Allen/hex are easier to find, and absolutely fine. Torx are not needed but would be fine.
Interesting thead link, Marmax
I had not seen a pinched astigmatism thread from collimation screws and had always wondered how likely it was.
That takes a really large amount of force!
Also interesting since I've seen repeated mention on CN that tight collimation screws reduce collimation shifts.
So tight, but not as tight as you can go! Use your hand / wrist muscles, not your arm, and avoid long L shape Allen/hex 'keys'/wrenches.
There are also reports of stripped secondary support pick threads, and snapped collimation screws so some folks go go as tight as they can, I would think, causing stripped heads.
DONT 'put your arm into it' .
The screw head design should not be viewed as your 'torque limiting device', so I'll stick to at least Allen/internal hex. I'll take Torx too, I know my tools won't pop out by accident.
I realize most folks have no tool experience, but they have to try to use common sense.
Not using T head or long L wrench tools is a very good way to avoid damage.
A 75mm or 100mm L hex/Allen wrench can really exert a lot of torque.
Many or most SCTs come with Allen head adjusters AFAIK these days.
Phillips were deadly from the standpoint of stripping heads or 'oops, there goes the collector coating' bounce out of the screw head onto the plate accident. I've stripped enough soft Phillips heads. One issue is there are several slightly different head designs and matches are often poor. Once I found and bought Phillips patent/trademark licenced screwdrivers problem were greatly reduced.
Screwdriver type Allen or Torx tools don't have the long (literally) lever arm of the cheap L wrench usually used. I would say always used, since few people have Allen 'screwdrivers'.
You can get decent torque on Allen or Torx 'screwdrivers' but the small head on the driverhandle is limiting. I can get far more torque using a L wrench.
I would not recommend a T head wrench if overtorquing is a concern, they can really crank it on.
I guess it helps that I have torque sensitivities from decades of working with my hands from mechanical watches to SUVs, but I think 'screwdriver' Allen or Torx are much less risky for most people than an L wrench.
As to Torx and Allen heads being dangerous due to ability to overtorque, that is really the reason they are safer- they are far less likely to pop or skip out and damage the optics.
So folks won't strip the fastener head before they overtighten and flex the 1/2" / 12 mm thick aluminum puck, that just means tightening to a sensible level, sometimes called 'hand/wrist' tight level, not 'elbow' or 'whole arm' tight. That description of the muscle groups involved helps some folks with automotive tightening.
Installing the Sorbothane or UHMW is somewhat drought with hazards.
So caution is nothing to apologies for.
Many recent SCTs were aligned at the factory by intentional placement of the corrector off center in the cell, with 'rotation' fine tuning to place the secondary exactly in line with the primary axis.
Older SCTs just centered the corrector with cork and just used the rotation of the secondary (not always goes concentric to the support pick). The relative secondary and corrector rotations were marked, but not the corrector position with one cell. edge HDs do this with grub screws
So if you try installing it photograph the exact cell/corrector relationship, and follow directions on finding and restore the factory alignment marks.
I've has two misassembled after cleaning SCTs, one monstrously comatic (Meade put the rear cell on a bit crooked), they other just had every adjustment wrong and was unusably soft. Both are great now.
Wing screws if you find them might be okay, but be sensible.
Email Bobs Knobs to see if there is a European distributor, or if they ship direct.
The product is light so I would expect that is likely. I get stuff from Europe all the time.
