Guest Posted December 23, 2008 Share Posted December 23, 2008 I am going to get a stock of tanks in for you lot SW Quote Link to comment Share on other sites More sharing options...
huffhuff Posted December 23, 2008 Share Posted December 23, 2008 Will that work Nick? i'm just thinking the fuel tank is likely to be opaque in most cases. Also, if it does work and you set the pot when sun was shining, it could cause problems if it gets darker etc? I'm no expert though so more than happy to be wrong!?! Quote Link to comment Share on other sites More sharing options...
woody Posted December 23, 2008 Share Posted December 23, 2008 you might be right Ben, and as I said its cheap enough to build and tinker around with That could also be true of any opto-sensor device, although to measure fuel accurately you need to use a capacitance probe. I have a circuit for one of those, wich is cheap enough to build, but getting the probe right would be expensive. Woody Quote Link to comment Share on other sites More sharing options...
huffhuff Posted December 23, 2008 Share Posted December 23, 2008 Yep, capacitance is the way really. You don't need to drill holes in the side of your tank either. But I like this idea. The fluid literally disrupts the optical flow. Also just found this, but can't find a price yet... http://www.gemssensors.com/content.aspx?id=2340 Quote Link to comment Share on other sites More sharing options...
woody Posted December 23, 2008 Share Posted December 23, 2008 I agree, but dont want to drill my tank. Maybe this could be modified.... although I haven't looked in to it. http://www.airstuff.com/fuelmon.html Woody Quote Link to comment Share on other sites More sharing options...
edwardc Posted December 23, 2008 Author Share Posted December 23, 2008 A lot of good ideas on this subject (particularly Simons idea of stocking up on fuel tanks!). Ben/Woody If I were to be prepared to fit a float switch (or switches) in my tank can you advise what I would need for the LED part, ie battery, LED, resistors, wiring diagram etc. maplins numbers would be great. Cheers Eddie Quote Link to comment Share on other sites More sharing options...
huffhuff Posted December 23, 2008 Share Posted December 23, 2008 Sorry, I have one final revision which I think is better all round. This is a 3/4 position float device. It can be controlled simply (ie, no TTL/CMOS circuit) and will take power from either onboard 12v or PP9 9v 'square' battery (or even AA's if you prefer). There will be no drilling the tank, but you will need to drill the filler cap. The sensor will be a 1" threaded mounting into the cap (cap easily and cheaply replaced). As there are 3/4 positions, it can easily drive corrosponding LEDs (green for full, orange for half, flashing red for low). I'm waiting for a price but it is much cheaper than the optical sensors. The opticall sensors would be affected by ambient infrared light and various other factors. This new sensor works with reed switches so is magnet based. Quote Link to comment Share on other sites More sharing options...
irm750 Posted December 23, 2008 Share Posted December 23, 2008 Just seen this on ebay. Got all excited at first and then a bit disappointed. Gordon will be happy though! http://cgi.ebay.co.uk/Paramotor-Petrol-Checker_W0QQitemZ360118551386QQcmdZViewItemQQptZUK_SportingGoods_OtherSports?hash=item360118551386&_trksid=p3286.c0.m14&_trkparms=72%3A1298%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318 Quote Link to comment Share on other sites More sharing options...
nirmal Posted December 23, 2008 Share Posted December 23, 2008 There is quite a lot of splashing in the tank from the engine and prop vibrations. Liquid level sensors will probably not be very sensitive. The fuel level would have to fall much lower than the level of the sensor before splashing is a non issue. Capacitance is the most reliable method, but is complicated unless you are good at electronics and it is the most expensive. I think magnetic reed switches will probably be the cheapest electrical option that has a good chance of working. The key to making it work would be to have a narrow bore tube for the magnetic float and pin hole sized openings at the top and bottom of the tube to allow air/ fuel to flow in or out slowly enough to reduce the effects of splashing. The added bonus is that drilling holes in the tank can be reduced or even avoided. The cheapest option is to stick a small mirror onto a ski pass holder, and clip it to your belt or flight suit. You can simply pull it out to have a look at the tank whenever you feel the need to, and it safely retracts out of the way by itself when it is not needed. Quote Link to comment Share on other sites More sharing options...
nirmal Posted December 23, 2008 Share Posted December 23, 2008 Just seen this on ebay. Got all excited at first and then a bit disappointed. Gordon will be happy though!http://cgi.ebay.co.uk/Paramotor-Petrol-Checker_W0QQitemZ360118551386QQcmdZViewItemQQptZUK_SportingGoods_OtherSports?hash=item360118551386&_trksid=p3286.c0.m14&_trkparms=72%3A1298%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318 That is nearly £20 (including shipping) for something that you can make for about 2 or 3 quid Someone is taking the piss Quote Link to comment Share on other sites More sharing options...
Guest Posted December 23, 2008 Share Posted December 23, 2008 I have used a mirror for years. (polished stainless) Main thing to do is know how long your motor will fly for. Then fill it up each flight, add some 'ullage' and bobs your uncle. Running out of juice is not always a bad thing! I have found one of my private flying sites by running out of petrol on return from a long XC. That said, I like the idea of a fuel gauge of some sort. ANOTHER TOP TIP!!!!! Carry a 200ml bottle of 2 stroke (any garden shop) with your motor at all times! then you don't have to worry about running out of petrol. I landed at someones house a month or so ago and he had no 2 stroke but loads of petrol. Also... saves buying a 1L of 2 stroke and binning most of it. and yes... I have one in there now and it's always there in the side pocket. SW Quote Link to comment Share on other sites More sharing options...
gordon_dunn Posted December 23, 2008 Share Posted December 23, 2008 I don't want to get drawn into the fuel sensor debate again because i belive it's a waste of time- you can't beat a mirror- either attached to the harness on a lanyard, or on the cuff of your flightsuit sleeve. Anyway i've been thinking about the problem/solution- i really don't like the solutions being proposed, as they mainly tell me when the fuel level passes pre-defined levels.... they don't actually tell me how much fuel is in the tank at any given point. Perfect for your home heating oil tanks, but not for paramotors . None of the solutions aired have any regard for splashing either- rendering them quite useless. Perhaps the solution would be to not measure how much fuel is in the tank, but how much air has been drawn into the tank via the vent during the flight- this would be immune to the effects of splashing, would work in almost any flying orientation, and would provided a potentially infinite range of readings between 0 and 10 litres. The volatility of the fuel could trigger a slight level of incuracy, but it would be better than float switches, LDRs or reed switches. The problem would be accurate measurement of the air though the vent...... perhaps a mechanical solution, as opposed to electronic. Whatever the solution is, it must be easy used (easier than a mirror), cheap, reasonably accurate, infinitely calibrated, and easily installed. GD Quote Link to comment Share on other sites More sharing options...
phatboy Posted December 23, 2008 Share Posted December 23, 2008 The solution that I use is; I completely drained the tank. Then added 0.5L of fuel as a reserve. Then added 1 litre, marked the tank with a permanent marker, added 1 litre & remarked & so on until full. I also marked half full with a bigger mark, also qty of fuel written in mirror image. Yes I did mark it up while it was being hang tested to get the angle of dangle. Pictures in my picasa web album http://picasaweb.google.co.uk/paulwally ... 9847311842 I hope this helps. I just find that simple things usually work best. Paul Quote Link to comment Share on other sites More sharing options...
gordon_dunn Posted December 23, 2008 Share Posted December 23, 2008 Phatboy, Similar method, but replacing the marker pen with a vinyl cut decal Position the 1 litre mark 80mm from the bottom of a standard H&E 10l tank and you've got a 500ml reserve too. The numbers are reversed so that you can read easily with the mirror. 'Negative cutouts' of the numbers have been used so that the surface area of the decal has been maximised, to minimise the risk of petrol dissolving the adhesive. First version i did had individual marks and numbers... gradually they all came off. This new version has been on my tank over a year now. Quote Link to comment Share on other sites More sharing options...
t_andrews Posted December 24, 2008 Share Posted December 24, 2008 Fuel Gauge: http://www.ultralightnews.ca/fuelsystem/fuelgauge.html These folks have been impossible to get a response from tho... Regarding Simon's suggestion, I found a 200ml bottle locally as a child's pop/soda bottle at my local megagrocery. Sturdy cap that won't come loose and bottle is a little thicker than the thin walled plastic bottles that are common here (Eastern Canada). Probably the same blank used for 200ml as 500ml. unlikely to be punctured. About the size of an apple. Good advice that if you expect to drop in somewhere to top up and certainly worth the flight weight of 10L mixed for the flight home. Nice decal post too - snagged me a copy, thanks. Quote Link to comment Share on other sites More sharing options...
gordon_dunn Posted December 24, 2008 Share Posted December 24, 2008 Also thinking too... instead of a bottom end sensor, perhaps a header tank would be a better option- these are always mounted in a very prominent visible position- when you see it starting to drain, you'll know exactly how long you've got to land safely. I remember running out of fuel in my 5th or 6th flight- I was at 3000ft or so, and to be honest i'd a lot of time to get back down- landed back at the field easily. Quote Link to comment Share on other sites More sharing options...
edwardc Posted December 24, 2008 Author Share Posted December 24, 2008 What a great response to, what I thought, would be an easy question! Loads of great ideas and I am sure that between us we will find a cheap option for a ,reserve, light or better. Meanwhile I would like to wish everybody (except the scum that stole Pete's equipment) a great Christmas and a Blue sky new year. Cheers Eddie Quote Link to comment Share on other sites More sharing options...
Phil_P Posted December 24, 2008 Share Posted December 24, 2008 The most elegant solution in my opinion is to use a flow sensor in the fuel line. Tell the system the capacity of your tank and reset when you refill. Then you get a current burn rate, plus fuel left, plus time to empty at current burn. The only problems other than cost that I can see are a) the low consumption of our motors makes it difficult to find a sensor to read at that rate, and b) air bubbles in the line, a perennial problem with mine, make readings on these sensors inaccurate. Quote Link to comment Share on other sites More sharing options...
nirmal Posted December 26, 2008 Share Posted December 26, 2008 I remember reading somewhere about someone trying out a flow sensor and they experienced the very problem you mentioned. The lightweight cheap flow sensors were highly inaccurate because of the low fuel consumption rates. The more accurate ones were too expensive and bulky to be of any practical use. Quote Link to comment Share on other sites More sharing options...
edwardc Posted February 6, 2009 Author Share Posted February 6, 2009 I would like to thank all the contributors to this thread and I am sure you are all dying to know what I decided in the end. I marked the tank as per Gordons stencil and bought a mirror on a retractable line! Thanks again Eddie Quote Link to comment Share on other sites More sharing options...
gordon_dunn Posted February 6, 2009 Share Posted February 6, 2009 Wisdom prevails! Although i must admit to a rather funny incident that reminded me of this thread.... I was flying 2 weeks ago on my R80 machine..... I have 2 paramotors..... but only one fuel guage mirror.... Into the flight i realised that i hadn't changed the mirror over from my R120 machine, and knew that i wouldn't be able to check the fuel guage.... I was contemplating turning back and landing- as i was not prepared to take any risks, then i came up with an instant solution- something i'm sure nowone has thought of before.. I used my camera- just held it- pointed it at the tank and then was able to review the picture i'd jsut taken- perfect fuel indicator... given the situation i was in. Quote Link to comment Share on other sites More sharing options...
alan_k Posted February 6, 2009 Share Posted February 6, 2009 Brilliant thinking Gordon, making use of the tools available. Safe flying, Alan Quote Link to comment Share on other sites More sharing options...
edwardc Posted February 6, 2009 Author Share Posted February 6, 2009 On board CCTV now thats an idea we missed LOL!!!!! Quote Link to comment Share on other sites More sharing options...
alanhinsaudi Posted February 6, 2009 Share Posted February 6, 2009 Edward de bono would be proud of you! Quote Link to comment Share on other sites More sharing options...
dantheman Posted September 2, 2009 Share Posted September 2, 2009 I have spent the last 2 years timing my flights to the fuel burn, and occasionally taking a photo of the fuel level to double check. Thing is with photos I usually get all sky or an arse cheek in the photo instead of my tank, and last time I was up I found myself looking round to try to take the photo more accurately and guess what I saw - the fuel tank half full of fuel in clear view Quote Link to comment Share on other sites More sharing options...
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