Tool How would you use these blocks?

[trlvn]

I got a massive box lot via an auction last week. It included several sets of user-made parallels and clamping hardware (and LOTS of other stuff). The following blocks were included and I'm having trouble picturing just how they might be used:





First, the pictures look worse than they do in person. The 'rust' is really minor surface corrosion.

At first, I thought they were like little 1-2-3 blocks but only the two larger surfaces on each block is ground. Of the others, one has the guy's initials heavily stamped so that's not a good reference surface. The intersecting holes are 9/16" diameter so I could use 1/4" hardware to...do something?

BTW, note that there are 2 pairs of differing thickness. That surprised me--4 all the same would seem more sensible to me.

So, just a minor curiosity for me but I'm wondering what "JRB" had in mind when he made these! What do you think?

Craig

 

[whydontu]

my guess is they’re jigs, not gages. Custom cut for a specific machining process that got repeated often.

 

[Susquatch]

So, just a minor curiosity for me but I'm wondering what "JRB" had in mind when he made these! What do you think?

He must be buddies with the guy who made a bunch of my blocks. Not one of any of them have any standard dimensions. But they were valuable enough to him to put his initials in them. I even know who he was. He received an award when he was still alive as Ontario's machinist of the year.

There are dozens of ways that blocks like those can be used in pairs. So I think the old machinists just made them as needed and didn't bother making subsequent sets to the same dimensions.

The truth is that you can buy 123 blocks that are matched. But if you try to buy another pair later on, it won't match the first set.

Maybe making them different was a deliberate way to improve knowing which one went with which one!

 

[Former Member]

I make my own tooling and setups, you will find that nothing is standard other than it works best on/for the machine/application/machinist it was designed for.

So does it meet a standard, yes! What is that standard? It works!

 

[trlvn]

Note that the blocks are quite nicely finished--very consistent chamfers on every edge. I believe they are hardened but haven't actually tested yet. Maybe there was some job JRB was doing repeatedly that warranted that kind of effort. I'm just having trouble picturing it.

For example, each block has 4 holes drilled through but because they intersect you could only use a maximum of two at a time. Plus, say you put a bolt through and secure the block to a table via a T-nut, for example. The block is being pulled up on a non-ground surface so there is an increased chance that it will be out of square. Thus the ground surface of the block doesn't make a really good fence or stop.

If you were going to the trouble of grinding 2 surfaces on each block, why not do the other 4 as well?

Maybe these were just an apprentice project where the objective was to develop skills?

Craig

 

[Susquatch]

If you were going to the trouble of grinding 2 surfaces on each block, why not do the other 4 as well?

Maybe these were just an apprentice project where the objective was to develop skills?

Ya, that's a good question and a good point too. You wouldn't do that and neither would I.

Hell, I actually LOOK FOR excuses to grind nice surfaces! I seem to recall both @Dabbler and @Mcgyver warning me that this would happen!

Your explanation makes sense to me.

Send them to me and I'll finish them up for you. Or bring them to @Mcgyver and you can both have a good laugh at my expense!

Somebody might make unfinished blocks for a special project, but only a student would put their initials on them before they were ground on all 6 sides. Mine are oddball sizes but all 6 sides are ground.

 

[CWret]

I first got 1-2-3 blocks and parallels when i got my mill (10 months ago). Long ago I cut up a piece of cold rolled flat bar - a pair at 5” long and a pair at 8” long. One end at 90 degrees and other end at 45 degrees. Worked great for welding or in the drill press. The point is that the dimensions were not important but they were matched pairs and that’s all that mattered (and plenty accurate for non machining purposes).

 

[whydontu]

Whatever works. I was given an old 24” cast iron Stanley level. Vials were broken. A bit rusty but not too badly pitted. Cut in half, removed the broken vials, a few minutes with a file and I have two 10” long Gudenuff parallels for long stuff. I suppose @Susquatch would be chortling with glee for the chance to grind them nice and perfect. I’m too lazy for that.

 

[jcdammeyer]

If you use your caliper what are the exact metric dimensions?

 

[trlvn]

If you use your caliper what are the exact metric dimensions?

I did check that. They are not a round number in either metric or imperial.

Craig

 

[thestelster]

I have nine 1-2-3 blocks, and I mostly use them as spacers to raise stuff off the table. So in reality, it doesnt matter what the actual dimensions are, as long as they're equal.

 

[jcdammeyer]

Over the last couple of weeks I've been using mine as calibration standards to ensure that my G-Code and Tool Offsets are correct.
For example: Home Z axis and then move knee up until I can just slide the 2" length under the spindle. The negative value minus another 2" is the total distance from the bottom of the spindle (where the TTS tools register) to the table.

And then once I start testing tools I can again slide the block under the tool bit at +2" location from the Z=0.0.

 

[trevj]

I used to make up blocks, mount plates, and fixtures, whenever I though it worth the time, for various jobs that routinely came through the shop.

No telling what they were for, or even if they were for anything in particular, but you can use them as you see fit without much guilt, eh?

Are the pairs at least matched in any of their dimensions? If so, they could have been simple spacer blocks for a job. For all we will ever know they were used only on one job, or never were...

Edit to add:

One thought that springs to mind, is that the holes do not serve any purpose other than to reduce the heating time, in order to heat treat the material, if they are hardened and ground. Possibly to reduce warpage too.