Wednesday, 14 September 2011

Stone Bearing Block

Following my weekend of bow drilling, i figured today i would make a more substantial bearing block for use at shows and events, as the wooden ones, such as the ones made from green Elm, i was using this past weekend soon scorch and burn, even with the addition of green material in the socket to lubricate it, meaning that i have to prepare and take a good half dozen bearing blocks with me to be on the safe side.  I figured if i made a more substantial block that also offered less friction then half the battle is won.

So, with this in mind, last evening we made a quick trip to the beach, which resulted in the collection of a few  pebbles, all of which had been worn smooth by the wave action of the sea.

The pebble i eventually chose to make my bearing block from is pictured above, it's very ergonomic, filling the grip perfectly. Initially the pebble had a small "dimple" for want of a better word on it's surface, which also happened to be, more or less central on the stone face,  so i used this to my advantage as a place to make a deeper depression.

Now a lot of purists will say you should make the hollow using traditional tools, ie a stone tipped bow drill or pump drill, well i didn't do this, i used my Dremmel as it's one hell of a lot less effort, and lets face it, if our ancestors had access to the tools we have, well they would have used them in preference to tools that required hard graft, also, wasn't the pump drill or the bow drill "their" version of the Dremmel,? the historical record certainly shows different 'tips' were used with these drills, i dare say in a thousand years time our descendants will look back at the Dremmel and call it a primitive tool, so i cant see the difference, I'm using a tool that suits my needs as did our ancestors.
 
So having made the depression in the pebbles surface it was time to try it out, so i grabbed some unused bow drill sets and set to work, the pebble works a treat and even though it's not had a massive amounts of use so far, you can already see the inside of the depression i made beginning to polish up through the action of the rotating wood (Hazel in this case), over time i dare say the stone will polish even further resulting in a nice slick surface, that will be relatively friction free compared to the traditional green wood bearing block that i normally use, i will still continue to use wooden bearing blocks for the bow drill, but for demonstrations, this one will mean a whole lot less effort, both in terms of the preperation involved and the physical effort of a days bow drilling.

2 comments:

  1. Really helps with the demos using a stone or shell inserted bearing block. Great for getting folks over the other difficult stages of the process to.

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  2. I normally use a limpet shell in the block, but i dont want to make it too easy for folk and i think it's good for them to see that friction is a process that happens of both ends of the spindle when using a wooden block and then letting them see how this is overcome by reshaping the top of the spindle and using different forms of natural lubricant to reduce the friction, if im doing a day of non stop bow drilling, i normally use a block with a bearing set into it, but it feels a bit like cheating, i know it's not but you generally dont find bearings in the woods ;-).

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