In these Lock Down Days, I’ve been turning to all manner of different activities.
The workshop is (reasonably) tidy, the garden is weeded
– and there’s even been a bit of housework.
Instructables provides many an inspiration – and I’ve 3D printed (and adapted so that it actually works!) a small rope machine. Various experiments have shown it quite capable of making rope well over 10mm diameter (that’s about 1½” rope in old money, where they measured the circumference). So far most of my ropes have been small (a few mm in diameter and quite short. It seemed wise to do my initial learning in the privacy of my own workshop (called “The HellHole” in our family – which will give you an idea of how tidy it normally isn’t).
Those who know me will be aware that I like to stand at one end of a rope, with a large bell on the other. It is a natural progression then, to making a woolly sally for my ropes. Somebody pointed me at a YouTube video that showed one way to do it.
And so Project 2 was to design and print a wool winder. We start with some gears: The big wheel is twice the diameter of the small one. We don’t even need to invoke pi to work out that the big one has twice as many teeth as the little one. Every turn of the big gear will make the little gear turn twice. We’ll need to count the turns, so a X2 factor seems to be nice and simple.
Next, the gears need to go into a cage. All of the moving parts in the printed plastic are protcted, either by ball bearings or by embedded nuts (see the smaller gear). A great joy with this project has been to produce a working machine from simple pencil sketches – and to learn how to make those into proper 3D drawings that can be sent to the printer. Yes – I have got some things wrong. If I were starting again, I’d make some changes but not a lot!
Here’s the handle end. The knob is turned from a piece of Yew from a tree in St Andrew’s churchyard. It’s much, much nicer to hold than a plastic printed one!
On the other side is the drive shaft, created by jamming two nuts together. This needs to slip on and off the end of the mandrel we’ll use to wind the wool.
Here’s the full machine. The round mandrel is mounted between the drive end and a moveable bearing. The small bolt at the top screws down to stop the end from jumping out. The one at the bottom fixes the end piece so that it will cope with different length mandrels.
Each mandrel is marked off in 10cm sections. This is partly to help control the finished length of the sally (the 60cm shown here will wrap into around 40cm of finished sally) but it is also an aid to counting the number of turns of wool. A thin rope for a model bell will need about 10 turns per cm. A thicker one for a Wombel (or even a real bell) will need more like 40 per cm. It’s easier to count them in sections!
If I do find the need to make a longer sally, it should be possible (even if it is inconvenient) to make up two bunches of wool to install in each strand.
Three different mandrels here. The significant difference is not in the length but in the diameter, which, of course, determines the length of wool snippets to be incorporated. The black plastic one is 16mm diameter (48mm wool) and the large oak one is 22mm (66mm wool). While you need to be sure that there’s enough length for your sally, it’s important that it’s not too long. Not only does that waste wool when it’s trimmed, but it also interferes with the lay-up process.
Here’s the wool; wrapped round the mandrel, laid on the cutting jig, sliced and laid open. At this stage, the short lengths of wool are dangerously open to any passing breeze!
… now it’s safe! A batten is laid over the wool and a spring clamp applied to clip it to the bottom batten. That’s safe till we’ve made two more for the other strands and incorporated them.
Here’s the cutting board. The loaded mandrel sits in the Vee made by the permanent back board and the removable front batten. This will come out when clamped to the top batten with all those lovely lengths of wool sandwiched between.
And that’s all, folks!
If you want to find out how to make a rope and to incorporate the wool into it to make the sally, then you’ll just have to come back for the next exciting episode.
If you are all keen to make one yourself, the “.stl” files you’ll need are here, along with some notes (which you definitely need to read first!)