many years ago I made a small drilling spindle for use on my lathe and have only used it once in the last decade
but its a bit bulky for my hobbymat lathe and not fast enough to be used properly to regrind chuck jaws. then I saw this picture of a potts milling attachment
http://www.lathes.co.uk/potts/
and thought that if the motor was mounted from spindle body like the double pulley is it would be a better setup. I also decided to go for a 12v motor as I have a suitable power supply and they are readily available.
so I've been collecting a few parts off ebay for a while
the main spindle will be a ER11 collet 8mm dia 100mm long spindle like this
https://www.ebay.co.uk/itm/362053649273
I ordered one with a hexagonal nut (from a different supplier) but thats what turned up as the nut is smaller so may be a help at some stage.
I also picked up some er11 collets that are 1/4 and 1/8 diameter for holding grinding points
and I got a couple of 12v motors too,
one that has 15k rpm unloaded speed
https://www.ebay.co.uk/itm/222530067158
and one that has 4k rpm unloaded speed
https://www.ebay.co.uk/itm/222765407073
both are physically identical in size and with suitable speed reduction the bottom one may be suitable for drilling/milling (using tiny cutters)
for the drive pulleys, rather than making them I ended up buying GT2 pulleys and belts off ebay, as the belts are 2mm pitch timing belts so wont slip and the toothed pulleys are cheaper to buy than but aluminium bar to make V pulleys to use 5mm dia polyurethane round belts
bearing are standard 608ZZ bearings, 22mm o/d, 8mm i/d and 7mm deep. and three chunks of metal to make parts from.
I've finally got round to trying to make it. Im just making it up as I go along. I hope it will work ok, but dont know if the motors will be powerful enough. if I fail I can always clamp a dremel to my lathe
I decided to make the spindle body first, the mounting lug was made from black bar, just machined all over as it looks nicer. here being flycut
then cutting the curved profile for welding to the round body, using a boring head with a long series slot drill for doing the cutting as the boring bit I had wasn't long enough. the finish was pretty rough, but the shape was right which was the important bit
the pivot was then shaped and centre drilled to mark where the pivot bolt would go
this was then tig welded to the round bar to make the spindle body
not the best welding that's been seen on here, but I guess it'll stay together. and then I could machine it. I post how I did that tomorrow, but in the words of Blue Peter, here's one I prepared earlier, fully machined with bearings fitted
but its a bit bulky for my hobbymat lathe and not fast enough to be used properly to regrind chuck jaws. then I saw this picture of a potts milling attachment
http://www.lathes.co.uk/potts/
and thought that if the motor was mounted from spindle body like the double pulley is it would be a better setup. I also decided to go for a 12v motor as I have a suitable power supply and they are readily available.
so I've been collecting a few parts off ebay for a while
the main spindle will be a ER11 collet 8mm dia 100mm long spindle like this
https://www.ebay.co.uk/itm/362053649273
I ordered one with a hexagonal nut (from a different supplier) but thats what turned up as the nut is smaller so may be a help at some stage.
I also picked up some er11 collets that are 1/4 and 1/8 diameter for holding grinding points
and I got a couple of 12v motors too,
one that has 15k rpm unloaded speed
https://www.ebay.co.uk/itm/222530067158
and one that has 4k rpm unloaded speed
https://www.ebay.co.uk/itm/222765407073
both are physically identical in size and with suitable speed reduction the bottom one may be suitable for drilling/milling (using tiny cutters)
for the drive pulleys, rather than making them I ended up buying GT2 pulleys and belts off ebay, as the belts are 2mm pitch timing belts so wont slip and the toothed pulleys are cheaper to buy than but aluminium bar to make V pulleys to use 5mm dia polyurethane round belts
bearing are standard 608ZZ bearings, 22mm o/d, 8mm i/d and 7mm deep. and three chunks of metal to make parts from.
I've finally got round to trying to make it. Im just making it up as I go along. I hope it will work ok, but dont know if the motors will be powerful enough. if I fail I can always clamp a dremel to my lathe
I decided to make the spindle body first, the mounting lug was made from black bar, just machined all over as it looks nicer. here being flycut
then cutting the curved profile for welding to the round body, using a boring head with a long series slot drill for doing the cutting as the boring bit I had wasn't long enough. the finish was pretty rough, but the shape was right which was the important bit
the pivot was then shaped and centre drilled to mark where the pivot bolt would go
this was then tig welded to the round bar to make the spindle body
not the best welding that's been seen on here, but I guess it'll stay together. and then I could machine it. I post how I did that tomorrow, but in the words of Blue Peter, here's one I prepared earlier, fully machined with bearings fitted