toto Posted January 19 Share Posted January 19 Once a models engine is " set up ", is there any benefit in having a digital tachometer fitted onboard that can be visible sya .... in the cockpit or any other appropriate siting ? I am thinking specifically of with my two Stinger petrol two strokes which are destined for my Flybaby and my Valiant. My reasoning is that once you fire up the model, you would get a reasonable indication of its idling speed etc just by looking at the onboard tachometer if made visible. Toto Quote Link to comment Share on other sites More sharing options...
Outrunner Posted January 19 Share Posted January 19 No benefit. Quote Link to comment Share on other sites More sharing options...
Eric Robson Posted January 19 Share Posted January 19 I bought an unused petrol engine of a fellow club member it came with a tachometer and the instructions said to disconnect the tachometer before flying. I have only used it once and found it confirmed my settings were correct. As the flights were OK I did not need to change props or settings so it remains unused. I t may have a use someday if I can remember where I put it🙂 Quote Link to comment Share on other sites More sharing options...
toto Posted January 19 Author Share Posted January 19 Sounds like a non starter. It would have been good if it were possible to send data down to the transmitter to give an indication of what's happening in the air as well as initial idling speeds. Toto Quote Link to comment Share on other sites More sharing options...
leccyflyer Posted January 19 Share Posted January 19 You can fit a tachometer to give that information via telemetry, if you really want to, but to be honest you are better off just learning how your model(s) fly at different throttle settings. Strikes me that the most useful telemetry is that which is provided as audible warnings - perhaps via an earpiece to avoid annoying others on the flightline - I know some folks have a constant inflight readout of say battery voltage, which they then use to determine whether it's time to land or if there are any issues in flight. 3 Quote Link to comment Share on other sites More sharing options...
Outrunner Posted January 19 Share Posted January 19 It's best to concentrate on what the model is doing rather than how fast the engine is going. If the engine slows down the model descends, if the engine speeds up the model climbs. Simple. But you must concentrate on flying the model at all times. 2 Quote Link to comment Share on other sites More sharing options...
Jon H Posted January 19 Share Posted January 19 36 minutes ago, Outrunner said: No benefit. Agreed Tach's are handy for comparing props, and getting a general idea of engine performance but they are not an every day use item. 1 Quote Link to comment Share on other sites More sharing options...
steve too Posted January 19 Share Posted January 19 27 minutes ago, toto said: It would have been good if it were possible to send data down to the transmitter to give an indication of what's happening in the air as well as initial idling speeds. I have a petrol model with a petrol engine and rpm telemetry. I installed it more out of curiosity than anything else, but it is useful on landing where, due to a combination of the nature of the model and the size of the patch that I fly from, I find a low rpm alarm is useful. 1 Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted January 19 Share Posted January 19 As said, ok to verify different settings on the ground, but no use in the air, the only way to see haw a prop performs on your plane is to fly it. I did post the other day a video with a camera inside my Dle 20Ra with its 'pipe', just to see what sort of rpm it delivered on different props in the air, and boy was I surprised at the difference !. A 16 x 8 master airscrew gave me 8.800 rpm on the ground and 11.800 in the air, I did it only to see what sort of tip speed a prop would need to give it that screaming sound. 1 Quote Link to comment Share on other sites More sharing options...
toto Posted January 19 Author Share Posted January 19 Thanks for the responses chaps, By the sounds of it they have definite but limited use .... mainly on the ground. It's always worth throwing the question out there though. Toto Quote Link to comment Share on other sites More sharing options...
Nigel R Posted January 19 Share Posted January 19 1 hour ago, toto said: Once a models engine is " set up ", is there any benefit in having a digital tachometer fitted onboard that can be visible sya .... in the cockpit or any other appropriate siting ? I am thinking specifically of with my two Stinger petrol two strokes which are destined for my Flybaby and my Valiant. My reasoning is that once you fire up the model, you would get a reasonable indication of its idling speed etc just by looking at the onboard tachometer if made visible. Toto And what will you do with this information? Learn to walk before running, etc. Quote Link to comment Share on other sites More sharing options...
toto Posted January 19 Author Share Posted January 19 Not intended for anytime soon Nigel. Just thinking out loud. If you are able to monitor your rpm in the air does that ot give any feedback as to how well the engine is performing at various throttle inputs etc. ..... maybe not. Quite probable that most will be able to tell that by merely looking at the models reactions and sound anyway, merely asking the question. Toto Quote Link to comment Share on other sites More sharing options...
GrumpyGnome Posted January 19 Share Posted January 19 Unless you fit some better after market silencer to those Stingers, you'll easily hear any change in engine performance/revs....... and you won't need to take your eyes off the model. 1 Quote Link to comment Share on other sites More sharing options...
Brian Cooper Posted January 20 Share Posted January 20 I have an onboard tacho installed in one of my fleet. It is on the dashboard, and lives there with three voltage gauges. One for ignition battery voltage. One for the radio's lipo voltage (before regulator). And one for the regulated voltage going to the radio equipment. Radio battery voltage is monitored via telemetry so there is absolutely no point to them other than to add a bit of bling .... and kids having trial flights think it all looks seriously cool. 🤣 Gotta keep the kids' imaginations alight. Quote Link to comment Share on other sites More sharing options...
Nimiq4 Posted January 20 Share Posted January 20 9 hours ago, Brian Cooper said: I have an onboard tacho installed in one of my fleet. It is on the dashboard, and lives there with three voltage gauges. One for ignition battery voltage. One for the radio's lipo voltage (before regulator). And one for the regulated voltage going to the radio equipment. Radio battery voltage is monitored via telemetry so there is absolutely no point to them other than to add a bit of bling .... and kids having trial flights think it all looks seriously cool. 🤣 Gotta keep the kids' imaginations alight. When using LiPo's in more aerobatic electric models, I find LiPo pack voltage telemetry and setting up an alarm preferable to just elapsed time when deciding to land. LiPo pack voltage telemetry means I'm clear on the battery charge level and when it is time to land (typically I set for around 20-30%). No more engine shutdowns at inopportune moments.🤯 The only other "handy" telemetry is altitude for information when flying gliders and looking for lift. However as already commented, best to keep eyes firmly on the plane especially aerobatic ones! 1 Quote Link to comment Share on other sites More sharing options...
Rich Griff Posted January 20 Share Posted January 20 Hi toto, never be afraid to ask ! Have a great day, the white stuff has disappeared here only to be replaced by the wet stuff, grrrrrrrrrrrr 1 Quote Link to comment Share on other sites More sharing options...
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