Cabling through the mount of PMX

[Paul Haese]

I wanted to discuss an observation I have made of the wiring through the mount of the PMX (latest version)

Hmmmm, how to say this without being totally insulting. Was Software Bisque high the night they designed this aspect of their new mounts. In the images below you will see cables hanging out the front of the mount and out the top and the back. Pay attention to the image with the cables coming out the front of the mount. Its not terribly good but you can see it is a tight fit.

Now to get those cables through the mount you have to use a cable tie (which they supply) to fish the cable around the actual Dec shaft which has a space of around 15mm all the way around it.

The real trouble of this is when you have to feed a lot cables through it becomes very congested (given there is already cabling in that space for the versa plate) and it finally becomes impossible to feed any more cables through it. Well at least my levels of patience have been expelled by the fourth cable and there is little space to get everything in to the space.

The other side to this is that cables such as the STXL power cable which is supposed to go through a mount will not fit through this space with all the other cables in place. Even if I removed all the other cables I put in first, it would not fit through because there is not enough room to swing the head of the power cable. I was going to say a cat but that would clearly not have fit.

Why on earth did SB think this type of cavity would be better than the PME type which you can get your hands in to run cable through?

Anyway totally stunned and a little bewildered.

How has other people got past this issue? Would be really interested to know.

[PRejto]

Hi Paul,

If I were you I'd not run the power cable through the mount! There is already a camera power cable running to the versa plate. It's unpowered but there is a socket at the bottom of the mount where you run your camera power in. SB sells camera power leads with their plug on one end and the camera power plug on the other. Or, you can purchase a lead with their plug on one end and bare wires on the other so you can add your own plug. That's how I did it and it works fine! I think 4 wires is too many, but I've got 3 running through my mount (but not a heavy power lead!).

Peter

[Logieberra]

(Post edit - incorrect information removed)

[Logieberra]

Paul, it's straightforward once you get the knack :)

[gregbradley]

I don't use through the mount cabling but do use the power outputs and USB sockets on the end of the Versaplate. Better check the manual to make sure you are doing it right as I can see some chopped off cables if not done correctly.

I only have 2 usb cables coming off the mount. One for the camera and one for the mount.

Greg.

[Logieberra]

Look at this-

[Paul Haese]

Thanks guys, but I followed the instructions to the letter in the SB manual. It says to run the cables around the shaft and leave 8 inches of play. The cables poking out have been pushed back in and now it rotates from one hard stop to the other without any dramas. There is just not enough room in these mounts.

Thanks Logan for the video I will take a bit more of a look.

[Paul Haese]

Logan I looked at your video but the mount cables run around the outside of the dec shaft. In the manual it says to run the cable around the shaft too with 8 inches of play. When the dec axis rotates doing it your way the cables could be broken.

[Paul Haese]

That's a bit impractical for me. I need a coms cable for the rotator, the focusor, camera and power cable for the mount hub pro.

You cannot run cables outside the mount if you want to run the scope remotely. There are just too many things that can snag up.

[Logieberra]

Good luck :)

[Peter.M]

Paul you fool obviously your supposed to cut the ends off the cables before you pass them through the mount!

[Paul Haese]

Quoting from the SB PMII and Paramount users guide.


Insert the cable tie into the RA Cable Conduit until the end is visible through the cable conduit access cover. The cable tie (and cable) must be threaded through the outside of the internal shaft and cannot pass directly through the lower access holes. Rotate the cable tie so that its natural bend forces the tie toward the outside of the shaft. Use a pair of needle-nose pliers to grab the end of the tie then pull the cable all the way through the right ascension axis.
8. Remove the cable tie and feed the end of the cable up the declination shaft, through the upper access hole until it appears at the top of the declination axis.
9. Run the top end of the cable through the access shaft that is machined into the top of the declination axis and the Versa-Plate, out to the left side of the Instrument Panel (page 55).
10. Once the cable has been passed all the way through the mount, make an 8-inch loop in the cable and carefully tuck this loop inside the outer shaft of the declination assembly to allow the declination axis to rotate completely without any interference from the cable itself (see Figure 9). Rotating the declination axis from hard stop to hard stop more or less does the work for you, but allowing additional slack in the cable is recommended.

Now from my reading that means passing cable directly through the mount is not what is required. Feel free to prove me wrong. I want to get this right.

[Paul Haese]

:lol::lol: Needed a good laugh, well done Pete.

You should see it all now mate, looking very shmick.

[Logieberra]

Paul, I re-read the material. You're spot on. But, your cables are massive. The SB optional cables that Peter referred to are your best bet, which make use of the internal power extension lead so to speak, already within the MX, and come with connectors for the major CCD brands.

I personally use the 12v output on the versaplate. It's low amp but Robofocus loves it. One less internal cable!

[Paul Haese]

In the end I only have USB cables in and the power cable for the mount hub pro, so no harm there. I had a cable which I adapted for the my STL11 which also powers the STXL. So the big cable for the camera is not in the mount.

I might consider using the USB outlets and removing one or two of the cables later though.