Switch Failures or ???
 

I am seeking some guidance on the best quality switches to use on our planes. (Or some other input on what might be going on here)
We recently lost 2 planes due to apparent radio failure but have not been able to find anything wrong with any of the flight equipment. At the time we thought that the planes went in due to radio interference which had happened to a fellow club member a week or so before.

I was running up a new plane last week with a "still being run-in" Saito 1.00 in it. When I brought the throttle up to half way there was suddenly no response from any of the servos - Luckily this was on the ground and I had the cowling off so I could pinch off the fuel line to cut the motor. I checked everything over for loose connections etc, tried everything with the motor off - including tapping the Rx and found no issues. restarted the motor and it happened again. Because it is still running in, the Saito 1.00 is running rich so it is vibrating a lot. I bypassed the switch to see what would happen and the problem went away - It makes me suspicious of the switches on the other 2 planes that were lost - one was powered by a sweet running Saito 82, the other by a well run in 46ax. I have not been able to prove the switches were at fault on the 2 crashed planes as I automatically tossed them after the crashes but those switches were purchased at the same time as the one in the new plane.

Whenever we put a plane in I toss out the switches and battery packs and all flight battery packs are replaced every 12 - 18 months (between me and the two teenagers - we fly a lot and therefore we "replace" a lot). I also send the Rx's in for checkout before they go into another plane. Except for the Digital servos on the larger planes, I check the servos out myself.

The switches that I have been running until now are MPI units with the built in Charge Jacks (not the ones with the LED indicators) - I am running Hitec Q-PCM Rx's with 6v Sanyo Flight packs, Hitec servos (HS 475 HB's, 645 MG's and 985 Mg's - depending on the plane). I avoid Y harnesses wherever possible and whenever I use lead extensions - I put heat shrink over the connections to stop them coming apart.

Any thoughts?

RE: Switch Failures or ???
 

are the control rods in a plasic tube had an issue like this on a speed air 40 just straight rods to servo and links servos kept glitching put the control rods in plastic tubes and that done it for me just a thought but its a process of elimination huh hope ya crack the prob ;)

RE: Switch Failures or ???
 

I believe we are talking about the same switch.
http://www.bphobbies.com/view.asp?id...=T808660&img=l

My failure was with switch in the off position. Installed switch, made two flights, did a voltage check and got zero voltage. Checked several times and could get voltage only sometimes. Stopped flying.

Removed the switch at home and removed the plastic parts. The switch does not appear to have redundant contacts. Side pressure on the off/on slide appears to disconnect contacts. The failure happened a year ago but since you asked the question I may finish taking the switch apart.

Switch and charge jack together is convenient but problematic for a high vibration environment.

Bill

RE: Switch Failures or ???
 

I have been using the same switches for three years without any problem. I even use the ones with the LED indicators on my gas powered plane with high vibration, and they are currently working fine.

If you are concerned about switch failure, you can order the [link=http://www.maxxprod.com/mpi/mpi-21.html#Miracle%20Switch]Miracle Switch[/link]

RE: Switch Failures or ???
 

That's a different switch from the MPI units.

RE: Switch Failures or ???
 

Mabie its not your switch . . .a satio 1.00 delivers a lot of vibration . . .make sure everything like you receiver and battery have plenty of foam!

RE: Switch Failures or ???
 

Much more likely to be a battery/battery lead/connection problem here.
Check any twisted leads under a magnifying glass, check around the contacts.
You've a good chance of finding evidence of the plastic coating being rubbed away exposing wires.
Yes I'm talking from experience.

RE: Switch Failures or ???
 

I've had one in-flight switch failure.
A couple of battery failures.
The switch failure was repeatable after recovering the plane, which fortunately landed without incident, although some distance away.
The battery failures were instant destruction.

RE: Switch Failures or ???
 

Standard switches disconnect the positive and negative battery line (2 contacts)
HD switches usually are the same switch but only disconnect the positive line (2 contacts).
I would recommend that you get a HD switch for your planes.
Many companies make them.

RE: Switch Failures or ???
 

Thanks people
I like the look of the Miracle switch and the switches that I have been using do look similar to the one in BillS's post.

I have not been 100% convinced that it is the switches. When I was in the US recently I took advantage of the fact that the parts for this great sport of ours are significantly less expensive there than they are in Oz. I bought a bunch of these switches, Sanyo 6v flight packs, HiTec servos and various leads etc whilst I was there so everything I have been using is new. I purchased the brands that I did after asking around at the club that I flew at there (which has some excellent pilots with a lot more experience than I do) and seeing what they use on their stuff - I do not look at price necessarily because I believe that spending an extre $50 - $100 or so when building a plane will often save the hundreds or thousands that it cost in the first place.

Meanwhile I've taken the 1.00 out of the airframe to run a couple more gallons through it on the bench and will just have to make do with a 1.25 in the plane until the 1.00 is run in[&o] The plane in question is a U-Can-Do so, having had a 1.25 in its predecessor (I lost that one due to 100% dumb thumbs on my behalf) I am sure it will not be too much of a hardship for me to live with! I'll put in a new battery pack and switch and see what happens.

RE: Switch Failures or ???
 

The switch that failed on me was not a heavy-duty switch and it disconnects only the positive line.

Bill

RE: Switch Failures or ???
 

I have had a couple standard switches fail me on high perfomance racing planes, since moving to the JR Gold Heavy Duty switch I have had absolutely no switch problems. I'm also no JR shill, most of my radio equiptment is Futaba.