4 replies to this topic

[MountainAir]

I recently tried running a USB 3 cable through my iOptron CEM40's internal cable guides.  I only had one night with it since, but I noticed slightly worse guiding and some slight difficulty balancing it in DEC.  This is due to the fact that the cable has to twist as the mount articulates, and this adds some resistance.  If I spin DEC without the scope attached, I actually see it reverse and spin back at me.

 

I have not yet found any super-thin, flexible USB 3 cables yet.  I'll test this configuration a bit more before deciding to keep it or not.

Edited by MountainAir, 17 January 2021 - 12:02 AM.

[Midnight Dan]

I recently tried running a USB 3 cable through my iOptron CEM40's internal cable guides.  I only had one night with it since, but I noticed slightly worse guiding and some slight difficulty balancing it in DEC.  This is due to the fact that the cable has to twist as the mount articulates, and this adds some resistance.  If I spin DEC without the scope attached, I actually see it reverse and spin back at me.

 

I have not yet found any super-thin, flexible USB 3 cables yet.  I'll test this configuration a bit more before deciding to keep it or not.

Unfortunately, thin cables often translate to lower quality cables.  It's really hard to find cables that are good quality, flexible, and most important, remain flexible in cold weather.

 

ZWO ships flat USB cables with their cameras. They seem pretty well made and are quite flexible, even in the cold.  You might try looking for something like that.  Also, I'm not sure how the internal cable guides work, but if there's room, leaving some slack inside might allow for more freedom of movement.

 

-Dan

[MountainAir]

Unfortunately, thin cables often translate to lower quality cables.  It's really hard to find cables that are good quality, flexible, and most important, remain flexible in cold weather.

 

ZWO ships flat USB cables with their cameras. They seem pretty well made and are quite flexible, even in the cold.  You might try looking for something like that.  Also, I'm not sure how the internal cable guides work, but if there's room, leaving some slack inside might allow for more freedom of movement.

 

-Dan

Before setting up tonight, I took the cable I had and twisted it aggressively several times.  I don't know if it helped, but my guiding tonight has been better.

 

I did have a ZWO cable handy, and much to my surprise it is more flexible then the other "round" cables I tried.  I didn't really consider the flat cables because it seem like there would be more opportunity for it to "hitch" inside the mount... but I'll give it a shot!

[MountainAir]

For what it's worth, the flat ZWO USB3 cable seemed to have less of an effect on guiding than the round, rubbery cable I was using.  Hopefully this helps others who run cables through their mounts.

 

Ultimately, I am going to mount my Pocket Power Box Advance and RPi4 to the RedCat itself, with the help of a 3d-printed spacer.  Then I won't have any cables whatsoever coming off the DEC axis (the PPBA will be powered by the 12V plug built into the DEC saddle; I'll be way under the amp limit).  I may also add an EAF at some point, though I don't often need to tune the focus on the RedCat during a session.

[Linwood]

Are you going up the bottom, or from the end?   Some people don't even notice the pop-out cover.  Pick the one with the best angle and leave a loop in the cable below it to take up the twist, don't make it too short.  The area below doesn't hang or grab anything.

 

I actually removed the saddle USB2/st4/power interface plate and removed the wires from inside, to provide more room in the axis (I did not need any of those things)  Those wires were not well secured and organized inside the mount.  You might look at those also, make sure none of those are pulling tight as you rotate the axes.