Building a budget sized 50cc Electric

[Kiwi]

Gents,

It s a way off before I start this as the kit has not arrived but I am slowly piecing all the items together to build a 50cc sized plane on a minimal budget.

I make no apologies for looking too and buying the lowest priced items I can find yet still keeping a modicum of intelligence in selecting the hardware.

The speed control, motor, battery packs etc have been identified. The ESC is in my hands, the motor is on back order.

My target is to have a reliable power package for under $600. The ARF and servos etc are extra.

Should be fun.

[wiz310]

wow. $600 is pretty cheap for electrics. I had a dabble in them and apart from the noise factor found them to be a PITA. balancing and charging was painful and dangerous without an expensive charger, and the batteries would occasionally puff and be worthless.... expensive to replace too. I found the waiting for the charging and the flight times painful as well.
Have batteries come down that much in the last few years?. I remember paying around $100 for a 3c 2500Ma Lipo. that would be $600 for three sets of two for a days flying (provided you want to wait while they charge).
I do like the power and quiet though. I'll be watching with interest to see if electric is a viable option for a 50 size these days. good for slipping over the road to the park for a quick fly after work.

[3DHobbyShop]

We're using Hacker motor ($250 w/ mount) + Turnigy ESC ($100) + 12S 5000mah 20C Zippy ($200) and having excellent luck so far. In fact, we've had nothing but good luck w/ the $150 12S 5000mah 15C pack from Zippy, too. The turnigy ESC I'd still call experimental, whereas the $200 Castle 110HV is tried and true.

$250 motor+ mount (Hacker A60L+ Hacker mount)
$200 ESC (Castle 110HV)
$150 packs (Zippy 6S 5000mah 15C at $74.95 per 6S pack)
--------------
$600 (makes about 3500W)

Here's how this cheapo setup pulls out of hover at 17 lbs: http://www.rcgroups.com/forums/showa...mentid=2215253

...and here's how it handles in a larger, 19lb. plane: http://www.rcgroups.com/forums/showa...mentid=2214146

[Kiwi]

Ben,

You have named some of the products I have coming. I will do some testing etc before putting this thing together of course and I suppose given the goal is cheap cheap cheap I expect to make a few smoke events to get it right.

I just received the new 100 amp Sentilon HV100A esc. I will be fitting it up with gold plated 6mm bullet connectors for the packs but they are in another shipment and not here yet.

Rather than fill one post with a lot of data and details I will spread it out.

WIZ, A good 3S2500 pack will set you back about $25 to $30 these days. I just purchased three sets of 2500 MaH transmitter packs for all my radios (14MZ excluded) and they are $18 each. Charge my radio once a month needed or not. Seriously a very good result.

As for big packs a 6S5000 is around about $135 USD.

A good charger capable of 8S will hurt your wallet to the tune of $40 to $70. I use the Chargery 1010C and they are a bit more expensive but the features are out of this world. Best charger on the planet !!!!! No BS.

[Mr.Pickle]

Hello???

[rcpilot82]

Subscribed!!

[Kiwi]

Ok I have some of my gear arriving.

So Far I have the 100 amp speed control and programmer. The Selenion V4 controller set me back $100 dollars.

http://www.hobbycity.com/hobbycity/s...idProduct=4691

I also purchased the programming card ($10) because its just a whole lot easier and more accurate than doing it with beeps and stuff using the transmitter.

First glance says this thing is very well made, a large heat sink good quality wires. I will test it on the bench before it goes into a plane to see what it really can do.

The motor is on back order but this what I have chosen.

http://www.hobbycity.com/hobbycity/s...idProduct=5142

I already know I need to change the bearings in this motor as the originals are lucky to last the first flight. That has set me back $135:00 so we are in the hole so far for $235:00, that's the power package complete.

I will install ceramic stainless bearings and have some leads on where I can get these from. They will cost an extra $25:00 for the set. I know its a PITA to have to do this but this is project with a small budget and I cant find a better 6500 watt motor for a price any where close. Plus even if I could find one there is no guarantee that the bearings will be any better so I figure its part of the price of doing this on the cheap.

I also know I am stretching the capacity of the speed controller but I can control that with the right prop selection. Again expect a lot of bench testing and setup with this project and maybe even we will see some smoke. I hope not but you never know.

6500 watts equates to about 9 horsepower which is way too much for a 50cc sized plane.

Batteries I have not settled on yet until I get the plane (next week with luck) but I figure twin 6S5000 packs are likely going to be the choice. Using the 6S packs in series should give me a max prop speed of around about 6500 rpm. 130 x 48. If I use two 5S packs (which I have) then the prop speed is significantly slower and comes in about 5400 rpm. But the prop is the key to success here so I will be picking up a few large electric props to try out.

[LeSquale]

Hello Kiwi,

I have been reading this thread with interest. In your last post I think you over estimated the rpm you will get. Under the load the LiPo elements will deliver more likely 3.5V than 4V, so you should expect 5'450rpm with 12S and 4'550rpm with 10S from your 130kV motor.

Cheers, Sylvain.

[Kiwi]

LeSquale,

Thanks for the input mate. Its truly appreciated and that's what I need guys. What your saying is that maybe I should have looked at the 180 Kv motor or will my Prop RPM still be OK with 130 Kv at 3.5 volts per cell.

Given that I am looking for about 5 Hp or 3750 to 4000 Watts I will in no way stretch the capacity of the motor.

Also if I stick to that Hp requirement or 4000 watts maximum it means my peak current should be 95 amps give or take.

Now the prop selection becomes pretty critical to be sure I dont smoke up my 100 amp ESC.

Guys please join in here and throw me some advice, ideas etc. I am really excited with this project and the plane arrives tomorrow, all I need now are the servos and the battery packs. Its coming together faster than I planned.

I wont order the bearings for the motor until I have it just in case they changed the bearing size. We all know Murphy can be involved in these things so lets wait and see.

[lazyboyflyer]

Hi Kiwi, that's the wrong motor for a 50cc size plane, you could put that motor on a 75cc-85cc plane. Go with the smaller motor with the kv around 250. Get the HXT 80-85-A 250kv, also this motor is 300 grams lighter.

[LeSquale]

For a 50cc size plane, I would first stick to the 12S option, then choose the HXT 80-85-B 170kV, which seems to be closer to 200kV than 170kV (see "Test data result" under the description), and turn a 22x10. You will be just below 100A and have around 12-14kg of thrust, which should be enough.

[BoneDoc]

Kiwi,

I can't stress enough the importance of listening to Ben's recommendations. He has tons of experience when it comes to electrics and really knows his stuff. The motor you have chosen is simply too heavy. A typical outrunner for a 50cc replacement should weigh around 2 lbs or so, which the Hacker A60 16 or 18L fits the bill very nicely. That Hacker can be pushed to beyond 4000 watts.

I've had close to 75 cycles now with my 15C Zippy and they're holding out great.

This is what the system can do: Notice the pull out at the end of the video

Click the play button to start. Right click here to save the video " title="You Tube" target="_blank">You Tube

://young99.net/images/Videos/87SHP15.wmv

[BoneDoc]

The dreaded double post .


While at it, I love my NEU

Click the play button to start. Right click here to save the video " title="You Tube" target="_blank">You Tube

://young99.net/images/Videos/89SLICK13.wmv

Click the play button to start. Right click here to save the video " title="You Tube" target="_blank">You Tube

://young99.net/images/Videos/89SLICK14.wmv

[Kiwi]

Guys,

Where were you a day earlier. The motor I chose is on the way but I figure I can use it to power my push bike and lower my gas costs to get to the office and back. Seriously I will find a use for it.

OK I will place an order for that motor you have recommended and get cracking with that. I kind soul has offered to lend me two 6S5000 FP packs for some bench testing and setup so I dont have to go forking out dollars in vain with packs.

This is really starting to hype me up as I love electrics and this one is intended for my young guy to fly as he is taking a big interest in IMAC. I figure something that is way safer than a gasser to fly with will be an ideal learning platform for him.

[Kiwi]

	Quote: Originally Posted by BoneDoc
	Kiwi, I can't stress enough the importance of listening to Ben's recommendations. He has tons of experience when it comes to electrics and really knows his stuff. The motor you have chosen is simply too heavy. A typical outrunner for a 50cc replacement should weigh around 2 lbs or so, which the Hacker A60 16 or 18L fits the bill very nicely. That Hacker can be pushed to beyond 4000 watts. I've had close to 75 cycles now with my 15C Zippy and they're holding out great. This is what the system can do: Notice the pull out at the end of the video http://young99.net/images/Videos/87SHP15.wmv

Haaa BoneDoc, I was waiting for the splashasaurus. Nearly mate!!!!!!