Renzetti 1-2-3 blocks

https://www.youtube.com/watch?v=FxVPM08jnGM

Interesting idea for 1-2-3 blocks here.

Think I am gonna make some out of O1 tool steel (easier home heat treat than A2/D2) and borrow a surface grinder.

It actually makes me want to buy a surface grinder just so i can make a set !

If Tom lipton who made the video recommends them you can guarantee that they are worth making , even a set that has bee flycut would be useful in the home workshop .

While you are there checking out this video take the time to look at some more of tom's videos at his youtube channel oxtools and then check out robins at robrenz ,both channels have some amazing videos on them .

Ian .

Funny enough I have had sets of ARCs 10-20-40 and 20-40-60 blocks since they came out at least two years ago and never found the need to screw them together yet though I do use them a lot.

I made a set as an apprentice over 50 years ago, use them most weeks for something but mine have no holes to fix together.

People are popping up all over the USA with derivatives of JS's blocks claiming they are a 'new' invention...

www.arceurotrade.co.uk/Catalogue/Workholding/Vee-Blocks-Angle-Plates/10-20-40-and-20-40-80-Blocks

Neil

Haha that's Mercans for you! Reinventing everything and putting stars and stripes on them, even when made in China.

No disrespect to Robrenz, mind. Very interesting and impressive stuff he does, rather than trying to become a member of the Youtube celeb club.

Merry

The counter bored holes are a useful addition that JS did not include.

These are a couple of views of a block I used to have. They were about 4inch square and 6inch long every face was drilled and tapped with 1/4 BSF taped holes about 3/4 inch deep at bout 1/2 spacing, a step which had a small undercut at its root and a V was cut to hold small pins and rods. In the bottom was cut a larger V but running the length of the block. case hardened to maximum depth and fully ground all over so any face was square and true. This was an apprentice piece and it was stolen just short of my retirement. you could hold anything and once clamped with the many small clamps etc. that were acquired over the years one of the best tools I had.

David

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No offence intended to any of those involved; but it's worth noting that [prior to JS re-inventing them] the metrology versions of such blocks [Brown & Sharpe for example] typically had counterbored holes.

MichaelG.

John's 'Invention' was combining more useful 1:2:4 proportions with tapped holes.

David George1. I still have a couple of the blocks you describe, here in the Midlands we knew them as "Grinding Blocks" why I don't know as they get equal use on the mill and spark eroder. Thankfully I worked with trustworthy people and all my tools came home with me when I retired.

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I beg to differ, Neil

I think John's real 'Invention' was to produce something of workshop quality at an affordable price.

MichaelG.

I think JS's contribution was making metric blocks, the Americans have not done that yet

Imperial blocks from several of our suppliers cost about the same as 2-4-8 blocks from Arc and are of similar quality but you can't screw them.

Edited By JasonB on 07/09/2017 13:12:50

My set of JS blocks (or copy of them ) don't get much use as they are not on spec or a matched set , one comes up 25x50x75 the other is 25x50x75 and a little bit but fortunately the little bit is oversize and can be fixed or could be if i had a surface grinder .

Edited By XD 351 on 07/09/2017 15:54:30

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That's fine, Jason ... My reference to affordable pricing was in comparison to the 'Metrology' blocks

MichaelG.

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ferinstance: http://www.starrett.com/metrology/product-detail/706BZ

Edited By Michael Gilligan on 07/09/2017 18:01:17

I'd have to sell one of my puppies to afford a pair of those

I have it from a good source that the reason behind the two sizes of blocks is that both are smaller than the standard 1-2-3 blocks which are too big for most model engineers vises.

Secondly they are made and DO bolt together, something the last 10 years worth of production 1-2-3 blocks cannot do as someone left the plain holes as tapping sizes when they got copied in China and India.

A very bad copy then as I never designed any 25-50-75 blocks

Arc sell a metric version as do Ausee here in OZ .

I think the point tom lipton was trying to get across was about the counterbored holes and waisted shank cap screws which means all of the holes can be threaded giving the blocks a little more versatility .

Ian.