Semi DIY Temporary Obsy & Motorising Project

[upahill]

The only idiot lights here are family ones, which I can usually control. Ocassionally the farmer likes do drive around with his 80,000,000 candle power torch but if he does that the subs are gonners anyway. I couldnt think of a practical reason - more an aesthetics thing really. A blue/grey would be nice and hide a multitude of sins.

Haven't really checked for any dew/humidity issues yet. The previous owner had a dehumidifier in the dome.

Going to write up a list of jobs I want done by winter to make it useable, then prioritise them and see which 10% i can actually get done

 

[sloz1664]

3 minutes ago, upahill said:

The only idiot lights here are family ones, which I can usually control. Ocassionally the farmer likes do drive around with his 80,000,000 candle power torch but if he does that the subs are gonners anyway. I couldnt think of a practical reason - more an aesthetics thing really. A blue/grey would be nice and hide a multitude of sins.

Haven't really checked for any dew/humidity issues yet. The previous owner had a dehumidifier in the dome.

Going to write up a list of jobs I want done by winter to make it useable, then prioritise them and see which 10% i can actually get done

 

You will need a dehumidifier, I suggest you also get a Hydrostat to ensure it keeps the humidity to an acceptable level.

Steve

[upahill]

2 minutes ago, sloz1664 said:

You will need a dehumidifier, I suggest you also get a Hydrostat to ensure it keeps the humidity to an acceptable level.

Steve

Thanks, I did get the dehumidifier that the previous owner had, the hydrostat looks like a good idea, and simple to use. What do you set yours to?

I have been thinking about the sticky shutter issue - I cant really figure out how to motorise that yet, but I could ease the operation by bolting some skate bearings to the inner aperture where the shutter presses against - the outer edge of the bearing a few mm proud of where it rubs. Should only cost a couple of quid and make the opening and closing significantly smoother.

Current list of jobs to do:

+ all the usual stuff actually related to the telescope, I havent tried the new china mini guidescope yet, the EQ6 needs a bit of a clean/service and I need to source better/shorter cables for everything to improve cable management.

Sooooo excited to actually use it. The further I get with it the happier I am about delaying the ASI1600 to fund this. Even with a DSLR for a while longer my nights should be a lot easier and more frequent.

[sloz1664]

1 minute ago, upahill said:

Thanks, I did get the dehumidifier that the previous owner had, the hydrostat looks like a good idea, and simple to use. What do you set yours to?

I have been thinking about the sticky shutter issue - I cant really figure out how to motorise that yet, but I could ease the operation by bolting some skate bearings to the inner aperture where the shutter presses against - the outer edge of the bearing a few mm proud of where it rubs. Should only cost a couple of quid and make the opening and closing significantly smoother.

Current list of jobs to do:

+ all the usual stuff actually related to the telescope, I havent tried the new china mini guidescope yet, the EQ6 needs a bit of a clean/service and I need to source better/shorter cables for everything to improve cable management.

Sooooo excited to actually use it. The further I get with it the happier I am about delaying the ASI1600 to fund this. Even with a DSLR for a while longer my nights should be a lot easier and more frequent.

I set my Hyrostat to cut in at 60%.

Regarding the shutter I am currently building the electronics to automate the shutter via Levesdome. This is to be wirelessly controlled. Once this is working I will get my head around the physical movement of the shutter.

Steve 

[upahill]

2 minutes ago, sloz1664 said:

I set my Hyrostat to cut in at 60%.

Regarding the shutter I am currently building the electronics to automate the shutter via Levesdome. This is to be wirelessly controlled. Once this is working I will get my head around the physical movement of the shutter.

Steve 

Hmmm some more reading - never even considered wireless. But it has prompted me to think whatever solution used for the shutter its going to require power, and therefore either a battery in the dome section or a cable which would obstruct full rotation. Im guessing if you are going for wireless control your mechanics will be battery powered?

[sloz1664]

1 minute ago, upahill said:

Hmmm some more reading - never even considered wireless. But it has prompted me to think whatever solution used for the shutter its going to require power, and therefore either a battery in the dome section or a cable which would obstruct full rotation. Im guessing if you are going for wireless control your mechanics will be battery powered?

Yes, the Shutter movement will be battery powered. I have a couple of 12v 12ah batteries to use.

Steve

[upahill]

I need to model the dome in Solidworks really and then design the mechanism from that. Have played with hundreds of ideas in my head but stopped when I started considering roller shutters

I have a large batch of linear actuators from Riser Recliner chairs - so a sideways shutter would be a bit easier for me...

[JamesF]

22 minutes ago, upahill said:

Sooooo excited to actually use it. The further I get with it the happier I am about delaying the ASI1600 to fund this. Even with a DSLR for a while longer my nights should be a lot easier and more frequent.

I think it's well worth it.  I've used more kit, more often and for far longer since I got the observatory to the point of being functional than I have done in ages.  And I don't even have the solar Ha scope set up yet. Getting going is now so quick that even a gap long enough to grab a couple of subs is worth the time.

I've still got a long list of stuff to finish too, but given the amount of time I've put into it so far I've forgone doing some of that stuff in favour of actually using it (and doing a bit of catching up on the things I let slide a bit to get this far in the first place).

James

[upahill]

Well I almost ordered the belt last night, but then had a sudden panic.

The largest affordable belt I can find is a T10, 16mm width belt, of which I think ill need around 6.5m - with drive pulley this is well over £100.

The alternative I came up with originally was to use simplex chain glued into a rebate in the wooden ring and a drive sprocket. Now im genuinely torn, I feel like the chain method would sacrifice some resolution but engage deeper. But think it could suffer from a fair bit of backlash. The drive belt seems better but im worried about slippage / meshing. The last belt i used was GT2 stuff which is tiny so maybe in my head im just struggling to gauge the scale of the T10 belt.

One thing the drive chain could be used for is the shutter, bonding a chain, or even a duplex one to the inside of the shutter and then mounting a sprocket/motor in the roof would allow it to pull forward and back. I would have to lose the lip on the shutter but im not bothered about that and could secure with some form of electronic latch.

Also found these - https://www.ebay.co.uk/itm/DC12V-High-Torque-Turbo-Worm-Geared-Reduction-Motor-10-20-30-40-100RPM-Encoder/323593324134?var=512609259581

Which look like it could work, comes with an encoder that im sure I could figure out how to wire up. No idea if they are strong enough to push the dome but at £11 its not too much risk and at the very least I can use it for a test setup.

[JamesF]

Is this of any help?

James

[upahill]

52 minutes ago, JamesF said:

Is this of any help?

James

A good read, thanks. It seems that like myself he started with friction wheel idea but then moved on to the drive belt. I had considered using timing belts from vehicles, they are a bit wider and I feel will give me a better tolerance if the pulley is slightly off. 25mm wide T10 is £105 + vat for 7m,  I have just found 6 x 1.4m 25mm timing belts for £23.70 posted so thats good. The pitch is around 9.5 so fairly close not that it really matters except for having some good engagement on the teeth.

Camshaft pulleys go for around £20 all in so mechanically this cuts the costs of the dome rotation by 60% - perfect!

I wont buy the pulley until I have done a little more research but the belts are on their way. I can always 3D print a pulley for the testing stage 👍

 

 

[upahill]

Lovely evening, 700 degrees celsius but ill take it. It might not actually be that hot, but working tonight has really helped sweat out the last of this cold ive had the past few days.

First job was centering the dome to the pier - didn't take long and its within a few mm either way now. It will get anchored down tomorrow.

I could have taken the opportunity to rotate the walls a bit to put the door at the corner of the deck, but I think ill just build a step in between the todmorden and the deck to ease getting in and out, at the moment its not a graceful dismount - have to stick my rear out, then step down about 18" whilst trying not to bang my head.

 

I managed to cut some of the filler pieces for around the pier - one is a little tight so i need to shave a bit off it - ill use that as the one to drill the holes for conduit. It doesn't look like it but there is about a 5mm gap all the way round.

Plan is to run a conduit for power and a seperate one for data. In reality it will probably just be one USB 3 cable going to a hub and some chunky cable for 12v going to a distribution board on the pier.

I picked up some of the chequered rubber mats at a carboot - £2 for 11 tiles - which is just about enough. They are pretty dusty and i need to finish the edges but it will serve as a good temporary floor, and an insulated sub floor for whatever I decide to put down long term.

Also bought some timing belts on eBay and won an auction for a Velleman K8055N which I believe is what I need for the Levesdome

Before I put too much effort into automating the dome the rollers are going to have be replaced. I spotted a couple have completely disintegrated so will find some suitable replacements.

I feel like I am making progress though and Jupiter and Saturn watched me work for most of the evening - will be nice to get a scope back out soon!

[JSeaman]

For what it's worth the timing belt approach worked WAY better! I still use it every night I can and it doesn't miss a beat. I've now moved to Arduino control which is much better than trying to frig the movement based on proxy sensors, if I can offer any help at all I'm very happy to

[sloz1664]

Nice to see you have received your Velleman board & drive belt. The tiles are a great buy, they are exactly the same as I have in my Obsy and are brilliant, easy to clean & no dangers if you drop anything. One thing you must do with the tiles is to leave a 10 - 15mm gap around the outer edge, they expand in the heat and if there is no gap, they lift qute alarmingly.

Steve

[Gina]

As I discovered some years ago!

[upahill]

3 hours ago, JSeaman said:

For what it's worth the timing belt approach worked WAY better! I still use it every night I can and it doesn't miss a beat. I've now moved to Arduino control which is much better than trying to frig the movement based on proxy sensors, if I can offer any help at all I'm very happy to

Brilliant, im currently in search of a decent pulley (is it a pulley or a sprocket?) - the one I have found has a flange on both sides which would limit me to having a 25mm thick wooden ring. If only I had a lathe...... Then again it might still work depending on the thickness of the belt.

Which software/project are you using with the arduino - I went down the levesdome/velleman route as it seemed the most documented. I will probably search for a motor with encoders and im hoping this can be incorporated into the system.

 

7 minutes ago, sloz1664 said:

Nice to see you have received your Velleman board & drive belt. The tiles are a great buy, they are exactly the same as I have in my Obsy and are brilliant, easy to clean & no dangers if you drop anything. One thing you must do with the tiles is to leave a 10 - 15mm gap around the outer edge, they expand in the heat and if there is no gap, they lift qute alarmingly.

Steve

Hasn't quite arrived, just the listing photos - should be here today though. I had quite a bit of luck with those tiles as I havent seen any for months at the carboot, whenever I dont need something every second stall has them, as soon as a project requires they are like gold dust. Had a similar problem with the M12 nuts for the pier (then last week found a box of 90 )

I will trim back 10mm of the tiles once they are all in. There is a light dusting of spray adhesive under them to hold them flat but fully expecting that to be temporary. Need to find a new penknife as I was limited to holding spare blades by hand 😵

[sloz1664]

1 hour ago, upahill said:

Brilliant, im currently in search of a decent pulley (is it a pulley or a sprocket?) - the one I have found has a flange on both sides which would limit me to having a 25mm thick wooden ring. If only I had a lathe...... Then again it might still work depending on the thickness of the belt.

Which software/project are you using with the arduino - I went down the levesdome/velleman route as it seemed the most documented. I will probably search for a motor with encoders and im hoping this can be incorporated into the system.

 

Hasn't quite arrived, just the listing photos - should be here today though. I had quite a bit of luck with those tiles as I havent seen any for months at the carboot, whenever I dont need something every second stall has them, as soon as a project requires they are like gold dust. Had a similar problem with the M12 nuts for the pier (then last week found a box of 90 )

I will trim back 10mm of the tiles once they are all in. There is a light dusting of spray adhesive under them to hold them flat but fully expecting that to be temporary. Need to find a new penknife as I was limited to holding spare blades by hand 😵

They can be cut with a pair of scissors

[upahill]

7 minutes ago, sloz1664 said:

They can be cut with a pair of scissors

I lack the finesse 🤣 I have visions in my head of cutting smoothly around the edge a perfect 10mm gap with a sharp blade. Ill mash it right up with scissors!

 

 

[Gina]

Stanley knife is the ideal tool.

[Davey-T]

27 minutes ago, Gina said:

Stanley knife is the ideal tool.

Always guaranteed to cut your finger as soon as you put a new blade in it 😂

Dave

[Gina]

As with any sharp blade, you have to be careful!  Mind you, you can get a very painful cut from paper too.

[upahill]

12 minutes ago, Gina said:

As with any sharp blade, you have to be careful!  Mind you, you can get a very painful cut from paper too.

Power tools I can handle, CNC's, even lasers with invisible death rays - but put me near a stanley blade and all co-ordination seems to dissapear.

It's not a project if you haven't bled for it 🤣🤕

[upahill]

 

Next two parts ordered and should be with me by the end of next week. I have gone for a wiper motor which is a slightly less elegant solution than the high torque motors with the built in encoders, but may switch it out.

The more I look at Levesdome the more I think it might exceed my electronics capability. Im usually fairly confident with electronics projects when I can see lots of simple diagrams, youtube videos, etc but I cant even get the CHM help file to open. I have joined the yahoo group (reminds me of the old BBS days) so hopefully I can coble it together on a test bench.

I feel like its screaming for an arduino based revival, but thats probably just me. I have a lot of learning / re-learning to do.

[JSeaman]

Normally called a cam pulley, flange on both sides is handy for locating if it's a bit wobbly, prevents unexpected runout! 25mm should be plenty of real estate

I just wrote my own code from scratch on the arduino with a little .net app talking to it

Encoders are one route, I didn't want the complexity in mine though

[upahill]

1 hour ago, JSeaman said:

I just wrote my own code from scratch on the arduino with a little .net app talking to it

Any chance of that going open source? Interested in what options are out there - im going to give Levesdome a try but I genuinely cant believe that this is what a youtube search reveals....

But "licking a fish" gives 939,000 results. 😋🐟