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Magnet Update: Prototypes Arrive!

By April 12, 2021 News

Checking in with another update, and we have some nice progress to discuss as the first functioning Magnet prototypes go for a test drive.


You may recall the molding issues we looked at in our last update, preventing us from forming the rubber grips. The good news is that, for the most part, the factory has figured most of that out, enough to get grips working and a prototype unit assembled and sent over to us. As you can see, it’s starting to look a lot more like the final product:

Not only that, but the Magnet does actually work and grips the phone as it should:

Rubber Bubble Toil and Trouble

There are still a few remaining isses with the rubber molding process, including some bubbling on the grip pads:

Considering this is a functional grip, the bubbling isn’t just an issue of appearances. We want the rubber surface to be as uniform as we can, to get as much grip on the guitar as we can. So getting these bubbles removed is a priority. The good news is that the factory is optimistic they’ll be able to work this out completely.

On a more cosmetic note, the molding process requires that there be some point where the molten material is injected, and this unavoidably produces a dimple in that spot. In some cases we can hide that, like on the main grips between the uprights:

If you peek in there, you can see a dime-sized spot where the rubber enters the mold. Given the large size of the grip, this is probably not a mechanical concern – there’s plenty of rubber surface there to snug up the phone.

In the case of the plastic parts, some of these dimples occur in unavoidably visible locations:

We can’t eliminate these entirely, but they may end up disguised somewhat when we apply the final texture to all the flat plastic surfaces. This very subtle finishing touch is something we’re planning on doing anyway, and it may have the side effect of making these slight surface imperfections a little less visible.

Splay to Play

One final concern that does affect the Magnet’s core function is something we call “splay”. A picture should make it pretty clear what we mean by this:

If you look closely where the phone meets the Magnet, there’s an air gap at the top with the left-side upright. So the phone is really only being gripped securely at the base. This can cause the phone to swivel inside the magnet and go crooked. Not falling out, but pivoting just enough to screw up your filming.

The cause of this, again, is what we’ve been calling “splay”. In order for the Magnet to open and close smoothly, there has to be some looseness in the tolerances of the sliding parts. If they’re too tight, it becomes impossible to open and close the Magnet without the upright sticking or jamming against the track it slides on. The tradeoff is that leaving some looseness lets the phone force the upright legs to “splay” past parallel. When this happens, the rubber can’t grip the phone flush, allowing the swivel to happen when you move around with the Magnet on the guitar.

Splay was always an issue with the Magnets we made by hand. We’d get parts back from the printer with almost perfect tolerances, but then you couldn’t really pull them apart in actual operation. So we’d hit them with sand paper until the tolerances got loose enough to operate smoothly. The trick was allowing just enough looseness to let the Magnet open and close, but not so much to create splay where the phone loses grip and goes crooked.

In this case, the factory has already tightened the tolerances as far as they reasonably can without impeding the smooth sliding of the Magnet. But in our tests, we’re still seeing more phone swivel than we’d like, especially while moving the guitar around with the Magnet on.

What we’re going to do is simply taper the rubber grip to take up the remaining gap. By adding a wedge of a few millimeters to the top of the grip, this should allow the upright to splay while the rubber still rests flush against the surface of the phone. In our testing, tacking on a thin strip of rubber at the top of the grip works very well to fill in the gap. So a precise, continuous taper should work even better.

To make this final modification, we have to cut into the steel “tool” or mold, and that requires sending it out to a specialist for a week or so. Since this affects the core operation of the Magnet, we can’t really skip this step. The good news is, this should result in the best Magnet we’ve made in terms of gripping the phone securely and reliably, while still being easy to open and close.

Electrical Box

As we work in this, we’ll leave you with an advance look at the Magnet packaging. We sweated the logo on this to figure out how to incorporate the electric bolt motif into the design in an unobtrusive and fun way. We hope you like it!

We’ll be back in touch soon with an even better functioning prototype.

Top Comments

  1. Looking good, I will buy one when it’s all sorted. Recording close ups can be such a pain in the ass with normal mounts.

  2. Had mine for years. :slight_smile: Love it! It absolutely helped me learn USX DSX and DBX properly, by running cable from the phone to my mac screen to have immediate close up and slow mo feedback. (Yes, it’s better than a mirror) :wink:

  3. Avatar for Troy Troy says:

    I’ve done this. Two things. There’s typically some latency here in the lightning cable method which can make it a little odd.

    However, more importantly, I don’t really recommend trying to watch yourself in a mirror or on a screen as you learn picking motions. If you’re lucky, and learn something, you still tend to become dependent on the mirror to establish the form, essentially learning “mirror picking”.

    More commonly, you end up spending too much time micromanaging what something looks like instead of what it feels like, frequently tricking yourself into thinking you’re making progress when you’re really not. If it’s not fast and smooth, by feel, without looking at it, it’s usually not right and you’re better off trying something different — again, by feel — until you land on something that works.

  4. Sup @tommo!

    Sure! hopefully this (albeit convoluted) pic shows the setup.

    Hand → Magnet + Phone → lightning cable → USB port → Quicktime ‘Movie Recording’, using iPhone as the camera. :slight_smile:

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