Thread: Extended live centres

Here's a crew-in tang at arc euro trade:

Drill Chuck Arbors - Arc Euro Trade

G'Day Fellas,
Most live centres have a sealing screw in the end, replacing it with a short cap screw overcomes the ejection problem.
Regards,
Martin

I found this one on ebay from RDG
LONG NOSE 2MT REVOLVING LATHE CENTRE MYFORD LATHE | eBay

Dave

My latest cunning plan fell through -
I had the idea that it may have been possible to buy a spare tip from Piper and change the tip in my U302 live centre, turning it into the extended nose version. Talking to them on the phone it appears that would not work because they use different bearings to cope with the load being "further out".
It's a pity I haven't got a centre grinding capacity, as given the price difference between a live centre with standard tip and the extended version, disassembling and regrinding (or making from new) would be a relatively cheap way around the problem. Regrinding an existing tip would even get around the increased load issue that concerned the Piper guys. Given that this is for home use and is lightly loaded, a reshaped standard tip to give better clearance for 1/2" carbide holders would be all that was needed.
The screw-in tangs and for that matter the screws that have been suggested may solve my ejection problem (stop sniggering you in the back row!). However, I would need to tap the back of the taper as it's centre drilled and not a thread. This will then depend on whether the taper is hardened or not.

Michael

How much is the distance between the ejector and the tool taper,if possable put something in the bore to lengthen the ejector for tool removal.

... Or tap the end of the leadscrew to take a cap head. It is the end of the screw that does the bumping right? Would mean sacrificing the centre...

The end of the lead screw does the bumping, but if I add a screw to the end, it means all the other things that do have tangs (drill bits for example) will then require the tail stock to be (say) 10mm further out.
I guess another option is very carefully TIG a steel block onto the back of the taper to act as a tang. I have a few second hand drill bits that need to be repaired that way before I can use them, so one more for the list...

Michael

Put a ball bearing or piece of brass,etc in the tailstock and push it out.