15-12-2013, 04:59 PM
Hi,
Thanks Lawrence; is it harder to cut dry dead trees than green ones?
At last I've broken free of jobs around home for the moment. I still feel a bit unsettled after all the hard graft in removing the storm damaged conifer but I did wander into the garage this morning to resume work on this bandsaw.
I was awake in bed last night thinking about the broken main bearing casting; David was ahead of me with this because in an email he thought it would bug me if I didn't sort it properly and not resort to a bodge job; well David is of course correct because it was bugging me.
Ignoring the original casting design I took the problem right back to basics; I want the motor power to transfer to the bottom band-wheel so how would I achieve this starting from scratch? Yes I would need a main-shaft unless I was to add direct drive which is an option still open to me?
I came up with the idea of upgrading the shaft and doing away with the original casting design altogether. The original shaft is 5/8" dia but I could increase this to 3/4" or even 1" diameter very easily. I could buy a pair of suitable rectangular cast iron four hole bearing housings together with bearings quite cheaply through eBay. These two housings could be bolted back to back sandwich fashion to the bandsaw.
With this in mind I found I only had one short length of 3/4" dia BMS to hand but it was long enough. What I had forgotten was the limitations of the Clarke metal lathe. The Clarke head-stock mandrel will only accept 5/8" dia so immediately threw up the first problem in how to end face and center the bar end? 6" material sticking unsupported out of a chuck just isn't on so I set about rigging up the fixed steady and getting the bar to run true clocking with a DTI (dial test indicator). This is standard lathe practice but the fixed steady on my Clarke although little used and like new leaves a lot to be desired; clamping the three guides ruins the fine adjustment ending up in frustration; all I wanted to do was to sort the bar end out without all this extra hassle. I finally got the bar running true and applied lots of oil. The tail-stock is a pain to use because to lock it to the bed is a spanner job; anyway I started to reduce the bar end but noticed the oil was starting to fume indicating heat? Due to all this messing around and my own incompetence I managed to reduce the bar end too much so gave up in disgust.
This little Clarke lathe is actually a nice lathe and also has plenty of power after I upgraded it but it drives me mad with its limitations and distracts me from what I'm trying to achieve. My old Colchester lathe would have laughed at such a tiny turning job allowing me to do the job in minutes but a couple of frustrating hours ended up in failure using the Clarke; a poor man blames his tools but I'm used to doing such work on proper kit and possibly in the New Year I need to get a proper lathe?
This afternoon I've bought six cast iron welding rods through eBay; lets try a different approach? One way or another I'll sort this silly little job out to my satisfaction. I still feel worn out which hasn't helped but when I settle with the this restoration things will come together; I'll not quit but thought it worth while adding this story because even after 50 years of using lathes things can still go wrong.
Kind regards, Col.
Thanks Lawrence; is it harder to cut dry dead trees than green ones?
At last I've broken free of jobs around home for the moment. I still feel a bit unsettled after all the hard graft in removing the storm damaged conifer but I did wander into the garage this morning to resume work on this bandsaw.
I was awake in bed last night thinking about the broken main bearing casting; David was ahead of me with this because in an email he thought it would bug me if I didn't sort it properly and not resort to a bodge job; well David is of course correct because it was bugging me.
Ignoring the original casting design I took the problem right back to basics; I want the motor power to transfer to the bottom band-wheel so how would I achieve this starting from scratch? Yes I would need a main-shaft unless I was to add direct drive which is an option still open to me?
I came up with the idea of upgrading the shaft and doing away with the original casting design altogether. The original shaft is 5/8" dia but I could increase this to 3/4" or even 1" diameter very easily. I could buy a pair of suitable rectangular cast iron four hole bearing housings together with bearings quite cheaply through eBay. These two housings could be bolted back to back sandwich fashion to the bandsaw.
With this in mind I found I only had one short length of 3/4" dia BMS to hand but it was long enough. What I had forgotten was the limitations of the Clarke metal lathe. The Clarke head-stock mandrel will only accept 5/8" dia so immediately threw up the first problem in how to end face and center the bar end? 6" material sticking unsupported out of a chuck just isn't on so I set about rigging up the fixed steady and getting the bar to run true clocking with a DTI (dial test indicator). This is standard lathe practice but the fixed steady on my Clarke although little used and like new leaves a lot to be desired; clamping the three guides ruins the fine adjustment ending up in frustration; all I wanted to do was to sort the bar end out without all this extra hassle. I finally got the bar running true and applied lots of oil. The tail-stock is a pain to use because to lock it to the bed is a spanner job; anyway I started to reduce the bar end but noticed the oil was starting to fume indicating heat? Due to all this messing around and my own incompetence I managed to reduce the bar end too much so gave up in disgust.
This little Clarke lathe is actually a nice lathe and also has plenty of power after I upgraded it but it drives me mad with its limitations and distracts me from what I'm trying to achieve. My old Colchester lathe would have laughed at such a tiny turning job allowing me to do the job in minutes but a couple of frustrating hours ended up in failure using the Clarke; a poor man blames his tools but I'm used to doing such work on proper kit and possibly in the New Year I need to get a proper lathe?
This afternoon I've bought six cast iron welding rods through eBay; lets try a different approach? One way or another I'll sort this silly little job out to my satisfaction. I still feel worn out which hasn't helped but when I settle with the this restoration things will come together; I'll not quit but thought it worth while adding this story because even after 50 years of using lathes things can still go wrong.
Kind regards, Col.
Happiness is a wreck of a cabinet to restore.
