Frank Skilbeck Posted January 9, 2018 Share Posted January 9, 2018 Jon the Rexcel opto electronic switches are very good, plus if you lose power to the rx the switch cuts off the supply to the ignition too. Link to comment Share on other sites More sharing options...
Chris Walby Posted January 9, 2018 Share Posted January 9, 2018 Cheers, Firstly mine does not have a ball joint, only a L bend and clevis on the servo end. Although point taken about servo failure. I fly 8 minutes and its more than 1/2 way through a tank although at 1/4 throttle I am likely to take a lot longer to finish the rest off!. Can't see how you can cut a glow if the throttle servo has failed unless you do the same as the pylon guys and pinch the fuel line. With luck another club member might bring a seat and some tea out while you wait! The question related more to logging the total run hours, but as you say its very variable so I'll just have to fly some more and work it out myself oh drear what a shame having to listen to that lovely 4 stoke cruising around the sky. Link to comment Share on other sites More sharing options...
Geoff S Posted January 9, 2018 Share Posted January 9, 2018 Posted by Martin Harris on 09/01/2018 21:19:45: Just be very sure that the ball joint retaining nut is securely locked - a detached linkage, partial throttle on an economical engine and a large tank can make time drag a little... Yes, I use cyano on the threads. At this time of year it gets dark early, too I'll look for a smaller tank. Geoff Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted January 9, 2018 Share Posted January 9, 2018 Posted by Chris Walby on 09/01/2018 22:15:07: With luck another club member might bring a seat and some tea out while you wait! We've certainly played pass the transmitter on a couple of occasions over the years... Link to comment Share on other sites More sharing options...
Jon H Posted January 10, 2018 Author Share Posted January 10, 2018 Posted by Frank Skilbeck on 09/01/2018 21:48:16: Jon the Rexcel opto electronic switches are very good, plus if you lose power to the rx the switch cuts off the supply to the ignition too. one of these little chaps? https://www.ebay.co.uk/i/322868605760?chn=ps&adgroupid=49939730778&rlsatarget=pla-380792705664&abcId=1129946&adtype=pla&merchantid=118959099&poi=&googleloc=1006786&device=c&campaignid=974198600&crdt=0 Edited By Jon Harper - Laser Engines on 10/01/2018 08:59:11 Link to comment Share on other sites More sharing options...
Ron Gray Posted January 10, 2018 Share Posted January 10, 2018 They're the ones that I use on all of my gassers Jon, work a treat. Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted January 10, 2018 Share Posted January 10, 2018 That's the one, you'll need to put it on a separate channel (unlike an on-board glow driver) and you can switch it on and off from your transmitter then. I have mine on the same switch as the throttle cut, but not all radios allow a switch to be used for two duties. Link to comment Share on other sites More sharing options...
bert baker Posted January 10, 2018 Share Posted January 10, 2018 I use both RCExele and Mr RC World switches, The advantage of mr rc word is ic can be set up so it won't cut out if signal is lost. Link to comment Share on other sites More sharing options...
Jon H Posted January 10, 2018 Author Share Posted January 10, 2018 Nice. I will get a few on order as im sure they will come in handy. My tx has 8 channels and the stampe only uses 4 so its easy to sort that out. Link to comment Share on other sites More sharing options...
bert baker Posted January 10, 2018 Share Posted January 10, 2018 In my opinion, all petrol engines should have them, Link to comment Share on other sites More sharing options...
Ron Gray Posted January 10, 2018 Share Posted January 10, 2018 @Bert, I'm with you on that one. On of our club members had his kill linked to the throttle so that on minimum throttle the engine would cut out. However, the electronic, Rexcel type ones give instant cut, safer IMO. Link to comment Share on other sites More sharing options...
Geoff S Posted January 10, 2018 Share Posted January 10, 2018 I have 3 ways of killing the engine on my Super Stearman/ Mackay 30cc petrol engine. The 'kill' switch on the transmitter closes the throttle right down; a second switch enables/disables the ignition via a Rexel electronic switch; or, if the model is on the ground, I can physically switch off the ignition battery. Geoff Link to comment Share on other sites More sharing options...
John Stainforth Posted January 10, 2018 Share Posted January 10, 2018 I am of the view that *all* model aircraft should have a kill switch for the engine set up in the TX. I think this is as important as a radio failsafe - or more so. But as far as I can see the BMFA and the clubs are not insisting on this. (Mind you, many clubs are pretty lax on the failsafe requirement.) Link to comment Share on other sites More sharing options...
Jon H Posted January 11, 2018 Author Share Posted January 11, 2018 Part of my training role at my club is making sure students understand how their failsafe works and what its for. I think its important the function is used where available. Personally though i would not turn off the engine with my failsafe as i would like to still have it should the radio come back. Also the sound of the idling (and it must be idle) engine can help alert those below the model to its approach. Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted January 11, 2018 Share Posted January 11, 2018 Posted by John Stainforth on 10/01/2018 22:54:48: I am of the view that *all* model aircraft should have a kill switch for the engine set up in the TX. I think this is as important as a radio failsafe - or more so. But as far as I can see the BMFA and the clubs are not insisting on this. (Mind you, many clubs are pretty lax on the failsafe requirement.) How can you as a modeller post that ? "many clubs are pretty lax on failsafe requirement" what evidence do you have to support the claim that, many clubs operate unsafely and don't follow correct procedure. I have no evidence myself of what other clubs do, but I'm confident they don't fit your description. Link to comment Share on other sites More sharing options...
bert baker Posted January 11, 2018 Share Posted January 11, 2018 It's his Veiw, I am a member of many clubs, and at no point so far has any one or a safety officer ever asked me to display that my fail safe is working. Perhaps this needs to have its own thread Link to comment Share on other sites More sharing options...
bert baker Posted January 11, 2018 Share Posted January 11, 2018 Getting back to technical stuff, I have a 150 that was original fitted with a straight cylinder it came to me as a rebuilt engine but using the barrel shaped cylinder, so would it remain as a 150, Link to comment Share on other sites More sharing options...
David Holland 2 Posted January 11, 2018 Share Posted January 11, 2018 Bet that hasn't got much compression!! (sorry) Link to comment Share on other sites More sharing options...
Jon H Posted January 11, 2018 Author Share Posted January 11, 2018 Posted by bert baker on 11/01/2018 11:09:34: Getting back to technical stuff, I have a 150 that was original fitted with a straight cylinder it came to me as a rebuilt engine but using the barrel shaped cylinder, so would it remain as a 150, The external barrel shape was purely cosmetic so nothing will have changed Link to comment Share on other sites More sharing options...
Ron Gray Posted January 12, 2018 Share Posted January 12, 2018 Is there enough space between the carb on my Laser 155 and the bulkhead? Hopefully there is otherwise I’m going to have to cut and build an air channel. Link to comment Share on other sites More sharing options...
Chris Walby Posted January 12, 2018 Share Posted January 12, 2018 Jon will be able to give a definitive answer, but my 2p is it will be okay (might not get the absolute maximum last fraction of full power) but if you look at the K&N filter web site they supply engine air filters (all be it for much larger engines) pan head filters that are shorter than their inlet diameter. at least it won't be sucking a load of dust and runway debris if its tucked away. PS in theory I think you need about 5 diameters to get close to laminar flow, but I haven't see an inlet tract that long as its not really practical plus that's assuming you are at full throttle most of the time! Link to comment Share on other sites More sharing options...
Jon H Posted January 13, 2018 Author Share Posted January 13, 2018 you might just get away with that one Ron. If you find the engine is slightly erratic in flight then you likely have some turbulence over the intake and will need to make a small mod. Its up to you if you want to try it in the air or just mod it now and be done with it. if you do it now don't go mad, just take a small section out about the dia of a 2p. you can then back fill with either a balsa block or use the cardboard inner from a roll of covering. Once done paint it up with thinned epoxy and you are good to go Link to comment Share on other sites More sharing options...
Ron Gray Posted January 13, 2018 Share Posted January 13, 2018 Thanks Jon, I was thinking of using a half section of a bit of plastic pipe epoxied in position making an air channel to the underside. Link to comment Share on other sites More sharing options...
Jon H Posted January 13, 2018 Author Share Posted January 13, 2018 Posted by Ron Gray on 13/01/2018 16:30:19: Thanks Jon, I was thinking of using a half section of a bit of plastic pipe epoxied in position making an air channel to the underside. yup, that will work nicely Link to comment Share on other sites More sharing options...
Chris Walby Posted January 14, 2018 Share Posted January 14, 2018 Now with half a tank of fuel run through the Speed Air (Laser 70) I have really started to explore the flight envelope and had a couple of problems this morning (one self induced so does not count!). First up after a number of successful stall turns, the next at full throttle and then as I eased it to 1/4 throttle it seemed to momentarily "cough" and as I turned to vertical down it slopped. Dead stick back on the runway although the hedge did look a bit taller than normal. Based on the need to make it richer by 1/3 of a turn to get it through the noise test and stop it dying at full throttle I backed it off 1/2 a turn (leaner) went for another fly. All seemed okay until I did a long slow low fly pass and throttled up and it died, this time I had no option but land in the adjacent field (very soft mud). Thus I went back to previous setting plus another 1/4 turn richer. Flew ok but did cough once on another vertical climb. Most flying at 1/4 to 3/4 throttle with short duration at full say 5 seconds max. Throttle response seems ok and issues appears in latter part of flight time (land with 1/4 tank left). Okay question time! 1/ In the vertical position the fuel level is furthest from the carb by about 6 inches (with tank 1/4 full) would this be pushing my luck (especially if I progressively back the throttle off to idle for the stall turn)? 2/ I have a nice loop from the tank to the carb, should this be ?as short as possible as it just adds effective negative head as the fuel has to go higher than the carb 3/ As the temperature was 10C today which is about 10C warmer than most of the other flights, which way does the mixture drift with temperature? The higher ambient air temperature the leaner its runs or is it richer? Just so I am ready for when it warns up! Current flight score for 2018 IC flights = 10 Electric = 4 Link to comment Share on other sites More sharing options...
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