Lubrication

[Jmk89]

In my earlier aeromodelling life, all my rubber-powered models had motors that were tight between the hooks. That was so even if the plan or other instructions called for a longer motor which was pre-tensioned (often by braiding).  I was young(er) and ignorant(er) then!

In those days, my motor preparation system was based on the one explained by Ron Coleman in his 1974 Aeromodeller series on rubber models. I would make up my motors and store them dry in a plastic bag in a dark box. Then the day before flying, I would lubricate the motors I was going to take and put them in a plastic bag. A few would be attached to loading sticks which could then be used in conjunction with a PVC winding tube. When I got home I would wash and dry the motors, put them in a plastic bag and store them in a dark box.

Since returning to flying, I have been wondering how to fit braiding into this regime. Do people store their braided motors after flying still braided or do they unbraid them, wash them clean and then  re-lube and re-braid before going out to the flying field?

PS - I've always preferred applying lubricant to the motor at home - I don't seem to be able to keep dust, bugs and general detritus out of my motors if I try to lubricate them on the flying field.

[Spiros]

I usually have all rubbers per plane in a bag (or bags if using different widths) and keep them moist in a silicone lubricant.

This proved to be a good practise for me. In any case, I"m usually not using them for more than a certain number of flights.

Of course, if washed and kept dry could be an option to use them more, but honestly never tried it.

[TheLurker]

I usually have all rubbers per plane in a bag (or bags if using different widths) and keep them moist in a silicone lubricant.

More or less what I do although I usually have one small bag per motor with a card holding the motor's details.  Pic later off to Trinity.

[Jmk89]

Thanks Spiros and Lurk

Do you braid or otherwise pre-tension your rubber motors?

ISTR that you both mostly fly indoors - the washing and drying is to get the dirt and muck that flying outdoors inevitably seems to stick to lubed rubber.  I've always been concerned that leaving the dirt on the rubber will likely lead to it chaffing the rubber leading to breakages (usually at the worst of all possible times)

[Spiros]

Correct. I only fly indoors so far, thus there is no actual dirt.

I never pre-tension my rubbers. I don't see the need for this.

Definetely there differences in comparison to the outdoors but I really have no experience on this

[calgoddard]

Jmk89 -

Rubber motors are braided to prevent bunching and CG shifting. Typically rubber motors are braided when used in outdoor models where the length of the undwound rubber motor is more than 1 1/2 times the hook-to-peg distance. By taking advantage of braiding, experts like Tom Hallman can use rubber motors in their scale models that are four times the hook-to-peg distance before braiding. Usually a wobbly motor peg is used to assist in the rubber motor distribuiting itself uniformly longitudinally (along the length of the fuselage) during the unwinding. There are a number of videos on YouTube that show how to braid a rubber motor and the beneficial results of braidiing. This extra step in preparing a rubber motor is not needed where the prop assembly has a tensioning mechanism such as those included in folding prop mechanisms and in the Gizmo Geezer prop assembly. I make up all my rubber motors before a contest. Each is stored individually in its own plastic snack bag with a detailed ID sheet give all the important parameters. I apply DOW CORNING 33 or NAPA Sil-Glyde lube to a selected rubber motor at the flying site, often wearing a Nitrile exam glove. I never wash rubber motors. When they are fatigued from to much hard winding or they break, they are discarded. In top level outdoor contests, fliers wind to near breaking torque, and never use that rubber motor again. Indoors, if you have a rubber motor made of a precious btach of TANN II rubber, you can eek out 3 or 4 really competitive fights in a Penny Plane, for example. Sometimes it is helpful to allow an rubber motor used on an indoor stick duration model to rest for an hour or two before another hard wind.

[TheLurker]

Do you braid or otherwise pre-tension your rubber motors?

ISTR that you both mostly fly indoors...

True on both counts, and the models that I fly outside have the motors safely surrounded by a fuselage so dirt & grit isn't (or hasn't been) a problem for me.  Anyway, a pic of how I organise my motors.

The flight count is a rough (very rough) indicator of how "tired" the motor is.  If I have a number of motors made up at the same time the first motor can be flown to exhaustion to give me the "dead count" so for the second and subsequent motors I know when to think about swapping out for a fresh motor.

[nickhawk]

Guys it's a rather sensitive subject.....did you realize you are talking about.....rubbers....and lubrication??? I definately learned alot.......

[Spiros]

Guys it's a rather sensitive subject.....did you realize you are talking about.....rubbers....and lubrication??? I definately learned alot.......