Orion Mini Fifty extension tube

[bluemaxroe]

Hi All, just thought i would show the results of a little project.

I have been guiding with my Orion Mini Fifty with great success using a ED80 F7.5 scope to image through.   recently though i wanted to get a little closer to some of the objects coming up in the summer sky.   M13, M3,  M33, M27, Cygnus wall, m101, wizard nebula... etc etc the list goes on.  

I will be trying with my 2x barlow giving a focal length of 1200.  Which should be OK guiding with my mini fifty, but i wanted to try and match the pixel ratio a bit better to see if it helped, BUT i cannot get focus on the mini fifty when i use a 2x barlow on that...   i can screw the barlow lens directly to the end of my QHY5ii_L mono but the focus point puts the camera about 1mm out of the back of the tube.   TOO CLOSE to use a barlow as an extension tube because of the internal shoulder.... hmm dilemma.   

Now i am a product designer so to the drawing board i went....well to Sketchup anyway.   Money is always tight so an aluminium turned part was out, but a rigid plastic 3d printed part was on the cards.     And as luck would have it, my work bought a new SLA 3D printer (Form2) from form labs) capable of printing to 25 micron resolution.   I thought Christmas had come early!

attached are images of the final part attached to the rear part of the Mini Fifty, ready to be screwed in place.   Not sure how i managed it but i got the tolerances right first time....and measuring the rear part with a ruler. 

fitting diameter to slide over the rear part of the min fifty = 42.25 diameter.
fitting for the camera (1.25") = 32.5 diameter.

as you may have noticed i will need to add 3 x M3 threaded inserts to the back end of this to clamp the QHY securely in.   i can post images after this is done.

if anyone wants this model i can provide it.  None of the internal/external detail is needed really, but this was to see what the Form2 could do.   And i can say ........it is amazing.  (for everything but closed cavity printing.

 

clear skies everyone.

 

[RT65CB-SWL]

Nice!