Making a Toolpost Grinder Part 16: Drawbar 1

[@g.tucker8682]

Thanks for this content, James! I’m gradually working my way through all your uploads. I found your channel from a review of the Teco L510. Your series on that drive is excellent. I referred it to others, who found it as useful as I did. Indispensable for me, really.

[@kylebracht]

Turning your tool post there after getting the shoulder done really got those chips to break nice!

[@greybeard3759]

Please! When polishing near the chuck, position your fingers on the under side of the revolving part! Your fingers will be knocked out of the way of the chuck, not sucked into it. G'head, ask me how I know. ;o) Two broken fingers later... Oh, also, not a critique but curious as to why you don't set your desired dimension into the mic, zero it then read the differential? Truly enjoying your videos!

[@Clough42]

I have had a finger jammed by a tip strike on a chuck jaw, and it hurts, but I hadn't considered the possibility of pulling the finger in. Thanks for the tip. Sounds like you learned that one the hard way. Using the incremental mode on the mic is a good idea. I often do that with a caliper, but didn't think to do it with the mic.

[@g.tucker8682]

This the kind of commentary the KZbin community should strive for! Both points are pertinent and useful. Thanks Grey Beard. Here’s my two cents on handling the risk of polishing near the chuck: The next step was removing the part to turn it end for end. So I’d have just extended it a couple of inches to do the polishing, since concentricity wouldn’t be a concern for that. No need to have the knuckles within an inch of those jaws if one can avoid it.

[@z08840]

Not sure it's a correct way to center drill a rod - obviously it's not quite straight - when you extend it - it deflects, and when you push it with center - it bends to straight, then you turn diameter, and when you remove center - it springs back - and voila - you've translated that non-straightness to a finished part... you suppose to either center drill it when it's at full extent or center drill both ends and turn it between centers...

[@ronwilken5219]

Also never once checked for taper when turning to the live centre. Every lathe is different but none turn dead true all the time. If you're taking the time to make sure everything's concentric then taper should also be corrected. The "bulge" in the middle might have been corrected with a spring pass or two rather than the hit or miss of a file. Resorting to cutting the threads after removing the centre and turning it around is also a mistake if you want truly concentric threads. Turn them in the same setup then there's no question of their concentricity. The "nut end" will be near enough true in the three jaw chuck. You'rer going to cut a hex or flats anyway so your 0.003" TIR won't make a blind bit of difference.