Introduction: Zero-cost Vinyl Record Clamp Made From Upcycled Plastics.
There are various views about the sonic benefits of record clamps and weights/pucks that hold your vinyl firmly in place on your turntable platter, thus stabilizing the disc and reducing vibrations. My own findings are (a) that they do make a difference on certain turntables with certain kinds of music (b) the permutations of turntable and music aren't remotely obvious and (c) while they tend to be associated with audiophile listening they can have as much if not more effect on the very cheapest of turntables as on the most expensive models.
One thing that's indisputable is that a vinyl record is an inherently resonant object; park a 12" on the tip of a pencil and tap the label area firmly with a fingertip and it'll go thunggg, often at an identifiable pitch. Removing this resonance from the playback process can't hurt and while the weight of the disc on the platter will do that to a large extent (probably less on a smaller-than-full-sized platter, though), a clamp will do an even better job, like choking a cymbal.
For all of these reasons I tend to have a few of these items around (they come at a wide range of price points, mine being cheap!) but given their uncomplicated construction I concluded it would also be perfectly easy to make one. This version costs absolutely nothing, has environmental benefits and can also function as a no-risk trial model.
[Just for the record (sorry!) this is a clamp rather than a weight, which makes it particularly well-suited to low-powered turntables. The two terms are sometimes used interchangeably, which isn't helpful. Note that a clamp won't work on turntables that have a fixed, non-rotating spindle.There aren't many of these, but they do exist.]
Supplies
The basic idea is simple: you make a small hole in the middle of a flexible plastic bottle or jar lid, then press it into place on top of your disc, so the disc is clamped into place on the platter. Job, to all intents and purposes, done; that's all you need if you just want a utilitarian version.
However, it seemed more interesting to make a clamp that looked more like a 'real' manufactured product. To do that, I retrieved two plastic lids from my recycling bin. One was a robust screw-top lid from a particular brand of fruit juice that had a slightly tech-looking easy-grip design. The other was a small aerosol lid, probably from a bathroom product.
The odds of your finding 100% identical items are unpredictable, so you may well end up adapting or approximating this design, which is fine - it's the mechanical principle that's important. The only things to be aware of are (i) the lid you'll be making a hole in - which could of course be the only one you use - needs to be made from a flexible, rather than a rigid, plastic and (ii) the wider this lid is, the better the results - a small plastic top from e.g. a bottle of water would be fiddly and would only create downward pressure on a very small area. Anything bigger, so long as it doesn't overlap the record's label, is better.
In terms of tools, anything that can make a hole in plastic will serve for the basic version. For my more perfectionist model I used a small drill, a reamer, a sharp craft knife and a pair of calipers (mine happened to be digital).
Step 1: Construction
Firstly, use either your calipers, some other measuring device or just a keen eye to determine a hole size that's fractionally smaller than the spindle on your turntable, then cut this hole in the exact center of the gripping lid, using whatever tools you prefer; I find that a small drill followed by a reamer gives the best results with plastics in general. Many or most plastic lids have a sprue mark at their exact centre point as a result of the molding process, which helps. This done, return any plastic swarf to your recycling bin to stop it ending up inside a fish.
You then need to use your knife to cut four small slots extending outwards from the hole. The result doesn't photograph clearly, but hopefully the above doodle. which isn't to scale - the slots need only be 1/8"/1-2mm in length - will show what needs to be done.
Now, it so happened that one of the lids I selected was a perfect yet tight fit inside the other! By assembling the two components in this way the result was as you see here. You may or may not be so lucky, but the basic principle is easily adapted to whatever lid(s) come to hand. Alternatively, you may care to monitor your recycling until suitable candidates present themselves. As this item is essentially made from trash any initial problems such as accidentally over-sizing the hole can simply be remedied by replacement.
Step 2: The Clamp in Use
The introductory photo shows this. Simply press the clamp onto the spindle until it makes firm contact with the disc; if you've done this properly you should be unable to rotate the disc without rotating the platter as well. When both deploying and removing the clamp, use a light twisting action. The four small quadrants created by the hole slots will flex and grip the spindle.
And there we have it! Upcycling arguably beats recycling in that it's all about re-using things as they are, rather than having to reprocess them, so be pleased about that if you choose to make one of these.