temp sensor on my dx8 gone wild..!

[hadi10]

hey all
2 days ago i was hovering my heli when the temp sensor on my dx8 gave me an alarm.. i landed and checked to find the temp 1000 F on the dx8 screen !!
i disabled the alarm on the DX8 and continued my fllying

what could cause such a fake warning.!

[gehrbox]

Originally Posted by hadi10

hey all
2 days ago i was hovering my heli when the temp sensor on my dx8 gave me an alarm.. i landed and checked to find the temp 1000 F on the dx8 screen !!
i disabled the alarm on the DX8 and continued my fllying

what could cause such a fake warning.!

Failed sensor? Software bug? Mr Fusion?

[mc82]

I had on on mine that registered 158 when it was cold. replaced the sensor wire and all is good.

[hadi10]

after inspection.
here is what i found..
could that be it?

[gehrbox]

Originally Posted by hadi10

after inspection.
here is what i found..
could that be it?

The picture is a little blurry, does it look split from wear, heat or defective heat shrink?

[hadi10]

Originally Posted by gehrbox

The picture is a little blurry, does it look split from wear, heat or defective heat shrink?

yes.. i think the heat shrink is cut , maybe from over heating .
and because its touching the engine head , it makes some kind of a short..!
thats why im getting the 1000F at my dx8 ?

[gehrbox]

Originally Posted by hadi10

yes.. i think the heat shrink is cut , maybe from over heating .
and because its touching the engine head , it makes some kind of a short..!
thats why im getting the 1000F at my dx8 ?

Seems reasonable to assume a dead short to a thermister would give high reading. There two types. One has resistance that raises with higher temp and the other resistance lowers with high temp. If the sensor that comes with the dx8 is the latter the tm1000 would see a high temp if the sensor shorted.

[hadi10]

ohh.. so if i shrink wrap it again it should work with no problems?

[gehrbox]

Originally Posted by hadi10

ohh.. so if i shrink wrap it again it should work with no problems?

Depends on the shrink wrap. If it can take around 250 deg it should be ok. If it is a cheaper shrink wrap it might melt at the temp in the head area. If you have an Ohm meter you can test it to make sure it responds to heat from your fingers. The resistance will change when you grab the thermistor.

[hadi10]

is there any other way i can reuse this thing ? i dont think the shrink wrap i have can handle the high temps of the head.

[gehrbox]

Originally Posted by hadi10

is there any other way i can reuse this thing ? i dont think the shrink wrap i have can handle the high temps of the head.

From what I read online for heat shrink tubing specs even the cheapest is good up to around 275 deg F. The highest I have seen anyone report temps is around 230 deg F on an engine, which is pretty hot for a glow motor head temp. Usually motors like the OS Hyper 50 run around at 200 - 220 deg F max. The temp will rise 10-20 degrees after it shuts down, but even at that its still below the 275 deg heat shrink spec.

[hadi10]

now the problem is .... how do i install it on the temp sensor !!! both ends of the wire are inside the connector..!

[gehrbox]

Originally Posted by hadi10

now the problem is .... how do i install it on the temp sensor !!! both ends of the wire are inside the connector..!

You should be able to use a pin or exacto knife to release one of the pins in the connector that plugs into the tm1000.