chris edwards 3 Posted December 20, 2012 Share Posted December 20, 2012 hi guys am in the process of pricing up the parts nessary to build the agritug plane from the july 2011 plan. anyway to cut a long story short was pricing up when "dust up" came on on quest, and i said those regretfull words " i bet i could do that" and now im on the prawl to find a small but high velocety electric pump to to spray water out of a bar on the wings. anyone know of such a product or if there even is one on the market, if you do please let me now as this is one of my crazy ideas that i think might work and look pretty dam good in the process. chris Quote Link to comment Share on other sites More sharing options...
Tony Bennett Posted December 20, 2012 Share Posted December 20, 2012 why not just dump talc from a bomb bay under the center of the fuselage. Quote Link to comment Share on other sites More sharing options...
chris edwards 3 Posted December 20, 2012 Author Share Posted December 20, 2012 not a bad idea tony, if the pump idea is not going to work this will definatly be my plan B Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted December 20, 2012 Share Posted December 20, 2012 The trouble is that you can't scale water down and making the spray nozzles to work would be very hard. Quote Link to comment Share on other sites More sharing options...
chris edwards 3 Posted December 20, 2012 Author Share Posted December 20, 2012 i was just going to get some small copper pipe and dril some holes in it and see is we get spray. Quote Link to comment Share on other sites More sharing options...
chris edwards 3 Posted December 20, 2012 Author Share Posted December 20, 2012 going back to the talc idea, would bomb bays out on the wings work? Quote Link to comment Share on other sites More sharing options...
Former Member Posted December 20, 2012 Share Posted December 20, 2012 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Mr.B. Posted December 20, 2012 Share Posted December 20, 2012 I built a HM218 side wall hovercraft with a working fire monitor using a car windscreen washer pump and can say - 1)If you accidently leave the pump switched on it will burn out in about 60secs 2)It's dificult to get a scale looking atmosided spray. It looks more like a squirt from a water pistol. Quote Link to comment Share on other sites More sharing options...
Welshboy Posted December 20, 2012 Share Posted December 20, 2012 Pump from a caravan/camping shop. Spare sprayer nozzles are usually available from local agricultural merchants or from here if 3/8 pipeline isn't too big . **LINK** Quote Link to comment Share on other sites More sharing options...
IanR Posted December 20, 2012 Share Posted December 20, 2012 Hello Chris, would air pressure do it? Similar to a hand held garden spray system, perhaps even using their nozzles to provide a fine spray. An air retract system could be used to pressurise a reservoir on demand. Ian Quote Link to comment Share on other sites More sharing options...
Simon Chambers Posted December 20, 2012 Share Posted December 20, 2012 Using air pressure idea would be a good idea. No pump to fail, and probably lighter from the lack of additional batteries, pump and motor. For the nozzle, I reckon you could use a piece of brass tube and squash the end flat. Tubing you probably could use fish tank pipe and valves (to even out the two sides and control the spray pressue). I wonder if you'd need to put food colouring in or something to make it more visible as it is released in the air. Sounds a fun project! Si. Edited By Simon Chambers on 20/12/2012 21:25:04 Quote Link to comment Share on other sites More sharing options...
TheFlyingCrust Posted December 20, 2012 Share Posted December 20, 2012 Can you adapt the pressurising system from a Sparklets Soda Siphon. Just need a sparklets bulb per discharge. Alternatively in a cycle puncture repair hit I have (Halfords) there's a sparklets bulb with a brass adaptor to reflate a bike tyre rather than use a pump. Hmmmm. Now you've got me thinking! Ian Quote Link to comment Share on other sites More sharing options...
001 Posted December 20, 2012 Share Posted December 20, 2012 An empty soft drinks bottle (cola, lemonade etc.) will pressurise to a quite high pressure with a footpump or tyre inflator, can be wrapped for safety, costs and weighs very little. As used to propel toy rockets using air and water. (Not sure how big the plane is?) Test carefully before use. Quote Link to comment Share on other sites More sharing options...
Tim A Posted December 21, 2012 Share Posted December 21, 2012 Some late model cars have mist spray nozzles instead of the old water jet type. Probably the spray pressure is higher but adapting a pump and nozzles would be easier and less complex than using air pressure. Switched by a separate channel would be easy and in 40 years working on cars I can't recall burning out a pump motor (unless it was the old Lucas type) when the bottle was empty! Quote Link to comment Share on other sites More sharing options...
chris edwards 3 Posted December 21, 2012 Author Share Posted December 21, 2012 i think i will probably go with the windscrean washer pump idea as this will give me a consistant spray, only problem will be what batterys to use on it as im not sure what would be best to use the only reson im not going for the pressure spray at the moment is i dont know how i would seal the fill line and it would loose pressure really quickly. Quote Link to comment Share on other sites More sharing options...
chris edwards 3 Posted December 21, 2012 Author Share Posted December 21, 2012 have found this pump which i will probably buy,i have also found some spray nozzels from an irigation system kicking about in the garage, just need to find a switch and a battery to run it from. any ideas? Edited By chris edwards 3 on 21/12/2012 12:24:52 Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted December 21, 2012 Share Posted December 21, 2012 A standard 3S Lipo would power it just fine Chris......you'd only need a very small capacity too as I guess you wouldn't be running it for long. For fun you could power it via a brushed ESC connected to the throttle channel via a Y lead.......the pump would run faster as you opened the throttle..... & if you got a Lipo friendly ESC would protect the battery from discharging too far as well... Alternatively HK do a radio controlled switch which you could use to just turn it on & off again..... Quote Link to comment Share on other sites More sharing options...
chris edwards 3 Posted December 21, 2012 Author Share Posted December 21, 2012 what size 3s would be fine with it? and i was not going to have an esc running it i was planning on just having a on/off swith because it wount be running for long perods of time. Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted December 21, 2012 Share Posted December 21, 2012 As small as you can find!!!! Size & weight will be your problems here I think so how about this one I think your pump will take about 2.5 to 3A..... this Lipo should supply 4.5A at 25C. If your pump pulls 3A it will give you about 3.5 minutes continuous running which should be more than enough. Be aware that if you run the Lipo down too much you will ruin it......hence I wondered about a brushed ESC with Lipo support. If the voltage dropped too much the ESC would cut out protecting the battery. It would also allow you to fine tune the water supplied by the pump......if you had a spare proportional channel on a rotary dial you could connect the pump ESC to that & control the water flow that way...... Another method is to control the ESC with a cheap servo tester......use the servo tester to set the pump motor speed (by twisting the dial) & then just use an RC switch to control the battery power to the ESC.......happy to do you a drawing if you like..... Quote Link to comment Share on other sites More sharing options...
Tony Smith 7 Posted December 21, 2012 Share Posted December 21, 2012 I wonder if you could use a pressurised vessel and a valve, rather than a pump? Quote Link to comment Share on other sites More sharing options...
chris edwards 3 Posted December 21, 2012 Author Share Posted December 21, 2012 steve, if you could send me a drawing it would help me understand what you are saying. in turms of running the lipo down i would charge it after every flight, also dont think the water tank would hold enough water for 3.5 mins of running!! Edited By chris edwards 3 on 21/12/2012 14:14:05 Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted December 21, 2012 Share Posted December 21, 2012 OK lets try this.....first off if you used a brushed ESC connected to a proportional channel on the Tx then this would be pretty easy to arrange see the sketch below Plug the "throttle control" from the ESC into the correct Rx channel & you can control the pump from "Off" to Max speed (flow) via the proportional control (rotary knob or slider) on your Tx independant of the main throttle control The second idea to to preset the motor speed via a cheap servo tester.....see below You plug the throttle lead into the servo tester & set the required motor speed via the rotary knob on the servo tester.....the RC switch is controlled via an on/off channel on your Tx....when the R/C switch is activated the ESC/servo tester are powered up & will run the motor at the preset speed. A third option might be to combine the two......get rid of the Servo Tester, plug the ESC throttle control into a proportional channel on the Rx & the R/C switch into a non proportional channel....only when the R/C switch is activated will the ESC switch on & then you can control the flow rate from the proportional channel on the Tx....in this case probably best to disconnect the positive lead from the ESCs Rx plug..... Does that help? I hope I've explained it OK.... Quote Link to comment Share on other sites More sharing options...
chris edwards 3 Posted December 22, 2012 Author Share Posted December 22, 2012 you have explained it brillantly steve. because i fly from a DX6i would another option be for me to plug and esc or witch into say the flap or gear port and controll it that way? Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted December 22, 2012 Share Posted December 22, 2012 Chris I'm a Fuby man so I'm not sure about Spekky stuff.....a "non-proportional" channel would be something like the "Gear" channel....often used for retracts.......it drives a servo from one end of its travel to the other....on or off if you like.....ideal for controlling an R/C switch. A proportional channel is something like that used for flaps......the servo would follow the movement of a slider or a rotary dial. Connect this to the ESC & it will control the speed of the motor for you... Quote Link to comment Share on other sites More sharing options...
Mr.B. Posted December 22, 2012 Share Posted December 22, 2012 Steve, I think your over complicating it. On my fire monitor set up I drive the car windscreen washer pump from a brushed ESC and seperate 3 cell lipo. The esc is plugged into an on/off channel (Spekky DX6i or DX8). Switching on just gives the ESC 100% throttle. If you want to adjust the speed you can use the end point adjustment. And I have never burned out a pump in a car either but run on for over 60 secs and it will. They are not meant for continual running. I like the air pressure idea. Quote Link to comment Share on other sites More sharing options...
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