Chriske

The upper part will be printed in two separate parts. I cannot print higher then 210mm(yet). So 2x200mm = 2x 12hours printing time. They will be bolted together.

Painting all inner surfaces...

Assembling...

Some more corrections during filing and sanding...

After this first drawing I made a few corrections of course

I know 'a bit' about folded scopes...;-) In the past I've built lots of Kutter schiefs and bino-Newts. If you do not want to build a completely closed system then you need to pay attention about cutting the oblong hole in the tube. You need to cut it very precise and add a few baffles if needed. And btw I do not draw using lining paper anymore, I do it all on my computer these days. Far more accurate. 😉

The inner parts of an old mimo. I'll keep these for the endstops. Laser + batteries + holder Endstop + battery pack in place...

there's another lens waiting to be transformed into a scope. That second is a 140mm and a whopping 3500mm FL. Don't know yet what I will be doing with this one. it will be folded but I'm thinking of transforming it maybe into a drumscope.

Adding a laser-unit instead of a finder-scope. This the only location to add that laser-unit, (the rest of the refractor is 'filled' with optical path) between the lens and the secondary mirror. I did not want to mount the laser-unit externally. The complete unit can slide in and out and is blocked by the large knurled knob(left) The smaller knurled knob(right) is to activate the laser, by pushing the micro-endstop. That little endstop is cannibalised out of a old microsoft-mouse. They're just a few mm across. All the parts in the laserunit : * two AA batteries(mounted in a holder) * a green-laser unit(15mW) * small endstop * Collimation ring * on-off knob * Larger knob, at the side of the telescope, to lock the laser-unit in place * Cover, to protect the collimation bolts while handling the unit. In winter time a green laser will not work properly. In freezing environments it will even stop working completely. So I can remove the unit from the telescope and store it under my coat, close to my body, to keep it warm. Starting another observing session I slide the (warm)unit in the scope and find me another object in the sky. When done I remove it and tuck it away under my coat again. To be sure that every time again the unit is correctly inserted at the exact same location in the telescope, it is pressed against a V-shape wall

I use PLA printed bearings in combination with felt these days, not for very large and heavy scopes of course.

Again... nicely done..!!

Nicely done.. What process did you use to smooth up the surfaces of these Grado's..?

Most of my printed telescope parts are made with my 0.4 and 0.7 nozzles. The bigger nozzles are exclusively used for printing model rockets. So far I made 'a few' of these rockets. They're all show-pieces at our local observatory. So far I've printed five SaturnV rockets 2.1m high. Two Falcon rockets 2.2m high. HST 2.5m long and also JWST 3m long. This very moment we're busy building/printing another SaturnV, this last SaturnV will be 4.2m high. Most of the rockets are printed in 'Spiral Vase' modus. To give you an idea, a 2.1m high SaturnV rocket takes me about 25hours to print with 1.5 nozzle.

Yep, PETG, great stuff too... And yes it's a myth about PLA and biodegradable. It's not because it is made out of corn that PLA will shrink away in your compost heap. Eventually it will, but it'll take many years.

These hotends I was telling you about, well this my set. They're all designed for my printer(own design also). Just two M3 bolts to remove the hotend from its extruder unit. It's a matter of 1min(max) to swap hotend. I do not believe in swapping nozzles as many claim to be possible, because the centre piece of the heatbreak is veeeeeeeeeeeeeeeeeeeeeeery thin. Two friends have asked me in the past to repair there extruder because of breaking there hotend during nozzle swap..😳. anyway... This my set of hotends, partly printed, that is perfectly possible because that printed part is at the very top of that hotend and stays cool. The one on the left is my 1.5mm hotend with a 70mm radial fan. The right one is my 0.7mm hotend with 50mm radial fan. On top(in the black box) you see the 2.5mm nozzle, not used yet. The electronics connectors are also own idea. In the extruder body there is a male part, and as you see here (on the hotend parts) is the female part on these connections. These connections are for PT100, heater cartridge and also the parts cooling fan(also a 50mm radial fan). There's also that external connector for the heatsink fan. So I can use that fan on all my hotends. I Use these huge radial fans because I want to print as fast as possible with these big nozzles. Using these E3D-V6 I can print very fast. With the E3DVolcano they say you need to slow down printspeed. But instead of slowing down printspeed I print @ temp. of 250°C(PLA). To do that you need LOTS extra cooling on that heatsink. And that's why the 70mm radial fan.

I do use a mix of 3 nozzles, 0.4 for the very small parts and were needed I use a 0.7mm and also a 1.5mm nozzles. These 3 hotends are my standard nozzles I can use with 1.75mm filament. A 2.0mm and a 2.5(!)mm nozzle is waiting to be used with my new printer(almost finished) and (of course) 2.85mm filament. A huge 70mm radial fan is added to the heatsink of my heater to print as fast as my other big nozzles. Using my 1.5mm nozzle btw I can print @ about 60mm/s. For this one I also use that 70mm radial fan.

Until now I've printed 5(if Im' not mistaken) telescopes. All white, and yes I can leave them outside in the sun all day. Except for my very first Newt, I printed I've printed black. Most of these telescope and mounts are rather large. The last one I also posted here is a 152mm binocular refractor. There was also a 250 f/24 Gregorian, a 125mm f/31 Kutter binoscope, and also a smaller Kutter, all printed in pristine white. You can look them up here at SGL. And no these scopes are not show-pieces, the do work. The Kutter bino's optics only need coatings to have it fully operational. To be clear, these scope I've printed are not 'all printed' of course. I always start with a frame, most of the time aluminium on which I start adding lots of printed parts. It is a delicate balance between strong stiff aluminium and lots of printed parts. I'm a mechanical engineer so I know were to add reinforcements if needed. With my background it makes it lots easier to assemble a light, yet stiff telescope. As a matter of fact with most of my scopes there's no visible trace at all of these aluminium parts. I always try to give the impression that the scope is 'all printed' but as I said, non of my scopes is. It wouldn't work...!

Out of topic, sorry... Companies building telescopes, why do some brands make black telescopes(at the outside) these days...??????? It is the most ridiculous thing to do imo. At night it's ok to have black shiny telescopes but using a black telescope during daytime observing the sun.... In the old days telescopes were all pristine white. At least they knew why in those days..! Why do some modern brands forgot about 'white' telescopes.??? Aaah, yes.... maybe it looks sexy... That's why...😄

This is one of the tests I performed with a few filaments. Filaments were PLAblack - PLAwhite - ABS - nGen These rings were very thin, the walls were only 0.8mm thick They were all hung up outside in our garden facing south in direct sunlight(all day long) To start I added 1/2 liter of water in the bottles, but after only a few weeks I filled them up to 1L. Midsummer(we had a severe heatwave that year) it looked like this... And at nearly the end of autumn this was the result... One black and the blue were ABS and nGen The other black was the big looser(as I expected). And the winner is..... White PLA...! As a matter of fact, PLA white was the only one to get (almost) back to it's original shape when I released the bottles from the rings. ABS and nGen did not. After that test there was only 1 mm of difference in diameter with the PLA. The rings were about 150mm in diameter. Problem on the internet is, the more you read about PLA not usable in the open and the sun the more people will believe it. (A huge problem with internet imo) In the beginning, when I started printing, I also believed it but at least I did a test of my own to see if it was all true. I'm sure not just white colour will do the job in the open/sun. One of these days maybe, just maybe, I'll try yellow or other lighter colours to see if they withstand the heat of the sun. Dark colours are a 'no go' in the sun.

Well you said it yourself 'under a dark cover'. With PLA it does not work. Using PLA outside in the backing sun The only thing that works is 'White'. The only place were it does not work is in a car or a greenhouse.

All true guys...! BUT, lots of posters on Thingiverse(or other sites) do not know how to draw things that needs to be strong. Lots of these guys see a part, any part, want to coy/print it and draw it exactly the same size as the original and expect that printed part to be as strong and stiff as that original. Parts made of aluminium or zamak are very strong, these part are made slimline to be very nice, and they all look very nice indeed. Sorry to say so but lots of Thingiverse project are rubbish when it comes to be strong. In fact most of them. When I started printing 10 years ago I was tempted too to use Thingiverse parts, but soon stopped copying and very soon started drawing my own parts and I still do. When you want to make/print a part were force or tension is involved you need to make it bigger, lots bigger. And yes sometimes it does not look nice if i's not slimline. My point is I do not care whether that part looks nice or not. It must do it's job, and that's all it has to do. Most of the time these parts (during observing) are in the dark....!!!I If there is not enough space to make a part bigger, print a hole in it and force and glue a piece of threaded rod in it(ore a few). And as I said before if you do not want a part to bend in the heat of the sun, print it in white. I have lots of parts for many years now in our garden, nothing happens, even during long heatwaves. I have some pictures of a test I performed a few years back about PLA/Sun, Ill post them later on...

correct, and PLA can even be used for outdoor use if parts are printed in white. Even when exposed to the sun all day long. Not to be used during summer in a car, were heat accumulates..!

Lens cell ready. Still to do paintwork.

A while ago I got a 150mm lens from a old member of our society. A few months back the man passed away and it was his son who gave it to me for free. Build something around it 'in honour of my father' he said. And so that's what I'm doing right now. This is how far I got right now. As usual there's a 3D printer involved. Only the cell for that 100mm flat to draw. The lens cell is already completed, busy printing the rest of the parts right now. I decided to have this scope folding up because of it's rather long FL, it is a 150mm f/15.7 The flats are 45mm and 100mm diameter. I also added a printed dual speed focuser. The lower tube is not printed, it is a standard 160mm PVC tube. The 480mm long upper part is printed.