Mini Protos plastic in the cold?

[flyingw]

Made a FBL setting change and I could no longer wait to test it despite the weather. The ground here in Northwest NJ is covered with snow and there is new snow falling. Nevertheless I placed a 4x4 foot square of cardboard out in the back yard on top of the snow covered grass and did a hovering test. Great fun and wish I had more room. Maybe a set of pontoons for snow operations.

Gitbse: I really tempted fate this time as far as temp-affected FBL units go. Because of the falling snow I didn't let the heli sit and acclimate to the cold for a minute or two like I usually do. Luckily she stayed steady for the short test and I am happy with the result.

In an earlier post here I speculated that the belt expanded in the cold. I may have been wrong: I now think that it is the screws that hold the motor mount and top pinion bearing support. They loosen in the cold and this lets the mounts move and hence allows the belt to go slack. I'm thinking of putting a minimal application of thread lock on these screws for the cold.

[sp00fman]

The manual does state threadlock is needed there.... so good plan i think. Just as well threadlock all the other screws except the two on the front.

[FoamAddict]

Originally Posted by sp00fman

The manual does state threadlock is needed there.... so good plan i think. Just as well threadlock all the other screws except the two on the front.

I have not thread locked mine yet not that has been mentioned. Do most people thread lock them on their Mini? I have put 15+ flights on it with no issues and forgot about those bolts.

[JustPlaneChris]

Originally Posted by flyingw

In an earlier post here I speculated that the belt expanded in the cold.

I think you'll find that it's the aluminum tail boom that shrinks in the cold, thereby making the belt loose.

[desertstalker]

Originally Posted by JustPlaneChris

I think you'll find that it's the aluminum tail boom that shrinks in the cold, thereby making the belt loose.

Yup, cold makes things shrink (all things, barring a phase change in the case of water and a few other exotic oddities, but even ice shrinks the colder things get).

Al shrinks rather a lot when cold, so for those flying in places of extreme temp variations you will need to let the heli cool to ambient and re-adjust belt tightness for the winter. A CF boom would reduce this dramatically (maybe completely) but has its own issues.

[flyingw]

Made a set of "pontoons" from an old pool noodle.

A careful hover test showed no adverse flight characteristics - at least for hovering.

Take offs and landings performed from a spot flattened and firmed up a bit with a piece of plywood. The second photo shows the footprint from a touch and go on the softer virgin snow.

Such fun.

[DMala]

Cool, how do you keep them on?

[MiataJohn]

Cut one side of the noodles lengthwise, slip them over the skids and fasten with 8" cable ties.

[flyingw]

Yes, Slit the noodle lengthwise and push it over the skid. I also inserted a small piece of bubble wrap into the hollowed out center section of the noodle to keep the skid from moving around in there. This setup was only tested with hovering - if I was going to do forward flight with the floats I would likely fasten them with cable ties as MiataJohn said.

[flyingw]

What do static discharges do to the heli in flight?

I suspect that cold dry weather is ideal for creating static electricity as that belt runs through the airframe, isn't it?

[Russell Harding]

Mini protos is not static prone. There was an earlier thread rehashing this looking for experiences, and it seems to be a non-issue.

[grovey]

Originally Posted by Code3Medic

Mini protos is not static prone. There was an earlier thread rehashing this looking for experiences, and it seems to be a non-issue.

Could it be because of the carbon frame?

[Aryemis]

Originally Posted by grovey

Could it be because of the carbon frame?

I believe the tail boom holder is made of conductive material, and that's in direct contact with the carbon frame, which is in direct contact with the alu motor support, so yeah there are no static problems.

[flyingw]

I had some static problems with my MP and SK-540C. Skookum looked at the flight log and saw random spikes. Suspecting the BEC, I setup an Rx battery instead and still had the hits.

Moved the cable from the remote Rx to the FBL unit away from all the other servo and ESC cables. Still some hits.

Then got food-grade silicone spray and applied some to the belt and that seems to work. Skookum declared the last flight's log to be spike-free.

Next time I have the heli apart I will check to see if there is good metal-to-plastic contact between the tail rotor box and the boom, and the boom clamp and the boom.

Zero degrees and 50% humidity the next few days will provide a good test if I'm nuts enough to try it.

[ZeXx86]

I fly with miniprotos for two years even in -16°C, almost all parts are still stock.
Absolutely no problem in any condition including 100% humidity