Aces High Bulletin Board

General Forums => The O' Club => Topic started by: 100Coogn on November 17, 2021, 03:50:13 PM

Title: Junkers JU 52 Gauge Identification
Post by: 100Coogn on November 17, 2021, 03:50:13 PM
Does anyone know what this gauge is/what it's for?   :headscratch:  It's on the Junkers Ju 52.

(https://i.imgur.com/uG0RKo2.jpg)

(https://i.imgur.com/ZDwLwDo.jpg)

Coogan


Title: Re: Junkers JU 52 Gauge Identification
Post by: Rocco on November 17, 2021, 04:06:54 PM
It's a pressure gauge but not sure for what. Something really low pressure, 0.5 kg/cm is about 7psi

I'm thinking vacuum gauge?
Title: Re: Junkers JU 52 Gauge Identification
Post by: 100Coogn on November 17, 2021, 04:17:51 PM
I thought at first, maybe a fuel pressure gauge.  Then like you, noticed the low reading on it. 
I'm curious, because somebody brought up the forums on MSFS 2020 and at the time of posting this, nobody has an answer.

Coogan
Title: Re: Junkers JU 52 Gauge Identification
Post by: Rocco on November 17, 2021, 04:29:02 PM
Interesting. Any idea where in the cockpit it is?

It's the right range for the gyro suction gauge, top end a little higher than most suction gauges these days but not much. I can't really think of anything else that deals with such low pressure in an aircraft.
Title: Re: Junkers JU 52 Gauge Identification
Post by: 100Coogn on November 17, 2021, 04:44:33 PM
Interesting. Any idea where in the cockpit it is?

It's the right range for the gyro suction gauge, top end a little higher than most suction gauges these days but not much. I can't really think of anything else that deals with such low pressure in an aircraft.

I'm still trying to find a good photo of the cockpit of one of these planes.  All the ones I'm seeing are too far away to identify the gauges.
I'm going to keep looking...

Coogan
Title: Re: Junkers JU 52 Gauge Identification
Post by: Treize69 on November 17, 2021, 04:47:28 PM
i believe that's one of the three kraftsoffdruckmesser (fuel pressure gauges), the diagram shows them having a max reading of 0.5kg/cm2. Number 20 on the diagram.

(https://burdigalaproject.files.wordpress.com/2009/06/pic-81.jpg)

(https://burdigalaproject.files.wordpress.com/2009/06/pic-91.jpg)
Title: Re: Junkers JU 52 Gauge Identification
Post by: 100Coogn on November 17, 2021, 04:59:03 PM
i believe that's one of the three kraftsoffdruckmesser (fuel pressure gauges), the diagram shows them having a max reading of 0.5kg/cm2. Number 20 on the diagram.

(https://burdigalaproject.files.wordpress.com/2009/06/pic-81.jpg)

(https://burdigalaproject.files.wordpress.com/2009/06/pic-91.jpg)

The ranges on the gauge does appear to be correct.  I'm looking at #20 of your image.
I wonder how that would convert to US lbs...  I think the fuel pressure on my truck is around 50psi or more.

Coogan
Title: Re: Junkers JU 52 Gauge Identification
Post by: alkali on November 17, 2021, 05:07:34 PM
Fuel gauge if my German does not fail me.
Pages 184 and 185 of the 1939 user manual to be found here: https://stephentaylorhistorian.files.wordpress.com/2020/04/ju52-betriebsanleitung-1939.pdf (https://stephentaylorhistorian.files.wordpress.com/2020/04/ju52-betriebsanleitung-1939.pdf) (from this site https://stephentaylorhistorian.com/2020/04/16/ww2-aircraft-manuals-downloadable/ (https://stephentaylorhistorian.com/2020/04/16/ww2-aircraft-manuals-downloadable/) )
It does state the 0 to 0,5 kg/cm2 pressure range.
Best,
Marc
Title: Re: Junkers JU 52 Gauge Identification
Post by: alkali on November 17, 2021, 05:09:02 PM
Ach! Didn't see Treize69's answer posted above - looks like we're on the same page anyway.
Title: Re: Junkers JU 52 Gauge Identification
Post by: Treize69 on November 17, 2021, 05:12:11 PM
I agree that the range seems very low for a fuel system, but that is what the diagram key seems to indicate. Nothing else has that range of readings.
Title: Re: Junkers JU 52 Gauge Identification
Post by: 100Coogn on November 17, 2021, 05:12:30 PM
Ach! Didn't see Treize69's answer posted above - looks like we're on the same page anyway.

That's just confirmation to me.  Always welcome.
Thank you guys for clearing this up.   :salute

[Edit]  It looks like some of the guys on the MSFS 2020 forums are leaning towards fuel pressure too.  MSFS 2020 Forums (https://forums.flightsimulator.com/t/what-is-this-ju-52-gauge/471627/21)

Coogan
Title: Re: Junkers JU 52 Gauge Identification
Post by: Rocco on November 17, 2021, 05:22:21 PM
Good find! Yeah by that diagram the suction is #10 and it's in atu.

Definitely low for modern fuel pressure but I guess right for 80yrs ago.
Title: Re: Junkers JU 52 Gauge Identification
Post by: alkali on November 18, 2021, 01:58:35 AM
Section 10-16 of the manual reads that fuel pressure must be between 0,14 and 0,25 atü, leaded 87 octane.