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Daz,
Apparently it happens pretty often. Re-collimation is the most common reason for Takahashis being sent back.
I have just spent a very interesting morning at CSIRO with my Father-In-Law who was research physicist there for some years.
Amoung his colleauges were Optical Engineers, Materials Scientists, Electrical engineers etc. etc.
I got to yakking with one of the optical people and naturally we got onto telescopes (he makes his own refractors with CSIRO cast-off blanks). He's very conversant with Taks as he owns 4 including an uber-rare, maybe 12 made, FCT125. He called one of the materials blokes over to join the discussion. This bloke is currently working on semi-rigid, non petroleum based, polysomethingorothers with high thermal retentative propertie. Insulating Foam to you and me.
To cut a very long story short, the way Takahashi packs their telescopes practically guarantees trouble.
The triple-box, Excelsior (foam thingys) and rigid Styro-foam construction is "highly sub-optimal'. The styro is in full contact with the scope lens cell. It is much too rigid and transnits too much energy to the OTA. As the rest of the OTA is effectively free-floating, the energy has nothing to do except bounce around inside the tube and cause mischief.
You can simulate this by hitting a bit of pipe on the end. It'll ring like a bell. Plant the pipe in the ground however, and all you get is a dull thud. The Excelsior that surronds the OTA does nothing to absorb the shocks.
There followed a lengthy and rather over-my-head conversation about 2nd and 3rd order wave propagation in solid media........
Again the upshot being:
In order for Styro to be effective, it needs to be molded or cut to the shape of the object, and then, itself surrounded by a superior shock absorbent material.
The front runner material by a long stretch? - Bubble Wrap!
This cheap, ubiquitous stuff is evidently regarded by in-the-know types as something of a wonder material and all are very jealous that none of them hold the patent.
Pound for pound, nothing even comes close.
Thiis particular department of CSIRO designs stuff for industry including delicate instuments for whatever. Before the final thing is sent off, and in order to simulate the stresses it will endure in-transit, the instrument's model or prototype is bubble-wrapped and tossed out the window onto the slope below. If it breaks, they add more bubble wrap until it doesn't. Experimental physics at it's finest!
The consensus was that Takahashi could save themselves a lot of grief and money by simply bubble-wrapping the OTA before packaging.
There you have it.
The Boffins have spoken and no-one need ever worry whether or not bubble wrap is good enough for their gear.
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