Andrew and John, Thanks for the kind words, I must admit I had some trepidation before starting, but really, it's a no brainer as long as you have a couple of easy-to-buy tools ready before you start.
Tools: Pointy long nose, digital calipers (Jaycar), lots of Chux-type rags and a good set of Allen wrenches, maybe a set of medical forceps (an invaluable tool to have anyway), and a plastic dish to clean things in.
Day 4, and the clouds have rolled in of course.
Finally got the head all reassembled, ready to be inserted in the mount. Oh, BTW, just in case anyone else is in the same boat, I am fortunate to have a small obs and pier, so I decided to leave the mount base attached to the pier as it was drift aligned reasonably well. Removing the DEC/RA head was quite easy. Couple of small points. Since the RA shaft is fixed to the head, the alignment of the worm gear shaft to the worm gear ring seems to be less critical. Just measured the spacing as per the DEC instructions and confirmed that the mesh was centered. Didn't have to change the shim size. Anyway, after redoing all the bits I undid yesterday afternoon in my panic mode, I was ready to insert it into the mount RA aperture.
Tip. Check worm gear operation and backlash adjustments as you wish, but don't tighten them up, as you'll need them loose when you reinsert the head to the main mount. Final worm backlash adjustments must be done after it's all together on the mount.
Tip: Degrease both worm gear rings at the top large groove (not the gear end). This is where the brass clutch pads bear. Seemed to me a bit silly to have that area greasy.
Tip: The ball bearing that sits in the main RA mount hole does not sit flush. It sits proud about 5mm. Trying to make it flush was how I got into trouble yesterday......Nobody mentions that little fact.
Inserted the RA shaft, inserted greased taper bearing at rear and locknut hand tight. Mini panic #2 - The DEC shaft didn't want to go all the way down over the DEC worm ring. Obviously a misalignment problem, as there are three ball bearing holes to keep things straight. Turned out that it's best to keep the worm gear cover bolts a little loose, so that the worm gear ring can move to accommodate the shaft as it passes through. DEC now seated properly, taper bearing in and tightened, as well as RA locknut. DEC counterweight shaft inserted and a couple of weights added at top end to keep things sturdy while tightening everything. Don't put them at the bottom as there is no weight on the saddle, and so the mount would be grossly out of balance and strain the motors during initial test. ( I know, I did it
).
Electronics panel reinserted and connectors on. Put the D saddle back on and after applying power, checked for smoke etc. All good. Hand tightened cover bolts on DEC and RA covers prior to adjusting worm gear backlash. Main thing to remember is to try and align the covers so that the edges are aligned to the lower casing. Whether it's just for aesthetics or to ensure better backlash, I have no idea, except that's the way it originally was, so seems like a good way to replace it. Lightly clinched up the backlash grub screws on DEC and RA housings. Jiggled the D saddle and adjusted the DEC grub screws until all rotational movement had just stopped. RA's a little harder due to grubscrew placement, but same idea. Used my spirit levels to set the mount to my default SCP park position. I have glued small spirit level tubes on both mount axes to make this simple. Highly Recommended. Whenever you park for the night (presuming you have an obs of course
), you can check that all's well.
Time to try it. Turned on the mount-control eeePC 701 laptop and cranked up EQMOD. Reset park counters and reparked to make sure. Grabbed the wireless controller and let her rip on slow speed. DEC motor rattled at me. Oops, a tad too tight. Redid grubscrews just a smidgin and retightened cover bolts, and all then sounded good. RA seemed fine. Proceeded to rotate DEC 370 degrees and RA 190. Both worked very smoothly and no noises. Hit park to ensure it would do that. It did. Remounted scopes and gear to the D saddle and hooked up the cables so we had a real life system. Then proceeded to rebalance. It seemed much smoother and free'er than before and to do both axes only took a few minutes. Reparked and reset, then used the handcontroller to drive the mount to all extremes at 0, 45 and 90 degrees DEC, with +/- 100 degrees of RA at each position, stopping and starting the mount at each spot. Smooth as honey. No rattles, no whines, no jerks.
But of course, lots of clouds outside so no piccies tonight! After all, that's the final proof. Show me some round stars and no PHD error messages! If necessary, I'll return to the DEC and RA grubscrews for some fine backlash tuning, but it sure looks sweet so far.
Many thanks to all the IIS and other contributors for their advice, and to Peter 4059 for his support and spare bearings/shims
. I'll drop you a PM re returning the wooden mount frame and the pics. Final recommendation to EQ6 owners thinking about it: Be like Nike, Just do it!
.
Someone had shrunk the RA shaft length by 15mm, meaning the nut wouldn't engage the thread when the assembly was inserted into the mount housing... 
The little aluminium taper bearing collar thingy at the back, which was shrouding the RA shaft, really wasn't supposed to be there! It had moved back during my hammer and dowel persuasion of the RA bearing to seat in the mount.
