We normally don't hear about Titan drives as they are rarer than the G11 or GM8 or GM811.

?

I got a Titan RA drive on my G11T.? I asked Mr Losmandy at his shop how much torque should be on the 4-hole end retainer threaded (~30 mm OD ) plug.? He said "Just touching."

?

That did not work well for me, as over temperature changes, the pressure from the end cap on the worm bearings could get too tight or too loose.? So I added 2 Belleville spring washers for that sized bearing (30 mm OD 10 mm ID) cup to cup so the outer edges of the spring pair touch the worm bearing and at the end of the 30mm plug.? This gives about 1mm of extra plug compression room for temperature expansion.? If there is no compression... just touching...there is zero force on the worm bearings.? But you can get as much force as you like by torquing the threaded plug in with the spanner wrench.? So I compressed it about 1/8 yo 1/4 turn to give a light, and adjustable force.? This force will not change much as the temperature changes because the springs will just expdmd or compress very slightly.??

?

Paul's note suggests he or maybe the Losmandy originally put in a Belleville spring in at an earlier time.? My G11T had no spring in the Titan drive to start with.??

?

Here are some photos of the drive and showing the Belleville springs I used.? I have some left so if you need a few contact me.? My "spanner wrench" (USA usage...I think in UK it can mean something else) is an inexpensive tool I got off eBay long ago.? There are many types on the market, and are used extensively for automotive C clips.?

?

I also tried to measure the worm thread center to ring gear center. That is supposed to be as close to the same level as possible for worm drives...a critical adjustment.? It was almost dead center, but my measurements showed also the need for a tiny maybe 0.02 inch shim under the worm block.? I used some thin brass shim stock for that (also off eBay).? Here are some pictures of that.??

?

The worm to ring gear should be as low friction as possible. Otherwise you can experience "chatter" as the ring gear is vibrated like a violin string by the movement of the worm gear acting like the "bow".? I tried Superlube ("Cincolon" Teflon only) there but it did not suffice...still chattered.? I tried a product called CRC Brake and Caliper Grease (MolyD, Graphite, and Teflon in an anticorrosion grease) and this eliminated the ring gear chatter.? I thought that ring gear chatter issue from worm friction would not be a problem for DEC only RA, but recent discussion of a DEC glitch also causing an RA glitch makes me wonder!

?

That's not all... my G11T drive story is not finished yet.? I'm still comparing the 3 gear tucked motor drive to a belt drive to see what's lowest for PE.? ?I have switched already to a McLennan 25:1 gearbox.? My PE with the belt drive is running 1.77 arcsec RMS and no trouble in autoguiding to round stars in 500 sec exposures.??

?

Have fun,

Michael

??

?

?

?