shaddin digaflo-l

[rick bell]

anybody have a shaddin digaflow-l and have an indication on one engine go to zero, if so was it software or an mechanical malfunction. if mechanical what was it? shaddin is taking thier time responding and i'm assuming someone may have experienced the same problems, if i would appreciate any suggestions.
1973 p337
thank you rick

[Bob Cook]

Rick

Could be defective sending unit, or it coud be some dirt foulded it up.

Suggest swapping sensor leads to unit then you know if it is the sensor or the unit.

My opinion it is the sensor at fault! Most of the circuit in the Shadin handles both inputs except for the pulse count (digital) from the sensor.

Most likely a dirty connector or poor connection causing the problem.

Is it intermittent or has it completely failed ?

Bob

[rick bell]

I'LL TRY SWAPING LEADS. FRONT ENG WINDOW STAYS COMPLETELY BANKS. THANK YOU RICK

[rick bell]

the cannon type plug locking tabs were not locked back down and nine months of flying after the new avonics package was installed led to the minor vibrations having the plug work loose.
it's very hard and time consuming to try to doubble chech everything after major mods. when someone sticks thier hand into small cramped areas the may distrube something, especially ages and brittle wiring, hoses ect. thanks for all the suggestions
rick

[Bob Cook]

Rick

You are absolutely correct. Big hands do no go together with skymasters. I have had numerous problems after work has been done in the avionics bay.

As a matter of interest, if you have a KCS-525 compass system or a flux gate compass and the DG becomes intermittent or appears to periodically stick; then check out the small 5 pin connector on top of the flux gate compass out on the port wing.

I spent, literally, thousands of dollars only to find out this connector was prone to corrosion. There is a BETTER connector out now (later version) that has better contact grip.

The avionics shop always seem to leave off the defroster hose on pax side as well as the cooling hoses to the lower portion of the radio stack!

Not surprized it was the connector, they usually are the first to generate problems.

Bob

[Ron Ball]

I had same problem 3 times, in last few months. Rear went blank for 5 min or so and recovered. Happened after new engine installed. Will check the connector.

[rick bell]

shaddin finally got back with me and e-mail a trooubble shooting guide plus wiring diagrams. if anyone wishes this info send me your e-mail and i'll attach it back to you(haven't figured out how to do any atchment from this spot.

rick

[Ron Ball]

Rick, my e-mail is rball@goodmanball.com. I fly a 1973 P and a T-337-B 1967 Would like the data

[rick bell]

Originally posted by Ron Ball
Rick, my e-mail is rball@goodmanball.com. I fly a 1973 P and a T-337-B 1967 Would like the data
i just emailed webmaster with the (3) pages to post. not real bright at making attachments so i used three mailings (my be better if he post it. if you want me to try, let me know and i'll try emailing you. same type 73p337

[kevin]

The following 3 messages are Rick's 3 files...

First page:

[kevin]

Actually, the board software noticed that two of Rick's files are identical, so there is just this 2nd attachment:

[Bob Cook]

Has anyone accurately tested the digiflo against usage ?
if so what were the results ?

Has anyone accurately calibrated a Digiflo against a known flow rate?

Does anyone have it connected to their GPS?

Bob

[kevin]

Another page from Rick

[kevin]

And another page from Rick. Total is four now.

[Mark Hislop]

Bob: I have used a digiflo in my 73 P337 for 4 years now, and in a Seneca II for 4 years before that. I find them to be extremely accurate, although I have only empirical data to back up my claim. I always keep the tanks full. If I fill the tanks myself, I'm always within .5 gallons per side. If I have somebody else fill up the tanks, I'm usually within 1-2 gallons per side, but I attribute this to differences in what the line guy considers to be full. Sometimes I'm off "over" and sometimes "under". The differences average out to be within my .5 gallons personal usage.

As a double check, I find that the fuel flows presented by the digiflo match almost exactly the book values for a given power setting, temp, and density altitude.

I highly recommend the Shadin system.

Mark

[rick bell]

Originally posted by Bob Cook
Has anyone accurately tested the digiflo against usage ?
if so what were the results ?

Has anyone accurately calibrated a Digiflo against a known flow rate?

Does anyone have it connected to their GPS?

Bob

have not tested accurately, just by knowen distances and setting and it seem close,
finall got mine hooked up to the gps(some of the older models of gps were not compatable, gx55 is)
rick

[Gord]

Bob - also use Shadins in my T337H, keep the tanks full, and am within 1 gallon per side when filling myself. Never have had any problems. Gord

[Bob Cook]

I have a Shadin as well, however, I found I needed to calibrate as after 6 or more partial fills, I found I was out be about 15 gallons per side (out of 74 gallons / per side.

I eventually made adjustments to more accurately reflect the actual flow. If you just fill the tank each time then I found the error to be within a gallon or two and within the accuracy of trying to fill the tank..

Guess we are dealing with accumulative errors and I was trying to compare notes. Not always able to just fill the tanks, consequently I end up with more fuel than anticipated.


Bob

[Kevin McDole]

Bob, I use Shadin DigiData systems in several aircraft and each exhibits their own small, but predictable error. In every case it errs on the "safe" side (says more fuel was consumed than actually was). The worst case unit indicates about 6% too high of a few burn. So when I fill it up, it takes a little less fuel than the Shadin predicts.

This should be a simple thing to calibrate - although I've never taken the trouble to do it. The fuel flow transducer has a "K-Factor" printed on its tag - and this number gets entered into the Shadin through a setup menu. The K-Factor is the number of pulses per gallon that the fuel transductor will output. As I recall, one of my units had a 28,500 K-Factor. To make the 6% correction I should be able to tell the Shadin that the K-Factor is 6% higher than the tags says. In other words, if I enter 30,210 into the Shadin it should cancel out the error.

I have no idea whether this is legal. You'd have to check with your avionics shop or Shadin to see what the rules are.

[Bob Cook]

Kevin

Re calibration

I was planning on doing this calibration. I find I am off about 6-7% over 500 gallons (same on each engine). There is a 1.5-2% difference between front and back engine.

When I go to add 120 gallons I can't get all the fuel in. This gets frustrating when you are running close to gross weight .... 180 lbs (or more) than requred. This is the error I need to correct. I am usually fighting a gross weight take-off.

Depends which error you can live with; too much weight or not enough fuel..........

I have the shadin interfaced to the kln90B which gives to fuel totals for EACH engine and alternate reserves if put in your flight planned route. Works very well.

The sensor values (K factor) are the same for each sensor which leads me to believe the sensor is not calibrated to a finite value.

Bob