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How to avoid cable snagging ?

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I've been reading on a few threads recently concerning poor autoguiding being possibly caused by cable snagging. Assuming one cannot eliminate cables altogether what is the best way to avoiding the cables snagging and dragging ? Is it best to use loops in the cable, use cable clips or velcro to clamp the cables to the tube and mount ?

I know each persons setup will be slightly different but there must be a common theme as to what works and what doesn't, so hopefully looking for some advice on this.

Many thanks, Andy

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That sounds about it...

You want enough "slack" to allow each axis a full range of motion whilst supporting the weight as much as possible.. you want to avoid cables dragging on anything whenever possible...

Also look into the cable wrap function on the mount controller if it has it as this stops cable getting wound up by limiting the rotation in any direction...

Peter...

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I use kitchen twist ties to hold cables to the telescope, dovetail bar and to one another and always pass them in between the heads of the two retaining bolts that hold the dovetail in place - this ensures that the cables 'rotate' around the centre of the mount and don't just hang free. Kitchen twist ties will also come undone easily if they're put under too much pressure - rather the cable ties slip than the cables catch and get damaged.

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To start in dream land, Astro Physics really looked at this with the Mach1 GoTo. It routes all camera cables in a really clever way through the mount. If you are casually wealthy, just - ahm - buy one!!

Back here on Earth I think the thing is to bunch cables together and just look carefully at where they are and where they will be in two or three hours. MatrinB had some nifty velcro ties and I have used wire ties to hold things together. Because I have to be flexible (guests bring their own kit and mix and match it with mine) I don't want all my cables permanently bunched.

Also, have a think about which way to route your USBs, depending on which side of the sky you are imaging.

During a run stop the exposures from time to time to ensure that nothing is about to snag.

I am sure there will be better ideas and I look forward to hearing them!

Olly

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Ideas - yup... cable wrap if you've got it on your mount - could eliminate cables using wifi - or slew in reverse direction after each object. Can allways make sure you've got enough cable spread loose by the scope - or pop out and keep checking it between exposures. Can't think of anything else right now :)

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At the moment I loop each cable around the bottom dovetail leaving a little slack to the guidecam/DSLR/Dewstraps, I loop it there because as the mount moves there is very little real movement at that position.

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cable wrap if you've got it on your mount

Unless you're using a Celestron CPC. "Cord wrap" on these mounts does exactly what it says on the tin ... one way to absolutely guarantee that the scope will reel in anything attached to it. First thing I do every time is to disable the damned cordwrap function. [Otherwise the scope is just about perfect.]

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If you are worried about cable snags the only way around it is not to do imaging :):)

it will happen

my setup is in a dreadful state

3 ccd's all with at least 2 cables each

power leads

auto guide cable

dew bands

remote focuser's

in other words a right rats nest

I must tidy it up

again !

I'm not trying to be flippant after a night of imaging and a couple of slews the cables can be a nightmare (remember any 2 cable left on their own will tangle)

just keep and eye on them take as many cables back to the centre of the mount so as to minimise the problem

Steve

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I got around the problem by knocking up a 'hub' that sits between my guide scope and my main scope on the centre of the mounting plate.

This means that all of the cables for guider, cam, filterwheel, dew bands etc move with the scope and can be kept short. The only ones that don't are made into looms using sleeving and heat shrink. One taking the eqdir cable, guide cable and power to the mount and one taking a USB, 2xCAT5 and 12v DC to warm room (aka tent)

I'd post a link to my home made hub thread, but I'm using tapatalk and haven't worked out how to do that yet.

Hth

Mike

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Mike sounds organized! One thing, though; I find USB cables have a limited life expectancy and I chuck them away pretty regularly. The slightest contact difficulty can ruin a set of images or a night out so I sling 'em on suspicion. I wouldn't want to have to rebuild too many combined cables as a result.

WiFi? Sounds nice but also sounds like one more thing to go wrong... But then cables go wrong. Oh dear, oh dear.....

Olly

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I put an elastic band round my OTA, I then form a large loop in the cables and retain them under the elastic band, that way should anything go wrong that puts strain on the cables, they pull free from under the elastic band which gives them plenty of slack and me time hopefully to sort it before any permanent damage can be done.

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I don't have imaging cables, just the power cables for the drive motors, but as others have said, I use kitchen twist ties to keep things together so they don't get too snarled up.

Rik

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From a non technical point of view, being as imaging is usually a pre-planned exercise, perhaps it would be a good idea to manually run the scope through its intended path and check the cable positions before you switch the lights off or before it gets dark.

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From a non technical point of view, being as imaging is usually a pre-planned exercise, perhaps it would be a good idea to manually run the scope through its intended path and check the cable positions before you switch the lights off or before it gets dark.

Indeed it is... and when your using the mount to track Satellites or the ISS this is "essential" as it isn't just a slow tightening of the cables then....:)

Peter...

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This works for me and reiteraties what some others have said.

1) feed cables from both cameras, focusers and what not over the saddle of the mournt and adhere in place with electrical tape. You don't need to leave much slack, just enough to enable focusing. Make sure set up is balanced first.

2) take cables to RA axis above counter weight shaft and stick in place with electrical tape. You need to have a loop of cable between the saddle and the RA axis to be taken up as the scope slews in dec. swing the dec through full travel in dec in both directions and make sure you have enough slack cable.

3) tidy up these cables by binding them together - velcro ties work very well.

4) if you are using a pier fix the cables to the pier using electrical tape al loop sufficient to allow for a full swing of RA

Tidy cables isn't just about avoiding tangles, all those cables hanging off your kit can make a variable pull on your mount and affect tracking

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Thank's for the many helpful responses, no doubt other people will have also benefitted from this thread.

My main area of concern which hopefully I can now address before it happens was making sure the cables do not drag so altering the tracking rate while imaging rather than winding them round the mount.

Andy

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mine used to look like this Astrophotography but after tidying they are as in the attached pic. Seven wires here and they are normally anchored closer to the mount adaptor plate.

Dennis

post-15519-133877436626_thumb.jpg

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