Digital display of oil temperature and pressure?

[Richard Mole]

Rod, my projected complete panel weighs less than that.

Also I am wondering whether your stated weight includes the weight of the connectors?
And I guess there is a question over the advisability of stand-by electrical power and what that might weigh?

In general, there is always a fascinating tension between general purpose digital devices (eg standard issue laptop or PC) and those digital devices that are limited in function and/or by a 'controlling authority' eg some Apple products.

I think that for small aircraft it may well turn out (at the moment anyway) that installing a number of display devices with different failure modes may offer the balance of advantage over a single system where overall reliability has to be engineered by clever duplication and the rest.

Or put another way, the amateur mixing the best of the old with some of the new technology may get a good result - without incurring any significant probability of having by mischance installed a 'system' that could misbehave to the point where safety is compromised.

[Rod1]

On micros it is not a requirement to have any form of backup. Assuming a simple, single seat, VFR only machine, what is going to bite you?

“the amateur mixing the best of the old with some of the new technology may get a good result”

I would certainly agree with that. My mk1 and mk2 efforts combined glass and steam. The mk2, with the Enigma and two Infinity units plus 5 traditional instruments gives me two duplicate systems except for engine monitoring. With 18 months experience of running the two side by side I have found that;

Traditional instruments have a lot of lag. The computerised solution moves at least as fast as your “bum” when changing speed etc, the traditional solution is often way behind. When you get to a stable state, the traditional units catch up and all agrees.

By messing with different display options, you can, over time, optimise the display to your requirements / personal preferences. The MGL kit is very flexible and as you gain experience and confidence you can transition from pictures of standard instruments to more modern displays.

If you want to monitor all aspects of the engine, plus have an AH and magnetometer based DI, plus a GPS, then you will save a lot of weight. My old GPS was 2/3 the weight of my complete Enigma solution including wiring and connectors. A traditional electric AH would have put the enigma in credit and we have not even considered the DI + 12 engine instruments…

Having said all that I have decided not to go for a MK3 with all glass with imbedded radios + minimum backup. The first reason for this is cost / benefit. An all glass system will not increase functionality significantly over what I have, but it will cost around £3k on top of what I have already spent.

Secondly, modifying an existing panel is much harder than building from scratch. My last upgrade (the MK2) took me 150 hours from start to fully finished and calibrated.

Thirdly, is the ease of use. As the system is set up at the moment a “traditional” pilot could fly the aircraft with a short briefing, by ignoring the advanced features of the glass and using the steam plus the default Enigma page with engine info at the bottom. Full glass, with radio / transponder controlled remotely (not have them visible) etc etc would look wonderfully minimalist, be very efficient and I would have no problem driving it (having set it up) but it would take hours and hours to convert onto and frighten the traditionalists to death.

If you would like a “play” with my set up you are welcome to come over and have a flight.

Rod1

[Brian Hope]

'On micros it is not a requirement to have any form of backup. Assuming a simple, single seat, VFR only machine, what is going to bite you?'

Crap weather, unfamiliar terrain and the airspeed and altimeter go down. No thanks.

[steveneale]

I'm looking for a very light-weight digital display that will accept the inputs from standard automtive VDO senders ?

Stratomaster do various dispaly units eg the E3 is about 100g plus connectors.

Does anyone know of something lighter by any chance?

Richard we have an MGL E3 in our aircraft and the actual instrument weighs very little. I would say our analogue (VDO) oil pressure sender weighs more that the gauge. The wiring probably weighs more. So if you are looking to save weight the senders and wiring may be a better place to concentrate on. Digital senders are a lot lighter (but also a lot more expensive). We have our E3 wired to a red LED on the panel that acts as a master alarm for all the sensor inputs (including oil pressure warning) so we didn't need a dedicated sender for an oil pressure light. There is also a built in hobbs that you can program. We have ours set up to alarm on CHTs, voltage, oil pressure, temp and rpm over speed. You cancel an alarm by pushing the knob on the gauge. The only defect in the gauge is it will only take 4 thermocouple inputs so we use them for our 4 CHTs. Apart from that it's a gem.

Had you found their simulator?

http://www.stratomaster.eu/download/mgl ... ulator.exe


Steve

[Rod1]

“Crap weather, unfamiliar terrain and the airspeed and altimeter go down. No thanks.”

Brian, that is a reasonable comment if you are flying a Jodel. This is a single seat short-range micro. When I flew my Nipper it never got near crap weather. The chances of the unit falling are also tiny compared with engine failure. However the rules state no backup is required, so don’t shoot the messenger.

Rod1

[Bill McCarthy]

As a fuel gauge, what's wrong with the old tried and tested wire and cork device.

[Nick Allen]

Cork? Wire? That's far too heavy for Richard to contemplate!

[Brian Hope]

Hi Rod, micros (several over the years) have flown to Australia. However, Richard's aeroplane is not a microlight, it is a very lightweight single seater which will also be capable of long distance flights.
Did not intend to shoot the messanger, just making the point that a single failure of the type of electronic kit you are talking about for micros can leave you with nothing. Not a problem unless you are already in the soup. Agreed odds are small, but ekectronics in a micro in particular do take a fair hammering from vibration and potential electrical supply problems.

[Richard Mole]

Steve, thanks for your input. I also have an E3 in my Jodel and like it a lot. I would have used it in my new project except for the fact, or so I believe, it requires a 'proper' tacho sender unit and not just a wire wraparound the HT spark plug lead. But if I'm wrong on that point then do please tell me! I like the E3 and myJodel one is set up for tacho,oil P and T only as I have another display for 4 off CHT & EGT.

Nick, floats for showing fuel cotents can work fine - but not when the tank is behind your seat!

[Bill McCarthy]

Is Richard taking his project to Sywell. I'm itching to see his build ideas.

[ColinC]

Richard,

Are we talking about just measuring the volts out of a transducer for temp and pressure?

It should not be beyond our wits to design an led bar graph type of expanded scale voltmeter display for not many grams if such a thing is acceptable.

regards,

Colin

[steveneale]

Steve, thanks for your input. I also have an E3 in my Jodel and like it a lot. I would have used it in my new project except for the fact, or so I believe, it requires a 'proper' tacho sender unit and not just a wire wraparound the HT spark plug lead. But if I'm wrong on that point then do please tell me!

Ours is simply connected to the P lead on one mag (via a high ohm resistor) so no sender. If you have coil ignition you connect to the LT on the coil. It's all in their manual (page 25 in mine). They say any pulsed voltage between 5 and 100v will do the job.

Steve

[Richard Mole]

Steve,

thanks so much for that. Having now checked properly (!) I find that I do indeed have a Hall effect sensor output on the electronic ignition which will be perfect for the E3. Doh....I had just assumed.... or maybe its the big A announcing itself. So the E3 will display everything I need (tacho, 2 off CHT (& 2*EGT if I stomach the sender weight), oil temp, oil pressure warning light (& actual pressure if I fit the heavier sender).

Good job it will be directly in my line of sight as the display is pretty tiny (its in front of the passenger in my D18 and I have to lean across to get a decent chance of reading it).

Many thanks to everyone that helped. Its horrible to have to admit to being so muddled-headed but I guess it happens to all of use from time to time.

[Richard Mole]

thanks for the link - interesting stuff!