Author Topic: Moving a Lathe  (Read 492 times)

Rob Templin

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Moving a Lathe
« on: 23 June, 2020, 05:43:27 am »
Well some other volunteers at our Historic Village made a concrete block in our engine and machinery shed and moved a donated lathe onto it. I came back from illness and found we now had a lathe and I needed to turn down a shaft for the milling machine I was making at home. The lathe is way way out of alinement. We don't own a machinist level and so back to my old text books from Bendigo Technical College. Went there instead of High School. We covered a lot of trades as well as the usual maths, science and english. The training took one year off your normal 5 year apprenticeship. The book was first printed in 1941 and I haven't touched a lathe since I was about 20. So we are talking almost 60 years ago. Alining a lathe without a level can be done using home made gadgets. So I made a device with a plumb bob to make sure that the bed is alined, as despite being made out of heavy cast iron, they apparently can still twist. I'll test it out today. Hopefully a photo tomorrow. I have asked the local machinery shop to make me a true round bar about 600mm long and approximately 25mm in diameter but true as their machine will do along it's length. But that will be next weeks task, to check the accuracy along its length when fitted up in our lathe. Accuracy of centres and of course the chuck which is where I expect the main error to be.  Of course our lathe will depend on the accuracy of their lathe but it'll probably be close enough for what we need to do. Hopefully more to follow.

John 54

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Re: Moving a Lathe
« Reply #1 on: 23 June, 2020, 08:23:20 am »
 Hi Rob
You should be able to true the headstock and tailstock to the bed using a straight piece of bar stock add a dial indicator. First set the bar stock up in a 4 jaw chuck accurately at the chuck with the dial indicator in the toolpost, then go to the end of the bar stock and check that it is true, if it is not true then either the bar stock isn't straight or there is a problem with the chuck or head stock. If the bar stock is true run the dial indicator the length of the bar "0' it at the chuck this will tell if the the head stock is lined up horizontally adjust as required. Do the same along the top of the bar. Now fit a sharp centre in the head stock and bring the tailstock up with a sharp centre in it and align the two points. Drill centre holes in each end of the bar stock and place it between the centred. using the dial indicator check that both ends are true to the centre by rotating them. Now "0" the dial indicator at the chuck then move it along the bar stock to the tailstock it should be "0" if not adjust the tailstock to "0". Now run the dial along the bar it should stay on "0" all the way. The headstock and tailstock are now aligned to the lathe bed.
regards John       
John

cobbadog

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Re: Moving a Lathe
« Reply #2 on: 23 June, 2020, 04:28:28 pm »
WOW, talk about perfect timing on this topic.
I started making some new valve guides and what I did was to stick the round rod of cast iron into the chuck (3 jaw only) and centre drilled the end so that a live centre would fit into the centre hole.
Next I made a couple of very light skims across the length of the rod, about 200mm as the rest was in the jaws.
Once I had a constant cutting action across the rod I then took out the digital calipers I have and made some measurements. From the chuck to the tailstock it reduced in diameter of 0.14mm.
I noticed that you suggested to adjust the tailstock. This is the part that I do not know how to do or if it is possible to do on my genuine Chinese made lathe.
Yes, there is always a catch isn't there?    :o
Cheers, John & Dee. Coopernook. NSW.

rustyengines

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Re: Moving a Lathe
« Reply #3 on: 23 June, 2020, 06:33:18 pm »
My expensive Chines lathe you can adjust the tail stock
undo the screw on one side a very very small amount and tighten up the other side
Ian
Southern Cross Engines, Lawn Mowers and old tools * TOWNSVILLE

famous fitter

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Re: Moving a Lathe
« Reply #4 on: 23 June, 2020, 07:30:36 pm »
Cobba,

Ian is onto it - just put a dial indicator on it to see how much it has moved - it doesn?t take much to move .1mm (Which is .2mm on the Diameter !!!)

You tube is your friend !!!! Have a look

I just bought another lathe - from memory it?s 10HP, 2m between centres and can spin 660mm in the gap,
When I worked at the engineering works I probably spent over 1000 hours standing in front of it !!! Could fill a wheel barrow with little chips before smoko !!! Loved rough peeling off the metal. Will have it home soon.

Cheers Justin. 


cobbadog

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Re: Moving a Lathe
« Reply #5 on: 23 June, 2020, 09:58:03 pm »
Thank you to both of you. I have not noticed any screws on the sides but I am a 'blindman' by trade. Will have a real good look next time I can get out to the shed.
Cheers, John & Dee. Coopernook. NSW.