If you have ever tried winding a spiral coil ("pancake coil") with more than a few turns, you know how hard it is, to make it even and completely flat
Duplicating that effort is even harder and forget about making several identical coils (or claim artistic freedom, when they turn out slightly different).
You can buy a tool for making small spiral coils of 16mm (5/8") and 32mm (1.25") respective maximum diameter, but you can make one yourself, for almost any (sensible) diameter spiral and if you have any experience with simple tools, it should be doable in an afternoon and at a lower price..
Step 1: Materials and Tools
- Acrylic - I used 2 pieces of 90mm x 67mm x 3mm (3.5" x 2.6" x 1/8") but around twice the thickness would be better (more on this later).
- 4 machine screws 3mm (1/8") in diameter and at least a 5mm (3/16") longer than the thickness of the 2 sheets plus the maximum diameter wire you plan to use - longer is fine. I used Inhex/Unbrako heads.
- 4 nuts and plain washers for the screws.
- 1 pc. 90..100mm (3.5-4") steel rod 4mm (5/32") in diameter - Brass might be used as well and will be easier to work.
- Scribe (or pointy piece of steel - a nail perhaps)
- Hacksaw, Jewellers Saw or similar.
- File or emery paper (200..400 grit).
- Drill Bits - one sized for your screws (3mm) and one for the steel rod (4mm) - oversized holes comes with inbuilt punishment.
Optional but helpful tools
- Drill Press
- Rotary Tool with cutting disk
Step 2: Cut & Drill
Decide on the largest diameter spiral that you want to be able to make and that will be the diameter of the blue circle in the drawing and hence the minimum width of the smallest side (making it wider than necessary will only make it weaker). You can make each part square, of course, I just happened to have a couple of leftover pieces and thought that the extra bit at the end might come in handy for mounting (I haven't used nor changed it yet).
When you have two slabs of equal size, mark up one of them (on the protective plastic, if at all possible), stack them precisely on top of each other and drill the first screw hole. Using this as an anchor (screw, washer, nut), it is much easier to drill the screw hole opposite, with only light sideways control and when you screw down that hole too, the remaining screw holes and the larger hole for the rod/handle are easy to drill, as the two pieces are now locked to each other. While the sheets are still screwed together, make a slanted scribe mark (a permanent marker would do as well) on one of the sides, to make sure you get them correctly together later on.
If you use a hand held drill and lack the ability to Ride and Shoot Straight, use a small mirror to help drill perpendicular - skew the screw and the acrylic may well crack.
5 holes, one larger than the remaining 4 and you can round the corners (with a file or some emery paper).
Step 3: Make the Handle
Round one end of the steel (or brass) rod, to avoid getting wounded using it.
The hole through the rod, as marked by a red arrow in the first photo, is really not needed - it was just a brain farth.
The slit in the non-rounded end is needed however. I made it with a cutting disc, but a hacksaw and/or needle files just crave a bit more patience. The slit can be made after the rod is bent into a handle, then it's much easier to steady in a vice or clamp - it is tough holding it in one hand.
The width of the slit will depend on what size of wire you plan on using (but it's easy to make more handles, so just start with a guess). The length should be at least the thickness of one of the acrylic sheets plus the wire diameter.
Step 4: Making Shims
You need to make shims for (and of) each thickness of wire you will be using, but that is something that you just make when you start with a new wire diameter.
It is best to use the a bit of the wire itself, as that will be the best fit.
In the photos is shown one made as the letter "U", but I quickly discovered that they could be annoying, falling out (and away) whenever you need loosen the screws to remove a coil. The ring shaped, I first made by winding a helical on round nose pliers, but I found that it's easier/faster to just coil 4 times around one of the screws. Snip them into rings with whatever cutter you have, no need to flush cut the ends.
Step 5: Assemble the Tool
Start with the bottom sheet and put the screws through the holes. Add a shim to each screw and put the top sheet on the screws. Add a washer and a nut to each and make sure you don't over tension the screws.
Insert the handle and you're ready to roll.
Step 6: Load the Wire
Insert the wire from one of the sides. Do not put it as far as in the first photo, as that will result in a skewed spiral.
The wire should be flush with the side of the handle, a bit longer than in the other photos, for best grip.
Step 7: Take Your New Tool Out for a Spin
In the first photo, you see the result of my brain meltdown. I loaded the wire through the hole in the (pre-slit) handle and made a fairly OK (for an initial try) spiral and had to dismantle everything to get the coil out (doh). Then I added the slit, as it is needed to remove the handle of course. Then it was just as I wanted it and I have made spiral coils of copper as well as zinc plated iron (~1.4mm fence) wire. The large coil in the last photo is ~47mm in diameter (1/8" shy of 2"). However...
Step 8: Improvements
I decided to add yet a slit, this time through the two acrylic sheets, to be able to press/control the wire for bronze wire, which is far more springy than copper and iron and hence needs more control. This could have been done by drilling two holes and filing/grinding the material between them. However, I used a drill press and an X/Y-vice, since I had it. I went much too fast (with the drill much too slow for routing), so it got a little rough edged (400 grit paper helped). I have not used this yet. Second and third photos show how the spiral zig-zag'ed a bit, so I strongly recommend twice the thickness. The bottom layer could be metal of sorts, you only need to see through the top side.
The last two photos show the reflections from an under-cupboard LED light reflected in both layers and the curvature shows how much (or rather little) flex will give less flat spirals.
While I have yet to try it out, I think that a light coat of lube (of sorts) on the inner sides will help, as I am certain that it is caused by the increased friction of a large spiral.
Step 9: Spirals
These photos show some of the spirals I have made with this tool. The leftmost in the first picture is the one I had to cut from the handle and from the first to the last photo, you see a quick progression and it only takes a handful of tries to get it down.
If you are handy with a chain nosed plier, you can bend the middle pin out, drop a bead onto it and bend it back, but this is about making the tool - what can be made with it deserves its own write up.
Step 10: In Parting
Please feel free to ask below, if there is something unclear to you, or tell me if my grammar went South somewhere (English is not my first language after all).
I showed you mine, now show me yours :)
Thanks for the visit!