Gina's Observatory - The Build

[Gina]

No actual work on the build today but out shopping this morning I did manage to get the wood I need to finish it off and a couple of other bits and pieces.

Been working on the focus motor control unit. Have the circuit board and switches connected up and ready to put in a box. Later I might add circuitry for computer control. I had already put the pulley on the gearbox output shaft and screwed motor/gearbox to plastic box last night.

No viewing or imaging available tonight - thick cloud and it's raining!

[Anweniel]

Hey Gina, thanks for the link was really interested to comapre capture results considering the only real difference in our equipment was the mount (unless you captured the vid with new scope?).

Anyhow it seems the mount has done a good job of keeping the target near the centre of the FOV, obviously this is where I have the most difficulty and where castrator comes to my rescue

It looks very much like the first few attempts that I had made to image Jupiter myself and seems very over exposed hence the bright disc and lack of detail, clearly with the moons as good pricks of light - your focus is well in but with some adjustment to your settings in the capture software I think you should be able to get a whole lot more detail (perhaps a barlow may be handy too I seem to remember you saying your OH was getting you one for christmas)

Being fairly new to the imaging game myself I am by no means qualified to criticise or give you a perfect response to the required settings but I could perhaps dig out the ones I used as I did manage to capture two equitorial belts and what is either a storm or a passing moon shadow (too indistinct to differentiate).

Hope this may be of some use to you,

Barry

[Astrokev]

Yes, I'm going to put acrylic sheet on the other side of the door frame and probably put a desiccant bag in between.

You could always put polystyrene between the acrylic sheets to give further insulation

Seriously though - continuing to look great. I want one.

[Gina]

Hey Gina, thanks for the link was really interested to comapre capture results considering the only real difference in our equipment was the mount (unless you captured the vid with new scope?).

I did use my new scope actually.

Anyhow it seems the mount has done a good job of keeping the target near the centre of the FOV, obviously this is where I have the most difficulty and where castrator comes to my rescue

Yes, particularly as I haven't yet polar aligned. I don't think it's far off though.

It looks very much like the first few attempts that I had made to image Jupiter myself and seems very over exposed hence the bright disc and lack of detail, clearly with the moons as good pricks of light - your focus is well in but with some adjustment to your settings in the capture software I think you should be able to get a whole lot more detail (perhaps a barlow may be handy too I seem to remember you saying your OH was getting you one for christmas)

Being fairly new to the imaging game myself I am by no means qualified to criticise or give you a perfect response to the required settings but I could perhaps dig out the ones I used as I did manage to capture two equitorial belts and what is either a storm or a passing moon shadow (too indistinct to differentiate).

Hope this may be of some use to you,

Barry

Thank you Yes, definitely very overexposed - hope to get that better next time. Whenever that may be Too many cloudy nights

[Gina]

You could always put polystyrene between the acrylic sheets to give further insulation

Seriously though - continuing to look great. I want one.

Thank you Progressing slowly

[Gina]

Today's progress.

Not had time today to do much to the build but I have attached the focus motor unit to the scope and taken some photos. These show the focus motor mounted on the scope mounting bar (using the bolts used to stop the scope sliding right off if the fastening knobs are undone), from various angles and ending with a photo showing how it's fixed on.

[GJBC]

That is excellent Gina. what a wonderfull little project that focuser is. love it

Have you had it running yet?

where did you get the gears etc.

i will take my hat off to you you turn you hand to anything and always succeed or in this thread anyway. Congratulations

[Gina]

Thank you Grahame

No. I haven't had it running yet, need to finish the controller box first.

The motor/gearbox came from Maplin Model SN36P :- Multi Ratio Motorgearboxes : Motors & Gearboxes : Maplin Electronics

I'll have to check where I bought the pulley and belt from tomorrow.

[Anweniel]

Careful with those orange gears it may get confused with a celestron!

[Gina]

That would never do!

[Gina]

Pulley and belt bought from Technobots

Pulley used two of these back to back :- Plastic Pulley 30/25 2.9mm

Belt was :- Pulley Belt 2.5mm x 70mm ID

The shaft on the motor/gearbox is 3.0mm so the 2.9mm hole in the pulley makes a good tight fit. These were the only pulleys shown that had this size hole - nearest otherwise would be loose on the shaft and didn't have a grub screw to tighten it. They only represent half a pulley (like railway wheels) so needed two back to back.

I got 3 sizes of belt as I wasn't sure what size I wanted. Turned out to be the 70mm as I thought.

[Aoraki]

That's a really nice mod there Gina, keep us posted when it's up and running, it could well be a mod for me (I would also need one for the C9.25 aswel though!)

[Gina]

Thanks I've finished the control box, I think. Will be connecting it up and testing soon. Fat chance of getting anything in the sky to try focussing on but I know roughly what speed I want the focuser to go for fine focussing and the 12-24v motor will be getting the full 13.8v for fast movement.

[Black Knight]

Gina, I've followed your obsy build with great interest. I'm really impressed with your build (I don't have an obsy yet), and I love what you are doing to motorise your focuser!

[Gina]

Tested the focussing motor and control box. The fine focus speed seems fine but the coarse speed would take several minutes to travel from end to end. Mind you, I doubt I'd ever want to do that - for coarse focussing I would replace the webcam with an eyepiece and use the usual knobs. Don't even need to take the belt off - it's tight enough to drive the very smooth Crayford slow motion knob but you can still turn the knobs by hand and the knob slides under the belt. It's easy enough to take the belt off though.

I'll post some photos later.

[yesyes]

doesn't the webcam and eyepieces come to focus at very different points? they do on my scope...

[Gina]

Gina, I've followed your obsy build with great interest. I'm really impressed with your build (I don't have an obsy yet), and I love what you are doing to motorise your focuser!

Thank you

[Gina]

doesn't the webcam and eyepieces come to focus at very different points? they do on my scope...

When I made the adapter for my MS LifeCam I arranged the focal plane to match one of my eyepieces but the Phillips is a bit different. It would be near enough to use the coarse electric focussing though. Another thought was to put marks on the draw tube for rough focussing of the 2 or 3 permutations for imaging.

Of course, with the DSLR I'd use the viewfinder for focussing.

[Gina]

Here are some photos of the focussing motor control box. One of the outside and two showing the inside.

I've tried to source momentary SPDT push button switches but without any success. This would have enabled me to have a push button for each direction. What I've done instead is to take a DPDT centre off biassed toggle switch and fit it with a paddle to produce the same functionality. SPST push buttons are easy to find and I already have some so I might use relays to provide the required function. I'll see how I get on with the paddle switch.

A final image shows the circuit diagram and a drawing of the paddle fitted to the centre off toggle switch. The other switch is a simple SPDT to select fast or slow (coarse or fine focussing).

[Ransu]

Wow, i'm impressed! Very smart and cost effective way to make electric focuser. Well done Gina:) It has been great joy to follow your obsy building.

[yesyes]

Agreed. Simple and effective... ;-)

But I would recommend adding filter capacitors either side of the LM317. I read that they do tend to oscillate without these caps.

[Gina]

Wow, i'm impressed! Very smart and cost effective way to make electric focuser. Well done Gina:) It has been great joy to follow your obsy building.

Thank you I thought you obsy looked very smart and blended in perfectly - nice job

[Gina]

Agreed. Simple and effective... ;-)

But I would recommend adding filter capacitors either side of the LM317. I read that they do tend to oscillate without these caps.

Thanks Chris Yes, I agree about the capacitors - I'll fix that

[Gina]

Christmas preparations are still interfering with any serious progress on the build! Hopefully for not too much longer

A game pad I ordered from eBay for a fiver came this morning. I was able to plug it in and XP installed it automatically. I have also tried it in the obsy and it controls slewing the mount via ASCOM perfectly So that's a result Didn't even need to set anything up but the joystick - left right up down, then save result. Easy peasy! I shall set up some of the buttons to provide the functions to my liking later.

It's not wireless but has a good length USB cable (about 2m) which will reach from netbook in warm room right up to the mount (with the door open). I can also plug it into a USB port in the hub at the mount if I want the door shut.

Several things need finishing off before I can really think of a long session of imaging.

1. The outer door needs a better latch/lock.

2. The inner door needs a catch and handles.

3. The door window pane needs fixing properly and the second pane fixed on the other side.

4. All the building clutter needs clearing up and taking away.

5. I need to make a case/stand for my various EPs, Barlows and adapters etc. I can never find what I want on the table

6. The cables, EQDIR unit and USB hub want tidying up and attaching to the mount.

7. Put a heater in the warm room. I have a 60w tubular greenhouse heater which I'll try but may want something a bit more powerful.

Then there are several cosmetic jobs such as cladding on the rest of the warm room walls and roof - they currently have exposed polystyrene insulation. I want to clad the scope room walls too.

[Bizibilder]

For eyepieces and things I use the regular foam filled flight case - If you are careful when laying out where all the bits should go (before you cut the foam) you can position them so that it becomes really easy to find stuff even in complete darkness. For example mine has the whole "regular" camera assembly laid out, in order, across the box ie camera, t-ring, 1.25" adapter, 2" adapter etc - Pretty much the same in the row below where all the webcam bits and bobs go, again in order of most common use. Hope this all makes sense!