johnsmachines

machines which I have made, am making, or intend to make, and some other stuff. If you find this site interesting, please leave a comment. I read every comment and respond to most.

Tag: lathe restoration

TNC lathe restoration completed.

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Miniature lathe mounted on an aluminium base, and hooked up to a new, variable speed motor. The pulleys were turned from aluminium.  The motor is controlled with a foot switch.  

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Headstock detail, showing the thrust bearing between the chuck and headstock, oil wells, pulleys and belt. I expect that an ER16 collet chuck will be used more often than the 4 jaw chuck.

TNC Lathe restoration progress

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The before picture.

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Current . After cleaning, holes filled, painting, new handles, new spindle shaft, new oil reservoirs, chuck refurbished, some parts nickel plated, new base. Gibs resurfaced. It all moves smoothly, with minimal backlash.

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Mounted on an aluminium base. Ready for its new motor with foot operated speed control and headstock pulley to be turned. I installed a thrust bearing between the chuck and headstock.

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TCL lathe renovation 1

I CNC’d a new handle to replace the broken one on the little lathe, but the new one made the old ones look a bit shabby, so they will all be renewed.  The new, deeply waisted handles are very nice to use.

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The headstock shaft was 3/8″ and was a bit undersized due to wear, and I intend to use a collet chuck with a 10mm shaft, so I decided to increase the shaft size from 3/8 (9.525mm) to 10mm.

The headstock bearing housing is split, to permit some adjustment with wear.  I used a reamer with spiral teeth to avoid the teeth snagging the split.  And all seemed to go very well using the setup in the photo below.

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…Until I finished and raised the milling machine head out of the work.

Due to my lack of familiarity with the CNC mill controls I  activated the X axis rather than the Z axis.  The side movement broke the reamer and partially gouged the newly reamed lowermost housing.  Bugger.  Bugger.

What to do.  Throw the whole project into the scrap bin?  (following a few others).  Change the shaft to the next size (12mm) and enlarge the housing holes to 12mm?  That would thin and weaken the housing.  And would be tricky machining.  Also, due to the damage in a lateral direction caused by the mishap, I was not sure that drilling and reaming, or boring and reaming, would not follow the same lateral path.

At least the uppermost housing  was undamaged, so whatever tool was used would be held concentrically, as long as the cutting edge extended the distance between the 2 housings.

So I very slowly drilled 11.5mm (the 11.5mm drill did span the distance between the 2 housings) and re-reamed to 12mm, again as per the above photo. Despite my misgivings, this time it all went well.   The 12mm shaft is rather tight, and the housings will need some lapping.  The housings appear to have enough thickness remaining, but time will tell in that regard.   The lateral direction of the shaft is not perfect, but in such a small lathe that is not a big consideration.

As a consolation, and to retore some self esteem after this muck up, I made a new chuck key.

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The chuck is held onto the shaft with a 3/8″ x 24tpi thread.  That thread was cut on the CNC lathe, and is probably fairly accurate.  The oil cups are spare from the beam engine build.

I plan to lap the housings, install a thrust bearing behind the chuck, and make a drive pulley.  I have a spare 12mm shaft ER 16 collet chuck, which will probably be used more often than the 4 jaw chuck.  Then a new handle for the longitudinal feed, a paint job, a motor and belt…

 

 

LATHE OBSESSION

I have a disease, and I do not know its official name, but it involves a compulsion to buy and collect lathes.  At last count, I had 9.  Varying from a 6mm Boley jewellers lathe, to a 2 tonne 400mm swing behemoth which occupies a large space in my workshop.

Well, now it is 10.

I noticed this one on Ebay, and thought that restoring it might be a nice project.  (that is, after finishing the triple expansion marine engine, the Burrell traction engine, the beam engine and the Bolton 7 horizontal engine.  Plus tidying up the workshop.  Plus selling off the remaining farm machinery.  And all of the jobs which SWMBO has lined up for me.)

It is an Australian made (I believe), TNC lathe with 6″ between centres, and a swing of about 3″ (centre about 1.5″ above the bed).  I paid the “Buy It Now” price of $A150, because I lusted after it and did not want to risk missing out in auction bidding.  Plus $A40 rather exorbitant postage, considering that it weighs only a kilo or so.

It needs mounting on a base, a new handle, a drive pulley cluster, possibly a new headstock shaft, a 3 jaw chuck, a motor, and repainting.  The paint looks original and is a horrible job.  I will give it a new colour, suggestions welcome.  The tailstock centre needs regrinding.  It is a tiny taper, about 1/4″ diameter.

Lathes.co.uk is not currently available so I do not have much information about the provenance, age, etc.  My guess is that it would be 1950’s 1960’s.

(lathes.co.uk is again online, thank you Tony!  The TNC was made in Australia under licence, a close copy of the Super Adept which was made in the UK.  Still not sure about the age.  The Super Adept was made as early as 1937.  The Australian TNC was listed after WW2).  The brass handles on my lathe are probably not original.

The cup of coffee is for scale.

The cup of coffee is for scale. (for sale if the price is right!)

4 jaw chuck. Not sure what the gears are for.

4 jaw chuck.  I have a nice 3 jaw TOS which will be installed.
Not sure what the gears are for or even if they belong to the lathe.

 

The muddy yellow-green-grey paint was revealed after an initial de-greasing.  The handles are brass.  All of the slides work, and there is no discernible wear.  The gibs are brass. One handle is broken.

The muddy yellow-grey paint was revealed after an initial de-greasing. The handles are brass. All of the slides work, and there is no discernible wear. The gibs are brass.
One handle is broken.

LATHE RESTORATION

I have been busy with selling farm equipment in my spare time lately and have only been in the workshop to get stuff ready for sale.   New starter motor and starting solenoid on the mower, for example, took a lot of time to identify the problems, source spare parts and then fit them.  Another story.

So to find some material to post I decided to show some pics of a lathe restoration I did several years ago.  Actually, it was two lathes, both  Smart and Brown, almost identical except that one was single phase and the other was 3 phase.  They had been imported from UK by the seller, a second hand dealer, and sitting in his back yard, uncovered,  for 5 years.  There was quite a lot of extra stuff, such as 6 cross slides, a capstan tool changer, 2 complete sets of collets, several tail stocks, several 3 and 4 jaw chucks, and all of this was interchangeable between the 2 lathes.  No lead screws, but 100mm of travel on the cross slide longitudinally.  I think that these lathes are termed “2nd process” or something similar.  They date from the 1940’s-50’s.  The shape of the base, cupboard, and headstock really appealed to me, so I decided to try to salvage them.

Amazingly, after I cleaned up the slides and beds, they were in excellent condition.  Whatever they had been coated with was incredibly effective.  There was minimal surface rust and no pitting at all.

The following photos are mainly the single phase machine.  Both machines looked fantastic after repainting.  At some stage I will have to sell both machines, because I have totally run out of space in my workshop.  I just really like the design and appearance of these lathes, and although I do not use them often, they are lovely to look at.  My architect wife appreciates the designs and says that whoever designed them was as concerned about form as much as function, which is unusual in machine design.

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The two Smart and Brown lathes sitting on my ute, ready for unloading. One was made of cast iron, the other of cast aluminium.

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The capstan, after partial disassembly.

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The capstan was frozen solid with rust. I had to crack it to complete the disassembly, by putting it a 20 tonne press after pre-soaking with WD40.. With huge pressure, it eventually went “bang”, and then showed some movement. I was then able to take it apart. Nothing broken or bent.

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The collet closer on the three phase machine, after some cleaning and lubrication, and prior to disassembly.

The single phase S&B after restoration, painting, new tool post, attention to motor and wiring and switches.  A lovely, quiet, accurate machine.  Just no thread cutting.

The single phase S&B after restoration, painting, new tool post, attention to motor and wiring and switches. A lovely, quiet, accurate machine. Just no thread cutting.

Cast aluminium brand plate.

Cast aluminium brand plate.

I did install a quick change tool post.  No apologies.  Not historically accurate, but very useable.

I did install a quick change tool post. No apologies. Not historically accurate, but very useable.

A good selection of collets.

A good selection of collets.

New, modern belts for both lathes.

New, modern belts for both lathes.

The 1 morse taper tail stocks are a pleasure to use.  Smooth, no discernible play.  Modern lathe makers could take a lesson from these handles.

The 1 morse taper tail stocks are a pleasure to use. Smooth, no discernible play. Modern lathe makers could take a lesson from these handles.

The motors on both machines were checked by a motor rewind specialist.  No major problems with either motor.

The motors on both machines were checked by a motor rewind specialist. No major problems with either motor.