Cable routing options

[gnomus]

I've recently taken delivery of a new mount (Mesu). I would like some thoughts on how best to route all my cables so that they do not catch or snag. So far I have tried 3 or 4 different systems and have not been too happy with any of my solutions.

I would be grateful if folks could share their thoughts as to the best way to deal with the mess of cables in a typical imaging rig. Photographs would be especially useful.

Thanks in anticipation.

[ChrisLX200]

What I do is run the cable loom up towards the centre of the mount and anchor it there (use a cable ties or some industrial Velcro). That takes the weight of the cables off the camera and stops it pulling on the focuser. Then I form a loop and make another anchor point attaching the loom to the top of the RA axis casing (a bit of the mount that doesn't move during slewing/tracking). The loop is long enough to allow the mount to point anywhere and also perform a meridian flip. During a full model run my mount will 'flip' about 25 times as it slews to various points in the sky, and I've done around 20 full model runs now without a problem so I'm quite confident the system works.

ChrisH

[NigeB]

Hi Gnomus,

I took the same approach as Chris; I found I had to extend some of my cables to make this work properly in my setup.

One thing I found with my Mesu was that I was getting a few snags and nips. I've tried to become a little more disciplined in the way that I stow the RA and Dec hooks since then. But I was also not happy with the appearance of the cable bundle, and the spiral wrap that you can buy never looked quite as good as I wanted. So I ended up going to the aquatic section of my local garden centre and buying three metres of pond hose (20 - 25 mm diameter, black spiral reinforced stuff) which easily accommodates all the cables and USB connectors you're likely to need. A single, beefy pipe looks much better (to my eyes) than a bundle of different types of cable, and it can't fall into small gaps and become trapped.

Nigel

[perfrej]

Keep it tidy, boys and girls! Nylon braided sleeves are your friends

/per

[gnomus]

Firstly, thanks everyone for your help.

That is certainly neat Per.  As far as I can tell from the photograph, you have used these plastic cable ties to attach the sleeve.  Do you have a cable tie looped through a spare hole on the dovetail plate too?  Does it make any difference which side of the scope the cables route along (you have it on the left side - as viewed from the camera end)?  

Chris you seem to have it attached to the dovetail plate at the rear, correct?

Nigel: that is what I am finding too.  The 'top plate' is enormous compared with my CGEM and I am a little anxious that something is going to catch.  

At present, I have (nearly) all cables running up to the midpoint where they are velcroed onto the underneath of my guidescope rings (I am sure this is sub-optimal).  Cable length is an issue - I am trying to avoid getting them too long as they already have to go through 2 USB powered hubs to get to my warm room desk.  The main problems have been the ridiculously short leads on the dew-heaters and the short power leads on my Atik Camera and Filter Wheel.  I think I have solved the first of these problems with this: http://www.amazon.co.uk/gp/product/B00FJ2LNFA?psc=1&redirect=true&ref_=oh_aui_detailpage_o01_s00   As to the second, I think it would be be better to avoid a female to male extension and just make up new 3-4 metre power leads.  I'm currently trying to source the power plug which seems to be 5.5mm 2.1mm short (and I assume that they are tip positive).

I'm wondering if I might be able to find a non-moving point on the Mesu to which I can attach the loop (à la Chris).  I hadn't thought of the 1" diameter pond hose.  I think this is what I have carrying the cable that run under my observatory floor (it is black and ribbed - correct?)  Nigel: have you found any difficulty with this causing drag because of its relative inflexibility? 

Keep these suggestions coming please.

[ChrisLX200]

I bought a couple of these but have yet to fit them: http://www.amazon.co.uk/gp/product/B0096PUZ7S?psc=1&redirect=true&ref_=oh_aui_detailpage_o03_s00

My cables currently are just taped together into a bundle but that makes the loom fairly stiff, using a sleave would be better I think.

In the photo the first attachment point is to a patch of Velcro stuck onto one of the scope rings. I need to remove and re-mount each session so the whole lot needs to be easily dismountable without disturbing anything. After many uses the velcro came unstuck from the ring so I replaced it with a small cable tie. The second attachment point is more stable and uses a larger patch of Velcro so I don't expect a problem with that one.

ChrisH

[perfrej]

Yep, the sleeve is braided nylon and there are cable ties around the CW shaft and on the Losmandy plate (spare hole). No snags here

/p

[gnomus]

Thanks again Per. I've got hold of one of these sleeves. I'm going to have to make a little button hole in it to release my electric focuser cable about half way down. I've found a couple of spots on the dovetail plate (front and rear) where I can put a cable tie. I may also consider trying a cable tie around the bottom of the clamshell of my Tak FSQ85. I think I'm nearly there.

[cfpendock]

I use sleeves as Per above.  They keep everything tidy, and it means I only have a single sleeve returning to the shed, as shown on the attached.  The box on the ground is for the focus control and a couple of USB hubs.

Chris

[NigeB]

I'm wondering if I might be able to find a non-moving point on the Mesu to which I can attach the loop (à la Chris).  I hadn't thought of the 1" diameter pond hose.  I think this is what I have carrying the cable that run under my observatory floor (it is black and ribbed - correct?)  Nigel: have you found any difficulty with this causing drag because of its relative inflexibility? 

Hi Gnomus,

Yes, it's black with a spiral-wound rib reinforcement - this sort of thing:

http://www.pond-planet.co.uk/ponds-pond-pipework-fittings-flexible-pond-hose-flexible-pond-hose-25mm-p-374.html?gclid=CjwKEAjw4s2wBRDSnr2jwZenlkgSJABvFcwQGnl2LhqfIXrwN1JJ-xSiARunTZHKq4PPXHcPJDl7ExoCrN7w_wcB

So far, no dragging problems that I've detected - I've got a generous loop which helps. The ribbed reinforcements are more of a worry, but no issues yet. Keep in mind that I don't use my system robotically - I'm always in the observatory when the scope is slewing to target, and I only leave once I've set an imaging sequence off.

I like Per's braided tube approach - I guess it's the same type of stuff that the Mesu's own cable harness is wrapped in. I was a bit of a cheapskate when I bought the hose, and it has the advantage of being able to thread new cables in without disrupting the existing ones. But the braid is narrower and smooth, so probably worth the extra cost.

Oh dear. I feel more expenditure coming on...

Nigel

[NigeB]

I use sleeves as Per above.  They keep everything tidy, and it means I only have a single sleeve returning to the shed, as shown on the attached.  The box on the ground is for the focus control and a couple of USB hubs.

Chris

IMG_2153.jpg

Hi Chris,

Where did you source your sleeving?

Thanks

Nigel

[cfpendock]

Hi Chris,

Where did you source your sleeving?

Thanks

Nigel

http://www.cablenet.co.uk/catalogue/cable-sleeving.htm

I got the 25mm sleeve, and it contains two USB cables and two fairly hefty power supply cables for the scope, camera, and dew heater.  the good thing about the sleeving is that it is expandable - hence you can actually feed through something considerably bigger than 25mm - the sleeving subsequently contracting to fit snugly around the cable.

Chris

Chris

[ollypenrice]

Keep it tidy, boys and girls! Nylon braided sleeves are your friends

/per

   

Per is Mr Cable. I am his nemesis, Mr Mess, not 20 metres from the picture above.     

What's my excuse? USB cables are a heap of junk and a ruddy nuisance and frequently fail for reasons closely guarded by the IT industry. When they fail I want to replace them. Life is too short for autopsy or coroner's report. In the bin, replace and get on with it. Do I want to unbraid a braided cable, unravel a ravelled (is that a word?) cable and spend two hours re-faffing the whole lot? Here's an Olly Penrice Not-Very-Guarded secret: I do not!

It must be said that, as custodian of Per's neatness, it has given me no problems to date and it does have a certain charm. But when you have to replace a cable (and after ten years of this with numerous rigs I know that sometimes you do) I like accessibility.

Olly

[gnomus]

Too late I'm afraid Olly. I have just finished making the buttonhole (for the focuser cable and heater cables) and have zipped the nylon sleeve around all of the spaghetti. It's not quite as neat as Per's, but it is an improvement. Zipping, unzipping doesn't take too long if you need to swap something out. And with my prostate I've got pretty quick with the old zipping/unzipping malarkey.

[ollypenrice]

Too late I'm afraid Olly. I have just finished making the buttonhole (for the focuser cable and heater cables) and have zipped the nylon sleeve around all of the spaghetti. It's not quite as neat as Per's, but it is an improvement. Zipping, unzipping doesn't take too long if you need to swap something out. And with my prostate I've got pretty quick with the old zipping/unzipping malarkey.

Heh heh, a great post.

Per and I will shortly have a chance to fight this out over pre-christmas Champagne. (His round.      )

Olly

[strutsinaction]

Hi Chris,

Where did you source your sleeving?

Thanks

Nigel

What about this?

http://www.ebay.co.uk/itm/150899408011?var=450115825431

Regards

John

[skybadger]

Hi

the answer to braided cable is to use desktop umbilical. This looks like a spinal cord and you can insert and remove individual cables as you need. Mine comes up from the south side of the mount and attaches to the dec head so all cables rotate with the mount. The only cable not meshed is the dec drive cable.

Why do these come out rotated when they went in straight ?

regards

Mike

[perfrej]

Without passing judgement, I find the desktop stuff snaggy. The nylon is smooth as silk and doesn't snag anywhere...

/per

[perfrej]

Heh heh, a great post.

Per and I will shortly have a chance to fight this out over pre-christmas Champagne. (His round.      )

Olly

Yes, we shall... As for USB cable failure, I can report that as a developer of technical products I have had reason to dig into the specifications of said animals. The cheap connectors are actually not specified for more than a thousand or so connect/disconnect events. The good thing about having a "manufactured" umbilical with nylon sleeve is that you connect once, then more or less never disconnect. Hence, a long life lies ahead for the animal.

Anyway, luggage permitting, I'll bring something a bit of age and we'll hack out the cable duel (which I think may come to a tie).

/p

[NigeB]

Hi Gnomus,

Well, having dived in here to tell you my approach, I've looked at the braided cable options suggested by others and I think it's a better bet - neater than my hose, and probably less prone to snagging. 

Once again, demonstration of the direct relationship between posting on SGL and spending money...

Nigel

[perfrej]

Yes, there is an exponential relationship for sure. Ask advice, then spend the money

[mcolbert]

Yes, we shall... As for USB cable failure, I can report that as a developer of technical products I have had reason to dig into the specifications of said animals. The cheap connectors are actually not specified for more than a thousand or so connect/disconnect events. The good thing about having a "manufactured" umbilical with nylon sleeve is that you connect once, then more or less never disconnect. Hence, a long life lies ahead for the animal.

Anyway, luggage permitting, I'll bring something a bit of age and we'll hack out the cable duel (which I think may come to a tie).

/p

 was that meant deliberately Per?  A tie?

and the other thing you wrote;

"Yes, there is an exponential relationship for sure. Ask advice, then spend the money  :)"

much better than the other way around! and subsequent sad / horror stories.

michael

[perfrej]

 was that meant deliberately Per?  A tie?

and the other thing you wrote;

"Yes, there is an exponential relationship for sure. Ask advice, then spend the money  :)"

much better than the other way around! and subsequent sad / horror stories.

michael

A tie in terms of no one being able to convince the other was what I meant You also have to consider that the bubbly drinks of Epernay may be in the equation as well...

The exponentiality of the advice to spend ratio can be quite horrific. Perhaps someone contemplated a relatively low cost CCD camera and asked here first. Said person would, for example, get two coinciding pieces of advice and subsequently buy a camera four times as expensive as the one originally contemplated. Two pieces of advice, four times the price. s = o * a², where s is amount finally spent, o is original contemplated price, and a is the number of coinciding and convincing pieces of advice...

/p

[gnomus]

A tie in terms of no one being able to convince the other was what I meant You also have to consider that the bubbly drinks of Epernay may be in the equation as well...

The exponentiality of the advice to spend ratio can be quite horrific. Perhaps someone contemplated a relatively low cost CCD camera and asked here first. Said person would, for example, get two coinciding pieces of advice and subsequently buy a camera four times as expensive as the one originally contemplated. Two pieces of advice, four times the price. s = o * a², where s is amount finally spent, o is original contemplated price, and a is the number of coinciding and convincing pieces of advice...

/p

You are neglecting one important factor. That is as follows:

1) Post here seeking advice

2) Get useful advice

3) Ignore advice and go with first instincts

4) When it doesn't work as expected, re-read (2)

I find that this procedure helps to multiply expenditure splendidly.

[perfrej]

Yes, so true