Hi folks, from across the pond!

I wonder if anyone can help me with what components are meant to be in the stack on the spindle in the headstock of a roller bearing 9" AR.

I bought it last year, and had it shipped down from the north Island to the south Island here. At my risk. After half a dozen successful freight transfers (logistics?) around the country, it was finally rolled off a forklift in my home town. Silver lining: no freight charge, and my contents insurance covered it! Great. Mal sent me some replacements for broken cast parts, and an engineer friend brazed another part for me, and I was away.
I had to file a little out of the apron casting to allow the screw cutting feed lever to move. I wonder if that was a non original part. The previous owner said he didn't realise it was meant to be screw cutting! With the fancy apron and the fancy gearbox?!
After figuring out the very basics, I learned that the amount of backlash and slack at the spindle nose was unacceptable, and possibly part of the explanation for breaking the parting blade. The take-up but didn't seem to have any travel left, so I thought maybe i'd check the main spindle bearings, and maybe do that needle roller bearing upgrade they talk about, in place of the fiber washer.
So I took the spindle out, but found no fiber washer under the take up nut, and also no thrust bearing behind the left hand spindle bearing. I'd read that there should already be a thrust bearing between the left hand spindle bearing and the back gear delivery cog.
But there doesn't seem to be space for one there. Is it only on the plain bearing machines? Or should my roller bearing machine have a thrust bearing as well? Maybe it doesn't need it.
Then the next question would be about the setup to the left of (outside of) the left hand spindle bearing. It seems the spindle bearing is flanked by large bushes on the spindle. The left hand one projects beyond the edge of the headstock casting, so when you tighten the take up nut, it bears against this bushing, which is bears against the roller bearing. That seems to defeat the purpose of the take up nut, which I would have thought was to pull the spindle through the headstock.
Thanks for sticking with me 🙂
I wonder about those bushes. Are they original? How wide should they be? I got a thrust bearing from the local engineering supplies, which I had hoped to fit inside the headstock (between spindle bearing and back gear cog) before I found there was no space. So instead I thought I'd put it in the outboard position. It's too thick to then do up the take up nut, unless I remove the large bush. The thrust bearing then transfers the force from the take up nut to the headstock bearing, and successfully pulls the spindle up tight. Rather than just leave that bush out though, and let all the oil leak out, I thought I'd face it down to a smaller width.
Before I took that drastic step though, of modifying potentially-original equipment, I want to check what I'm doing.
Hence: can anyone help me with what components are meant to be on the spindle of a tapered roller headstock Hercus, preferably including dimensions 🙂. I've looked for a diagram, but to no avail. I've emailed a couple of folks directly, but had no reply.
So I throw myself on your mercy.

Eric


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