Meade SN Focuser 1.25" adapter wobble -FIXED
No replies to this topic
Posted 21 November 2005 - 02:06 AM
OK...we all know that the 1.25" adapter has got way too much play. All the 1.25" eyepieces can wobble and the pesky screws scrape the eyepiece polished finish.
THIS 20min Project is about ZERO cost and give you a COMPRESSION effect 1.25" snug ADAPTER.
Ok...go down to the nearest home/auto radiator manufacterr....and get yourself a piece of the copper/brass foil they use to make the fins. It appears around 0.2mm thick...and it does not crumple like aluminium kitchen foil. All you need is a scrap. About 4" long.
Cut it to 3.9" by about 1" rectangle with a scissors. Wrap it firmly around an eyepiece 1.25" shaft, it should exactly fit with mebbe .5mm clearance. You can get by with up to 2mm clearance, but overlap is a no-no. The Copper (foil tube) should extend PAST the tip of the eyepiece by at least .25". More is fine.
Now notice that one side of the copper strip u cut is prepolished ....ok get a bit of emery paper and clean the Un polished side....to prep for glue. That means 220 to 320 grit is good. You are NOT trying to get a polished surface here...a clean "rough" one is best. Also, sand the inside surface of the 1.25" section of the adapter a little....to prep it for the glue.
Now set out the following items....the 1.25" adapter, an old eyepiece, the copper foil strip, a tube of crazy glue, some tissue paper, a plastic spoon (handle) or anything flat to spread the glue. A toothpick to dab the glue might help.
Step 1) Get the tube of glue ready to squeeze SMALL amounts.
Step 2) make sure the adapter screws are FLUSH to the inner surface of the adapter and the adapter has been wiped clean of any sandings & grit.
Step 3) Dab small amounts of glue at a few spots on the inner surface of the adapter 1.25" ring but not in-line with the screw holes! Spread the glue flat..do not leave drops, use a MINIMAL amount.
Step 4) Quickly wrap the copper around the eyepiece 1.25" shaft, sanded side outward, and slowly insert the wrapped eyepiece into the adapter. It will be reasonably snug.
Step 5) once inserted - Push the eyepiece ALL THE WAY IN. It must seat on the adapter shoulder.
Step 6) Spin the eyepiece to assist with removing any potential uneven surfaces /air pockets on the copper. Remove the eyepiece. Clean it if u managed to get glue on it.
Step 7) Look into the bottom of the adapter... you will see that the copper extends into the adapter by maybe a half inch, and the excess glue will have settled on its surfaces. Once the glue is hard...30min if u have a lot of excess. Use a small scissors (Wife's manicure set.) and snip the copper at perhaps 6 spots to create equal sections. Then Fold or push the sections outwards towards the adapter 2" housing so that the glue bumps would not impact on your viewing, or affect any collimation tools like a 1.25" sight tube.
Step 8) Clean up ...yor're done.
One tip....using the plastic spoon handle...press against the top inner edge of the copper ring and in a circular motion burnish it against the adapter. This gives you a very slight chamfer at the top edge of the adapter for easy eyepiece insertion. You can use a metal spoon for more effect as the copper is soft.
BTW if u screw up as I did the first time and put too much glue ...just peel off the copper and resand it, u can re sand inside of the adapter 1.25" ring if there is a lot of excess glue as well.
For almost zero cost....a drop of glue....a bit of emery paper...a bit of free scrap copper foil, and 20 minutes....you have made a snug 1.25" adapter with a compression ring effect which will NOT mar your eyepieces.
For those of u who cannot get the copper foil ...send me $5.00 bux (S&H) and i will send u a piece pre cut, as i have a couple feet of the stuff. Its great for shims. email@example.com reaches me.
Clear skies & Bright eyes!