MORE ON TIMER MAINTENANCE
A new customer asked us about timer cleaning and rather than refer him to the instructions or what we had already posted on this site, I wrote a reply to him. It is pretty much of a rehash of information elsewhere, but it is good to rephrase it and repeat it. This is one of the most important things you can do to make sure your timer lasts a long time. We like to think they are good forever.
Glad you asked about cleaning. So many just ignore it.
Let me start with the cardinal rule: NO OIL! No WD40, no anything. on the gears. More timers than I can count have been screwed up with oil. It is fine to oil the springs on the metal clock timers, particularly those with the extended run spring can on the back. Use only very thin non gumming spring oil or something like Outers Gun Oil. The spring leaves have to slip and slide on each other and some oil film here is good. You can also use a fine wire to put the tiniest amount of oil on the gear pivot points. This is especially good after cleaning.
Now, the first thing is to keep it clean. The first step is to build a little box in the fuselage and seal it up well with dope or thinned epoxy to keep all the balsa dust and crud inside the fuselage from getting in the gears. I will soon come out with a line of formed plastic covers that can be glued to the inside of the fuselage and make a nice clean home for the clock works.
The big variable is stuff from the outside getting in. Engine exhaust (depending on where the exhaust is and the timer is mounted), sand, dust, dirt, pollen, weed seeds, etc.. This will be a function of where you fly and how much. Since I tell you to use screws to mount the timer, and not glue, it is easy to take the timer out and inspect it. If you can actually see stuff, then you have a real problem to take care of. Most problems are caused by particles you can not see without a magnifier. I use aerosol carb or brake cleaner and spray the clock real well, followed with an air gun blow out. If is seed or fleck of something is stuck in a gear, it sometimes takes a pin point to pop it out. I troubleshoot by seeing if the stoppage is repeatable and then associate it with the position of a specific gear to zero in on the problem area.
More than you ever wanted to know, right? If you keep oil off it and do not fly in dust storms, and build a sealed box, you likely will not have any problem at all. All these timers use very tiny gears and it does not take much to jam them. Most of the old Tatones and KSBs that will not run and are in junk boxes are perfectly good if you take out all the oil that the factory in Japan put in them. By now, the oil is like grease or jelly. And, oil provides a nice place for dust to stick!!!!