waynemackie67 Posted September 16, 2017 Share Posted September 16, 2017 (edited) For the last 18 months I've been building a electric paramotor at the moment I fly with a fresh breeze solo 210. 1.2m prop .I've used that as my base to get the rpm required as I'm using the same size prop on the electric. I was shocked at how much power I got from the batteries and had to calm it down a bit .hopefully this week we shall be doing the first flying test but all test so far have been really good . I fist looked at one of these on line and the 12k price tag was well out of my limits I've managed to finish mine with in a budget of 1200 .if anyone is doing a similar project it would be great to chat Edited September 18, 2017 by waynemackie67 Spelling and grammar 1 Quote Link to comment Share on other sites More sharing options...
AndyB Posted September 17, 2017 Share Posted September 17, 2017 I have built and flown electric model planes with up to 18 Kw motors. Quote Link to comment Share on other sites More sharing options...
waynemackie67 Posted September 18, 2017 Author Share Posted September 18, 2017 (edited) I'm using the hobby king 150cc rotomax motor running with 250amp esc at 66.6 volts . just waiting for weather to clear for first flight Edited September 18, 2017 by waynemackie67 Quote Link to comment Share on other sites More sharing options...
waynemackie67 Posted September 18, 2017 Author Share Posted September 18, 2017 Also a 2.5》1 reduction drive Quote Link to comment Share on other sites More sharing options...
AndyB Posted September 18, 2017 Share Posted September 18, 2017 I have that on an Acro 2.4m wingspan plane with a 300 amp esc. Motor is rated at 9.8Kw or 12.9hp. This uses 15 cell 10 amp/hr batteries, that weigh 5Kg. Esc will not take full power for more than 15 seconds, after which it cuts out on overload! Flight time 8 to 10 minutes. Quote Link to comment Share on other sites More sharing options...
waynemackie67 Posted September 18, 2017 Author Share Posted September 18, 2017 I tested it for 30min at 3500rpm seems OK. I guess the real test is to come .I'm not running the motor flat out. take off should be about 70% max rpm but let's see what happens under load. only time will tell .do you know of any better motors Quote Link to comment Share on other sites More sharing options...
AndyB Posted September 18, 2017 Share Posted September 18, 2017 What current was it pulling during your test? It is always best to tune prop diameter/pitch to ensure max current does not exceed allowable and then measure current at various rpm. Remember current * voltage = power. Hence you will know whether you are running it at a power that sustains level flight. I think you will have been running at very low power. Are you using 15 cell and what size batteries? Quote Link to comment Share on other sites More sharing options...
AndyB Posted September 18, 2017 Share Posted September 18, 2017 Pic below is a 4.2m half scale plane. It uses two 9Kw motors mounted on a single shaft, with the coils aligned carefully so that the two speed controllers work together. Esc's are 300a each. Batteries 15 cell, 30 amp/hr. It also uses a solid state safety cut-off device that can be switched remotely, thus preventing loss of limbs! 1 Quote Link to comment Share on other sites More sharing options...
waynemackie67 Posted September 18, 2017 Author Share Posted September 18, 2017 Cool stuff .I'm using 14s 60v 20amp Quote Link to comment Share on other sites More sharing options...
AndyB Posted September 18, 2017 Share Posted September 18, 2017 So stored power = 60*20 = 1200 w.hours I estimate that it needs at least 9 hp or 6.75 Kw to keep a small pilot (sub 60 Kg) in level flight.....probably more! So time aloft = 1200/6750 = 0.178 hours or 11 minutes. This does not account for higher power used at take-off, which will reduce this time. I think that until the advent of super batteries, elec paramotors will only ever be good for launching a PG up then fly using thermals. Quote Link to comment Share on other sites More sharing options...
waynemackie67 Posted September 18, 2017 Author Share Posted September 18, 2017 Well only a real test will tell now. but test pilot is no light weight lol Quote Link to comment Share on other sites More sharing options...
waynemackie67 Posted September 18, 2017 Author Share Posted September 18, 2017 Will put the video on you tube as soon as we've had a test flight Quote Link to comment Share on other sites More sharing options...
Hodders Posted September 18, 2017 Share Posted September 18, 2017 Really, really look forward to this. Electric paramotors solve just so many issues. Keep us posted ! Do you have any technical details in terms of batteries/thrust/motors/current etc ? Quote Link to comment Share on other sites More sharing options...
AndyB Posted September 18, 2017 Share Posted September 18, 2017 Electric also creates a new and VERY dangerous hazard. When batteries are connected and ready to go, but throttle at zero, the prop is stationary. The machine looks like it is off! However, the maximum torque and hence maximum damage potential is at that point. Many rc plane fliers have lost fingers because they thought it was switched off. This is why on all high power electric machines we use solid state cutoff devices......you can't have a "big switch" because the current is massive. Quote Link to comment Share on other sites More sharing options...
AndyB Posted September 18, 2017 Share Posted September 18, 2017 Hodders, I think electric creates more problems : Very limited flight time. From my experience of high powered rc planes (double the power being used in this elec paramotor ) even 20 Kg of battery would give just 20 mins of flight......Maybe 25 mins if very careful. Safety: Needs a cutoff device. Also, even the best of fire proof bags would struggle to contain a fire. Just one cell going short cicuit would set off the whole lot! A 20 Kg battery might have between 30 and 60 individual cells. Charging. It takes a monstrous amount of very high powered chargers to recharge battery packs of this size. I have used three, 300 amp mains power supplies to recharge....and it still takes 2 to 3 hours. A spare battery pack costs lots and gives you even more batteries to care for. Running the batteries at high load (current) often creates a cell failure. Unless the battery packs and electronics are designed to cope with this then you either have instant total power loss....or, much worse, a cascade failure because the remaining battery cells are over loaded. I am expert in high powered electric setups and would not want to fly with an unprotected fire ball on my back. Providing protection adds more weight. 1 Quote Link to comment Share on other sites More sharing options...
waynemackie67 Posted September 18, 2017 Author Share Posted September 18, 2017 We have a big red switch .and a fire proof box for batteries and an emergency eject pull cords to eject the paramotor Quote Link to comment Share on other sites More sharing options...
waynemackie67 Posted September 18, 2017 Author Share Posted September 18, 2017 And the test pilot is a priest and no I'm not joking Quote Link to comment Share on other sites More sharing options...
AndyB Posted September 18, 2017 Share Posted September 18, 2017 9 minutes ago, waynemackie67 said: And the test pilot is a priest and no I'm not joking Lol. Sounds good. Experience of fire proof box/bags is they are only good for a short time. Eject is a good plan! LiPo bags are not up to the task for long so has to be a box. Here is a test on a heavy fire proof box with just one small LiPo. Imagine having 20 or 30 of them all going up. Quote Link to comment Share on other sites More sharing options...
AndyB Posted September 18, 2017 Share Posted September 18, 2017 ps. If you are using a physical switch rather than solid state, make sure it is rated for continuous current. Most DC switches are only rated for full current for a short time. With elec motor power systems they can see the high current for much longer. This is another source of fires! Quote Link to comment Share on other sites More sharing options...
Guy Posted September 19, 2017 Share Posted September 19, 2017 Google 'Paracell' they seem to have one up and running plus a larger battery for use with a trike. Quote Link to comment Share on other sites More sharing options...
AndyB Posted September 19, 2017 Share Posted September 19, 2017 Yes, if I remember correctly they use Lithium Ion batteries costing £1600 each. Quote Link to comment Share on other sites More sharing options...
waynemackie67 Posted September 19, 2017 Author Share Posted September 19, 2017 Cost of battery is not an issue at the moment getting a test flight to see if the project is worth any more time is what's were about at the moment. I've spent £600 on batteries at sub 14kg total frame weight including batteries we can double up on them Quote Link to comment Share on other sites More sharing options...
AndyB Posted September 19, 2017 Share Posted September 19, 2017 Sounds good. Post some vid/pics of it when you run. Would be great to see. Quote Link to comment Share on other sites More sharing options...
waynemackie67 Posted September 20, 2017 Author Share Posted September 20, 2017 First flight done you can view it on you tube " first electric paramotor flight- east anglia " pilot weight Aprox 17 stone battery used 28% for all tests last night .next test is powered timed flight 1 Quote Link to comment Share on other sites More sharing options...
waynemackie67 Posted September 20, 2017 Author Share Posted September 20, 2017 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.