Piper Cub

Is this a good spec motor for the cub? Cub weighs between 5lb and 5lb 11oz. L3520-7 650 KV (45A) This is a '600W' class motor, equivalent to a .40 or .50 glow engine and is recommended for planes up to 8 lbs (128 oz / 3.6 kg) total weight using 4-5 LiPo cells.   The motor is capable of packing a serious punch - i.e. 14.8 volts x 45 amps x 93% efficiency means you've got 620 watts of power (short bursts only) - at the prop!  A 20c battery running flat out wont last long, so you're probably better off with a 15c. Ideal battery for this motor would be a 3000 - 4000 mah, 4 cell, 15c.  Specifications No. Of cells: 4 x Li-Poly RPM/V (KV): 650 Efficiency: 93% Max RPM: 6500 Max loaded current (A/60s): 45 Maximum efficiency current:26A Voltage: 13.5v Idle current: 1A Recommended Prop Direct Drive: 13x8What I dont seem to understand is you can get motors of very similar specs but when some quote Max Load current and Max Efficiency Current and other dont, how do you compare them!?

Has anyone tried fitting the new TT Ecureuil \ Squirrel fuz to a Hirobo Sceadu 50? Does the Sceadu fit inside the fuz and line up ok?

Hi Timbo. Yes, thanks for all the info. Sorry if I seemed to be rejecting your advice, wasnt meant to come over like that. I did get to thinking perhaps buying a separate charger and balancer would, while being a little more expensive, result in better quality parts. I didnt think about the compatibility issue. Many thanks for pointing that out. looks like its a combi job then! Im not too bothered about the unit meeting all future needs because things change so fast, its bound to become obsolete in a few years. One thing that does bother me though is the balancer leads. There seem to be many charger \ balancers out there but no consistent balancer plug leads. I guess its a question of sticking to one type of lead  and buying batteries that match or, buying a number of different leads to match the packs! Hmmmm.

Is it better to buy a separate charger AND balancer rather than a combined unit (obviously cost will be a bit more)? Just wondering if, say like hi fi stuff, you get better quality if you have a separate charger and a separate balancer than an all in one. What's people's preference?

My present charger wont do lipos but is great for the nimh car racing packs my sons use. Its an AC \ DC charger which is the type I prefer. Ive notice there arent many AC \ DC chargers out there that do lipos as well as nimh with decent spec chargers tending to be DC only. My requirements for a new charger are AC \ DC (preferably) but would consider DC with a PSU ability to handle 5amps charge minimum able to charger lipos, nimh, nicads & sealed lead acid built in balance for lipos able to charge 5 cell lipos oh, and idiot proof! Any suggestions for a good charger?

If you dont want to convert a pc PSU, modelmaniacs and other places have PSU's from about £18 to £25. Look at top of this page and also towards the bottom. http://www.modelmaniacsonline.co.uk/categories.php?CatID=464&SubCatID=465

Having flown ic planes, Im familiar with the usual mounts for ic engines. I've noticed a lot of brushless motors come with a metal 'cross' type fixing plate which I assume you fix to the engine compartment bulkhead and then attach the motor to it (or is it the other way around!?) I've also seen some 'stick' type mounts that have a round disc attached to one end. How do these work? Again, I assume the motor is fixed to the round disc and then the stick is attached to the engine bulkhead but how's this done? Is it just a question of cutting a square hole for the stick then gluing in place! Seems a very dodgey idea to me if it is or is there some other bracket you need to fix the 'stick' end of the mount to the bulkhead?

Seen some reference to a watt meter. OK I know they are for measuring watts but how do you actually use them? Should you always have one 'in line' as it were or are they only used during setting up, if so, how do you do this? Do they actually display the theoretical flight time for your motor \ battery combination? How do they tell you the most efficient (best) prop to use and whether you motor gearing is good or bad etc? What are good examples of watt meters and an indication of price? Do they work with nicad, nimh as well as lipos? TIA

This may seem a daft question but are there 'different' props for IC and electric!? Do you have to buy a prop specifically for motors as opposed to the ones available in model shops for IC? Have I explained that properly!?

Cheers Timbo. Where are you getting the motor from at that price!? Cheapest in the UK I found was £35! Would I be better with the Cub going for 2 packs in parallel rather than series? Im assuming parallel gives duration while series gives more speed (which I dont want for this model)? The model only needs 3 servos so would you recommend a BEC ESC in this case, if so, could you suggest something suitable? (The ESC in the earlier link seems to have changed!) Ta!

OK, think I've decided on the model Piper Cub to get as a first leccie. The J Perkins Piper Cub is 68" span and weighs in at a reasonable 5.5lbs. Its ARF so minimal build, although will need converting for electric and has a good scal appearance. Best bit its available for under £50! At that price, even if it gets a bit of hangar rash I dont think I'll have been robbed. Probably look to get an HXT 50 55B motor havent decided on ESC yet but thought a Hi Model Fly 60Amp OPTO (no BEC) Anyone had one of these Perkins Cub's and thoughts on motor ESC combo?

As a matter of interest, for the larger type scale plane, I'd assume a battery pack of 14v would be the norm (at least for the approx 1\6th to 1 \5th Piper Cubs I've been looking at.) So, this would seem to cause a problem down the field when you want to fly and need to recharge your batteries since most car batteries are 12v unless you get a 24v wagon battery! Now if I have two motor batteries in parallel say 14v 4000mah packs to give 1 @ 14v 8000mah, it effectively means I have to charge at home with a 240v charger since I'll be lucky to get both these batteries charged fully from a 12v supply. Alternatively, Im looking at buying 4 14v 4000mah packs so I'd have sufficient batteries for more that 2 flights and I'd have thought that could be costly? Or am I missing something? How do other flyers address this ie field charging large voltage packs? TIA

Hi. Anyone know any good places (in the UK) to get battery parallel leads from ie to double up the amp hour capacity of flight \ motor cell packs? I've done a google search but that drew a blank. next, I visited some of the electric flight specialist sites and couldnt find any! Surely they cant be that rare or does everyone make up their own? TIA

Does anyone know of a reliable, compatible Futaba Tx & Rx charger where both outputs are better than 120mah? With Tx & Rx batteries now in the region of 2500mah, even a 120mah charge rate takes over 20 hours to fully charge!

Hello, its me again! OK, BEC's are very popular in rc cars and boats, mainly because it means there's less weight to lug around. If a nimh or nicad powered car \ boat's battery gets low, you lose steering and power but, this isnt really a problem as you're already at ground level. But in a plane...........! So, is it advisable to use a BEC ESC in a plane? When is it best to have a non BEC ESC and is this relevant to the size of plane \ motor size etc? I guess what Im getting at is why would you ever have a BEC ESC in a plane? EDIT. Sorry also what does OPTO mean with regard to an ESC? What does it do if anything and can you get an OPTO BEC ESC as well as a non BEC ESC? Finally whats a program card and how do you use these? Er, thanks!!

The murkiness is starting to clear, slowly! Thanks for these snippets Timbo.

Hi Malcolm. The slower flying capability of the cub is one of the things that appeals to me, besides thinking they are just such a good scale subject. Did you not get the Hangar 9 electric ready version of the cub or did you ditch the kit motor or is the dual sky 4250 and ESC (google doesnt find anything for this!) What sort of flying times do you get on your set up? I used to fly gliders and would liked to have had an aero tow with a cub!  Thanks

Ouch! My brain hurts! Looking at the Lipoly you suggested Timbo. What does the 15 - 25C signify and what's the difference between this and a similar Lipo pack that's stated as 20 - 30C? More importantly as an example, how do I know when 15 - 25C, 20 - 30C or something else is suitable for whatever set up \ plane its intended for? Sorry to ask dumb questions!

Hi Timbo. Many thanks for the info! Are you UK or US based as Im wondering about the UK availability of the items mentioned. The cost of those items is a real eye opener! Im assuming they can be bought in the UK, probably for around the sterling \ dollar equivalent cost. Even so this would represent a fantastic saving. What sort of flying time would you expect on that size lipo? Assuming you're not racing about the sky with a Camel, of course. Once again, thanks for your patience with a newby.

Thanks for the info. Im starting to think I should go along the Hangar 9 route for my foray into electrics (I've flown ic before) since this is 'made' for electric rather than ic and just lob a few electric bits into it. Once I've got more experience of electrics then, I think I'll be better placed to selected say a DB Piper Cub kit and build that specifically for electric. For the Hangar 9 Cub (approx one fifth scale, flight weight approx 7lbs, this comes with a E Flite 46 so would assume the manufacturer knows its neither under or overpowered. Recommended Lipo configuration is 4S2P or 5SX (what does this mean?). Is it better to get two 4S2P packs, cost approx £132 each! A Pheonix 60amp ESC would cost approx £80. Is all this a good combination? Recommendations for an alternative ESC would be welcome. Thanks!

I see lots of kits stating electric flight should use 4S2P Lipo packs or even 2 4S2P packs so have a couple of questions; Can Lipo packs be wired in series? One Piper Cub kit I've seen (quarter scale) recommends two 5SX cells or I think one 10S2P. Would one  combination give a better flight duration than the other? Im assuming the 4S2P means 4 cells in Series 2 in parallel but what is the like for like difference in capacity between a 4S2P and a 4S1P or isnt there any? Would there be a difference in performance between these two pack configurations ie flight time, or has one pack just got more capacity? When buying Lipo packs, should one generally buy say a 4S2P as opposed to a pack that only has 1 parallel cell ie 4S1P? Thanks for all the info!

Hi. Sorry Im new to electric but who would you say were the top 3 or 4 brushless motor manufacturers? Ta.

A lot of kits are now being marketed as IC or electric. Sometimes, the manufacturer will state the size of brushless motor required which is great. But if they dont, what the easiest way to find out what brushless motor is most suitable and how do you determine which size lipo to use! Any sign of the article for newbies yet? Havent been able to find it on the site.

Hi all. Im seriously thinking of going down the electric flight path(!) since lugging all the associate IC gear around is just too much. I just love Piper Cubs and have spotted a few models \ kits on the market. Ones Im thinking of are the DB Scale 84" Cub, Hangar 9 Power 46 Arf 80" and SIG 84".  Any thoughts on which would be best for leccie? Obviously the Hangar 9 Power is designed for electric while the others would need to be build as electric flyers. It seems a brushless motor along the lines of the EFlight Power 46 or bigger (60?) would be suitable. Any other suitable suggestions as the EFlight motors look a tad expensive (I get a bit confused over the brushless motor ratings. Is there an easy way to find what size motor would suit a model based on weight \ wingspan??) Lipo's look too expensive at the moment IMO so would look to go down the NiMh route but using as ESC that could take both NiMh or Lipos. Are Lipos & Li Ion the same? Thanks for any advice & happy New Year!