Sun Ship Game Question

I was rewatching the SunShip Game since its raining cats n dogs down here. I noticed both Moffat’s and Drew’s open cirrus’s did not have total energy probes showing. What were those guys using back then to obtain reliable total energy or netto information? Im pretty sure they were flying before the days of electronic compensation, unless they both had early prototype versions.

On Wednesday, March 4, 2020 at 8:18:59 AM UTC-6, wrote:
I was rewatching the SunShip Game since its raining cats n dogs down here.. I noticed both Moffat’s and Drew’s open cirrus’s did not have total energy probes showing. What were those guys using back then to obtain reliable total energy or netto information? Im pretty sure they were flying before the days of electronic compensation, unless they both had early prototype versions.

While I am not an expert, I think there were several Devices to give TE, one was an insulated 'can' which may have been called a Schuman box, another was a device which used a flexible diaphragm.
The Schuman device (if that is the correct name) had at least 5 pneumatic ports and was the topic of much speculation about how it worked, I think if you shook it, it vibrated like it contained springs.
Any oldtimers have better information?
Scott

On Wednesday, March 4, 2020 at 9:46:20 AM UTC-5, Scott Williams wrote:
On Wednesday, March 4, 2020 at 8:18:59 AM UTC-6, wrote:
I was rewatching the SunShip Game since its raining cats n dogs down here. I noticed both Moffat’s and Drew’s open cirrus’s did not have total energy probes showing. What were those guys using back then to obtain reliable total energy or netto information? Im pretty sure they were flying before the days of electronic compensation, unless they both had early prototype versions.

While I am not an expert, I think there were several Devices to give TE, one was an insulated 'can' which may have been called a Schuman box, another was a device which used a flexible diaphragm.
The Schuman device (if that is the correct name) had at least 5 pneumatic ports and was the topic of much speculation about how it worked, I think if you shook it, it vibrated like it contained springs.
Any oldtimers have better information?
Scott

They were using diaphragm compensation that required a lot of fussing we don't have to do.
UH

On Wednesday, March 4, 2020 at 11:54:34 AM UTC-5, wrote:
On Wednesday, March 4, 2020 at 9:46:20 AM UTC-5, Scott Williams wrote:
On Wednesday, March 4, 2020 at 8:18:59 AM UTC-6, wrote:
I was rewatching the SunShip Game since its raining cats n dogs down here. I noticed both Moffat’s and Drew’s open cirrus’s did not have total energy probes showing. What were those guys using back then to obtain reliable total energy or netto information? Im pretty sure they were flying before the days of electronic compensation, unless they both had early prototype versions.

While I am not an expert, I think there were several Devices to give TE, one was an insulated 'can' which may have been called a Schuman box, another was a device which used a flexible diaphragm.
The Schuman device (if that is the correct name) had at least 5 pneumatic ports and was the topic of much speculation about how it worked, I think if you shook it, it vibrated like it contained springs.
Any oldtimers have better information?
Scott

They were using diaphragm compensation that required a lot of fussing we don't have to do.
UH

The 40-years-old Schuemann Box in my HP14 (the one built by Kai Gertsen) worked pretty well without any fussing. Too bad the wreckage got sold in an auction with that box included. Unless who bought it is rebuilding it, not recycling the aluminum. Sigh. (The glider was damaged on the ground, and the guy who bought it from me said he was going to restore it.)

On Wednesday, 4 March 2020 11:54:34 UTC-5, wrote:
On Wednesday, March 4, 2020 at 9:46:20 AM UTC-5, Scott Williams wrote:
On Wednesday, March 4, 2020 at 8:18:59 AM UTC-6, wrote:
I was rewatching the SunShip Game since its raining cats n dogs down here. I noticed both Moffat’s and Drew’s open cirrus’s did not have total energy probes showing. What were those guys using back then to obtain reliable total energy or netto information? Im pretty sure they were flying before the days of electronic compensation, unless they both had early prototype versions.

While I am not an expert, I think there were several Devices to give TE, one was an insulated 'can' which may have been called a Schuman box, another was a device which used a flexible diaphragm.
The Schuman device (if that is the correct name) had at least 5 pneumatic ports and was the topic of much speculation about how it worked, I think if you shook it, it vibrated like it contained springs.
Any oldtimers have better information?
Scott

They were using diaphragm compensation that required a lot of fussing we don't have to do.
UH

The diaphragm-type TE compensator was tee'd into the line going from the flask to the vario. The other side of the diaphragm was connected to pitot pressure. From my layman's perspective, when a glider zoomed up, normally air would flow out of the flask and through the vario to indicate lift. But as the speed dropped, the diaphragm that had been pushed out by higher pitot pressure (from higher airspeed) would return to its normal position, precisely matching the amount of air exiting the flask. So instead of the vario needle jumping wildly up in the "stick" thermal, it would move smoothly to the sink rate at the slower speed. That's what was supposed to happen if everything were adjusted properly, which involved adjusting the volume of the flask+tubing plus the diaphragm range.

The original [Wil] Schuemann box was a self-contained flask and bellows (instead of the rubber diaphragm of the ubiquitous PZL compensators) and included a small capillary that bled pitot pressure into the line between the flask and vario to exactly offset the air entering the flask through vario as the glider descended. So when everything worked, the vario read zero all the time except when in lift or sink. Magic!

The original Schuemann box had to be adjusted for one altitude range. The later model included a second bellows that adjusted the system for different altitudes.

IIRC, Wil Schuemann also included insulation on the outside of the flask and metal mesh inside to mitigate the effects of temperature changes plus gust filters that helped remove the effects of gusts without appreciably slowing the response times of the varios in use then.

I loved my Schuemann box, which worked very well. I flew mostly Eastern contests at the time so I seldom needed the altitude compensation once I got the box adjusted. It was a little bulky, had some steel in it (read: don't mount it directly below the compass), required some setup/config time, and once in a great while needed service from the maestro himself (apparently the big "can" was soldered shut). In the LS-3, I had to mount it behind the spars, which required very small diameter tubing runs forward to the vario to keep the total volume of the flask+tubing within limits. In addition to Wil's instructions for setting them up, there are tips and tricks for adjusting the netto for different gliders as well as when the plastic connectors break away from the brass pneumatic fittings.

But is anyone still using these?

Chip Bearden
JB

My LS-6a, winner of the 85 Worlds, had one.Â* That with the Scheumann
(Sage) variometer worked really well!

On 3/6/2020 12:19 PM, wrote:
The diaphragm-type TE compensator was tee'd into the line going from the flask to the vario. The other side of the diaphragm was connected to pitot pressure. From my layman's perspective, when a glider zoomed up, normally air would flow out of the flask and through the vario to indicate lift. But as the speed dropped, the diaphragm that had been pushed out by higher pitot pressure (from higher airspeed) would return to its normal position, precisely matching the amount of air exiting the flask. So instead of the vario needle jumping wildly up in the "stick" thermal, it would move smoothly to the sink rate at the slower speed. That's what was supposed to happen if everything were adjusted properly, which involved adjusting the volume of the flask+tubing plus the diaphragm range.

The original [Wil] Schuemann box was a self-contained flask and bellows (instead of the rubber diaphragm of the ubiquitous PZL compensators) and included a small capillary that bled pitot pressure into the line between the flask and vario to exactly offset the air entering the flask through vario as the glider descended. So when everything worked, the vario read zero all the time except when in lift or sink. Magic!

The original Schuemann box had to be adjusted for one altitude range. The later model included a second bellows that adjusted the system for different altitudes.

IIRC, Wil Schuemann also included insulation on the outside of the flask and metal mesh inside to mitigate the effects of temperature changes plus gust filters that helped remove the effects of gusts without appreciably slowing the response times of the varios in use then.

I loved my Schuemann box, which worked very well. I flew mostly Eastern contests at the time so I seldom needed the altitude compensation once I got the box adjusted. It was a little bulky, had some steel in it (read: don't mount it directly below the compass), required some setup/config time, and once in a great while needed service from the maestro himself (apparently the big "can" was soldered shut). In the LS-3, I had to mount it behind the spars, which required very small diameter tubing runs forward to the vario to keep the total volume of the flask+tubing within limits. In addition to Wil's instructions for setting them up, there are tips and tricks for adjusting the netto for different gliders as well as when the plastic connectors break away from the brass pneumatic fittings.

But is anyone still using these?

Chip Bearden
JB

--
Dan, 5J

Thanks Chip, I suspected them having schuman systems. My bro had one back in the day, fantastic once he got it all dialed in but it was definitely a chore. I would’nt mind having one even now.
Dan

Not sure when the Schuemann system was first available. In a quick search, I found what looks like an early ad for it in Soaring in 1973. We were using a tail venturi in the early 1970s. Wil was playing around with water ballast in his 301 Libelle before then and then diagnosing the drag chute deployment problem in his ASW 12 after that. But I'm almost certain the SunShip Game came before the Schuemann box. So: diaphragm compensator is my best guess: likely a PZL.

Chip Bearden
JB