SAGE Total Energy System

[Bill Tisdale]

I appear to have what is a SAGE Total Energy System installed in my SGS 1-35C connected to a Winter Mechanical Vario 5-STV-5-3.

There are 6 connections at the top of the SAGE system. 2 are connected together, 2 provide Static and Capacity to the Winter vario, 2 receive Pitot and Static inputs.

Does anyone know the inner workings or plumbing of the SAGE system and how it works? My reading says the Vario is now a NETTO vario?

I would like to learn as much as I can about this system before it fails and I need to replace it.

I also have a Borglet B-40 vario connected directly to a TE probe with no other inputs.

Thanks

Bill

[John DeRosa]

I believe that you are speaking about the large Sage device that is a squat round foam insulated thing (not the slender tall type).  See the image below.

I was doing a panel rebuild back in 2015 when I first came across this device labeled B-526-0777.  When asking about it on old RAS I swear that someone sent me a picture of the interior of a pried open unit - unfortunately I can't find it.  

I did write to Sage about how best to use the device - which must have been forwarded as I received the following response from Rex Mayes of Williams Soaring.  

"What you have there is a Sage B box.  The box is a total energy compensator device.  When they work,, there is nothing better.  We do not have any calibrating technology or knowledge to support these any more. These boxes were replaced by the Compensated static probes call TE probes.  These boxes are very good to use as a second source of TE when multiple varios are installed and one wishes not to have them plumbed in parallel. There are also handy for motor gliders so one may have a vario unaffected by the prop wash. The down side is the space they take up or if they get damaged, there is no one who knows how to fix them. If you have the space to mount it, I would recommend using it.   Just hook it up according to the labeled ports."

Best of luck with your project.

- John (OHM)

[Bill Tisdale]

Thanks John, I believe that is what I have... the writing on top is all faded. It sits behind the lower instrument panel in my SGS 1-35C and connects to a Winter Vario.

Yes it is rather large. I have an "antique" Borgelt B-40 connected to a TE. I'll study the Winter more inflight and try to determine if it is acting more like a NETTO and not a standard vario.

I found that picture on one of your presentations which led me to believe that is what I have.

Bill

[John DeRosa]

You were looking at my "working with Glider Air Lines" presentation.  https://aviation.derosaweb.net/presentations/#airlines.  I realized that the Sage device images were mis-labeled as capacity bottles (flasks).  This has been corrected.

As I (dimly) remember that internal organs of the Sage device is that inside was only a bunch to tubing.  I do not remember any sort of capacity flask which would have stood out.  There may have been restrictors that would have basically been invisible.

Best of luck.  Keep us informed.

- John (OHM)

http://aviation.derosawab.net/presentations.

[John Iacobucci]

I attach most of my collection of writings on the workings (including diagrams) of the Wil Schuemann-Gene Moore Total Energy Sytem in PDF format.  It is a compilation of what I could find regarding the Total Energy System of Will Schuemann.  Included in the PDF is a diagram of a calibration workbench as well as the diagrams of the model "A" and model "B" sytems.  Within the attached PDF there is also mention of a 16mm movie made of the calibration workbench during an exercise of the calibration method that was shown to the audience during that particular Soaring Symposia.  At one time, the workbench for calibration was in a workshop in California by the proprietor who took over the Sage variometer business.  I inquired about the workbench and was told is presence is unknown.

I do know that the calibration was used to determine the length of a fine capillary tube, which was unique for a particular polar curve of a particular sailplane.  When the Total Energy System, also known as the "Schuemann TE Box", was connected to a Sage mechanical variometer one would obtain netto vertical airmass velocity.

I think it is entirely possible to reconstruct the method of calibration.  It would take someone with a substantial understanding of fluid dynamics and mathematics.

I wonder if that 16mm movie of the calibration testing is archived somewhere.  I believe that Gene Moore gave that very presentation.

I have heard that the clear U shaped tube that can be seen on the top of the cylinder of the Total Enery "B" box is very fragile and takes great care to disassemble/reassemble, to change the length of the capillary tube (for polar compensation).  That U shaped tube carries the capillary tube necessary for polar calibration from one compartment of the "box" to another, totally separated, part of the box.  Helmut Reichmann's book of Cross Country Soaring has a diagram of how this length of capillary tube is theoretically derived for a netto variometer.  It is quite useful to review this chapter as a basis of understanding the Schuemann-Moore variometer.  The difference between an "A" model and "B" model is that the "B" model had an addition mechanical mechanism for compensating for different static air pressure at different altitudes.

Good luck with your efforts.  If you make significant advancement in your quest, I would appreciate the news.

Sincerely,

John Iacobucci NB

[Bill Tisdale]

Thanks John!  I appreciate the document... I'll go through it. I just finished reviewing Reichmann's book on the "instruments". I'm afraid if I do anything with the box, I'll break something and it will never work again. I wonder how many are still out there.

Bill

[Gordon Wingate]

If anyone is trying to get a highly-responsive Sage vario to behave on a TE probe, know that you have to have a gust filter restrictor on the TE line. A capacity-style gust filter (fuel filter type) will not produce the right results. If the TE probe is supporting other slower variometers also the Sage vario is the only one that gets the restrictor. It should have its own line that Ts off from the other TE-driven vario(s) as far upstream toward the probe as possible. Attached is a document from Oran Nicks describing the design of his Nicks Tube TE probe and the effects of high-frequency gusts on sensitive variometers along with his recommendations on sizing restrictors. Also is a document from Peter Masak on how to size a restrictor for a Sage vario.

Gordon

[Chip Bearden]

Agree with Rex. I haven't seen anything better. That said, the Sage compensators (AKA Schuemann boxes) are old (50 years or so). The tubing can crack (there are smaller diameter tubes pushed over the brass fittings comprising the connectors that slip inside conventional instrument tubing and they get brittle, but are easy to replace). The stainless steel bellows (part of the TE system) inside can crack (not so easy to replace). The netto capillary (inside the tube connecting the two ports) can get clogged (easy to replace or clear). Or a small leak can develop. And they take up space. 

And if you have long lines running to it (e.g., if mounted back in the fuselage), the volume inside the capacity line is added to the 1/2 liter capacity of the bottle inside the box itself, which means that the bellows isn't large enough to compensate fully for TE purposes (the fix is to use smaller diameter tubing for the run from the instrument to the box, or to pour a small amount of epoxy into the connector with the box held carefully in a very specific position to partially fill the capacity--not recommended today!!). Wil Schuemann discusses how to leak test and calibrate the setup in articles and handouts that are still available in the Soaring archives and online. 

If you have one that works, use it!! Don't try to open it up. The netto capillary can, indeed, but tuned by installing longer capillaries (when your glider has higher performance) or trimming it (for lower performance) and it's not terribly difficult to make the swap, or disastrous if you crush or damage the capillary (it's just a piece of small-diameter plastic tubing). It works really well on a conventional (i.e., 1/2 liter capacity-based) mechanical or electric vario as-is (I believe there's an internal gust filter but not 100% certain). Don't trash it! It was a revelation in the early 70s when it debuted. Alas, Wil and one or two others were the only ones who could work on them. 

Chip Bearden

JB

[Bill Tisdale]

Thanks Chip! 

The one I have in my SGS 1-35C appears to work just fine. It is connected to a Winter Vario. The differences I see between the Winter and a Borgelt B40 on a TE probe make sense if the Winter is in NETTO mode because of the Schuemann box.

Bill