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Project:Clark Trailer Mast: Difference between revisions

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Project:Clark Trailer Mast (view source)

Revision as of 20:00, 27 September 2015

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→‎Sladen Clark Mast Braindump Notes (Thank you Paul!): editorial notes added
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Manage the easy stuff first, perhaps bring in the top two pieces indoors of the mast and work on the bits inside:
Manage the easy stuff first, perhaps bring in the top two pieces indoors of the mast and work on the bits inside:


* be mindful that the screws may be too long (even by a millimetre – we do not want the screws to scratch the tubes by being too long – be prepared to lathe them down on the end.  (Turns out this IS the case!)
* be mindful that the screws may be too long (even by a millimetre – we do not want the screws to scratch the tubes by being too long – be prepared to lathe them down on the end.  <span style='background:yellow;color:black;'>''It ended up being the case. Bought shorter screws, did the trick.'' </span>


* The easiest of the tubes may be easiest to manage (start small and build up)
* The easiest of the tubes may be easiest to manage (start small and build up) <span style='background:yellow;color:black;'>''The largest were easiest - the smallest was the bent one. Thanks to Andy and about 12 tonnes of pressure, we got it straightened again.''</span>


* If the tubes are bent, it may be reasonable to actually shorten the tubes themselves to make it work better – i.e. a compromise tube will be better to do that way as well and won’t be a major impact to antenna abilities
* If the tubes are bent, it may be reasonable to actually shorten the tubes themselves to make it work better – i.e. a compromise tube will be better to do that way as well and won’t be a major impact to antenna abilities <span style='background:yellow;color:black;'> ''This was a last-resort consideration - very lucky we were able to bend the span back.''</span>


* Shortening the tubes may also make it easier to hack on inside – then will also enable the ability to work on the heavier tubes <span style="color: red;"> ''This is a last resort, people - let's exhaust every other possibility!''</span>
Get the mast actually working in a limited fashion – could we get the bottom two to work and use that as a temporary setup?  That would be our workaround temporarily.  Use massive jubilee clamps to fit things together perhaps?  (Let's just keep fixing things up)


Get the mast actually working in a limited fashion – could we get the bottom two to work and use that as a temporary setup?  That would be our workaround temporarily.  Use massive jubilee clamps to fit things together perhaps?  (Let's just keep fixing things up)
While using the mast at the space: Use an electric compressor – much easier to manage accordingly than the petrol 20psi compressor that’s there.  Equivalent of a Chinese 230v / 12v jobby would make sense – note that we need a volume of air instead of the high pressure tank to move these segments up.  (Remember these original designs are meant for soldiers with hand-pumps to pump up the mast in battlefield) <span style='background:yellow;color:black;'> ''This is still planned, especially as we have a SCAM12 mast that will need this.''</span>
 
While using the mast at the space: Use an electric compressor – much easier to manage accordingly than the petrol 20psi compressor that’s there.  Equivalent of a Chinese 230v / 12v jobby would make sense – note that we need a volume of air instead of the high pressure tank to move these segments up.  (Remember these original designs are meant for soldiers with hand-pumps to pump up the mast in battlefield)  
 
Paul Sladen has a box of spare parts that are mainly the top and bottom of bent tubes that have been cut off – they are not useful in themselves but they can be the models of how things should appear / how things should be accordingly.


Clark Mast designs haven’t changed for 50 years – the 127.0mm spec tubes are actually imperial sizes that have been around for a long time.  
Clark Mast designs haven’t changed for 50 years – the 127.0mm spec tubes are actually imperial sizes that have been around for a long time.  
We could possibly use a donor SCAM mast for the smaller tubes that move – in case we want to have an alternative, spares, or something that could get us going – but the generations are compatible within each other.  Something to think about if we see something at a reasonable to good price on ebay or at a ham swap meet.
There are chamfer seals that  could be replaced, but probably costs too much to create the short-run for the small amount of hobbyists. 


FYI - The locking collars that we have are completely optional – they will hold the tower but they should not be depended on because they might bring water in, they are just for static setups and could get us in trouble if/when it goes below freezing.  
FYI - The locking collars that we have are completely optional – they will hold the tower but they should not be depended on because they might bring water in, they are just for static setups and could get us in trouble if/when it goes below freezing.  


Often these particular masts of similar were often used for ‘birds eye views’ of properties in addition to the typical comms requirements we'd expect them to have.  
Note that these particular masts of similar were often used for ‘birds eye views’ of properties in addition to the typical comms requirements we'd expect them to have - the era before GPS-stabilised drones carrying impressive cameras.  


* Note - Locking collars inside the shack are not spinning freely – they should be able to screw out and in without any trouble.  This could be a small project to get them freely moving.
* Note - Locking collars inside the shack are not spinning freely – they should be able to screw out and in without any trouble.  This could be a small project to get them freely moving.
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