Lambda Top Solid Brass

My friend Joe, from Scout Leather Co., had been telling me for months that I should make a top. My response was always, "I make tools, not toys." But I was intrigued. Who doesn't like tops?

One afternoon I had a few hours to play around on the lathe. I had no plan, I was just cutting a top free-hand on the manual lathe. No measurements, no design drawings. Instead of cutting a cone for the tip, I dug around in an old project box and came up with a ruby sphere I bought for another job. The first time I spun the top it was obvious that I created something totally different in performance and physics from anything I had seen before. I showed the prototype to a few people and the most common response was, "Wait, it's still spinning? Are you sure? It doesn't look like it's moving.There is no way it's still spinning." No one else had seen anything like it either. I thought that was pretty awesome, and I believe awesome is worth sharing.

The secret ingredient (beyond a solid design based on Newton and "the physics") is the instrument-grade ruby sphere. You heard me right, I said ruby. This type of manufactured ruby is used in things like Rolex watches, super-precision measuring instruments, fiber optic transmission lines, and other really expensive and/or sciency stuff. The hardness is 9 on the Mohs scale. Diamond is one of the few harder materials and scores a perfect 10. That alone is awesome! This material has five times more abrasion resistance than carbide, zero porosity, high temperature tolerance, extreme chemical resistance, and extreme hardness.

Instrument Ruby is a crystalline form of Aluminum Oxide and called Corundum. Corundum is a naturally occurring mineral, but instrument rubies are synthetic. This material has the distinction of being the very first gem mineral artificially created in a laboratory. A small amount of impurity (Chromium) gives ruby the distinct red color.

So why all the fuss about exotic contact points? Ruby is MUCH harder than stee ball bearingsl, and will spin more efficiently. It's like the difference between ice skating and snow skiing...both water...both fairly "solid" but which one is more efficient for sliding on?

It depends...on a lot of different factors. How long "will" it spin is entirely up to you. How long "can" it spin is entirely unknown. My personal record (unofficial) is over 12 minutes. Check out the video below for a "bar-setting" unedited 10 minute spin. Your spin-time can (and will) vary. However, I'll leave you with the guesstimates below. These are based on my personal experience, and observation of other people testing the Lambda. If you can't seem to hit the numbers below, give it a little more "wax on, wax off!" That means "practice" in case The Karate Kid was after your time. Not the new one, the old one :) 6 Minutes: Most people should be able to hit this without trying too hard. You have to have a good surface where the top can actually stay on it for that long. Try a plate or bowl to keep your top from falling off the table.
8 Minutes: Put in a little practice and 8 minutes can be reached...some of the time. This was the first big milestone. To go past 8 minutes you have to have a good surface...and good technique. At this point I can break 8 minutes almost every time. 10+ Minutes: If you practice a lot, you'll start seeing spins over 10 minutes...but that isvery hard to do. Even now, I might get 1 out of 5 spins that are over 10 minutes. Just keep in mind that trying for a long spin is one way to enjoy your Lambda, but it's not the only way!

Spin time is up to the spinner more than the material. However, the heavier the top the more momentum it can conserve, and a heavier top will theoretically spin for longer. Of course a heavier top is harder to spin in the first place, because it has more inertia (resistance to motion), so we are back to the person spinning the top as the primary factor in determining spin time.

In my experience it doesn't really make a difference. But if you are looking for the most potential spin time then ruby is the only material to choose.

You are going to be tempted to overthink this one, but don't bother. Just buy a shaving mirror. I tested a lot of different surfaces in search of the best one. I tried marble slabs, granite surface plates, glass dinner plates, ceramic bowls, various mirrors, optical lenses, and chemistry lab glass. The Lambda may spin for so long that you won't have a flat enough surface unless you work in a laboratory or machine shop. After a couple minutes it will "drift" and eventually fall off the edge. The best thing to use is any kind of concave dish. However, I had a hard time finding anything in my kitchen where the center of the plate/bowl was actually the lowest part. Most had a raised or uneven area in the middle and this throws off the top. Right now my favorite surface is a little 5" shaving mirror (12x magnification) that you can buy from Amazon. It's a reasonable size, is fairly durable (for a mirror) and has a flat back so you can set it on a table. The smooth curve of the mirror means you don't need a perfectly flat surface, the top will naturally find the lowest point. NEVER use a Foreverspin base. These are coated in DLC (Diamond-Like Carbon) and will ruin your contact point. They chose this material for it's extreme hardness...but DLC is harder than ruby. Remember, the only thing harder than ruby? It's diamond. You literally could not pick a worse coating. Don't use them.

This results from a less than ideal spin. This skidding is noise generated by friction. This occurs when the top has a large orbit because the ball is skidding slightly on the side, and not spinning directly on the tip. Typically the top will circle towards the center and stabilize, but this also means you've lost some total spin time because energy has been converted to noise and friction, instead of being conserved.

Yes this is a video...it's not a still image! If you stared at it for a few seconds and then said "woaaah," we are on the same page. Welcome to my project :)

Traditional tops use a "pointy" contact point. Let's agree to call it a cone. A cone isn't a very good shape for the contact point because you are always on one side of the point...or the other. This means the top will have a hard time balancing upright, wasting energy during the early spin, and then falling over early during the late spin when the top is losing RPM. It's inherently imprecise. The perfect sphere means there is a perfect point of contact with the surface, wasting less energy and spinning longer. It also means the Lambda is better able to spin along its axis; therefore, it does not exhibit the large amount of precession (angular wobble) that you see in a traditional top (above).

The "sphericity" of the Lambda's Grade 25 ruby is 25 millionths of an inch. Take an inch. Divide it into one million (1,000,000) slices. The amount of error is less than 25 slices...out of a million. The majority of machined parts are manufactured to within about 0.001 inches. I created the chart below to make blowing your mind easier on your brain.

Below is an electron micro-graph that will give you a reasonable comparison between a metal "machined" surface and the surface of an instrument ruby. The image on the left is the ground edge of a razor blade. This is a much smoother finish that you will see with machining. However, compared to the surface of a ruby sphere at the same scale, it looks like the Grand Canyon.

* Lambda Top
* Presentation Box