Member postings for David Clarke 21

Back to the original posting,

As Hydrogen is clearly not the useful fuel-gas that it might seem, maybe the intention was to create Oxygen to boost the power of a conventional (propane, etc.) torch?

Electrolyse water, collect and use the Oxygen, the Hydrogen (lighter than air) will just float away and ...

The radio tuning drives are originally from Jackson Bros., and still available (in the new year) and manufactured by Mainline Electronics in Leicestershire

https://www.ebay.co.uk/itm/Jackson-Bros-4511DA-1-4-Ball-drive-new-stock-H3-/292084783788

https://www.mainline-group.com/collections/reduction-drives-classic-6-1

https://www.royalsignals.org.uk/jackson_bros_caps/index.htm shows dimensional drawings.

David Clarke.

I was recently working with a product designer using M6 bolts into 3D printed parts. Thinking that the strongest result would be to have a metal - metal thread, Helicoils were being inserted into the plastic parts. Unfortunately, they appeared to self-tap into the holes without needing to used the supplied tap to cut a thread first.

The result was that on inserting the M6 bolt, the coil tried to extend to its design pitch which internally de-laminated the printed part, seriously (though not terminally) weakening it. Not visible from the surface, but recognisable by the creaking sound of the material splitting internally.

Although this was the result of incorrect process, I imagine that simply self-tapping a machine screw could have similar results, especially if the metal thread pitch 'beats' with the layer thickness.

David

(long-time lurker from Nottingham)

Strange thing,

a HUGE pile (3 x the normal quantity) of issue 251 (February) appeared in Nottingham W H Smiths today.

Never seen so many before. I do hope they don't hold back the issue 251 (March) copies until these are sold.