Simon Wyatt Posted September 30, 2022 Share Posted September 30, 2022 I would prefer up to 8s but will consider 6s for a decent unit. I'm not looking to break the bank, just trying to electrify my 1/4 scale cub on a budget. Quote Link to comment Share on other sites More sharing options...
Shaun Walsh Posted September 30, 2022 Share Posted September 30, 2022 80A ESC 110A Esc Quote Link to comment Share on other sites More sharing options...
kc Posted September 30, 2022 Share Posted September 30, 2022 Do you really need lots of power for scale flying? Whats the weight? Quote Link to comment Share on other sites More sharing options...
kevin b Posted September 30, 2022 Share Posted September 30, 2022 80A ESC 125A ESC Quote Link to comment Share on other sites More sharing options...
Simon Wyatt Posted September 30, 2022 Author Share Posted September 30, 2022 8 minutes ago, kc said: Do you really need lots of power for scale flying? Whats the weight? Around 7kg, it's the required ESC for the motor that I plan on using. Quote Link to comment Share on other sites More sharing options...
Simon Wyatt Posted September 30, 2022 Author Share Posted September 30, 2022 Thanks for the links I was hoping to repurpose rather than buy new 😋 Quote Link to comment Share on other sites More sharing options...
kevin b Posted September 30, 2022 Share Posted September 30, 2022 Used ESC You can buy new alternatives cheaper ! I wouldn't risk any of my models using an ESC that I didn't buy new, or knew its history (ie from a club mate). Unlike an ic powered model, if the motor / ESC stops working then you lose control. Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted September 30, 2022 Share Posted September 30, 2022 kevin b Loose control? Only if the ESC gets completely "fried" otherwise its BEC will continue to power the rx & servos. Some bigger electric use a completely independent power supply for the rx/servo so no different to IC if the motor stops. Quote Link to comment Share on other sites More sharing options...
PatMc Posted September 30, 2022 Share Posted September 30, 2022 1 hour ago, Simon Wyatt said: Around 7kg, it's the required ESC for the motor that I plan on using. The size ESC, in terms of current handling capacity, is determined by the load placed on the motor, not the motor. A 7kg Cub should only need a max power of 750W. So a 6s battery would draw about 34A, which a 50A - 60A ESC should handle with a safe margin. On an 8s battery draw should max at around 26A but I doubt you would find an ESC rated below 60A that will also take an 8s battery. What's the kV figure for the motor & what size prop have you in mind ? Scale prop would be 18". Quote Link to comment Share on other sites More sharing options...
PatMc Posted September 30, 2022 Share Posted September 30, 2022 1 hour ago, kevin b said: Used ESC You can buy new alternatives cheaper ! I wouldn't risk any of my models using an ESC that I didn't buy new, or knew its history (ie from a club mate). Unlike an ic powered model, if the motor / ESC stops working then you lose control. The ESC you've linked to isn't BEC equipped so would require a separate Rx battery. So like an ic (un)powered model you wouldn't lose control. Quote Link to comment Share on other sites More sharing options...
kevin b Posted September 30, 2022 Share Posted September 30, 2022 54 minutes ago, PatMc said: The ESC you've linked to isn't BEC equipped so would require a separate Rx battery. So like an ic (un)powered model you wouldn't lose control. I agree. I was just making a point about buying "used" electronic components of unknown heritage. Also, if I was looking at using more than 4S I would certainly use a separate RX battery, if only because it would be a more valuable machine and the extra weight would probably be used as ballast. 1 Quote Link to comment Share on other sites More sharing options...
Simon Wyatt Posted October 1, 2022 Author Share Posted October 1, 2022 The motor I will be using is a 40cc equivalent. It is 200kv and suitable for 18-20 diameter props. I will be reducing throttle output for the cub and using 6 cells. The reason I am looking for an 8 cell ESC is to have a multi purpose system I can use on a large variety of models. Quote Link to comment Share on other sites More sharing options...
kevin b Posted October 1, 2022 Share Posted October 1, 2022 12 hours ago, Simon Wyatt said: The motor I will be using is a 40cc equivalent. It is 200kv and suitable for 18-20 diameter props. I will be reducing throttle output for the cub and using 6 cells. The reason I am looking for an 8 cell ESC is to have a multi purpose system I can use on a large variety of models. In that case, with the high value system and model, are you penny pinching ? I would have thought that quality and reliability would have been the highest priority. Quote Link to comment Share on other sites More sharing options...
Simon Wyatt Posted October 1, 2022 Author Share Posted October 1, 2022 😂 yes I am penny pinching. You can get some good equipment second hand. For half the price of new. I have just posted a brand new 56cc rcgf motor, never seen a drop of fuel for £100 missing the CDI. Because I don't need a motor that size anymore and I am converting all but one of my models to electric. Quote Link to comment Share on other sites More sharing options...
PatMc Posted October 1, 2022 Share Posted October 1, 2022 17 hours ago, Simon Wyatt said: The motor I will be using is a 40cc equivalent. It is 200kv and suitable for 18-20 diameter props. I will be reducing throttle output for the cub and using 6 cells. The reason I am looking for an 8 cell ESC is to have a multi purpose system I can use on a large variety of models. A 200kV motor is not suitable for use with 6 cells, in fact I doubt it would be any use in this model on 8 cells. On 6 cells with no load the motor would only turn at around 5000 rpm with a useable load it would drop to around 4000 rpm. IMO the model only needs around 750W power for scale like performance, that is less power than a modern 60 2stroke or 90 4stroke ic. Quote Link to comment Share on other sites More sharing options...
Simon Wyatt Posted October 2, 2022 Author Share Posted October 2, 2022 Motor spec attached and is suitable for a 6 cell battery. Post on this forum showing a real test of the motor. And the results are exactly what I am looking for. Quote Link to comment Share on other sites More sharing options...
Piers Bowlan Posted October 2, 2022 Share Posted October 2, 2022 I don’t know which quarter scale cub you have Simon but the World Models cub (104inch span) has a flying weight of 6.3kg and a 120 to 160 4 stroke is recommended. So about 14lbs in old money would need about 1400W (?) which could be provided by a 6s LiPo pulling 60A I suggest. The only thing is with a very low kv of only 200v, I tend to agree with Pat Max, the rpm would be low (<5000) and you might need a very large propeller indeed to achieve the target 1400W? Being a cub it would probably fly OK on less power than that in a scale like fashion. Simon, have you thought of chatting to George Worley of 4Max and see what motor he would recommend? Might be an interesting comparison to your motor. Quote Link to comment Share on other sites More sharing options...
Simon Wyatt Posted October 2, 2022 Author Share Posted October 2, 2022 Thank you Piers. It is the balsu USA cub at 108" wingspan and 12-14lb flying weight. I took the wattage from the rizzla model build that I posted above at 1700w on a 17x10 and 6s is plenty of power. I don't need the speed with the cub so this sounded perfect. For a more speedy setup I would up the pitch and run it on 8 cell. 1 Quote Link to comment Share on other sites More sharing options...
Simon Wyatt Posted October 2, 2022 Author Share Posted October 2, 2022 What motor would you recommend for a 14lb cub using props ranging from 17x8 - 18x12? I messed up buying the low kv motor 😒 I have 6s 6200 batteries to spare, I also have some 4s 3700 that I could use. I would prefer 6s as I can use them in my fms Corsair too. Quote Link to comment Share on other sites More sharing options...
Piers Bowlan Posted October 3, 2022 Share Posted October 3, 2022 (edited) 4Max recommend this motor for a 96in Telemaster on 6S and a 17x5 prop. I think the weight of a Telemaster is only about 7lbs though so a bit of a floater. It has a slightly smaller span too than your cub. You may find that your Cub is lighter than 14lbs Simon on just a 6s LiPo. However that motor will only provide about 1200W so you may find your model a little underpowered with it. I suspect you may need more cells with such a large heavy model. Personally I would give 4Max a phone and ask them what they would recommend. Even if you don't buy one of their motors at least they would point you in the right direction regarding the required spec. Edited October 3, 2022 by Piers Bowlan Quote Link to comment Share on other sites More sharing options...
Simon Wyatt Posted October 3, 2022 Author Share Posted October 3, 2022 That is pretty much the same as what I have gone with. I made a school boy error thinking the lower kv would be better. I have chosen a predator 5060 360kv motor swinging an 18x12 prop 90a ESC and 6 cells. This setup looks to be perfect for what I am looking for. Quote Link to comment Share on other sites More sharing options...
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