Stiction: Physics = “The friction which tends to prevent stationary surfaces from being set in motion”

I have an older Meade “medium duty” equatorial mount.  Last night (August 31, 2022) was beautiful with low humidity, and temps in the lower 60’s.  It’s been a while since I’d used this mount, and when locating planetary Nebula NGC 6772, but last night, the RA and Declination shafts were “jerky” or sticking, called “stiction.”  

This mount has teflon/nylon split bearings, and over the past 30 years, knowing that a petroleum based lubricant can attack plastics, nylon and teflon. I have always disassembled and used paraffin.

It occurred to me to use some Mobil 1 synthetic motor oil in a tiny plastic dropper. 

So, today…with another great night coming up, I had to correct the problem, without disassembly.  I removed the counter weights, and flipped the RA and Dec shafts in all angles, and dripped small drops of Mobil 1 synthetic motor oil into areas that would allow permeation of the internal surfaces. 

I learned about Mobil 1 for lubricating bushings, spacers and other, by cleaning and reassembly of Zipp Carbon Fiber Road Bike Wheels. Zipp advocated the purchase of their “special” Zipp Wheel lubricate for internal spacers, and warned not to us a Petroleum based.  But, somehow, I found out that the Zipp Special Lubricate “might be similar” to synthetic motor oil, like Mobil 1.  

I’ve cleaned and disassembled many Zipp wheels, for myself and others for more than 10-12 years, and lubricated the internal parts of the freehub assembly with Mobil 1, and all are doing fine.  The carbon fiber wheels are hand-built, with each “individual” wheel requiring many hours (maybe 25 or more hours per wheel) to manufacture.

How did the lubrication work?

The Meade Medium Duty mount seems to now work beautifully, but with the waxing moon, I’ll have to wait till the 2nd or 3rd quarter moon to attempt NGC 6751 again.

Hopefully this post might be of benefit to others with “sticky” equatorial mounts.

I have also found out others are using Mobil 1 in astronomical applications also.

Information from Mario Motta, as following:

Hello Roger,

Once a year I carefully clean off old grease from my 32-inch drive gear, and add back Mobil 1, which gives me a much smoother tracking.

Mario Motta

The declination gear is aluminum alloy made by a machinist in Alaska in 2004. It is 16.6-inches in diameter with 360 teeth.

The RA gear is a beauty, made by Byers. (There is a long story behind this gear). It is 23-inches in diameter, and has 718 teeth. 

It is extremely accurate as all Byers gears are. I was originally using my Byers gear from my previous observatory, 15.5-inches, but just a bit too small for a 32-inch telescope. 

Byers got in touch with me just before he closed his shop at age 91, and gave a special offer, which I gladly accepted!  

Mario Motta

Byers advertisement from 1975

The passing of Edward Byers:

https://www.dignitymemorial.com/en-ca/obituaries/barstow-ca/edward-byers-8979478

This entry was posted on September 2, 2022 at 2:32 pm and is filed under Roger's Articles. You can subscribe via RSS 2.0 feed to this post's comments. Both comments and pings are currently closed.