TEK Probe and pressure connection

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Carbo
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TEK Probe and pressure connection

Post by Carbo » Sun Jul 13, 2014 5:40 pm

Here some experiences when equipping openxsensor/-vario with a TEK-Probe:

Pressure connection first try:
Firsttry.jpg
Result: the tube broke out when loaded
Broken1.jpg
Better versions with supported connections, second one with silicon:
Repair.jpg
MS5611_silicon.jpg
The tested probes:
Probes.jpg
The absolutely best "Braunschweiger Duese":
Front.jpg
Back.jpg
The idea and the plan is from here: Thanks Tempo

The used material: 4mm gold socket, 2mm and 4 brass tube, 9mm washer, solder
Parts_needed.jpg
Instructions:
Plan.jpg
Drill a 2mm hole for the 2mm brasstube, make a chamfer in the 4mm brass tube and solder it inside the socket, the chamfer ending exactly at the 2mm hole, solder the 2mm brass in the hole, remove eventally overcoming brass and solder inside the socket carefully with a 4mm drill (by hand, not machine!). Remove the overcoming chamfered brass at the inlet, smooth the inlet inside and outside (round it). Rasp the hole inside the washer to fit the outside of the socket and solder it. shorten the overcoming socket at the outlet. Rasp the outlet at the washer and sand it.

Important: check always if everything is airtight.

Mounting example:
Fuselage1.jpg
And here is the result, an overcompensated TEK. You can adjust it down for exact compensation by reducing the outlet with some tape (easy), or reducing the outside diameter of the washer (not so easy).
First testflight with rain and vario sound

Cheers Carbo


Carbo
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Re: TEK Probe and pressure connection

Post by Carbo » Sun Jul 13, 2014 5:45 pm

Another picture from the outlet to the inside, you see the chamfer:
inside.jpg

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Tempo
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Re: TEK Probe and pressure connection

Post by Tempo » Mon Jul 14, 2014 3:29 pm

@Carbo

Good idea to use gold socket and washer for "Braunschweiger Düse" 8-)

Your new horizontal tube connection on MS5611 allows a new feature:
Mount openxsensor inside vertical tail and you receive short tube connection to TEK-pipe at top end of vertical tail.
That´s best position for pipes outside of fuselage and wing flowfield.

Give it a try ;)

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Tempo
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What you had to know about TEK-compensation

Post by Tempo » Mon Jul 14, 2014 3:35 pm

This is a good source for understanding how pipes work and how to trim pipes:
TEK-Duese_deutsch.pdf
(100.61 KiB) Downloaded 324 times
TEK-Probe_english.pdf
(84.05 KiB) Downloaded 342 times

Carbo
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Full compensated TEK probe

Post by Carbo » Mon Jul 14, 2014 7:14 pm

After trying different diameters for the washer at the outlet, 6.1mm seems to be the optimum.

Short Video Loop and waves

The chamfer should be outside on the inlet, not inside. It did not change the effect, but on the original plan it is this way and its easier to produce.
TEK1front.jpg
TEK1back.jpg
Plan (thanks to my son) :
TEK_plan.JPG
TEK-probeWZ.PDF
(33.53 KiB) Downloaded 282 times
Cheers
Last edited by Carbo on Wed Jul 16, 2014 9:06 am, edited 1 time in total.


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Tempo
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Re: TEK Probe and pressure connection

Post by Tempo » Mon Jul 14, 2014 7:32 pm

Carbo wrote:...
And here is the result, an overcompensated TEK. You can adjust it down for exact compensation by reducing the outlet with some tape (easy), or reducing the outside diameter of the washer (not so easy).
First testflight with rain and vario sound

Cheers Carbo
Your video shows mounted filament. It´s a good idea. This way you analyse influence of yaw angle to TEK-probe.
I prefer filament mounted in the middle of brass tube. ( Not assymetrical of fuselage ! )

Yes, you use a V-tail glider with airscrew. In that case you positioned TEK-probe close to airscrew as possible. Try it with a little bit longer brass tube. Beware of fuselage and wing flow field especially in case of high angle of attack respectively in case of low speed in thermals.

Carbo
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Re: TEK Probe and pressure connection

Post by Carbo » Mon Jul 14, 2014 8:03 pm

Tempo wrote: Yes, you use a V-tail glider with airscrew. In that case you positioned TEK-probe close to airscrew as possible. Try it with a little bit longer brass tube. Beware of fuselage and wing flow field especially in case of high angle of attack respectively in case of low speed in thermals.
The length is limited by the length of the used socket - but it works. Today it was really complicated, to find a piece of calm air, i flew through all kind of thermals and downwinds. The vario tones were never inappropriate, so there is a good chance, the botched job does what its supposed to do :D

Cheers Carbo

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Tempo
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Ready for thermal hunting ?

Post by Tempo » Sat Jul 26, 2014 6:50 am

Total Energy Kompensation = you will only detect rising air or falling air. Learn more about and read
TEK-Probe_english.pdf
(84.05 KiB) Downloaded 359 times
2014_openXsensor_TEK_Braunschweigerdüse.JPG
Firstly built housing for sensor MS5611 :
GY-63_PCB.JPG
2014_openXsensor_TEK_Anschluß.jpg
Seal with slowly setting epoxy. Compound epoxy with elastic filler like sanding dust of balsawood or use "UHU endfest 300".
Cover with very light glass fiber fabric .
2014_openXsensor_TEK_Anschluß_oben.JPG
2014_openXsensor_TEK_Anschluß_unten.JPG
Secondly make leak proof:
Fix syringe and control about 5 to 10 minutes display of altitude. I produced airpressure for example of 5361 meters.
2014_openXsensor_TEK_Anschluß_Dichtigkeitsprüfung.JPG
Useful display for Taranis is LUA Telemetry Screen #2 http://www.open-tx.org/2014/06/30/telem2-lua/ .
LUA_Großzifferanzeige_Taranis.png
LUA_Großzifferanzeige_Taranis.png (22.37 KiB) Viewed 6847 times
Thirdly build TEK probe:
viewtopic.php?f=48&t=5632&start=30#p82456
Locate TEK probe outside of air flow of fuselage or wing !!
Connect sensor of variometer only with short tubes or hard tubes for longer distances.
2014_openXsensor_TEK_Braunschweiger_Düse.JPG

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Tempo
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Protect MS5611 of light

Post by Tempo » Sun Jul 27, 2014 7:42 am

Sensor MS5611 is sensitiv to light. Protect for example with black shrink tube.
2014_openXsensor_Lichteinfluß.JPG


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