Thread: 'Bigger' lathe nearing completion....

I've mentioned my 'bigger' lathe a couple of times before, e.g. here http://www.woodworkforums.com/showthread.php?t=149488.
It is still a mystery machine but I'm quite certain now that it started life as a conrod boring machine.
It had two removable headstocks, two motors and a very strange huge saddle with a vice-like centre-clamping cross slide (the screw had opposite direction square threads at each end). There was a slotted feed shaft going through the apron but it was driven by the drive belt of the left headstock and had no option for either vaying the speed nor reverse and the clutch was grabby and difficult to release.
I bought it from the famous 'Nik' off eBay from his store in Heathcote (obviously at a good price...) when he was closing down there. After a while I sold the two 3-phase 1HP motors and recovered half the purchase price

lathe1.JPG lathe0.JPG lathe2.JPG
I managed to get hold of a tailstock from another lathe of eBay eventually and pulled the thing apart to figure out what to do with it - apart from turing it into a lathe....

I machined the cross slide and converted one half of the clamping slide into a top slide. But I might revisit that - it's a bit short and could be more rigid.
I then set about sorting out the drive arrangements which would include a VFD and bigger motor.

From the photos when I first got it, it is apparent that the bed was bolted directly to the base - and all the swarf fell straight through to the floor!
So I wanted to fit a swarf tray in between. However, there was no way to get the swarf out form under the bed! There were no gaps.
Since there was little to loose and the bed was built like a brick outhouse, I cut 4 pieces out of the bottom - 2 on each side (there is a very large cross-rib in the centre - and rounded the edges so it looked as cast That was a bugger of a job involving chain drilling through 3/4" thick cast iron and then a very messy angle grinding job... WHile at it, I also cut a hole for the motor shaft, becasue I wanted the motor to fit inside the base.
Once the swarf tray was fitted and the bed back on (and the base and bed cleaned up and painted), it started to look like something.....

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Next I considered my options for a 'proper' feed or lead screw, and after checking all sorts of options to convert the apron, decided to ditch it and the feed shaft altogether.
This is when I came across the ELS (electronic leed screw) project on the CNCzone forum and decided to build one. That took quite a learning path and has only come together in the past few months. The leed screw will be driven by a stepper motor and the cross-feed by another, for semi-automatic threading, tapering and facing. It should also be able to turn to a diameter and do tapered threads, as well as 'broaching' keyways with the spindle stationary.

But first things first. It would be useful as a manual machine without threading capability.
So I found some chucks - a $20 8" three-jaw and a 10" freebee 4-jaw (both seized with a bit more than flight rust.....
One of the chucks has a taper mount which I really liked. So I made a toolpost to get started, while experimenting with the drive (see the link in the first line).
The first job I turned was the mounting for on the spindle that carried the boring bar (for conrod boring). I made a flange on the little lathe ('sandpit' CVA) and bolted that on. That became a taper mount to fit the first resurrected chuck, the 3-jaw.
Once that was mounted, I could make a backplate for the 4-jaw to match the taper mount of the 3-jaw.
Around that time I met RayG who donated a faceplate which had the right taper mount and fitted! All it needed was to have 4 bolt holes drilled to match the ones in now my headstock.

Josh (Brobdingian) kindly ground me a spacer for the tailstock which I machined a little while ago to fit the tailstock.

Then I started making the stepper motor mounts and fitted the leed screw (double AC bearings one end, single deep groove the other and tested it. The stepper motor and ELS could drive the saddle despite its massive weight - and cut metal! Even the quick travers is quite acceptable. So my estimations for stepper motor size was at least close. The tail end of the leed screw also got a hand wheel fitted for manual apron moves - since I no longer had the apron and rack drive. Using the lathe with a handwheel on the spindle is actually not much of an issue. I guess I 'm used to it from the CVA.

Quite a few turning jobs have since been done on the machine - consider them 'testing'. Some massive and certainly testing the envelope. This thing is RIGID. The headstock looks slender but it weighs about 60kg and the (adjustable) plain bearings have no play at all, The ball race thrust bearing is equally up to the task. I found the 960rpm 4Hp motor is capable to drive at even very low speeds - down to about 10Hz and nothing will stop it. In fact the primary belt slips before the motor stops, at even that speed. Since I haven't refitted the door to the base yet, I've put my foot on the motor a couple of times to increase belt tension and stop it from slipping! The only time I have stopped the motor in operation is when I accidentally drove the toolpost into the chuck one day!

This brings us up to the last few weeks.
I decided that the testing phase was completed and time to clean up and paint the headstock, saddle and tailstock - and everything mounted to it.
IMAG1252.jpg IMAG1253.jpg IMAG1255.jpg
Next step is fitting the ELS & VSD panel, refitting the stepper motors and guarding their toothed belt drives from swarf. Then will come a proper guard for the spindle belt drives and a splash back. I have clear ideas on all these and will photograph their progress if there is any interest....

IMAG1245.jpg

After that I have a couple of Shahe (= iGaging) DRO scales to fit - and the DRO is a Bluetooth Android pad or my smart phone - but that's a story for another day.

Wow Joe, You sure can master the art of resurrection... looks brilliant.

Ray

Nice work Joe, the cut outs look as thought they came from the factory. Certainly an interesting rebuild.
Kryn

Wow, very nice Jo

Please keep up updated

Ew

Originally Posted by KBs PensNmore

Nice work Joe, the cut outs look as thought they came from the factory. Certainly an interesting rebuild.
Kryn

Second to that Joe on your vision of an outcast.
Am sure that machine would be old enough that it would have been machining white metal[babbit]bearings.Hence the no fall through in the bed as they used to retrieve the swarf and send back to the melting pot.Not being marked makes be suspect it could have been a custom made unit.most con rod borers here were Warren and Brown later Repco Power machine.
will follow the electronic lead screw fit up as well.
Cheers John.

I have clear ideas on all these and will photograph their progress if there is any interest....

Somehow I dont think there will be any worries on that one.

Hi Joe,

Congratulations on the job so far. You forethought and vision for this machine are nothing less than amazing. Another machine saved from the scrap heap!

I look forward to seeing it in person!

Simon