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Making Tiny Blocks


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There has been a discussion elsewhere on the forum about scales for models and the subject of small scales lead to the mention of using wood to make very small blocks.

 

The system below was used by the late Gerald Wingrove to make very small blocks for a model of the Pilot Brig Bengal.  The blocks produced are probably more like the Late Nineteenth Century internally stropped blocks than the earlier rope stropped ones.

 

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Thanks, Roger, that gives me indeed some more ideas 👍

 

Internally stropped blocks are particularly difficult to make. I think I would mount the rod excentrically in the lathe, as the sheave sits a bit closer to the bottom end of the block. However, grinding such form-tools is probably the most difficult part.

 

The key idea probably is to wrap the wire around in a groove, solder it in and then file the cheeks of the blocks flat. Could be perhaps also done with (super)glueing, using some highly-viscous CA. As I said, gives ideas.

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I must admit that I tried this years ago to make double or triple blocks for davit blocks on a small scale model.  I was able to produce the machined blocks but when it came to soldering the wire, I wound up with an unsightly blob.  I have been building a resistance soldering unit.  By first tinning the wire and then resistance soldering I think that I can eliminate this problem

 

I’m looking forward to seeing how you adapt this technique.

 

Roger

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10 hours ago, wefalck said:

Internally stropped blocks are particularly difficult to make. I think I would mount the rod excentrically in the lathe, as the sheave sits a bit closer to the bottom end of the block. However, grinding such form-tools is probably the most difficult part.

 

The key idea probably is to wrap the wire around in a groove, solder it in and then file the cheeks of the blocks flat. Could be perhaps also done with (super)glueing, using some highly-viscous CA. As I said, gives ideas.

Good idea mounting the rod eccentrically to lower the sheave between the block faces.

 

While Wingrove's form tool reduces the number of cuts in half, if one sets a stop on their cross-slide, repetitive single cuts aren't that much more work. His form tool does permit exact repetitive spacing between the blocks on the rod, though. Perhaps it may be possible to mount two cutting tools side by side with a spacer shim between them and replicate Wingrove's cutting tool. Wingrove's book has a number of such cutting tools for things like cannon and belaying pins but those custom cutting tools are easier said than done, particularly in tiny sizes! It must be remembered that his forte was metal automobile models. He was a master miniature metal machinist.

 

It would seem internally stropped blocks can be made relatively easily by soldering a bent wire bail at the top and/or bottom of the block body. 

Edited by Bob Cleek
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59 minutes ago, Roger Pellett said:

I must admit that I tried this years ago to make double or triple blocks for davit blocks on a small scale model.  I was able to produce the machined blocks but when it came to soldering the wire, I wound up with an unsightly blob.  I have been building a resistance soldering unit.  By first tinning the wire and then resistance soldering I think that I can eliminate this problem

 

I’m looking forward to seeing how you adapt this technique.

 

Roger

Tinning and fluxing the untinned part may work with conventional heat alone. However, it sounds like you were using regular "soft solder" and too much of it. It's my guess you'd avoid the problem described by silver soldering the parts using flux, a speck of silver solder, (or silver solder paste) and a torch. The solder joint should be practically invisible if you're careful applying the flux (or silver solder paste.) This will also provide a much stronger joint. A resistance soldering unit can replace the torch if one prefers. They have their advantages. at a price. The "blob" was a "materials and technique" issue, I'd expect.

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I'm going out on a limb here because I haven't actually tried this. It's purely theory at this point, but it's something I anticipate attempting when I'm next faced with having to make a bunch of really small blocks.

 

think it may be possible to make quite small blocks out of oven-hardening plasticine modeling clay, such as FIMO. A mold could be made to form the blocks to any shape desired. When the oven-hardening FIMO is "baked" at 230 degrees Fahrenheit  it hardens. (There's also an "air hardening" FIMO, but I believe the oven-hardening stuff is stronger. Through holes in the blocks could be formed using a suitable diameter needle or awl. Metal wire eyes and bails could be permanently inserted in the soft FIMO before hardening, if desired. Basically, we're talking about FIMO beads that are shaped like blocks. 

 

It's a slow Saturday morning, so my creative juices are overflowing, but this is one approach I've been playing around with for some time. Imagine a pliers with block shapes in its faces, sort of like an old-fashioned round ball bullet mold. Quite a few blocks could be molded in short order.

 

I don't have any idea of the archival qualities of oven-hardened FIMO, but we have a few pieces around the house that were done with it by friends and they seem to have held up very well over the years.

 

If anybody's tried this, I'd welcome hearing of their experiences.

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55 minutes ago, wefalck said:

The idea is that the solder fills any gab between the wire and the slot, so silver soldering may not be ideal and one may actually burn away thin wires …

True. Silver solder won't fill gaps. If one wanted an externally metal-stropped modern block, they might have an easier go of it by rolling suitably-sized annealed copper wire into a flat ribbon section. 

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39 minutes ago, wefalck said:

Been down that road, but it turned out to be a cul-de-sac ... when you are working on 1 to 1.5 mm long blocks, this means that the strop is 1/10 the diameter, i.e. 0.1 mm. If you flatten that not much of substance is left ...

Ah, the voice of experience is always the most valuable. Scale is always the problem. I have a couple of models awaiting restoration and, for the life of me, I can't imagine how they made the blocks they did, smaller than a grain of rice and quite accurately convincing.

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3 hours ago, Roger Pellett said:

Clay shaping pliers-  Something like my super dooper deadeye strop crimper.

Absolutely! I have a kit for attaching brass eyelets for canvas work. It has a pair of vise-grip pliers which accept a variety of different shaped "heads" that will set brass eyelets or "cringles" and snaps and such for canvas and sailmaking. I'm thinking I could fashion a "head" for it that would stamp out molded FIMO blocks. A groove between the two head faces would permit running a wire through to make the necessary holes for the line to run through.

 

"(c) 2021 Robert J. Cleek" just in case you see it for sale in the MicroMark catalog someday! :D 

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This problem has been nagging me for decades actually. So mentally at least, I probably have been through most of the ideas:

 

- making a set of dies to shape a block from soldering tin around a wire - inspired by the lead seals you see on electricity meters and the like; could work for larger sizes, but it would be difficult to pull out tiny wires, even when you use tungsten or NiCr.

 

- same idea but using the dies to shape a ball of two-part expoxy (Milliput or similar); same problem with releasing the wire when set or distorting the block, when pulling it out while the epoxy is still soft.

 

- casting in some resin using silicone moulds with wires embedded to keep the hole open; again releasing the wire is the problem.

 

The last two methods would allow to imbed internal strops relatively easily.

 

Somehow, I came to the conclusion, that some rough-machining with good old hand-work in some reasonably hard and dense material (I prefer bakelite) is the solution - unless ...

 

- I have tried to entice a colleague for some time now to design some blocks and print them in his UV-curing resin 3D printer, but he hasn't got around to do it yet. Even if the printing doesn't keep the space above the sheave completely open, re-drilling it is much less work. All the grooves for the rope strops etc. would be formed on already, of course.

 

Making rope-stropped blocks is much less of a problem than internally stropped ones. However, one could 3D-print them, then add the wire-strops as per Wingrove's method and fill/seal the grooves with a tiny blob of UV-curing cement.

 

 

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7 hours ago, mtaylor said:

Instead of wire for something that tiny, would monofilament work?

Absolutely. I've also considered dental wax sprue wire, an easily sourced product. I know it is available down to #20 gauge and if not finer, I expect it could be reduced using a draw plate. It's a hard wax sold on spools like wire that's used in dental labs and by jewelers for lost wax casting purposes. It would have the advantage of melting away when the oven-hardened FIMO was baked.

 

The concept of stamp-molding oven-hardening FIMO isn't limited to blocks, either. There's really no limit so long as the object is shaped in such a way that it can be removed from a split mold. Cannon, cleats, belaying pins, etc. could easily be done. Mold halves could be made of hard injection-molded plastic like LEGO bricks are made of. Stock mold halves that mounted on a plier-like hand tool could be manufactured and sold for all sorts of parts in various scales. The real question is whether the tooling costs and production costs to produce a range of molds would "pencil out." There would probably be a considerable investment to manufacture them and I'm not sure there would be a sufficient market for such a product to turn a profit. 

 

But wait! There's more!

 

I did a bit of research on line. It's even easier than what I had originally envisioned. It seems now that FIMO and Sculpey clays are made in a liquid form for poured castings that cure to hard FIMO or Sculpey shapes. (Sculpey is another polymer clay product sold in the US.) So, all we have to do is make a master pattern and then make a silicone mold for what we are wanting to reproduce in quantity. The silicone mold can be used over and over again. We're so busy building ship models that we aren't keeping up with the modeling technology in other fields, I suppose.

 

 

Edited by Bob Cleek
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