Tosh McCaber Posted July 21 Share Posted July 21 I'm rebuilding my old Aeromaster biplane- electric this time. 1.2mm wingspan- +- 6.5lb. Original powered with an HP61 I know about- but- I'm consistently bamboozled with the ins and outs of electric components! I have so far been recommended to use a 5055-500kv or perhaps 5065-360kv motor, with a 6S LiPo. Can anyone guide me on their favourite brand(s) and sizes of motor, and ESC/UBEC to fit? Any suggestions/ comments appreciated! Quote Link to comment Share on other sites More sharing options...
Shaun Walsh Posted July 22 Share Posted July 22 Assuming the HP61 provides about 1.3hp, 1000w and you will be using a 6s battery then you need a motor/esc capable of handling approx 45 to 50 Amps at full throttle. I have installed this esc in a Brugger Colibri with a motor pulling 58A at WOT. https://www.modelshopleeds.co.uk/catalog/product_info.php?keywords=Hobbywing 80a&sort=1a&products_id=77984 Regarding a motor, I like 4-Max motors, reasonably priced, well made and spare bearings and shafts available. Something like this would be appropriate. https://www.4-max.co.uk/po-5055-500.html You may want a higher kv motor if you want to run a smaller prop, see the 4-max website for options. 1 Quote Link to comment Share on other sites More sharing options...
Shaun Walsh Posted July 22 Share Posted July 22 And don't forget that you will need a watt meter to check the current draw to optimise the prop size. 1 Quote Link to comment Share on other sites More sharing options...
Shaun Walsh Posted July 22 Share Posted July 22 A 4Ah 6s or larger battery should give acceptable flight times. Quote Link to comment Share on other sites More sharing options...
Shaun Walsh Posted July 22 Share Posted July 22 15 hours ago, Tosh McCaber said: I'm rebuilding my old Aeromaster biplane- electric this time. 1.2mm wingspan- +- 6.5lb. Original powered with an HP61 I know about- but- I'm consistently bamboozled with the ins and outs of electric components! I have so far been recommended to use a 5055-500kv or perhaps 5065-360kv motor, with a 6S LiPo. Can anyone guide me on their favourite brand(s) and sizes of motor, and ESC/UBEC to fit? Any suggestions/ comments appreciated! And if you can build it with a 1.2mm wing span weighing minus 6.5lbs, we would all like to see a build log please!😁 Quote Link to comment Share on other sites More sharing options...
Tosh McCaber Posted July 22 Author Share Posted July 22 Shaun, Many thanks for all that- I'll look into them all! I'm just looking over at my invisible-6.5lb AM on the bench, thinking how much it'll weigh when I stuff battery and electronics in! One other thing- should I use a UBEC? Quote Link to comment Share on other sites More sharing options...
Shaun Walsh Posted July 22 Share Posted July 22 44 minutes ago, Tosh McCaber said: Shaun, Many thanks for all that- I'll look into them all! I'm just looking over at my invisible-6.5lb AM on the bench, thinking how much it'll weigh when I stuff battery and electronics in! One other thing- should I use a UBEC? In terms of weight, add about 1Kg to the airframe weight (or more if you choose a bigger battery), plus whatever lead is required to adjust the CoG. If it will fit, I would rather have a bigger, heavier battery than add lead to get the CoG right. Regarding the use of a stand alone UBEC, that's down to personal choice. I usually rely on the ESC's built in BEC and choose an ESC with a BEC capable of delivering a good current to minimise the chance of brown out. The ESC I linked to can deliver 8A continuous, 20A burst which should be ample. Quote Link to comment Share on other sites More sharing options...
Nigel R Posted July 22 Share Posted July 22 There's pros and cons to UBECs. Personally - I've never used a separate RX battery on an electric airframe. There are other opinions, etc. Quote Link to comment Share on other sites More sharing options...
Nigel R Posted July 22 Share Posted July 22 1 hour ago, Shaun Walsh said: favourite brand(s) and I've had good results with Hobbywing ESCs. (exactly like Shaun's linked for you) Quote Link to comment Share on other sites More sharing options...
leccyflyer Posted July 22 Share Posted July 22 2 hours ago, Tosh McCaber said: Shaun, Many thanks for all that- I'll look into them all! I'm just looking over at my invisible-6.5lb AM on the bench, thinking how much it'll weigh when I stuff battery and electronics in! One other thing- should I use a UBEC? Back when ESCs had very simple BECs, typically 3A, with rather limited capacities for running several servos and with a tendency to generate quite a bit of excess heat in dropping the pack voltage down to a steady 5v supply there were very sound reasons for using a separate UBEC or SBEC, That was a necessity anyway in the case of so-called OPTO ESCs, where the link between the ESC was decoupled to reduce interference -especially on 35mhz -and such ESCs lacked any BEC onboard. More recently the BECs on the majority of ESCs are switch mode, generate far less heat and are rated for being able to adequately power several servos, even in a high current application. As Shaun says, it's very much a matter of personal choice, but a lot less necessary nowadays with more capable ESCs and much nicer, higher capacity 5-10amp BECs. I'm another happy user of Hobbywing ESCs and found them very practical in everyday use. Quote Link to comment Share on other sites More sharing options...
Nigel Sharp Posted July 22 Share Posted July 22 I expect the biggest challenge will be mounting the motor and being able to swap batteries as the nose is short and cabane struts forward toward the firewall. 5s is a smaller pack and the 5055 500 will most likely have ample power. Quote Link to comment Share on other sites More sharing options...
leccyflyer Posted July 22 Share Posted July 22 Tosh - the 5055 -500kv from 4-Max is equivalent to an AXI 4120/18 ,thought the AXIs are more expensive. If I'd known yesterday I could have shown you the AXI 4120/18 that I've just installed in the Modeltech P-51D that I was hoping to maiden. That turned out to be the perfect length to just mount directly to the firewall, once that had been restored and so was a relatively simple conversion. Battery access is via a top hatch, which, as Nigel said, could be a bit challenging with a short nose and cabane struts limiting the potential size of such a hatch. There's usually a solution though -if you ask Jim to show you some of his biplanes, those which can't fit a hatch on the top have one underneath, so that bears looking at. It's useful to sit with the plan and the battery - or a block of foam the same size - and weigh up how you'll best get access. The battery will likely want to be as far forward as possible and putting them in vertically is often a good thing. Alternatives are possible - if you look at how Derek managed with his Puppeteer, that had battery access through the prop, with the motor mounted on a motor mounting plate, affixed to the cowl, which is hinged and drops down to insert the batteries through the firewall. When that's done the cowl front, with the motor and prop is flipped back up and engaged with the firewall. A super neat installation for short nosed biplanes. Quote Link to comment Share on other sites More sharing options...
Tosh McCaber Posted July 22 Author Share Posted July 22 Thanks for all the (very helpful!) replies guys. I'll go with your recommendations! Quote Link to comment Share on other sites More sharing options...
Tosh McCaber Posted July 25 Author Share Posted July 25 (edited) All, I've decided that I'm going to go with your recommended 4-Max 5055-500kv, on 6S LiPo, along with the Hobbywing 80a 8S ESC, thanks all for the advice. (No UBEC!) I'll check on where the battery can be located in the fuselage- I pulled a pile of lead out of the nose area of my IC version when I was stripping it during the rebuild. So, I think, well forward! For interest, have any of you got any prop mfctr preferences- and sizes? I got a quotation email from 4-Max, quoting a JXF 15x8 prop. However looking at their standard advertising sales blurb, they recommend a 15X6! Once again, it would be second nature for me to specify an ic prop size/ mfctr for a .61 motor, but I need to be lead by the nose (pardon the pun!!) with the mysteries of electric combos!! Leccy, I'll have a look at the weekend at the local similar club bipes set-ups Edited July 25 by Tosh McCaber Quote Link to comment Share on other sites More sharing options...
Nigel Sharp Posted July 25 Share Posted July 25 Tosh, I recommend a subscription to prop calc or the ecalc application. See the link You can play about with all the necessary variables for an electri set-up Beats burning up motors. ESC and making bad choices. https://ecalc.ch Propcalc is probably all you need It's easy to use cost is small. At the end of the day it's Volts x Amps = Watts re arrange to suit. Plug in your weight, motor, ESC amps & propeller size and it will predict performance, temperatures, battery life. Airspeed etc. You can switch props or battery cells and re run the calc it gives you options. Enjoy 1 Quote Link to comment Share on other sites More sharing options...
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