A Spacer is a multi-point divider.

Initially designed for luthiers, it has turned out to be a really useful general-purpose tool - handy for anyone working with physical materials needing to accurately measure or sub-divide curved or uneven surfaces.

1. It is a concertina of equi-distant pointers. It can be used as a simple divider... or a bisector... trisector, quadrasector, penta, hexa, etc. It can handle them all.
2. The smallest space closed is 6.2mm, the widest 44mm.
3. Overall 6-pointer : smallest space closed is 31mm, the widest 220mm.
4. It is designed as a constructor-set, so if 6 points are not enough you can add more.
5. It is designed to be easy to repair, with easily sourced parts, and zero vendor lock-in.
6. It is open-source hardware - you are free to do whatever you like with it, apart from turning it into "Intellectual Property". (the licensing info)

Not a lot to maintain, really.

If the joints become loose they can be tightened with an Allen key. The bolts are held in place with low-strength thread-locker, so they're removable. If you're never going to remove them then I'd suggest a medium-strength thread-locker - they can still be removed, but you'll need to heat the joint first.

If the brass wheels starts to look a bit dull you can bring them back to life again by giving them a spin in an electric screwdriver against a Brillo pad or sandpaper. If you don't have an electric screwdriver you really need to get an electric screwdriver, they're incredibly useful.

The wooden cases are finished with linseed oil. If it starts to look a bit dull it can be brought back to life with quick rub with a tiny amount of oil.

If anything breaks or gets lost, replacements are available from analoggadgetfactory.com, or from the sources below.

Every joint is identical and consists of:

• Brass connector
• Upper laser-cut stainless steel arm
• 3D-printed nylon washer (minutely calibrated to maintain tension)
• Lower laser-cut stainless steel arm
• Stainless steel M3 3mm long bolt

Standard parts

Off-the-shelf hardware you can source yourself. Aliexpress or eBay are usually good places to start to get a feel for pricing and so on.

	Part	Qty	Search for
	Pointer end caps (brass, but can be anything M2)	6	"M2 standoff" - max 6 mm outer diameter. I use brass, 3 mm OD × 10 mm long.
	Red knurled nuts (anodised aluminium)	6	"M3 knurled standoff" - max 6 mm outer diameter. I use red, 10 mm long, but anything fits.
	Nylon-tipped grub screws	6	"M3 × 12 mm stainless nylon-tip set/grub screw"
	Plain grub screws	2	"M3 × 12 mm stainless grub screw"
	Pivot screws	22	"M3 × 3 mm ultra-thin stainless machine screw"
	Brass wheel (purpose undiscovered)	2	"Brass knurled thumb nut M3 wheel"

Bespoke parts

Made specifically for the Spacer. Each has a parametric STL / DXF / SVG generator - See the make your own menu above.

	Part	What it is	Generator
	Brass connector	Custom-made CNC brass - the threaded pivot barrel that spaces and joins the arms at every joint.	Generate connector →
	Nylon washer	3D-printed, sits between the arms and sets the joint friction.	Generate washer →
	Stainless arm	Laser-cut 304 stainless, the bespoke scissor-arm profile.	Generate arm →
	Needle pointer	Ground carbon-steel point, with an M2-threaded head.	Generate pointer →

1. The pointers are insanely sharp. I need people to tell me if this is a problem so future ones can be in enbluntened.
2. The laser-cut stainless steel joints are fairly thin at the edges. If anything is going to break, it'll break there. If this turns out to be a problem, I'll try making them from hardened steel. Stainless has nicer ergonomics though - so, absent issues, that's what I'll go with. It's never been a problem for me.

This is designed as a constructor set - but the STL generators in this area mean you could make the pieces any size you like… and it could well be that in future we make larger sizes.

The heads of the pointers carry about 4 mm of M2 thread, so anything that can take a thread can be attached to them - pencil-lead holders, for instance.

Part of the design philosophy is to leave a window open for serendipity… so there are parts included that don't serve any particular purpose, but are there because they look cool, or are funny, or seemed like a good idea at the time.

This SSD card is one of those things.

I am one of those things.

• Design files → CERN-OHL-S v2 · LICENSE-CERN-OHL-S-v2.txt
• Docs, photos, diagrams → CC BY-SA 4.0 · LICENSE-CC-BY-SA-4.0.txt
• Plain-English summary → README - Licensing in plain English.txt