Installation of the EQ3 SynScan Upgrade

I just got the Skywatcher EQ3 SynScan Goto Upgrade. It comes with lots of documentation. For example on how to wire up the controller boxes. However, it does not explain, how to mount the motors, that come with the upgrade box! And neither does the EQ3-2 manual.

Hence I will describe how I installed the motors. I don’t know if I did it correctly, but my SynScan seems to work, so I cannot be far off. If you use this description for assembling your own upgrade kit, you do it on your own risk! You have been warned… By the way, one screw was left over in the end. But isn’t it always?

So the first thing to do is to remove your telescope, your counterweights and the flexible tuning knobs. This leaves you with your tripod and your EQ3 mount. I am describing this for my EQ3-2 with aluminium tripod (rectangular legs).  If you have an EQ3, NEQ3 (round legged steel tripod) your mileage may vary. The manual first tells us to mount the holders for the motor controller and the SkyScan controller. The first one is a bugger: it’s made for the round legged tripod. But do not fear! We can use a rubber band to help it stay affixed to the aluminium legs. Make sure the ground plate has contact with the aluminium legs!

Next up are the gears for the motors. They are not labelled, so I had to figure them out myself. The big one is for the Dec motor, the small one for the RA motor. The motors themselves also were not labeled. The naked one is the RA motor, the boxed one is the Dec motor.

Ok, so we will begin with the RA motor. This is the place where it will be mounted:

There is already a screw here, and the axle for the gear. Mount the RA gear on the axle, so that it fits nicely with the end of the axle. This will be the right height for the RA motor gear. use the two small inset screws to firmly attach the gear. Make sure not to make it to loose, nor to tight! Then you can attach the RA motor as pictured on the mount point. The mounting plate will fit snugly into the corner of the mount, and will keep the motor in place. You can jiggle it around before fastening the screw, so that the two gears fit well together. Check the photos on how this should look from the front and behind.

You noticed that there is a cable hanging from the RA motor. Find the black casing with the two DIN sockets. It will have a fitting socket for the dangling cable. Attach both and put the casing on top of the motor and the gear assembly. Take good care to carefully wrap the coloured cables into one corner of the black box! They fit in there, without any trouble, but you have to find the right corner. If you managed to fit the box, you will see two screw holes ligning up on the front and top of the box.

Use the two tiny black screws to fixate the RA box. The top screw might be hard to reach, even with the small screwdriver that comes with the kit. I used a ratchet with a PH bit for this part.
Ok, that’s the RA assembly. Now for the Dec motor. The mounting point for this is on the other side of the EQ3. See the picture for details.

The mount point where the screw belongs is circled. first, attach the Dec gear. Leave about 1/2 mm space between the mount and the gear. Again, there are two small inset screws to fasten it. You can adjust the gear again later, if needed. Now attach the motor using a screw and a washer (they come with the upgrade kit). With both motors, test if the gears touch tightly enough, so they will not skip, and they will not have too much friction either. See the picture for a view of the mounted motor. Strangely, I could not get the Dec gear to be parallel with the motor gear. But still, the whole thing works. I might try to re-align it later.

That’s it! Now you only need to attach all the cables, as described in the manual, and you’re ready to go, or to go-to. 🙂 I still had one thing left: a black soft rubber thing. If anyone knows what it is for, please drop me a note. It was not described in the manual either.

18 thoughts on “Installation of the EQ3 SynScan Upgrade”

  1. I am using a rechargeable 12V lead-gel battery (35 Ah) using an adapter with crocodile clips on one end and a cigarette lighter socket on the other end. Works like a charm. These two things plus the charger for the battery cost 50 €. You can get it for a bit less, if you take a no-name battery, but I opted for a Panasonic one.

  2. You've provided a real service here. I'm planning to obtain the kit for use on a CG-4, which I am told is the US edition of the EQ 3-2. I still haven't found a kit in North America, though the Canadians may have it. It seems a bit silly to have to import one from Europe. But if I succeed, I expect to be making heavy use of your post.

  3. There should be some official Synta importers in the US… Anyway, good luck buying the kit, and good luck assembling it! Please do report back when you were successful, and if you had to augment my instructions.

  4. Update: Skywatcher says it is not available in North America. Teleskop-Service sells it in Germany for 325 E plus shipping. Would you suggest any alternative sources? Thanks.

  5. TS has the best prices in the Euro zone. You might want to check out UK stores, though. Depending on the USD to GBP exchange rate. I have no experience with those, though.

  6. Der neueste Bericht: I obtained the kit from Green Witch Astronomy in UK (highly recommended for North American customers). I succeeded in assembling it, thanks to your road map. It did take considerable trial and error to get the gears working smoothly and not making alarming noises during rapid slewing. I can't say I understand the backlash correction system. It seems to do weird and wonderful things to the slewing. Nor can I add any insight concerning the piece of sponge rubber. It is obviously meant to be stuck on somewhere with that strip of double sided tape, but I can't imagine where.

    Tracking appears to work fine, but GoTo is another story. It seemed to work initially, though it would tend to drift off after a few GoTo's. However I soon started to get more and more alignment failures, and now that's all I get! I am observing in the early evening, and the autoselected stars are Arcturus, Vega, and Altair. Arcturus is always way off, even though I start with the scope aligned to the polar axis and pointing at Polaris. The 2nd and 3rd stars come in pretty close, but the alignment still fails. I haven't a clue as to what the problem might be. Any insights you might have would be greatly appreciated.

  7. Weiterer Bericht: I was able to do a successful 2-star alignment and follow that with a successful 3-star alignment. Unfortunately, the fog rolled in before I could determine whether it was repeatable.

  8. Nur ein nachtraeglicher Einfall: Might the little rubber piece have a use in attaching the holder for the motor controller to a rectangular tripod leg? I can't quite visualize how it would work, and since the legs on my tripod are tubular, I can't try it.

  9. EVHAP: Maybe you're right with the rubber piece. I have to try that, if I can find it. 🙂 I used the mount a few times the last months, on my balcony, and alignment worked pretty nicely as well. For visual observations definitely great. Tracking is quite good, and slewing pretty fast, although a bit noisy. But I can live with that.

  10. Most recent experience: my handset appears to be failing. It started to freeze frequently, and then it simply wouldn't power up, either when connected to the unit or when powered directly. (It is getting plenty of power.) The problem is intermittent: sometimes it will power up and sometimes not. And, of course, it is just out of warranty. I have obtained a replacement, but that makes an expensive bit of maintenance, especially if the expected lifetime is only a bit over a year.

  11. EVHAP: Oh, that's really bad. In the EU we have 24 months of limited warranty. So that is usually good enough. If the hand controller is failing, but the stepper controller box still works, you can also use a laptop to control the telescope (or netbook, or other cheap computing machinery). I have never tried that, but the EQ-MOD project supposedly handles that: http://eq-mod.sourceforge.net/

  12. Skywatcher in Canada tried without success to troubleshoot it by e-mail, so I sent it off to them with a copy of the invoice showing that it was only 15 months old. Maybe they'll take pity on me. Otherwise, it's CAD70/hr plus parts and shipping!

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