Homemade movable rings system.

[Capt Slog]

Hi,

Like most with a Newtonian type set-up, I often find that the eyepiece is in the wrong place for the bit of sky I want to look at.  Even though I always have the tripod quite low, I'm often balanced on steps to see through the eyepiece or the RACI.  I have opened the clamps before and moved the tube around, but it's not ideal because the tube can slip out of the balance point.

I know you can get moveable clamp/rings, but they want money for those, and that's not something I part with readily!  However,  I do have a 'particular set of skills' and decided to use them to make my own.  Forgive the thread title, I don't know what you properly call them.

 

First, I bought some aluminium bar from the local metal merchants.  An off-cut of 3.9 meters cost me £6.

Next I wanted to make the aluminium into hoops the same diameter as the tube on my Skywatcher 150.  I could have just bent it, but to do it nicely without a lot of distortions, I made a set of rollers from bits I had lying around...

It's a bit rough and ready, but it only had to work twice, I operated the feed by a bar between those two screws sticking up at the back

I cut the metal to around 66cm, this is a bit longer than needed, but then the roller would not bend the last few cms of each end.  A few feeds through the rollers gave me some nice hoops, and I carried on until they were the correct diameter.  I then cut off the un-bent portions, and attached a piece of angle on each side of the joint with pop-rivets, this will hold the screw to make them clamp together...

You can see a notch in the ends.  I don't know if this was needed or not, but it seemed a logical idea to make sure they came together nicely and couldn't twist out of allignment.  I then lined each ring with insulting tape (  ) to make them grip the tube better, and also to stop it marking the paint to much...

They went onto the telescope fairly easily, I had to take it off the dovetail of course and I think there could still be a bit of positioning to complete.  I've replaced one of the original clamp bolts with cycling style 'quick release' that was in my collection of bits,  and the other bolt of the clamp (the one between the rings) is just loose enough for the tube to slip.  When I want to reposition the tube, I'll just undo the quick release, turn the tube and the relock.

 

At present, the brackets on the rings will foul on the dovetail and not pass it.  I doubt this will be an issue in use, I reckon I'm unlikely to need 360 degrees of turn, but I can probably sort it out if I need to.  It seems to work OK, I won't know for sure until it's used properly on a session.

Total cost to me:  One day in the shed + £6     

 

 

[fozzybear]

Excellent job done their on fabricating those tube rings . 

[CraigT82]

Nice. The use of electrical tape as a ring liner is new to me but makes perfect sense as a grippy interface 

The use of a bike QR Lever is inspired! 

Edited April 21, 2021 by CraigT82

[fozzybear]

1 hour ago, Capt Slog said:

At present, the brackets on the rings will foul on the dovetail and not pass it.  I doubt this will be an issue in use, I reckon I'm unlikely to need 360 degrees of turn, but I can probably sort it out if I need to.  It seems to work OK, I won't know for sure until it's used properly on a session

you won't need to. I modified an additional  tube ring for my 150PDS to do just what you have achieved the only Mod I had to make was recess the hinged section fixings on the dovetail rings and 3rd ring otherwise I could not rotate my tube  

[BCN_Sean]

Really liking the idea of the quick-release lever on the ring, might have to borrow that one for my current tinker project!

Overall, though, looks really neat and like it was bought not rattled up in the shed.

[iapa]

Very nice, but, I just can’t see how things fitted with the rollers to get the curve - I’m not bright enough to work it out.

[Capt Slog]

11 hours ago, iapa said:

Very nice, but, I just can’t see how things fitted with the rollers to get the curve - I’m not bright enough to work it out.

The two pale rollers are 'fixed' and the brown one can move closer to the gap between them.  It starts off so that the metal is just touched by all three, and then the brown roller is gradually pinched in tighter for each pass of the metal.  The metal HAS to go around a corner each time, and so takes on a bend.

[Capt Slog]

12 hours ago, BCN_Sean said:

Really liking the idea of the quick-release lever on the ring, might have to borrow that one for my current tinker project!

Overall, though, looks really neat and like it was bought not rattled up in the shed.

Thanks.

I have quite a collection in my shed...

 

Not easy to see, but there's a lathe, pillar drill, bandsaw and two vises.  Under the bench is a guillotine and a welder.  The shed was a 21st birthday present to my late father, he died 20+ years ago, and there are still a lot his tools in there (but everything mentioned above are my additions).  Where that vacuum cleaner sits, there is now a little homemade stove, it was very cosy yesterday.

I'll have to clean it, yet again, that photo was following a spring clean over a year ago.

[maw lod qan]

Am I correct thinking the movable roller is mounted on the one C clamp to make it adjustable?

That's bloody genius thinking!

Edited April 22, 2021 by maw lod qan

[BCN_Sean]

7 hours ago, Capt Slog said:

...

I've got shed jealousy! At best now I'm managing snatched hours here and there on the kitchen table... The downside of moving in to a first floor apartment!

[Capt Slog]

3 hours ago, maw lod qan said:

Am I correct thinking the movable roller is mounted on the one C clamp to make it adjustable?

That's bloody genius thinking!

I fibbed slightly for ease of explanation.  In fact it's the pale double rollers that are mounted to a swinging arm, and they close in on the brown (rusty) single roller.  But the principle is the same, and although I accept it is genius, it's certainly not my idea.  I've used a 'real one', that's how I know what to make.  It's actually just a collection of bits held together by the jaws of the vise.

Here is the set-up again.  In the first picture the rollers are fully open, but just in contact with the work piece, this time it's a length of mains cable...

 

In the second pic, the roller have been pinched together with the C-clamp (usually known as a G-clamp here in the UK), and the wire has been fed back and forth a few times...

When I did it for real on metal, it takes quite a bit of effort to turn the roller.  The forces were such that it had a tendency to 'burst' apart, so in the original photos you can see an extra clamp holding the other clamp in place.

 

@BCN_Sean Sorry, I'm retired now, I can play all day but it still looks a shameful mess.   

Edited April 22, 2021 by Capt Slog

[maw lod qan]

Nothing to be sorry about.  Semiretired here only work 3 days a week.

I love to tinker and "try" to build things!

[BCN_Sean]

57 minutes ago, Capt Slog said:

@BCN_Sean Sorry, I'm retired now, I can play all day but it still looks a shameful mess.   

Ah don't worry about that, nearly every week my other half comes in and starts complaining about the mess in my office (hers is pencil aligned perfect); and every time I'll tell her "A tidy desk is a sign of an empty mind..."

[fozzybear]

7 minutes ago, BCN_Sean said:

Ah don't worry about that, nearly every week my other half comes in and starts complaining about the mess in my office (hers is pencil aligned perfect); and every time I'll tell her "A tidy desk is a sign of an empty mind..."

I came home one day and all my astro equipment put into tote bins to my horror. The kids have left home and a spare bedroom to store my stuff I thought. the horror 😱 

[BCN_Sean]

1 hour ago, fozzybear said:

I came home one day and all my astro equipment put into tote bins to my horror. The kids have left home and a spare bedroom to store my stuff I thought. the horror 😱 

My other half can be like that, and she'll just throw everything in to places where she thinks is right; one day she put all the resistors I've got together in one tupperware (they're all blue, right?)... That was not what I had planned for that weekend!

[fozzybear]

42 minutes ago, BCN_Sean said:

My other half can be like that, and she'll just throw everything in to places where she thinks is right; one day she put all the resistors I've got together in one tupperware (they're all blue, right?)... That was not what I had planned for that weekend!

they never learn't about organised chaos. 

[fozzybear]

anyway back on track not to hijack the op's thread

[fozzybear]

we have one of these at work "cintreuse rouleuse" 

[wookie1965]

Very interesting I just used mini electrical trunking and a jubilee making kit. 

[Capt Slog]

19 hours ago, wookie1965 said:

Very interesting I just used mini electrical trunking and a jubilee making kit. 

If I'd thought of mini electrical trunking, I might  have done the same.  I was trying to think of a source of plastic which could be formed and clamped to the tube using jubilee clips, but curtain track and building type trims was where I went with that, and neither looked right.

I also knew that I could make the clamp for less than the price of the jubilee clips alone, not that money is that much of an issue, it's just that I've just worked to a budget for a long time, and habits are hard to break.

[wookie1965]

I too work to a budget a set of rings was to me too expensive so I went down the trunking route. £5.73 all in not as good as your solution or workmanship but it was good enough and slipped really well. 

[Capt Slog]

^^^^^^^Excellent!

 

There's a possibility that we might be related.

[Len1257]

I've used a pair of these https://www.hobbycraft.co.uk/bamboo-embroidery-hoop-8-inches/638405-1000 either side of my tube rings. They can go at the outer ends of course so you don't have to remove the dovetail.

[wookie1965]

2 hours ago, Len1257 said:

I've used a pair of these https://www.hobbycraft.co.uk/bamboo-embroidery-hoop-8-inches/638405-1000 either side of my tube rings. They can go at the outer ends of course so you don't have to remove the dovetail.

I did exactly the same but found turning the OTA sometimes was jerky so went the trucking route, I still regret selling that scope