Proper Way to Insert Multi-Probe

[Dan Marotta]

When I got my Stemme, I asked my instructor if there was a proper
technique to insert the multi-probe in the nose.Â* He said to just push
it in until I hear/feel a metallic click.Â* That's worked just fine for
the past two years but I wonder if I should lubricate the thing, say
with Vaseline or something.Â* I shudder to think of replacing internal
o-rings.
--
Dan, 5J

[Luke Szczepaniak]

On Thursday, 15 February 2018 10:24:24 UTC-5, Dan Marotta wrote:
> When I got my Stemme, I asked my instructor if there was a proper
> technique to insert the multi-probe in the nose.Â* He said to just push
> it in until I hear/feel a metallic click.Â* That's worked just fine for
> the past two years but I wonder if I should lubricate the thing, say
> with Vaseline or something.Â* I shudder to think of replacing internal
> o-rings.
> --
> Dan, 5J

Yes, you should lubricate the probe each time but very sparingly. Some people have plugged the openings by being a little over zealous....

Luke

[Dan Marotta]

Thanks!

On 2/15/2018 8:29 AM, Luke Szczepaniak wrote:
> On Thursday, 15 February 2018 10:24:24 UTC-5, Dan Marotta wrote:
>> When I got my Stemme, I asked my instructor if there was a proper
>> technique to insert the multi-probe in the nose.Â* He said to just push
>> it in until I hear/feel a metallic click.Â* That's worked just fine for
>> the past two years but I wonder if I should lubricate the thing, say
>> with Vaseline or something.Â* I shudder to think of replacing internal
>> o-rings.
>> --
>> Dan, 5J
> Yes, you should lubricate the probe each time but very sparingly. Some people have plugged the openings by being a little over zealous....
>
> Luke

--
Dan, 5J

[joesimmers[_2_]]

Lubricate with clear silicone you can buy at Lowes in the plumbing dept.

I use "sparingly" and several times per year seems plenty.

[Matt Herron Jr.]

On Thursday, February 15, 2018 at 7:24:24 AM UTC-8, Dan Marotta wrote:
> When I got my Stemme, I asked my instructor if there was a proper
> technique to insert the multi-probe in the nose.Â* He said to just push
> it in until I hear/feel a metallic click.Â* That's worked just fine for
> the past two years but I wonder if I should lubricate the thing, say
> with Vaseline or something.Â* I shudder to think of replacing internal
> o-rings.
> --
> Dan, 5J

Pinch your nose to get some skin oils on your fingers, and wipe the probe. Just enough lubrication, and readily available! Works like a charm.

[Dan Marotta]

I used to do that when assembling my fishing rod when I lived in Alaska!

On 2/15/2018 8:47 AM, Matt Herron Jr. wrote:
> On Thursday, February 15, 2018 at 7:24:24 AM UTC-8, Dan Marotta wrote:
>> When I got my Stemme, I asked my instructor if there was a proper
>> technique to insert the multi-probe in the nose.Â* He said to just push
>> it in until I hear/feel a metallic click.Â* That's worked just fine for
>> the past two years but I wonder if I should lubricate the thing, say
>> with Vaseline or something.Â* I shudder to think of replacing internal
>> o-rings.
>> --
>> Dan, 5J
> Pinch your nose to get some skin oils on your fingers, and wipe the probe. Just enough lubrication, and readily available! Works like a charm.

--
Dan, 5J

[[email protected]]

I ended up with a jar of what is labeled "O-Ring Grease" from way back. Probably from the swimming pool store. I also use it on my water ballast valves.

I add a very little to the multiprobe a few times a season when I can feel it getting stiff. You can see the various ports on the probe so I make certain there's no accumulation of grease there.

I twist the probe as I push it in. That spreads whatever grease is there and also seems to be easier on the o-rings. I've heard of a few people who have managed to replace them (M&H) but it's not something I would want to try.

Chip Bearden

[[email protected]]

On Thursday, February 15, 2018 at 10:47:02 AM UTC-5, Matt Herron Jr. wrote:
> On Thursday, February 15, 2018 at 7:24:24 AM UTC-8, Dan Marotta wrote:
> > When I got my Stemme, I asked my instructor if there was a proper
> > technique to insert the multi-probe in the nose.Â* He said to just push
> > it in until I hear/feel a metallic click.Â* That's worked just fine for
> > the past two years but I wonder if I should lubricate the thing, say
> > with Vaseline or something.Â* I shudder to think of replacing internal
> > o-rings.
> > --
> > Dan, 5J
>
> Pinch your nose to get some skin oils on your fingers, and wipe the probe.. Just enough lubrication, and readily available! Works like a charm.

I do the same thing. I also put a wrap of white tape just at the edge of the socket as a witness to make sure it is in all the way.
UH

[Charlie M. (UH & 002 owner/pilot)]

Yep, agreed.
Store the probe so it stays clean (lot of times we use one of the ASx side cockpit vents, also helps keep peeps from dropping something on it.....), wipe it off a few times a year, very thin smear of lube, twist while installing.
Yes, the "witness mark" tape is nice. If for some reason the probe sorta "hangs" on install, you may have a huge system leak/cross talk if it's not fully seated. Yep, did a spring flight like that once, helped fine tune my butt vario...... Just twist it in until the tape is against the tube in the fin, align the angled probe as required (some say straight up, some say straight down....).

[Steve Thompson[_2_]]

There are clear instructions by ESA at
https://tinyurl.com/ESAFAQEnglish
which suggest cleanliness, light lubrication, and give
orientation advice also. Just saying.

At 19:28 15 February 2018, Charlie M. UH & 002
owner/pilot wrote:
>Yep, agreed.
>Store the probe so it stays clean (lot of times we use
one of the ASx side
>=
>cockpit vents, also helps keep peeps from dropping
something on it.....),
>w=
>ipe it off a few times a year, very thin smear of lube,
twist while
>install=
>ing.
>Yes, the "witness mark" tape is nice. If for some reason
the probe sorta
>"h=
>angs" on install, you may have a huge system
leak/cross talk if it's not
>fu=
>lly seated. Yep, did a spring flight like that once, helped
fine tune my
>bu=
>tt vario...... Just twist it in until the tape is against the
tube in the
>f=
>in, align the angled probe as required (some say
straight up, some say
>stra=
>ight down....).
>

[kirk.stant]

On Thursday, February 15, 2018 at 2:30:07 PM UTC-6, Steve Thompson wrote:
> There are clear instructions by ESA at
> https://tinyurl.com/ESAFAQEnglish
> which suggest cleanliness, light lubrication, and give
> orientation advice also. Just saying.

Ah Ha! Oriented UP!

Let the arguing - and bogus explanations - begin!

(FWIW I've always been in the UP camp...position relative to the horizontal, angle of the probe when changing AOA, less chance of hitting it when installing tail dolly...)

Kirk
66

[Dave Springford]

>
> Ah Ha! Oriented UP!


Of course it goes up - it's more virile.

[[email protected]]

On Thursday, February 15, 2018 at 12:46:27 PM UTC-8, kirk.stant wrote:
> On Thursday, February 15, 2018 at 2:30:07 PM UTC-6, Steve Thompson wrote:
> > There are clear instructions by ESA at
> > https://tinyurl.com/ESAFAQEnglish
> > which suggest cleanliness, light lubrication, and give
> > orientation advice also. Just saying.
>
> Ah Ha! Oriented UP!
>
> Let the arguing - and bogus explanations - begin!
>
> (FWIW I've always been in the UP camp...position relative to the horizontal, angle of the probe when changing AOA, less chance of hitting it when installing tail dolly...)
>
> Kirk
> 66

I used to always put my probe up (whenever I had the opportunity), but then someone pointed out to me that when the probe is installed down and the glider is in flying position, the probe is quite close to vertical. Seemed that was likely the correct position.

[[email protected]]

The typical designed probe is designed to point up which gives the intended angle to the airflow and also keeps the tip high and as close to the line of the tailplane. See Rudy Brozel's articles.

Another quite common factor is to avoid the down pointing probe interfering with a fin pitot which is often close below. Dick Johnson tested this and showed that there was significant interference.

[krasw]

On Saturday, 17 February 2018 01:14:48 UTC+2, wrote:
>
> I used to always put my probe up (whenever I had the opportunity), but then someone pointed out to me that when the probe is installed down and the glider is in flying position, the probe is quite close to vertical. Seemed that was likely the correct position.

I'm confused. The adapter for the probe is pointing straight to airflow at flying angle-of-attack. The probe end sticking up or down would have same angle relative to airflow?

[[email protected]]

Most compensation probes are designed to function with an angle of 70°, not 90° (but some do), between the prong and the airflow. Whatever you do, that angle will change whenever you increase or reduce your airspeed, so the system must have some built-in flexibility. How much flexibility and in what direction (up or down) will probably depend on the design of the probe. So follow the instructions of the manufacturer, would be my advice. ESA Systems says prong up, so that's it for me.

There are two-pronged probes that should be placed with the prongs horizontal.
https://www.esa-systems.com/en/products/details/total-energy-probe-type-dnst-840-mm/
https://www.esa-systems.com/en/products/details/multi-probe-dnstatek/
According to a German study, this type gives the best compensation results.

[[email protected]]

On Thursday, February 15, 2018 at 4:54:24 PM UTC-5, Dave Springford wrote:
> >
> > Ah Ha! Oriented UP!
>
>
> Of course it goes up - it's more virile.

Aside from virility raising the sensing point by another 6 inches gets it further above the turbulence coming off the wing root, especially at low speed and high angle of attack.
Also less likely to catch it when removing the tail dolly.
UH

[TomNau]

This may be a silly question, but isn’t there only one way for it to be oriented correctly for the ports to line up properly?

[Charlie M. (UH & 002 owner/pilot)]

No, the O-rings seal sections of the tube in the fin, the ports in the probe just empty into that section.