# Rear toolpost & calipers



## arnoldb (Oct 3, 2009)

I've been a bit quiet of late, but some things did get done...

My father bought a box of "junk" at an auction a while ago. At the bottom of the box was a case with lots of very rusted calipers - he handed these to me while visiting:






I took a couple of the smaller ones and gave them a good soak (2 days) in citric acid, followed with some steel wool & oil, and in the case of the left odd-leg caliper, a new scribing pin and tightener:




All are good quality tools; mostly Moore & Wright - I needed that!

One of the items on my To-Do list was a rear tool post for the Myford - primarily for parting, but a multi-use post was better.
So I started off by turning a piece of mild steel rod down to 25 mm, made a base from some 10mm mild steel flat bar, and welded the two together. A block of mild steel square would become the parting tool holder - just faced off in the 4-jaw chuck:





Next up, I cut a keyway down the post using a boring bar and the post mounted in a vice on the cross-slide:





I milled a recess in the block for the parting blade, and then used a slightly unorthodox way to cut a "dovetail" in the bottom of it.





Just for the record, the "parting" blade is a HSS blade from a wood planing machine; I just ground off the original cutting edge on the bench grinder and was left with a nice piece of HSS 2mm thick, 20mm high and ~200mm long; I split it in 2 on the length - so LOTS of parting tool left ;D

A shot of the rear parting tool after it was used a couple of times - the tool block is not finished yet, as it needs a height adjustment screw for quick-changes, but I have to finish something else first...:





This makes parting off a breeze!

Regards, Arnold


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## zeeprogrammer (Oct 3, 2009)

Nice job on the tools Arnold! And thanks for that. Had it been me I would've trashed them thinking 'no way could they be restored'. This will make me hesitant should I ever get so lucky.

Liking the tool post too. I've seen several threads about that...and having had so much trouble with parting...I'm going to have to do the same.


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## Tin Falcon (Oct 3, 2009)

I have taken some pretty rusty tools and hit them with PB blaster and some scotch bright and they brighten up pretty quckly I guess the citric acid bath would make things a little easier. 

Z: 
On the little 7 x I have flipped the tool upside down and run the spindle backwards for threading and parting. the beauty of threading this way is you can run faster and not worry about crashing the tool. (with upside down tool and reversed spindle you thread away from the head stock) 
Tin


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## zeeprogrammer (Oct 3, 2009)

Tin Falcon  said:
			
		

> the beauty of threading this way is you can run faster and not worry about crashing the tool. (with upside down tool and reversed spindle you thread away from the head stock)
> Tin



Thanks Tin! That hadn't occurred to me. I was always just thinking of parting.


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## itowbig (Oct 3, 2009)

wow so much information thanks  i need a separate computer just to store info


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## ariz (Oct 4, 2009)

it's always nice to restore old tools and bring back them into existence

you made a very good work on the rear tool post too
well done arnold


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## arnoldb (Oct 4, 2009)

Thanks everyone 

Tin/Zee, yes using the tool upside down in the front toolpost and reversing the lathe would work well, as long as your lathe does not use a threaded mandrel. This is about the only disadvantage I have found to my Myford so far; cannot do this, but the easy changing of chucks more than makes up for it ;D. I'm building another rocking engine for my sister as a birthday gift, and the rear parting tool has saved a lot of time; just turn to size & part without changing tools :big:

As to restoring the old tools, personally that is effort well spent; I prefer older tools as they seem to be more robust than some of the new stuff being made, and here in Windhoek some tooling can be difficult to get and extremely expensive, so restoration is always an option 

Kind regards, Arnold


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## CrewCab (Oct 4, 2009)

Nice work on the toolpost Arnold, and good save with the tools 8)

CC


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## va4ngo (Oct 4, 2009)

Hello Arnold and Tin.
Good information there for derusting old tools

Question for you arnold, Do the tools ned to be neutralised after Citric Acid dip to prevent further rust appeasring later.


Tin

What is PB Blaster I haven't heard of that here is Oz.

I have previously used two different methods for derusting

1  Molasses bath for a week or so (not suitable for non ferous items)

or

2 Caustic soda bath with a battery connected to part and anode inserted in the bath but this method can be a little dangerous as hydrogen gas is given off.
  also not suitable for non ferrous items as they wont be there when you try to remove them from bath.

Does Citric acid also have these issues for derusting?


Cheers
Phil


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## arnoldb (Oct 4, 2009)

Hi Phil

No need to neutralise; a good wash with water when you take it out, dry it off, then scrub it with steel wool or scotch brite, and wipe with a good coating of thin (non-hygroscopic) oil. Before you drop parts in the acid though, they must be free of oil/grease, so a good wash with detergent before-hand is advisable (or stick it in the dish washing machine :big.

Citric acid is basically crystallized lime juice; you can find it in any grocery store in the section where housewives find ingredients for baking cakes. It is environmentally friendly - you can dump it down the drain when finished, not harmful/toxic to pets or children (it is used as a food ingredient).
I use about a table spoon dissolved per liter of water.

As far as I am aware, it is not harmful to non ferrous metals (definitely not copper/brass; I'm not sure about aluminium) - it is a good "pickling" solution commonly used for silver soldering.

Regards, Arnold


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## RobWilson (Oct 4, 2009)

Very nice Arnold 
rear tool post makes life allot easy-er ;D i never thought those rusty tools would come up looking so great :bow: :bow: :bow:


Regards Rob


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## Tin Falcon (Oct 4, 2009)

Phil:
 blaster is a US made general purpose rust buster penetrating oil rust prevention product
Cool retro themed web site look here
http://www.pbblaster.com/products.html
MSDS here some idea of ingredients. 
http://www.pbblaster.com/images/msds/PB-bulk-aug08.pdf

Blaster Corporation is pleased to announce the appointment of a representative in Australia:

Blaster Group, PTY Ltd
Unit 30, 8 Victoria Ave
Castle Hill, NSW Ave 2154



Tin


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