Kutter binoculars 120/f31

[Chriske]

The curved parts of that template were printed very thin, only one layer. Care had to be taken not to break that perimeter.

[Gina]

Does a binocular telescope actually give a 3D view of a planet or is it just that you get the extra light compared with a telescope of the same size with a binocular eyepiece?  I wouldn't have thought that tiny separation, compared with the distance of the object, would give actual 3D viewing but I'm happy to be corrected on that.

Edited May 7, 2019 by Gina

[Chriske]

No it does not at all, it is all to far away to see objects in 3D.
As a matter of fact most people do not know at all what advantages a bino-scope has over a 'single-scope'.
To be clear all mentioned here below does not count for binoviewers at all. A binoviewer-unit on a single scope is a completely different story. The only advantage that a binoviewer has in common with a bino-scope is that observing is done very relaxed because of that opened second eye. One disadvantage of a binoviewer is a little loss in magnitude.

- First of all there is a significant gain in magnitude when observing with both eyes open using a bino-scope. That has all to do with the brain. Physiologically the brain is not 'built' to observe with one eye closed. When we do observe with one eye closed, immediately the brain starts producing kind of a background' noise' to compensate for that 'lost' eye. Resulting in magnitude and colour loss.
You can all test this for yourself. Mount a regular pair of binoculars on a tripod. Just the same as you would do with a telescope. Do observe during daytime, say landscape. To begin with, close one eye and observe during two or three minutes one eye closed. Do protect that closed eye from light falling sideways into your eye, otherwise this experiment will not work. After a few minutes open that closed eye again and see what happens...
- Second : gain in colour
- Images are much sharper. That has to do because the brain likes to 'overlap' these two separate images. You can compare it with 'stacking' in a digital darkroom.
- relaxed observing. There's no need to get all your face strained up to have that one eye closed. That's why many observers do use an eye-cap btw.
- There is in fact a 3D-ish effect during observing. But that has nothing to do with real 3D. That 3D as many people noticed during observing through one of my Newt-binoculars has all to do with the fact that observing is done with 2 scopes thus 2 air-canals. While observing the air is always in motion, be it slow or fast. So the distortion of the images is not 'synchronised' in the two scopes. Depending one the direction of the motion of the air the eye receives the images a split-second out of phase. Resulting in a very pleasing way of 3D-ish observing. Needles to say it is not ok when there's to much turbulence. That 3D-ish effect, how I call it, is in fact nothing like 3D, but that is the best way I can describe it. You have to see it to understand. When people do observe and notice it, they all ask very surprised : Hey what did I just see..!. It's not always there.
This '3D-ish effect' is only visible while observing (especially) the Moon and planets. While observing Nebulae that effect is overshadowed by that gain in magnitude.

This is the fifth binoscope I'm busy building. This Kutter-bino is the first non-Newt.
Optics for my next(6th) Bino-Scope is almost polished out. The FL of hese two mirrors differ only 3(!)mm. That next one will be a 20" f/5.6 Newt.   It will be a superlight open truss. And there's a 3D-printer involved...!
Both focal length of two scopes to build a binoscope my differ no more than 5% of their FL, The brain can not handle bigger differences. That is in fact the hardest part while polishing. But to do that I use just one pitch for both primary mirrors. Regularly switching mirrors on that pitch is the key.
For this Kutter-Bino I'm building this very moment the FL of both mirrors need to be 100% the same. But that is very easy in this particular case because I grind/polish just one large set of blanks and will core both primary mirrors out of that larger one.
Collimating a binoscope, the first time it's a disaster, but after a while, like so many things, you get used to it. But in this case there are 8(eight!) mirrors to collimate, and it all has to arrive 'lined up' in that brain... fingers crossed..!!

Wish me luck..

 

[Gina]

Of course I wish you luck ?

I haven't enjoyed binocular vision for a number of years due to muscle imbalance (my right eye points slightly outwards) which has got worse over the years.  It was correctable when I was young by prism in my glasses but now it's beyond optical correction and also non-operable.  Also, quite severe astigmatism means observing is not good anyway and one reason I concentrate on imaging.  My brain produces 3D images if I'm walking or driving due to motion - the same way as hens do by moving their heads back and forth. 

I guess a suitable optical system with cylindrical lenses to correct astigmatism plus a mirror or prism system to bend the light beam inwards could be used to enable me to use a binocular telescope.  It would be horrendously expensive, of course!  Or would it??  I guess an old pair of glasses could provide the cylindrical component then a modified diagonal for the right eye.  My right eye is still good optically.

Edited May 7, 2019 by Gina

[Chriske]

Printing the baffles for the secondary tube.
I never use black, but for these baffles I made an exception.  The only thing to do is make the interior matt black with paint.
These baffles are printed using a 1.5mm nozzle(no not 0.15mm?) on my printer (special hotend - selfmade - Volcano-ish). Slicer is set to spiral vase, so the thickness of the baffles is just over 1.5mm.
I need about 20 of these 100mm long baffle-tubes. So doing the 2 secondary tubes are completely filled with these baffles.
I know I could have painted the interior of that tube. But these stainless steel tubes are very glossy at the inside. There's no way I could have blackened these long tubes perfectly using paint.
Anyway, because of the thickness of the used nozzle(resulting in a rough perimeter) I have lots of tiny baffles...
There's a bump in these baffles. That's no error. I drew that bump to allow passage to the wire connected to a fan that is mounted in the top of the scope. So looking into the secondary tube(through that oblong hole) there's no wiring visible. That thin wire will be installed between the tubes inner perimeter and these baffles.
There are btw 6 fans installed in that scope.

[Chriske]

Finished cutting and grinding the oblong holes in the secondary tubes.

Looking good from the primary's position.

[Chriske]

Printing the Kutter's-wedges.
Although I use a .7mm nozzle it'll take almost 19hours to finish. This will be the first time I print a part with a printing-time that long.
The two secondary tubes should stay absolutely perfectly aligned(parallel), that's why in the first place these wedges need to be that big/strong, no play is allowed here. And second, I'll add some extra connections(not yet in the drawing) between these two tubes, just to be on the save side.

[Chriske]

Need to decide whether I'm going for a EQ or a AZ  to mount that bino. Whatever path I follow it'll be driven by OnStep software.
It'll be a wooden mount and tracking system. Don't know yet if I would leave that wood as is or finish it with my lathe. The wood as is looks very rough, but I like it this way, very much as  matter of fact. The outside looks very old and is covered with a bit of moss. The centre of the tree and branches are in good condition(no rot).
It was a old tree that had to go. Not because it was old but it was in the way of a new house planned at that spot. The owner wanted to get rid of it, and I happened to be at the right spot at the right time, lucky me.
The thickest piece is  about 150mm(6") diameter and would be a good base for that mount. It's apple, there is some walnut too.

That wood-lathe(in the background) is already working, restored it a while ago(still need a bit of paint). I found a1.1hp motor on a shelve in my workshop and bought a frequency Inverter, very handy that inverter. Cost 54€. Anyway it works very well and I can go as slow as 20 rpm and up to 2100 rpm. Had lots of fun working with that thing already.

[Chriske]

Meanwhile drawing the IPD adjusting-parts. This is how it will look like.
Integrated is a ten revolution potentiometer. While adjusting the IPD that built-in potmeter runs along with it so I can read what the value is.

Edited May 30, 2019 by Chriske

[Chriske]

Assembling has begun,

Cutting the secondary tubes to it's correct length. It all needs to be very precise. Every mm counts. A difference of just 1mm between primary and secondary mirror will throw the focal point 3mm away from its original location.
Made a temporary 'device' to do that cutting. Used a few wooden blocks (leftovers) to hold grinder and tube

After that I cut a 50mm hole sideways in that same tube.

very

[Chriske]

Ready to assemble the IPD adjusting unit.

 

At the bottom of the unit is a 10 rev. potentiometer. Every revolution of that pot-meter is 2x1.25mm movement of the two eyepieces toward or away from each other.
Arduino Nano will do the math and make it visible on a display how far they’re separated.

[Mick J]

Outstanding piece of work, love the angle grinder setup to produce precise cuts, couple of old blocks and clamps - simple and easy. 

[Chriske]

Thanks..!

[Chriske]

Had no idea how much it all will weigh, I'm in fact a bit surprised. This is going to be a heavy bino...

This is just one wedge + secondary tube.

 

That's almost 5lbs..!
SS tube is only 1mm thick.

[Chriske]

IPD adjustment unit done..!
Wiring will be done later.

 

Oops forgot to remove that nut and washer

[Gina]

Progressing nicely.

[Chriske]

Assembling the green laserpointer.
Sits between the two primary tubes.
Laser is heated and stays at 18°C in winter.

 

The top layer of the largest part looks a bit weird. It is angled that's why. That is because the laser is at an angle to the primary tubes.

 

There's a big hole in the side of the unit. That hole is to allow the laser's wires to get through.
All electronics wiring will be hidden in the telescope's parts btw. Not one wire shall be visible.
To achieve this all parts have inside 'canals' to allow passage.

[Chriske]

Time for the focusers to assemble.
These are the parts for the left focuser.
As  said before, it is kinda 'reversed' Crayford focuser. The complete focuser rides on a 40mm tube. So here too 5 ball bearings and one 6mm focusing-rod.
The eyepieces are inserted at an angle, that's part of the concept. Every Schief or Kutter telescope is a bit different. So every system has its eyepieces at another angle.
The uppermost(centre) part in the picture is a 2" to 1"1/4  adapter. It is kinda springloaded at both the inner and outer perimeter, so the eyepiece is always at the very centre of the optical train.

[Gina]

I like the "old wireless tuner style" reducer.

[Chriske]

Done, this is the left focuser. Works incredibly well. To be honest I had some doubts(just a little bit) myself when I was drawing that thing in Inventor. There are lots of parts adding friction. But to reduce it I installed as many ball bearings as possible. + also four additional units to remove possible play.

Notice the angled position of that eyepiece.

Edited June 13, 2019 by Chriske

[Chriske]

Tuning that focuser to have a smooth 'ride'.
In this order :

1- Aligning the dual speed focusing knob(hight)
2- Adjust tension on the focusing rod.
3- Adjusting tension on the gears
4- Adjust belt tension

 

Edited June 14, 2019 by Chriske

[Chriske]

Cutting the primary tubes (160x200mm).
I did use the exact same setup as I did to cut the SS secondary tubes. Only in this case I used a saw instead of  a grinding disk.

This tube was a leftover and was not cut straight then.

So I had to guide that PVC tube against a large board that was fixed at exactly 90° to the cutting direction in two directions

.

 

[Chriske]

First temporary assembly. Just to see how it will look like... All will be painted pristine white.
It all fits very nicely. One thing I've got to change I think. These LMUU linear bearings I did use for the IPD units to run on, do not work very smoothly. So I will replace that system and use my own selfmade bearings.
But I will wait to decide that, until second test-assembly when all is firmly bolted together.

As it it now, completely 'empty', its weight : 7.4 kg
So a carrying belt will not suffice imho, I'll need a chain...

[Chriske]

Didn’t wait until second test-setup, abandoned the LMUU linear bearings and drew new IPD blocks were every third ball bearing in each hole is adjustable. Meaning there are 12 fixed ball bearings + 6 adjustable,  in each IPD unit. No play is allowed here. Its btw the exact same setup as I use in my 3D-printers I've built so far. All 5mm axis are removable(in case of ball bearing failure. But until now, in all the 3D-printers I've used this system not one ball bearing got broke.

Anyway, this is how it looks like now.
A 9 hour print using a .7mm nozzle - 60mm/s. After that all 5mm holes needs to be reamed to have a very tight fit.
Ball bearings I'll be using : 5x8x2.5mm(x36)

Even the long 40mm tube, coming out of the big top-hole, is adjustable. I press that 40mm tube(about 125mm deep) firmly into the IPD unit until it's stuck. Then I can tilt these tubes(at the top) about 1° in all directions. That's where 3 grubscrews are needed for. And that's why the 3 hexagonal holes inside. In these 3 holes : M6 nuts.

[Chriske]

New parts with selfmade linear bearings.
In all(36) 5mm holes sits a axis + ball bearing 5x8x2.5. All these 5mm holes are reamed to the correct size, so the axis are press-fitted in the units.

On the right the old system with these LMUU8 linear bearings and on the left the new system, with adjustable bearings. I use this system also in all my printers btw. Works perfect.