Washers to increase friction on mounts??

I am doing the last part of assembling a prototype mount that can be made in out-of-the-way places for small refractors (80 or less). The primary structure member is rough wood with some hardware and a single ring. I am relying on wood-to-wood surfaces for friction to hold placement and position in one axis and metal to wood to hold the second axis of movement. I have some nylon or plastic washers to keep wingnuts from turning off their bolts.

1. Are there any common substances I should try if I want to increase or decrease stiction that are commonly available in a small hardware store or home that would likely be found anywhere in the world? I have tried aluminum flashing and nylon or plastic.

2. Has anyone tried leather to adjust "stiction". If so, your findings regarding type, thickness, etc.?

3. If wingnuts tend to want to spin off with repeated movement about a bolt axis on a mount, what is a solution....other than a nut with a nylon insert?

Thanks for reading.

Roland
For your question #1, the platic from a gallon milk jug can be cut and serves to reduce friction, especially with two layers of it. And you can pour the milk over your Cherios.

On question #3, you can add an additional nut to tighten the wing nut against (double nut), but then you loose the easy adjustment function of the wingnut, so it probably isn't what you want.

Please post a photo when you get it built.

Steven Jindra

Regarding #2, I have used felt pads to add a little friction to a lazy-susan azimuth turntable, and also seen it used in place of teflon "buttons" as a bearing surface for altitude hubs holding a small OTA.

The trick with stiction is to get a bearing surface with some random irregularities in it. That is why Ebony Star formica works so well against teflon on Dob bases.

#1, milk jugs like steve said, most hardware store sell nylon washers to.
#2, leather will not be consistant with tempurature. Felt impregnated with oil maybe?
#3, assuming you have more than say 3/8 inch of threads past the backside of the wing nut, try a piece of vacuum hose ( with a smaller i.d. than the o.d. of the threaded portion) slipped over said threads. this will hold the wing nut in place and offer you the ability to adjust as necesary.

Leather has been the clutch pad shipped in the Losmandy Titan series for several years now. (it is also used as an all-temperature clutch).

Greg N

Thanks very much everyone. Excellent ideas. My brain was getting fried just dealing with shaping wood. Will try several of these. The good news: places where we go have plastic jugs for water and they wear out...so the ideas of washers from milk jug type of plastic is excellent. I saw felt pad but had not tried them; now I will; a double wing nut or putting a small piece of hose on the end of the bolt .... will try both. I think after that I will be fine. I had to redesign the wood shape a bit to avoid having to reset the scope in the ring in a dead area but I think I have that licked. Will post an article and pictures when done. Should that be here or somewhere else? Looks like this is coming together nicely, and a great way for me to tell my friends in very poor places to just get a piece of hardwood 1 meter long, hand them a small bag of hardware and the scope, and they can do it. Their part is just to put the wood against a vertical or horizontal anything that is secure (tree trunk, fence post, cross fence bracing, side of a structure, and they should have a secure rough mount for a small 80 (f/5 to f/7).