Mountings and Controls For Widefield Imaging Rig

[Gina]

ATM I can't work out how to clamp the lens whilst retaining a solid ring to rotate on the wheels.  It is going to need bolting together I reckon.  Maybe the whole thing could be in two halves bolted together to clamp everything like a clamshell.

[Gina]

I think I have the answer.  Split the casing/framework through the optical axis and bolt the two halves together to make a circular object and clamp the camera and lens.  With this arrangement everything should be accessible.  The spur gear could be kept in one piece attached to the bigger part.  The other end can be arranged to match up to provide a stepless join between the two parts to run on the wheels.

[Marci]

I think anything but a 3D Printer for my next purchase is gonna be foolish... loving this Gina. At the moment I’m having to make do with whatever I can cobble up out of modified current-gen meccano and my old late-80s/early-90s  technic lego!

[Gina]

Have to say I love 3D printers.  Quite amazing machines - fascinating to watch and so useful   Virtually nothing you can't make

[Gina]

This is the sort of thing I have in mind.  Might add some sort of keying to locate the parts together.

[Gina]

Firstly though, the gear part.

[Gina]

Making steady if rather slow progress on designing the rotation framework   Got up to the top of the filter wheel.  I might glue the the bigger part onto the gear part for added rigidity.

[Gina]

I would print them on their backs - like this, to minimise support material.

[Gina]

I think this is the finished model of the two parts of the rotation framework to take the 135mm lens.

[Gina]

Printing times are 8.5 hrs for the big part and 5 hrs for the small part - filament usage 68m and 36m or just over a pound's worth in all.  Though replacement filament might cost twice as much.  Currently uploading the big part to the SD card.

[Gina]

Hmm...  Printer doesn't like it - the support is not working properly.  Going back to vertical orientation.

[Gina]

Or maybe not - 12 hours printing time and over 100m of filament.  Have to split it up.

[Gina]

Separated off the running ring from the lens end (part that runs on the wheels to support the lens end) and the bigger part of the camera support to avoid the large amount of support material otherwise required.  Might do the same for the smaller part though that is less significant.

Bigger part sliced and now uploading the g-code to the SD card in the printer - there's a lot of it!  Estimated printing time 5h 16m and 44m of filament.  That's quite an improvement   I've found more filament at £5.80 a Kg reel which I've ordered.  400m at £5.80 = 1.45p/m so filament cost for this print will be about 64p to replace the amount used.

[Gina]

Now printing and so far so good.

[Gina]

Been looking at supporting the bigger and longer lenses which are a lot heavier than the 135mm or 105mm lenses.  The best place to support these longer lenses is at the objective glass end.  Unfortunately, this part moves in/out with focus adjustment.  A sliding arrangement might work but it's a likely that the clearance will change with temperature and cause either jamming or looseness.  Better would be three rollers like the rotation support.  I think the 45mm medium format lens and 200mm SLR lens could use this arrangement.

[Gina]

[Gina]

Coming back to long and heavy lenses...  I'm wondering if I could get away with either rubber or TPE to allow just the tiny amount of movement required for focussing.  I think I'll try it and see.  The wide FOV of the 45mm lens should mean this may work - the 200mm lens may be a different matter but this lens is lighter and longer so that helps.

(For anyone reading this that doesn't know, TPE is a rubbery 3D printing filament.  The flexibility can be varied by changing the infill density.)

[Gina]

Print nearly finished - looking good, but the proof will be putting it all together.

[Gina]

Print finished but needs to cool a bit before it will come off bed.

[tekkydave]

A good looking print. I find the Cura-generated support in the gaps just pops out when you push it. Miles better than Slic3r which created support all the way down to the bed which was difficult to detach from the exterior surfaces.

[Gina]

Thank you Dave   Yes, this printer is working very well now - very pleased with it   Took a while but got there in the end   And yes, amazing how the support just pops out or breaks away so easily.  I think this printer will be replacing the UP Plus 2 even for very small precision prints   If I can get my Titan printer working as well on a bigger scale I shall be well pleased

[Gina]

Seems one of my posts has vanished from the board!  It said the imaging rig fits nicely in the framework and the framework and gear part also fit together well - with photos.  I'll redo it and post tomorrow - off to bed now...  Meanwhile the print of the smaller part is well underway

[Gina]

Overnight print went well and the parts fit together perfectly   Photos shortly.  Next to model and print the camera support parts and the rolling ring.  Then I can think about the fixed support framework - might make use of an aluminium dovetail bar for rigidity.  The camera end is a simple triangular bracket - the lens end a large ring which could be more difficult.

[Gina]

Models of the camera supports and rolling ring in SketchUp.  Added extra holes on the bigger camera support to reduce filament used.

[Mick J]

Good work Gina, nice to watch this come along.