Author Topic: Harrison 140 lathe question  (Read 349 times)

Offline Ian.C

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Harrison 140 lathe question
« on: February 08, 2017, 02:03:27 PM »
Hi everyone, I wonder if anyone can tell me what thread the adjusting/leveling screws are as I need to tap out the rather crusty threads on my new toy, the lathe didn't come with the screws! I have measured the diameter of the bolts and found 21.9mm and 3mm pitch-ish but I would have thought they would been imperial. It is a metric lathe though?









Offline awemawson

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Re: Harrison 140 lathe question
« Reply #1 on: February 08, 2017, 03:41:25 PM »
Hi Ian welcome !

Can I suggest that if you are going to be using your new lathe much it's worth while investing is a screw pitch gauge. They are cheap as chips and will serve you well for years to come identifying threads - you'll need a caliper gauge as well to measure the diameter accurately.
« Last Edit: February 08, 2017, 04:32:09 PM by awemawson »
Andrew Mawson
East Sussex

Offline philf

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Re: Harrison 140 lathe question
« Reply #2 on: February 08, 2017, 04:05:15 PM »
Ian,

It's possibly 7/8" BSW which is 9 TPI (2.822mm Pitch) You did say 3mm-ish.

Phil.
Phil Fern
Location: Marple, Cheshire

Offline Ian.C

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Re: Harrison 140 lathe question
« Reply #3 on: February 09, 2017, 06:19:31 AM »
Hi Phil,

Thanks a lot for that, I didn't think the thread would be metric - I have ordered a set of imperial pitch gauges, I only had a metric set. I will report back.

Offline micktoon

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Re: Harrison 140 lathe question
« Reply #4 on: February 09, 2017, 12:43:18 PM »
Hi Ian, yes I can confirm 7/8 Whitworth threads on the levelling bolts.
  Cheers Mick  :thumbup:

Offline Ian.C

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Re: Harrison 140 lathe question
« Reply #5 on: February 09, 2017, 02:38:04 PM »
Thanks Mick, I have just ordered a new tap. She is getting a bit of a paint job this weekend not ideal weather conditions but I cant wait to start making some swarf. Ian

Offline Ian.C

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Re: Harrison 140 lathe question
« Reply #6 on: February 17, 2017, 05:25:19 PM »
Thanks to Mick and every one else the threads have now been chased out. I borrowed an engineers level and have the lathe as level as its ever going to be in my possesion, the level is accurate to 0.3mm and I focused my patience towards the front to back rather than along the length - I wish i knew the correct terminology! I was more concerned about twisting the bed. I will be making chips and swarf tomorrow. Ian

Offline micktoon

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Re: Harrison 140 lathe question
« Reply #7 on: February 17, 2017, 06:00:42 PM »
Hi Ian , glad you managed to get it sorted out in the end   :thumbup:
  Cheers Mick

Offline awemawson

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Re: Harrison 140 lathe question
« Reply #8 on: February 18, 2017, 03:03:22 AM »
Thanks to Mick and every one else the threads have now been chased out. I borrowed an engineers level and have the lathe as level as its ever going to be in my possesion, the level is accurate to 0.3mm and I focused my patience towards the front to back rather than along the length - I wish i knew the correct terminology! I was more concerned about twisting the bed. I will be making chips and swarf tomorrow. Ian

Along the bed is the Z axis, and across the bed is the X axis
Andrew Mawson
East Sussex

Offline mattinker

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Re: Harrison 140 lathe question
« Reply #9 on: February 18, 2017, 05:54:23 AM »
The Z axis is the driven axis.

All the best, Matthew