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Upgrading the clutch on a Meade RCX400 using EZ Clutch from Peterson Engineering


Meade uses a wet clutch system in all their scopes. This requires people to tighten the Declination knob really hard which can result in stripped screws and other problems. I perfomed this upgrade on my 10" RCX400. The instructions provided are quite clear (though the pictures are terrible and small). The instructions are also for the LX200, though the RCX400 is quite similar.

It took me about 80 minutes to perform the upgrade from start to finished cleaning up. Lets get started. Click on each picture for a larger version.

Well this is where we start. Nothing much to see here.
This is a real easy step, unscrew the locking knob and all the bits that go with it. You'll be left with what is pictured.
The kit comes with the correct allen key to remove the drive cover. You should see the worm gear and clutch plate covered in grease. If you haven't already done so, you should go get lots of paper towels. Line a work area with paper towels. Also get yourself some Isopropyl alcohol or acetone to clean the grease. I used nail polish remover which worked really well.
The instructions tell you to remove the clutch plate at this point, however I found that due to the suction of the grease it wouldn't budge (which was also mentioned in the instructions). I just left the clutch plate there and proceeded to remove the aluminium gear. Use one finger to lift the little arm on the right, that will pull the worm gear away from the aluminium ring gear. I had to wiggle the aluminium gear back and forth a bit to eventually get it out. Once the gear is off, that front clutch plate slides off easily.
Once the aluminium gear has been removed this is what you should see, a greasy inside clutch plate.
Now actually comes the part that takes the longest, cleaning. Using the paper towels start wiping away all the grease on both the inside clutch plate and the worm gear. The large chunks of grease come off easily with a paper towel. Once that is done whip out the acetone or isopropyl alcohol to remove any remaining grease. You'll also want to remove all the crease on the outside clutch plate and the aluminium gear. As in the instructions, I highly recommend using an old toothbrush to clean inbetween the grooves of the worm gear and the aluminium gear. Also make sure to get into the corners of the inside clutch plate.
Ahhhh... nice and clean. Now install the piece of cork included in the kit (not pictured) and lets start making a mess again.
Carefully apply the supplied grease onto the inner side, outer teeth and one side of the aluminium ring. Also apply grease onto the worm gear, be careful not to apply too much grease here, otherwise its all just going to collect up into a big wad. Also apply grease to the two little pins. Once this is done, there are two things to check for on the RCX400. First make sure that with the addition of the cork, your aluminium gear and worm gear are still lined up properly (i.e. center of worm gear with center of aluminium gear). Second make sure that there is deep positive contact between the aluminium gear and worm gear. My scope had neither of these problems (phew).
Now we test. After applying the grease to the spacers and standoffs on the Dec. knob/screw, put it on and test to see that the clutch is doing its job. At this point I also turned the scope on and ran the Dec. motor to double check the engagement of the aluminium gear with the worm gear.
Put the drive cover back on, screw the knob back and on and we're done. Don't forget to slap that 'Peterson Equipped' sticker on your scope.


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