3D Printing Fun

[Matt]

Done! And thanks again . I hate the whole bed levelling thing, somehow it seems to drift out after sitting for a while and I either get that elephant foot or lifting...

[Phmode]

Now I am beginning to feel left out as I don't have (or need, but wth has need got to do with toys) a ddd printer.

[Matt]

Nine and a half months or so after half arsedly starting this project, it is almost complete (note that's elapsed, if we count effort it's about a week).

First we can see the bottom bit with primary alignment knobs, and the middle part with the basic attachment for a mount. Coming next is that mount, possibly this one: https://www.printables.com/model/503969-strurdy-mount-for-hadley-telescope
Oh, and https://www.printables.com/model/268580-hadley-telescope-official-metric-remix is the page for the telescope itself. Or the metric remix as the original is in that nonsensical imperial measurement based on the average length of hens ankles or something.



And here we see the mostly built telescope. The black circle on the right side is resting there as I've just glued some knobs onto bolt heads, but it's actually the secondary mirror holder and will slot into the grey piece behind it. The primary sits in at the far left of the photo, though I'm waiting for some silicone glue to attach that. And some bravery as it sounds very easy to scratch. I may wait until I've fixed the printer here, so I can print a mirror cap to put on and keep it safe.



So there we are. Impressively easy to put together really, only took me an hour or so. Although I do have rather a lot of M4 hardware nuts and bolts left over!

Once I fix the printer (thanks again Andy) I'll print the mount linked above, the mirror cap/caps, and then install and 'collimate' everything. Oh! And thanks once again to Brian for lending me the eyepiece which I should finally get to try soon .

[Phmode]

Nice!

Now I am just waiting for someone to ask what stops all the stray light getting in where the optical tube isn't and the mirrors are open to the sky…

[Matt]

Yeah there are a couple of pages in the build instructions devoted to that. Apparently It should be pretty minimal and that black piece at the right, below the yellow accessory holder and next to the upper assembly, helps avoid any that would angle-of-incidence correctly to get in the way.

But we'll see. I have so many neighbours here doing their best to make the sky as bright as possible.

[Matt]

Whew! Self-imposed drama!

So the replacement part from Andy arrived (actually two, which was a good idea...) and I got to work rebuilding the printer. It didn't take too long following the online instructions. Unfortunately the instructions weren't aligned to the latest software, and so every time I calibrated the first layer it didn't store the data, and the next print would be messed up. There's actually a new menu item on the printer to trigger it, and you can't just print your own first layer thing.

Until I realised the new (covered in docs for newer printers) process, I assumed I'd messed up the positioning of the P.I.N.D.A  (Prusa Something Something Distance Something) which senses some spots on the bed to get the height. As such I was loosening nuts, moving sensor, tightening nuts, and repeating this many times. Unsurprisingly this eventually caused the holder to start breaking apart! I probably over-torqued.

Thankfully I managed to get it to sit in the right place long enough to print yet another replacement! This time with an improved holder for the P.I.N.D.A from a slightly newer printer version. I also upped the perimeter count (how many 'loops' it does before doing infill) to give it more strength for my undoubted future abuse.

So, a day and a half later, I've just calibrated X, Y, Z (it auto does it and tells you what to do if it fails), done the first layer, and am now printing a large single layer 3x3 grid on the bed so I can see any variations in height. These can then be offset in microns to get everything perfect. Ref the last picture.

The poor thing I broke! Sorry Andy


The newer version I discovered, using my 5 year old PETG


Fun precise calibration. Where you see gaps between the filled shapes it means the nozzle is too high, so i'll adjust it in the menu and try again


So thanks again to Andy, and sorry it only lived for a day

[Matt]

And the telescope is complete!

After printing and using this "Cheshire Collimation eyepiece" to perform the collimation stuff I was finally able to put Brian's eyepiece in and actually focus the thing... on a house alarm down the road .



Now I'm printing out bits like this that will go together with some more 12mm rods to create the basic mount for rotation on one axis.


Oh, and some more thumb screws for the things I'll be adjusting more frequently.

I must say it's been very satisfying just adjusting the secondary and primary and getting it all aligned. I was still expecting right up until that very moment that it wouldn't work for some silly reason.

Now I just need to chop down all the trees surrounding my house and street!

Oh yes, and an image of the double glazing.

[Phmode]

Well done lad!

Small steps is what is needed. Having spent $4,500 buying my 12" Big Blue, travelling to the USA to collect it from the friend who had purchased it for me, driving around the lower 48 with all 170lbs of it disassembled in the back of the minivan for 10 days, shipping it back via United, getting off almost Scot-free at customs, somehow cramming it into the back of my estate car at Heathrow, spending 3 weeks reassembling it and getting the orthogonality back to factory true(?) and waiting for a clear night, I then spent 3 hours studying the inner workings of the Olde-worlde imitation gas lamp sodium light whose pollution became the bane of my astronomical life. Small steps indeed.

[Matt]

One of the summer days you've got to invite me over for some stargazing!

Ironically, on light pollution, I think it's worse from all the back garden neighbour lights than out front here. But then the front faces south so at least for identifying Clangers it's not so bad. Just the trees to work around then.

OK so here's the finished thing. The construction of the mount was delayed as the 12mm rods I ordered ended up being 12.7mm, which as we alllll know is half inch. Thanks... Sharpe. I reprinted the plastic parts in 12.7mm guise and it slotted together a treat. I also printed some nice thumb screw knobby bits to remove the need for a driver when adjusting stuff.



Oh! As you can see, this is a pretty basic mount that only allows for... altitude adjustment. However thanks to the open source world I've already found a project I can adapt to create a geared azimuth adjustment.

I think this makes it an Altaz mount, but I'm still learning the pros and cons. Either way, driving it all by motors if I went all in, is possible.

Meanwhile I've started a new project



It's a tiny (roughly 36cm wingspan) lightweight fpv flying wing. Or at least it's a wing, flying and fpv are going to be the challenging parts! All up it should/must weigh less than 250g for all those fun drone-related reasons that make heavier stuff more complicated from a regulatory standpoint.

The wings themselves are quite innovative, its skin is a single layer, so 0.2mm thick, with a few spars which the top half folds over and locks into. The whole thing slots together as 3 parts and so replacing a wing should be a 2 minute job.

I'm awaiting various parts at the moment such as an 8g motor and other tiny tiny electronic parts.

[Phmode]

Not only the dreaded 250gm weight limit but also the absolute need to keep in within visual line of sight at all times. This means not only being able to see it but also to which orientation it is in; much easier for a plane than a drone...

And, if you are flying FPV you MUST have an accomplice (no need for a registered/qualified one) to keep it within VLS.

More regulations for drones and model aircraft than for hang gliders and no incidents apart from by the idiots who ignore all the rules and regs anyway.

And an invite will be in the post but I have to warn you that there not many stars to gaze at during summer days...

[Matt]

Progress Report!

I finally remembered I built a telescope on the same night we had clear'ish sky. But I stayed inside so this was from behind glass.

This is me holding up my phone to the eye piece.


This is zoomed to maybe 5x optical with phone.


And this is 10x optical with phone.


I was particularly amazed to be able to discern the craters on the profile of the moon even with just my human eyeball. I also had a revelatory recall the day after. Namely that I have a DSLR tucked away somewhere. So one of my next projects (so you know, in the next 5 to 10 years) will be to print an adapter to fit this to the telescope. I may need some ballast somewhere then too. Twist and shout.

My telescope roadmap always consisted of motorising it and moving towards the ability to search the sky etc. However whilst browsing Printables for ideas I found this: https://www.pifinder.io

It's an open source thingy that snaps a picture of where you're pointing and does lots of maths to tell you where to move it to get to some other place. Like the moon. There are a few spendy bits so it'll have to wait a while, but it looks pretty awesome and can remove the whole motorising requirement at least for a while. Still need to make a rotatey mount though.

The wing is coming together slowly. Mostly as a result of me being efficient on brain usage and buying the wrong stuff. My latest and hopefully last hiccup is the cheap Tx not supporting channel mixing; flying wings have to mix elevator and aileron to use the single elevons to do both. I've got an adapter that'll hopefully allow my very old radio Tx to work coming soon.



I tested the FPV thing and it works great, so I'm already thinking of other uses for that.

Oh! The BarButtons PCBs are on their way, and I'm hopeful I engaged enough brain to have done it all correctly.

[richtea]

Excellent!

Also liking the farm animals. 

[Matt]

The cow jumped over the moon, not onto it!

Also yes, mother made some "improvements" to my house when she cat sat during my New Zealand odyssey .