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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.

Moving a biggish lathe

My friend Jason asked me to help him move his lathe out of the shipping container which had housed it for 10 years, unused, into his newly constructed workshop.

I suspect that he was less impressed by my moving qualifications than my Landcruiser ute with its 8000lb Warn winch.

The lathe was an old English behemoth, with 2 meters between centers and weighing 2 tonnes.  It was bolted to 2 bits of U channel, which were to act as skids.

The lathe had to be pulled out of the container, turn 90 degrees, then down a gravel slope for about 15 meters, then another 90 degree turn and up into the shed.  Once inside the shed with its smooth concrete floor we figured the final positioning would be easier.

The winch pulled the lathe out of of the container without too much fuss.  But when the lathe encountered the gravel and ploughed in, the winch really struggled.  I had stupidly forgotten to bring a snatch block, which would have doubled the pulling power and halved the speed.

So, I used the 4WD’s engine, in low ratio reverse, to pull the lathe around and down to the shed door.  Even with that power , and downhill, it was a struggle.  And it really made a mess of Jason’s nice gravel paving.

Then a repositioning of the 4WD into the shed, to pull the lathe up a bit of a slope and onto the shed concrete slab.  Some judicious jacking with a very large crowbar, and insertion of wooden slides and steel rollers, and serious pulling by the cruiser, and the lathe was almost in the shed.  Fortunately there was enough room to drive past it and outside.  Then I repositioned the 4WD into a pushing position, using a large piece of wood between the lathe and the bullbar and pushed it inside.

Some more heaving with the crowbar, and use of steel pipe rollers, and 3 adults and 2 teenagers pushing, and the lathe was in position.

Jasons lathe - 1.jpg

Jason, John and lathe.  All smiles with the lathe running after 10 years of storage.

After a quick check to make sure that the chuck was attached, and nothing loose ready to fly off, Jason switched on his lathe….. and it ran!   As smooth and sweet as the day it was made.  Very satisfying.

The day was already hot, so we cracked a few beers to celebrate the move.

TAPPING GUIDE

I took another break from the triple to make this tapping guide…

tapping guide - 5

The tapping guide in use.  BA7. (staged photo)

 

tapping guide - 1

CNC drilling and reaming

tapping guide - 3

CNC milling the flanges

tapping guide - 4

The completed arms and flanges

tapping guide - 1 (1)

Milling the jaws manually

tapping guide - 2

The jaws in position

tapping guide - 3

Showing the jaws holding a tap. The jaw cover is removed.  The  hole in the side of the chuck is for the M5 grub screw which opens and closes the jaws.

tapping guide - 4

Showing the jaws cover in place.

tapping guide - 7

The 3 jaw chuck provides a convenient and accurate base. Alternatively, the guide could be supported in a hole in the bench.

tapping guide - 8

Very handy for tapping threads in items not readily held in a vise.

The biggest problem with tapping threaded holes is taps which break in a job.  Sometimes after many, many hours making a part.   Sometimes the broken tap is able to be removed, and sometimes it cannot, resulting in a ruined part, wasted time and much wailing and gnashing of dentures.

Keeping the tap vertical at all times during the tapping procedure, and using a sharp tap, suitable lubricant, and appropriate torque, are the keys to not breaking taps and saving teeth.

Usually I do my tapping with the tap held under a spring loaded guide in the chuck of the drill press or mill, and the workpiece in the vise.  This method prevents any inadvertent bending of the tap, which avoids one of the major causes of breakages.

But sometimes it is just not possible to hold the workpiece in the mill or drill press and the tapping has to be done freehand, aligning the tap by eye.  I am rarely satisfied that the tap is vertical after using this method.  Lack of accuracy, and higher chance of a broken tap is the consequence.

So when I saw this tapping guide in “Model Engineer”, and saw the possibilities for its accuracy and versatility, I decided to make one.  The fact that much of the machining could be CNC’d was an added attraction.   Also the 4 jaw chuck was intriguing.  I had seen one made by a colleague in the Melbourne Model Engineering Club, and I was keen to see if I could manage it.

The design was by Mogens Kilde and the plans were published in the August 2015 “Model Engineer”.    I made a few minor changes to the design, mainly using thicker aluminium in the arms and flanges.  I used stainless steel for the chuck body because that was the only free machining steel which I had in the size.  I used key steel for the chuck jaws, again because that was what I had available in my workshop.

The double parallelogram arms keep the tap vertical within the limits of the arm movements.  Using a 3 jaw chuck as the base of the unit provides a lot of flexibility in positioning the guide.

I will not comment on the actual building, because that is clearly explained in detail in the original ME articles.

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