Antikythera Episode 2 - The Main Solar Drive Wheel B1.

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• published: 22 Feb 2017
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Antikythera Episode 2 - The Main Solar Drive Wheel B1, by Clickspring. There are more than a few surprises hidden in the wreckage of this iconic part. If you would like to help support the creation of these videos, then head on over to the Clickspring Patreon page: https://www.patreon.com/clickspring ________________________________________________________ A very special thank you to Patrons: Mike Manfrin Mitchell Collins Sinking Valley Woodworks (http://www.sinkingvalleywoodworks.com) Florian Ragwitz Matthew Middleton Daniel Cohen Larry Pardi Sean Kuyper Samuel Irons Dan Keen Olof Haggren Stassinopoulos Thomas ________________________________________________________ Other Videos to Watch: How To Make A Clock In The Home Machine Shop - Part 1 - Making The Frames: https://youtu.be/B8Y146v8HxE Ask Me A Question: http://www.clickspringprojects.com/contact.html Follow Clickspring: http://www.facebook.com/Clickspring1 http://instagram.com/clickspring1/ https://www.tumblr.com/blog/clickspring1 https://www.pinterest.com/clickspring1 https://www.patreon.com/clickspring Abbreviated Transcript: 00:07 Its tempting to look at this part and assume that its a bit like a clock wheel. Formed from a single piece of raw sheet stock and then crossed out to reveal the spokes. 00:59 This part was fabricated, not cut from sheet stock. And once that fact sinks in, a whole bunch of questions arise. For example: What were the tools available to the original maker to form this part? We know for sure about some them, like dividers, hammers and files. But were there others tools we don't yet know about. And what about the dovetail join itself? 02:09 But whatever the reason, it must have been a very good one, because this is by no means the easy way to make this part. As per the original device, the cross members will be notched, drilled and then riveted together, and the dovetail joins will be filed to shape, 03:14 The slightest misalignment, and the other intersections become compromised. More metal than necessary would be removed, with the result being a poor overall fit. So I'm going to use a simple circular jig to make life a bit easier. I used the mill to clean up the raw cuts and also to drop in a reference hole 06:14 The process of riveting has drawn the 2 parts tightly together, leaving the rivets just above the surrounding metal surface. From here I can use files and abrasive paper to take them all of the way down to that surface, and then blend them into the surrounding metal. 07:38 With so much precision hand work, how did the original maker solve the problem of workholding? There's no doubt that a secure method of holding the work would have been essential. So what was the ancient equivalent to this modern screw vise? Filing small parts doesn't usually require a whole lot of force. And the vise also doesn't need to generate a particularly high clamping force, just enough to grip the work. 08:02 So I imagine a simple wooden clamping peg like this, could easily do the job, not unlike a modern pin vise. A clamping ring, designed to be a sliding fit over the tapered section, could be gently tapped into place to provide the clamping force. If it were solidly fixed to a simple bench at a convenient height, 08:19 I think it'd do a great job, and its consistent with the known technology of the time. Of course a lot of the detail of workholding devices like this will probably never be known for certain. But the mechanism has many features that strongly suggest a tool technology that goes well beyond files and hammers. 08:54 And as you can imagine at this point I was taking this nice and slow. Carefully checking after each change, and slowly working towards a close fit. In fact this is the part of the process where the jig really becomes useful. Indicating how much and from where, metal still needs to be removed. 10:09 The part was then mounted on the lathe and taken to final dimension, all ready to receive some of those amazing triangular teeth. Now there's a lot I'd like to talk about regarding the geometry and formation of those teeth, so rather than make this video too long, I'll save that discussion for a later time. 10:31 But after completing the first substantial piece of the mechanism, its becoming clear to me, that the story of how this machine was made is going to be as much about the tool technology used to make it, as it will be about the device itself. References: The CT and PTM data that the AMRP have made publicly available can be found here: http://www.antikythera-mechanism.gr/data Gear schematic can be found in Tony Freeth's 2012 research paper: http://dlib.nyu.edu/awdl/isaw/isaw-papers/4/ Credits: Clips from "The 2000 Year Old Computer" courtesy Images First Ltd. Antikythera Episode 2 - The Main Solar Drive Wheel B1, by Clickspring.