What size are the STL and RGH Desiccant Cartridge Threads

Hi,

Can someone - at DL Tech Support - tell me what the "thread pitch and diameter" is for the two STL & RGH camera cartridges. I would like to find an appropriately sized (nylon) screw to act as a temporary "dummy plug" for the exposed CCD chambers, during the 4+ hours the desiccant cartridges are being recharged - as an alternative to just using tape.

I checked - the SBIG CAD Drawing doesn't specify the thread spec for either cartridge. From my measurements, it seems to be about a ( 1/4" x 24 NF THD ), but that seems unlikely since nearest standard screw size diameters are either 3/16" or 5/16".

Thanks,
Joe

 

--- Thanks Doug,
That was a quick reply. Glad you corrected my original thinking based on using a thread gauge on those tiny and cramped threads on the cartridges I have in the oven.

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BTW:
Has anyone thought of making a small cylindrical "induction coil oven" with just large enough diameter for a couple (or so) cartridges?
Seems like a tremendous waste of energy to fire up the kitchen oven for 4 hours just for this job - not to mention the possibility of any evaporated grease that might still be there in that atmosphere, which might get into the desiccant sieve and coat it - making it less effective, or even impervious to absorbing CCD moisture.

I would AMOST be enticed into using the microwave oven - but don't relish the indoor "fireworks" display. Besides the manufacturers warn that drying desiccant sieve in a microwave, as I once asked, would fracture the crystals into a finer powder - (possibly dusting the CCD sensor chamber).

Perhaps something like an old style (scrapped) automotive ignition coil might work. There may be enough tunnel space in the center, to drop in a couple of cartridges, and possibly the induced current into the cartridge aluminum wall would heat the desiccant sufficiently, with lots less power - assuming the cartridge case seam won't de-solder.

As an astro-bonus - it does run on telescope standard 12 VDC, so in a pinch, could be used at a favourite dark site, if someone's desiccant wasn't quite dry enough that day.

Just a thought.

Joe Z.

 

Great idea, George,

I like your way of doing this - the standard kitchen oven also heats up the house, which is bad in summer, adding to air conditioning load.

Your "Toaster Oven" would be perfect. Can even operate it outdoors, after the hot dogs are done.

Joe