# Inexpensive engine monitor?

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#### Will Aldridge

##### Well-Known Member
Log Member
I got the specs for the screen so the pixel and character size would be accurate and redrew it for a rotary. Personally I think it turned out pretty decent for a first attempt, with room to add stuff if necessary. Fortunately the designer had space on the screen and circuit board for 6 egt and 6 cht gauges which means there's plenty of room for what I need. Just have to make sure it's reliable enough.

Edit: just realized Tracy Crook recommends a coolant temp gauge before and after the radiator so you know how effective your radiator is being. Probably going to move the EGT to the left, and oil and gly will switch places and add the second temp gauge.

S

#### SvingenB

##### Guest
Maybe these kind of DIY stuff will become the "new" thing in homebuilt ? I don't see why not. Flying VFR, the most important "instrument" today is the pad or phone, or whatever you use as a moving map, and this is good enough backup for alt and speed. The rest of the instruments is really more like nice to have, except maybe alt and ASI. Here in Europe we also need transponder and radio if we want to fly in controlled airspace, but these needs to be EASA certified anyway.

I mean. We need: A pad - transponder, radio (for controlled airspace)
The rest- might as well DIY IMO.

#### Will Aldridge

##### Well-Known Member
Log Member

Here's my revised layout which i think from a practical standpoint is actually very intuitive. The egt moved to under the tach which will help with leaning. Added an amp meter even though it's not on Tracy Crooks required list and added the Hobbs just because there was space available.

B Temp means before radiator and A means after with a delta T calculation added in for those of us like me that don't do simple arithmetic very well in our heads on the fly.

I'll have to see if i can rope my dad into helping me on this. This will be child's play compared to the stuff he designs and programs for work.

#### stuart fields

##### Well-Known Member
Thought for the Day: Mechanical Instruments

Agree or disagree, it's interesting food for thought.
I took a mechanical dual tachometer to a shop for an overhaul and re-scaling one of the two tachs to get an engine and rotor tach for my bird. The chief tech told me that if he was doing it he would go electronic. His experience with the mechanical tachs was frequent failures. He said a simple tach with two rows of led lites driven by a relatively simple circuit reading pulses from magnetic sensors would be more reliable and could be made for less than the overhaul and re-scaling I wanted. Not to mention the price tag on the tach generators needed to drive my tach was $250 ea. #### cluttonfred ##### Well-Known Member HBA Supporter These are not cheap but it could be fun for creating a custom instrument panel. The "5.5 Gauge Bargraph Analog Panel" would work well if you could figure out how to keep in tach mode and not alternate with the speedometer. Or you could get the DIY kit and leave out the speedometer. It would be fun to see the blank smoked plexiglas panel with just range arcs come to life when you power on. You might need a moving red light on the front of the cowling and have to call your plane "Kitt." ;-) https://www.intellitronix.com/product-page/6-gauge-bargraph-analog-panel https://www.intellitronix.com/product-page/create-a-dash-universal-gauge-kit #### ToddK ##### Well-Known Member HBA Supporter Belite has an engine monitor coming out. No pictures yet, but he is doing pre-orders for$499

PLEASE NOTE: Features and specifications may change; price is not completely firm; formal spec sheet is not published at this time.

Belite has developed a new Engine Monitoring System which captures and displays all common information for a Rotax 912UL / ULS engine and many other engine types. The information is displayed on a vivid, daylight readable color LCD display. User customization is possible, allowing different operating configurations for different pilot needs.

Other than a few truly scratchbuilt Arduino-based electronics projects that are more involved than I would be willing to tackle, the next best solutions I have found for relatively low prices are the MGL EMS E1 ($345 not including senders) and I have my eye out for their new color E2 model due out soon, price not yet set. To my eye, a flat panel display just doesn't suit something like a Pietenpol, Fly Baby, Volksplane, or other classic open-cockpit homebuilt. I could see integrating something like one of those MGL round gauges in among the analog airspeed and altimeter for a tidy panel. Otherwise, the best solution I have found are Speedhut custom auto gauges, say a quad OP/OT/Volts/Fuel and a separate tachometer,$380 for both or $570 if you want to add a separate CHT with warning light. #### Pops ##### Well-Known Member Log Member The go kart engine monitors I have seen such as those from Digitron are fairly expensive for what you get. For an ultralight with a two-stroke, then Trail Tech (TTO) series of digital gauges would do nicely, I like the surface-mount models because they come in three different colors, maybe tach (black), CHT (red), and voltage (orange) so they are clearly distinguished? All three together would run about$140 including the CHT sender. LIke the Tiny Tach, however, I don't think the internal batteries are replaceable, but that wouldn't stop me from opening one up to try. ;-)

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Other than a few truly scratchbuilt Arduino-based electronics projects that are more involved than I would be willing to tackle, the next best solutions I have found for relatively low prices are the MGL EMS E1 ($345 not including senders) and I have my eye out for their new color E2 model due out soon, price not yet set. View attachment 73353 View attachment 73354 To my eye, a flat panel display just doesn't suit something like a Pietenpol, Fly Baby, Volksplane, or other classic open-cockpit homebuilt. I could see integrating something like one of those MGL round gauges in among the analog airspeed and altimeter for a tidy panel. Otherwise, the best solution I have found are Speedhut custom auto gauges, say a quad OP/OT/Volts/Fuel and a separate tachometer,$380 for both or \$570 if you want to add a separate CHT with warning light.

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My Tiny Tach internal battery lasted 5 years. I dug in the potting on the left rear and found the little 3V round battery, removed battery and solder wires to the terminals. Epoxed back smooth. Bought a battery holder for 2 penlight dry cell batteries and wired up for 3 volts. Note-- Changed batteries every year but would take another set of 3V batteries with alligator clips to the battery holder terminals while changing batteries so to not lose the hours listed. Loose 3 Volts to the Tiny Tach and you lost the hours displayed. Still working since 2007.

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