long enough to yield the two pieces I wanted to ensure the cut remained on the line.
This blank was slightly over 75mm diameter and 100mm long. For novices to bandsaw work I must add a safety precaution; cutting round stock of whatever material freehand is asking to lose fingers; as the blade engages it behaves just as a belt does with a pulley; the blade will very quickly grab the material causing it to revolve at speed; with luck fingers will be spared but it is so very easy to have fingers pulled into the blade. To prevent an accident I always securely clamp two short lengths of timber or metal one each side of the material ensuring each is sitting on the bandsaw table and out of the path of the blade to prevent the material rotating then I use the clamp as a hand hold and if necessary a push stick to keep hands clear whilst the cutting proceeds; as with any machine in motion don't become distracted or look away from the cutting in progress; I'm not over the top with H&S but neither do I wish to inflict injury onto anyone. Two supports are needed because as the blade engages the work will be revolved one way but as the cut nears completion the work will revolve in the opposite direction.
Drat it; the blade wanted to wander? Trying a fresh bite again the blade began to wander so time for some adjustments to the blade roller guides; with plenty of tension on the blade and now fully supported it still wanted to deviate from the line. Open up the case and install a new blade. At last the cut was completed.
Now to the Clarke lathe. Bron kindly bought me this lathe for Christmas so I've not really had the chance to use it in anger; I set it up on the bench and gathered all the tooling. A sharp HSS (high speed steel) tool was nipped up in the tool post. Now for another major problem; the two 3" chucks would not open enough to securely hold one of the clutch blanks; not to worry I'll just install the "outside" jaws; even these wouldn't hold the blank. This was new to me because previously I've only ever used large lathes which would laugh at a 3" diameter blank? No face-plate either so I had to consider my options; go out and buy a face-plate or buy a 5" chuck; these would cost money especially the chuck?
What do I have in stock to get around this problem? Well I have plenty of steel bar and a big drill press. A plan was formed where I would bore each blank on axis at 5/8" diameter then A dummy mandrel would be turned this mandrel would be drilled and tapped at the outer end for 8mm.
To bore the holes the blanks were very accurately marked for center then center punched. The first blank was tightly secured into the machine vice and carefully positioned then the vice was tightly clamped to the drill table ensuring the table was locked. A small diameter pilot drill was run through but what's happening now? This isn't cast iron the swarf is coming away in ribbons; it's steel!! This lump of metal has been sitting under the bench for years together with my cast iron bar stock and I always thought it to be cast iron; it was rusty and the cuts had dulled so I never even gave it another thought; well steel it is. The pilot hole was enlarged then finally the chuck was removed and a 5/8" Morse taper drill inserted. The drill speed was much reduced and as the bit engaged to about 1" deep as usual the blank started to rock slightly even though everything was locked down tightly; by the time the drill broke through the rocking had increased but at least there was now a hole of sorts added; the second blank was also bored in like manner. I've never liked boring large holes on the drill press.
Boring at 5/8" on the drill press.
Now the dummy mandrel could be turned from a short length of 1" dia mild steel bar stock; this was easy and because of the hole boring problem the diameter of the mandrel was adjusted until the blank slid home; the mandrel was kept short on purpose otherwise the blank would "run out" even more. Next job was to bore and tap the end of the mandrel at 8mm. So far this job has been frustrating; the small Jacob's chuck supplied with the lathe was without chuck key; I intended to buy a key at Rufforth but when I wanted the chuck I couldn't locate it in the cold garage now I needed a key? Again not to worry because I'll simply borrow a chuck from one of the other machines? Oh yes here we go again; all the other chucks were fitted with tangs on their Morse taper ends. The roughest and oldest Jacob's chuck was selected and the tang removed using the hacksaw the cut being made good on the grinder. Now the tapping hole could be bored. Next to tap; the tap was nipped in the Jacobs chuck and engaged whilst the head-stock chuck was pulled around with the key; because of the small size of this lathe it was rather a fiddly job with the tool post in close proximity then to make matters worse the tap complete with chuck decided to revolve in the tail-stock so the tapping was completed by hand with a tap wrench with the mandrel secured in the large engineering vice. If I still had my big Colchester Triumph lathe this whole job would have been completed by now but more frustration was yet to come.
Dummy mandrel.
The largest blank was nipped up tightly onto the dummy mandrel and fortunately it wasn't a lot out of true as it was revolved by hand. At last after a few hours work turning could actually commence. The lathe was set in motion and the cut engaged; about an inch into the cut the tool started to complain? I was amazed when I inspected the HSS bit; the cutting edge had completely disappeared as though it had been ground away.
Blank mounted ready for turning.
The bit was re-sharpened but each time the same thing happened. The blank had an outer very hard skin and the cut was intermittent so was really punishing the tool. The Clarke instructions recommend a maximum cut of ten thou (0.010") which I had been applying. By now I was missing the Colchester and obviously to carry on in this manner I would be a very old guy by the time I turned this blank?
I knew the problem was the hard skin and scale on the blank and to reduce the cut depth would only make maters worse. The HSS tool was replaced with a brand new TC tipped tool; this new tool also objected so rather than carry on ruining good tooling I reverted back to my training from all those years ago. A tool likes to bury its nose whilst cutting otherwise it is liable to rub generating a lot of heat ending in destruction of the cutting edge.
Sorry Clarke lathe; you either turn this blank or get sold because I can't live with this any longer and I'll restore one of the Myford's before being beaten? Completely ignoring Clarke's instructions I dialed in over sixty thou (0.060"). With the lathe in motion I very gently engaged the cut and slowly peeled away the waste. The lathe was much happier with this greatly increased cut because the tool was now cutting as it should as can be seen in the picture.
Deep cut successfully applied.
I've done this many times over the years but on much bigger lathes; my Colchester could easily peel away half an inch without the slightest trouble but I was worried about damaging such a small lathe especially after reading the Clarke instructions. After a number of deep cuts I knocked off; whilst concentrating so hard I hadn't noticed how cold I had become and when I returned into the bungalow I felt perished; this is why I'm sitting here at the moment; I'm waiting for it to warm up a bit then I'll get cracking after dinner.
My plan is to reduce the outer diameter allowing the blank to be gripped directly in the head-stock chuck; this will allow the bores to be very accurately opened out; then new dummy mandrels will be made and hopefully this will enable me to complete both halves of the clutch knowing all diameters are concentric with the axis.
Had I been using cast iron (Meehanite) or even BMS (bright mild steel) the HSS tool would easily have done the job but I've always enjoyed raiding scrap bins and being given off-cuts; occasionally I'll come across some material which gives me some grief? The new bandsaw blade (Starrett) cut this easily enough but it was the hard skin which gave so much trouble during turning and add to this that I simply was not geared up after the long winter lay off. After dinner today I hope things go much better and I want to at least rough down both blanks. Little by little I'll get there and at this point I still don't know if the clutch will work; to add to the fun the camera batteries died I must be mad?
Kind regards, Col.
Over the last couple of days I've managed a couple of short sessions in the garage which on the whole has been nothing but frustration. Due to our prolonged winter I've forgotten what its like to potter around so have had to start from scratch.
The Clarke lathe was carried into the garage to clear bench space in the workshop so it wasn't set up for service and the tooling was scattered around.
First job though was to cut the cast iron blank into two lengths. This wouldn't be a problem using the big Startrite Volant bandsaw? I had been using the bandsaw to cut some flat steel but this steel was very tough and killed the blade so I installed a new blade only for the new blade to refuse cutting the steel; I ended up cutting this flat steel using the hacksaw.
The cast iron blank was very carefully marked at the cutting point and as the blank was only just long enough to yield the two pieces I wanted to ensure the cut remained on the line.
This blank was slightly over 75mm diameter and 100mm long. For novices to bandsaw work I must add a safety precaution; cutting round stock of whatever material freehand is asking to lose fingers; as the blade engages it behaves just as a belt does with a pulley; the blade will very quickly grab the material causing it to revolve at speed; with luck fingers will be spared but it is so very easy to have fingers pulled into the blade. To prevent an accident I always securely clamp two short lengths of timber or metal one each side of the material ensuring each is sitting on the bandsaw table and out of the path of the blade to prevent the material rotating then I use the clamp as a hand hold and if necessary a push stick to keep hands clear whilst the cutting proceeds; as with any machine in motion don't become distracted or look away from the cutting in progress; I'm not over the top with H&S but neither do I wish to inflict injury onto anyone. Two supports are needed because as the blade engages the work will be revolved one way but as the cut nears completion the work will revolve in the opposite direction.
Drat it; the blade wanted to wander? Trying a fresh bite again the blade began to wander so time for some adjustments to the blade roller guides; with plenty of tension on the blade and now fully supported it still wanted to deviate from the line. Open up the case and install a new blade. At last the cut was completed.
Now to the Clarke lathe. Bron kindly bought me this lathe for Christmas so I've not really had the chance to use it in anger; I set it up on the bench and gathered all the tooling. A sharp HSS (high speed steel) tool was nipped up in the tool post. Now for another major problem; the two 3" chucks would not open enough to securely hold one of the clutch blanks; not to worry I'll just install the "outside" jaws; even these wouldn't hold the blank. This was new to me because previously I've only ever used large lathes which would laugh at a 3" diameter blank? No face-plate either so I had to consider my options; go out and buy a face-plate or buy a 5" chuck; these would cost money especially the chuck?
What do I have in stock to get around this problem? Well I have plenty of steel bar and a big drill press. A plan was formed where I would bore each blank on axis at 5/8" diameter then A dummy mandrel would be turned this mandrel would be drilled and tapped at the outer end for 8mm.
To bore the holes the blanks were very accurately marked for center then center punched. The first blank was tightly secured into the machine vice and carefully positioned then the vice was tightly clamped to the drill table ensuring the table was locked. A small diameter pilot drill was run through but what's happening now? This isn't cast iron the swarf is coming away in ribbons; it's steel!! This lump of metal has been sitting under the bench for years together with my cast iron bar stock and I always thought it to be cast iron; it was rusty and the cuts had dulled so I never even gave it another thought; well steel it is. The pilot hole was enlarged then finally the chuck was removed and a 5/8" Morse taper drill inserted. The drill speed was much reduced and as the bit engaged to about 1" deep as usual the blank started to rock slightly even though everything was locked down tightly; by the time the drill broke through the rocking had increased but at least there was now a hole of sorts added; the second blank was also bored in like manner. I've never liked boring large holes on the drill press.
Boring at 5/8" on the drill press.
Now the dummy mandrel could be turned from a short length of 1" dia mild steel bar stock; this was easy and because of the hole boring problem the diameter of the mandrel was adjusted until the blank slid home; the mandrel was kept short on purpose otherwise the blank would "run out" even more. Next job was to bore and tap the end of the mandrel at 8mm. So far this job has been frustrating; the small Jacob's chuck supplied with the lathe was without chuck key; I intended to buy a key at Rufforth but when I wanted the chuck I couldn't locate it in the cold garage now I needed a key? Again not to worry because I'll simply borrow a chuck from one of the other machines? Oh yes here we go again; all the other chucks were fitted with tangs on their Morse taper ends. The roughest and oldest Jacob's chuck was selected and the tang removed using the hacksaw the cut being made good on the grinder. Now the tapping hole could be bored. Next to tap; the tap was nipped in the Jacobs chuck and engaged whilst the head-stock chuck was pulled around with the key; because of the small size of this lathe it was rather a fiddly job with the tool post in close proximity then to make matters worse the tap complete with chuck decided to revolve in the tail-stock so the tapping was completed by hand with a tap wrench with the mandrel secured in the large engineering vice. If I still had my big Colchester Triumph lathe this whole job would have been completed by now but more frustration was yet to come.
Dummy mandrel.
The largest blank was nipped up tightly onto the dummy mandrel and fortunately it wasn't a lot out of true as it was revolved by hand. At last after a few hours work turning could actually commence. The lathe was set in motion and the cut engaged; about an inch into the cut the tool started to complain? I was amazed when I inspected the HSS bit; the cutting edge had completely disappeared as though it had been ground away.
Blank mounted ready for turning.
The bit was re-sharpened but each time the same thing happened. The blank had an outer very hard skin and the cut was intermittent so was really punishing the tool. The Clarke instructions recommend a maximum cut of ten thou (0.010") which I had been applying. By now I was missing the Colchester and obviously to carry on in this manner I would be a very old guy by the time I turned this blank?
I knew the problem was the hard skin and scale on the blank and to reduce the cut depth would only make maters worse. The HSS tool was replaced with a brand new TC tipped tool; this new tool also objected so rather than carry on ruining good tooling I reverted back to my training from all those years ago. A tool likes to bury its nose whilst cutting otherwise it is liable to rub generating a lot of heat ending in destruction of the cutting edge.
Sorry Clarke lathe; you either turn this blank or get sold because I can't live with this any longer and I'll restore one of the Myford's before being beaten? Completely ignoring Clarke's instructions I dialed in over sixty thou (0.060"). With the lathe in motion I very gently engaged the cut and slowly peeled away the waste. The lathe was much happier with this greatly increased cut because the tool was now cutting as it should as can be seen in the picture.
Deep cut successfully applied.
I've done this many times over the years but on much bigger lathes; my Colchester could easily peel away half an inch without the slightest trouble but I was worried about damaging such a small lathe especially after reading the Clarke instructions. After a number of deep cuts I knocked off; whilst concentrating so hard I hadn't noticed how cold I had become and when I returned into the bungalow I felt perished; this is why I'm sitting here at the moment; I'm waiting for it to warm up a bit then I'll get cracking after dinner.
My plan is to reduce the outer diameter allowing the blank to be gripped directly in the head-stock chuck; this will allow the bores to be very accurately opened out; then new dummy mandrels will be made and hopefully this will enable me to complete both halves of the clutch knowing all diameters are concentric with the axis.
Had I been using cast iron (Meehanite) or even BMS (bright mild steel) the HSS tool would easily have done the job but I've always enjoyed raiding scrap bins and being given off-cuts; occasionally I'll come across some material which gives me some grief? The new bandsaw blade (Starrett) cut this easily enough but it was the hard skin which gave so much trouble during turning and add to this that I simply was not geared up after the long winter lay off. After dinner today I hope things go much better and I want to at least rough down both blanks. Little by little I'll get there and at this point I still don't know if the clutch will work; to add to the fun the camera batteries died I must be mad?
Kind regards, Col.
Happiness is a wreck of a cabinet to restore.
