1-2-3 Blocks

[Boucher]

Ever since the discussion of John Stevensons 10-20-40 metric blocks that can be attached to one another, I keep encountering situations where I would like to do that with my 1-2-3 blocks.
Since they are hard it would probably take EDM to enlarge the clearance holes. There are 15 holes. Would anyone care to hazard a guess at the cost. If one had several done at the same time would that be any cheaper per unit?

For use in my Home Shop the hardness is not that important. What if one dropped them in the wood stove overnight?

[oldtiffie]

Use "captive" bolts/screws - easy.

[Boucher]

I often overlook the easy solutions but I don’t understand the captive bolt/screws you mention.

[oldtiffie]

If your block that you want the screw through is say 2" thick, and all the blocks are tapped the same (say 3/8-unc) the bolt/screw needs to be a good quality (say high-tension) with its length needs to be say block width + 3 screw diameters minimum. Turn a plain section on the bolt shank that is at least block tickness + 1 bolt diameter (from the bolt head) from the head - screw shankplain section to be bolt/screw minor diameter (maximum).

Now screw captive bolt into the 2" long 3/8-unc tapped hole in the 2" block. The screw will be loose/free in the tapped hole with a 3/8-unc end section protruding from the 2" block. The protruding 3/8-unc section of the bolt can be inserted/screwed into another block and tightened as required. Use washers as required.

The bolt/screw is "captive" in the 2" block as it can rotate fully and move length-wise partially but cannot come out unless deliberately screwed out.

It also means that a block can be fastened to anything that has a 3/8-uns tapped hole without the need of clamps or packing.

Its use is not limited to "blocks" either.

There are numerous variations on the principle limited only by need and imagination.

I/ve seen and used this since my "early days" and it had been around for a long time prior to that.

[John Stevenson]

What you are describing is a waisted bolt but pray tell us how you get said wasted bolt thru a plain hole into the tapped hole.

If you had ever used a set of 1-2-3 blocks you would know that only some are tapped and it depends on the configuration you want to use what plain and tapped holes can be used.

Byron, I'd be more worried about distortion than lack of hardness but having said that I have 4 shafts to go into the hardeners tomorrow once splined and I'll send a set of 1-2-3 blocks to have them professionally annealed and report back.
I also am not that interested in hardness but interested in whether they will soften enough to drill with a cobalt drill.
I have tried previously to drill this set with a carbide drill and just wrecked it.

[.RC.]

You should just do what I did.... Got some rod that fits through the 3/8 tapped holes.... Cross drill and tap to 6mm or 1/4", then shove them in the holes and use 6mm or 1/4" bolts to hold the blocks together.

[Harvey Melvin Richards]

Universal 1-2-3 blocks from Travers $53.

http://www.travers.com/product.asp?r...397-57-020-413

[lazlo]

Ever since the discussion of John Stevensons 10-20-40 metric blocks that can be attached to one another, I keep encountering situations where I would like to do that with my 1-2-3 blocks.

Just buy the old stock Western (or Japanese) 1-2-3 blocks the Chinese copied. They all have the correct through-holes to connect together.

When the Chinese got the prints, they obviously confused which were tap drill sizes and which were through holes.

[jkilroy]

I have a couple of set of blocks like those Mr. Richards posted the link to. They rock, the holes are arraigned on the blocks such that you bolt them together with simple socket head screws. You can bolt them into just about any configuration you can imagine.

[Jaakko Fagerlund]

Or just build the EDM yourself, that way you get a new machine and invest money to a useful tool

[oldtiffie]

Originally Posted by Boucher

Ever since the discussion of John Stevensons 10-20-40 metric blocks that can be attached to one another, I keep encountering situations where I would like to do that with my 1-2-3 blocks.

Just buy the old stock Western (or Japanese) 1-2-3 blocks the Chinese copied. They all have the correct through-holes to connect together.

When the Chinese got the prints, they obviously confused which were tap drill sizes and which were through holes.

I think that the hole (whether tapped or not) is as much to do with ease of heat-treating and control of distortion and cracking due to internal stresses and with a reduction in processing time (and cost).

I can't see that the non-tapped holes are an issue at all.

[dp]

I think that the hole (whether tapped or not) is as much to do with ease of heat-treating and control of distortion and cracking due to internal stresses and with a reduction in processing time (and cost).

I can't see that the non-tapped holes are an issue at all.

They're too small to pass a threaded bolt or all-thread through unless you don't care if the bolt doesn't match the threaded holes. It means you can't bolt one block to another unless your bolt passes through both blocks and is nutted externally.

All the holes were drilled to the same size and some were threaded. The holes that are threaded are a tight fit, sometimes too tight, but the unthreaded holes needed to be drilled larger than the major diameter of the bolts to allow the bolts to pass through. That wasn't done. That this error has been going on for years and that no retailer has rejected the parts says much about QA in machinist tools.

[bob ward]

FWIW, on Australian ebay recently a trader was offering new sets of metric blocks 25 x 50 x 75 with.........3/8" threads. Sigh.

[John Stevenson]

They're too small to pass a threaded bolt or all-thread through unless you don't care if the bolt doesn't match the threaded holes. It means you can't bolt one block to another unless your bolt passes through both blocks and is nutted externally.

All the holes were drilled to the same size and some were threaded. The holes that are threaded are a tight fit, sometimes too tight, but the unthreaded holes needed to be drilled larger than the major diameter of the bolts to allow the bolts to pass through. That wasn't done. That this error has been going on for years and that no retailer has rejected the parts says much about QA in machinist tools.

DP,
Whilst I fully agree with what you say, I question why a retailer has to reject them given there is no 'standard' on how these things should be used or what they were used for.

Now if they were advertised as being able to bolt up in certain configurations then fine but the use of these things is very obscure.
Given there is probably 1 million sets out there why is there not 1 million unsatisfied customers ?
Probably because they all use them in different ways.

As regards the proper old design it's a chance you have to take, the old Starrett blocks were fine, current new one being sourced from China or India are wrong. I have a set of each.

[oldtiffie]

Dennis,

if it bothered me that much - or at all - which it doesn't I'd make a set of aluminium ones - but I can't see the need.

Aluminium is easy to take a "passing" ("clean-up") fly cut to restore a face if needed. It would not be difficult to machine another as well to maintain "pairing/matching" if needed.

Some of those "1-2-3" etc. blocks from LittleMachineShop are very good for accuracy and price:

http://littlemachineshop.com/product...Product+Search