Sunday, April 8, 2012

Hemingway Set-Over Centre: The Arbor - Completed

I don't really have a good feeling of what I'm doing on the arbor.  There was slight wobbling when the lathe was powered on.  I pressed on with the job despite that.  The morning session ended when I was at the threading part as I encountered difficulty to start the die cutting.  I bought the Proxxon Tailstock Die Holder from Mike and my dearest collected it for me in the afternoon while I was at work at a project called The MeyeRise.

The completed parts so far on the 2MT arbor installed in the tailstock:

The 2 cap screws have yet to be trimmed flushed.
The rest of the pics described what I did in 3 sessions.

Before I started work on the Arbor, I removed the locking screw I made for the tailstock as I couldn't get it tight enough at times and couldn't release it after tightening.  Heat was applied to removed the little handle.
With about 3mm diameter left to turn down, I decided to try turning between centre to see if I can enhance the concentricity of the business end. The sleeve was taken out of the spindle bore and I realized that the arbor was stuck in it. Will think of how to get it out after I completed this part of the job.
The Proxxon Centre Turning Accessory put in use. The round aluminium disk acts like a dog driving the job.
Too much pressure on the tailstock causing excessive heat. The grease was boiling, darkening the end of the section I was working on.
One thing I like about working between centers - I can remove the work and put it back without losing my reference. The workpiece was taken out to clean off the burnt grease and reapply fresh dose. This time, I went easy on the tailstock when applying pressure.
After turning down to the required diameter, I tried parting off the excess with the sleeve back in the spindle bore.  It didn't work. I can feel the job flexing away from the parting blade.
The spindle guard was removed and the hacksaw drafted into service.  Thank God I've only about 7.9mm diameter to saw through.
Some extra was left to clean up to length.
Facing done and sharp edges deburred with a file. The shoulder was also faced making it nice and flat.
Sherline's grooving tool in use. I find it rather expensive but it has proven itself to be a very useful tool. The groove created is the undercut for the threads. The live centre was only pressing against the stock lightly to keep the job in place.
Trying to employ the same method of cutting the 5/16" BSF threads using the die holder I made for the Sherline Tailstock.  It didn't seem to work this round, prompting me to get the Proxxon Die Holder set from Mike.  Too many other things I want to do then making a die holder set at this moment.  I may make a tap holder instead.
The Proxxon Die Holder Set. I supposed the sliding arbor, which has a parallel shank, is to be held in the drill chuck.
I was rather disappointed that the 5/16" BSF die, which has a diameter of 1", couldn't fit the die holder. All set screws were backed off. I even tried compressing the split die with a plier... sigh... A quick measuring of the Proxxon dies indicated that the die set that came with the box is a little smaller than 1".  Why?!
So I pressed on with what I was doing prior to trying the Proxxon Die Holder.  The 3 M6 cap screws were used as grip while turning the conventional die stock holder. Hope they wouldn't damage the threaded holes for mounting chucks and other accessories.
Threading completed.  I had to cut away the half formed thread near the shoulder to allow the Base to go all the way in.
Even that is not enough.  More were cut off to allow a good fit.
And finally...
The whole works on the arbor. Next is to find a way to get the 2MT arbor out of the 3MT sleeve.
The threaded end of the 2MT arbor is just a tad lower than the slot for easy knocking out with a wedge tool (I don't have one anyway...).
The 5mm Allen key and a small hammer did the job of breaking it free.
Though still short of the 2 adjustments screws, a group photo of its members so far doesn't hurt.

I'm getting excited as I'm coming to an end of this project.  Wanted to buy the 2 x 2BA screws but the shop I always frequent only have them in brass.  Maybe that will work.  Should have buy them to test than merely walking away disappointed.
I've yet to test if the centre lies up with the centre line of the lathe.  Feeling exhausted from the long boring showflat duty I was scheduled this afternoon, I decided to stop work, wash up, and do some reading before bed.  Got to get up early for Resurrection Day service tomorrow morning.  It is the most important day in history of mankind.


Sleazey said...

The metric sized die holder (25mm) won't hold imperial (inch) sized thread dies (25.4mm).

Metric sized die holders are all just a bit too small to hold the corresponding imperial thread dies.

Wongster said...

Thanks for your input. I learnt by mistakes... Lolz.

The Proxxon dies measured 25.2x to 25.3xmm. The BSF split die is 25.4" exactly. Looks like another project is underway...


GeneK said...

Wong, are you going to just leave us hanging? We're waiting to hear if the center came out the right height to match the headstock. Also on the dead center you have to keep them lubed and check quite often as they tighten up and loosen as they heat and cool.
I use STP, that automotive stuff on my dead centers for lube. It looks like honey but much thicker. It stays where you put it and takes a lot of pressure.


Wongster said...


Lolz... Not intentional but I'm pretty caught up with work to the extend of not wanting to go into the shop... I'll check it out hopefully tonight after my last meeting.