180kv outrunner powered offroad e-bike

[etard]

We are not trying to discourage you, on the contrary, we don't want you to blow through a controller get discouraged and quit the whole thing altogether. It's not a cheap hobby, but if you get a decent high end RC controller you might have a chance. You are also missing alot of periphery expenses that will come up during your build. You will still need to purchase a potentiometer based handlebar throttle, that charger is nice but you will need a power supply to plug into wall outlet, you will need a welder, sprockets, chains, adapters, freewheels, more adapters, soldering gun, capacitors, drill, drill bits, fasteners, wire, connectors... the rabbit hole will get deep, but if you start on the right path with a decent investment it will be worth it in the end. The SLA hub motor kits are as cheap as it gets, don't think you are going to beat that with an RC build unless it is friction drive, you are stressing the components near their limit as is (especially at 22 volts) and if you try to get that little controller to power your bike to 30 mph it is gonna pop when you are going 5 mph. Understand, it might do 30 mph on level ground sustained and might be happy, but it will heat up faster than you can let up on the throttle at the first log or root you encounter at 5 mph.

How and where will you mount the motor?

If you try inside the frame you might have pedal clearance issues, if you want big tire you might have chain clearance issues, if you want to mount it on the left freewheel you will have backpedal issues, if you try to do away with your pedals you might have motor startup issues, if you go with a hall sensored controller you might have controller mounting issues ( heh AJ :wink: ?).

Also your reduction math is a little off as Olaf described. I assume you are using a BMX rim which is 20" diameter with tire, so you will need that tire to spin at around 500 rpm at 30 mph. So you need roughly 5:1 reduction, but then your battery's voltage will sag a little under load to say 20 volts which with efficiency losses will probably require you to run a 4:1 reduction to reach 30 mph. I think a more realistic goal to start out would be a top speed of 10-15 mph, which will get you up hills so you can bomb down them with the assistance of gravity, and then when you can afford more batteries and better controller upgrade to 48 volt setup and you will already have the gearing and reduction work out for your desired 30 mph.

good luck!

 

[gwhy!]

If your serious about your budget then May I suggest a smaller motor with a hall sensor mod http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=7870 with a lyen 12fet controller ( then over come the cutting out prob on the controller ) this setup will cost around $150 you will need a overall reduction of around 20-25 to the back wheel (26"). ( I am running a modded 6fet controller so Im assuming a lyen 12fet would be up to the job ) This would be good upto around 30mph without pedal assistance ( but maybe not so good for real off road stuff :wink: ) limited to 75A max @ 44v, if you want to be dumped on your backside every time you open the throt then look at more towards the reduction nearer 20.. but a top speed nearer 20-25mph. This would be a cheap way in but give you room to expand and give you a feel for what its all about.

edit: ratios around the wrong way.. 20 more speed 25 more ass dumping

 

[Alster370]

thanks for all the advice guys I appreciate it. I like your idea too gwhy as its more aimed more my budget at the moment, I have looked at that motor before and considered it but as ususal the thought of more power tempted me away from it
I may have to settle with this motor instead of that turnigy to avoid air mail charges http://www.giantcod.co.uk/epower-bl5345-195kv-brushless-outrunner-motors-p-402690.html this one does a little more 3750w but its changeable. from what website would I be able to acquire this controller?

 

[Jeremy Harris]

The motor from the UK that you've linked to is only a 53 45, which is a fair bit smaller than the 63 74. I'm running one of the Turnigy 63 74 motors on my milling machine and it has a lot of poke. The much smaller 53 45 motor will be a lot less powerful.

The numbers refer to the diameter and length of the motor stator, BTW. The bigger the diameter and the longer the length, the more torque the motor will produce. In this case you're looking at a motor that has a stator that is only 61% of the length of the Turnigy and 84% of the diameter, so you can expect it to be a lot less powerful.

The Turnigy should end up costing around £55 or so delivered to the UK, the smaller 53 45 motor you've linked to would end up costing you around £45 delivered. The extra £10 would get you more than double the torque, I believe.

Jeremy

 

[fitek]

Just another +1 for not cheaping out on the batteries. They are the heart of the machine, if you get a good set, they will last you through several builds as you upgrade over the years. If you get crappy batteries, your bike will be crap and you will never ride it and all the money you spent will be wasted.

 

[Alster370]

ive had a think over and decided that maybe a road e bike would be best, and since im a fan of American chopper I thought why not give it a chopper frame? I looked at actual chopper parts on ebay and they were all over my budget but then I remembered a schwinn I saw a while ago and thought it would be an excellent base for the e bike. They are affordable too, I have seen ones for£50- £70 on ebay close by. I think il use a turnigy 130kv with a lyens controller like gwhy suggested.
Does anyone know the amp draw of this or similar motors when fitted to a bike?

 

[gwhy!]

ive had a think over and decided that maybe a road e bike would be best, and since im a fan of American chopper I thought why not give it a chopper frame? I looked at actual chopper parts on ebay and they were all over my budget but then I remembered a schwinn I saw a while ago and thought it would be an excellent base for the e bike. They are affordable too, I have seen ones for£50- £70 on ebay close by. I think il use a turnigy 130kv with a lyens controller like gwhy suggested.
Does anyone know the amp draw of this or similar motors when fitted to a bike?

The motor I suggested was a smaller one than the 130kv motor http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=7870

The motor I suggested draws 3A @around 46v the 130kv motor is more around 5.5A @ around 46V.... no load i.e not on a bike

 

[Alster370]

I decided that I would invest more money into the project than originally intended. and the prices for the 130kv here in the uk arent actually that bad, so I thought why not? Are those figures for a no load test gwhy? I also sent a pm to lyen about his motor controllers.

 

[Alster370]

sorry I didnt see the no load i.e not on a bike bit.

 

[TopCat]

ive had a think over and decided that maybe a road e bike would be best, and since im a fan of American chopper I thought why not give it a chopper frame? I looked at actual chopper parts on ebay and they were all over my budget but then I remembered a schwinn I saw a while ago and thought it would be an excellent base for the e bike. They are affordable too, I have seen ones for£50- £70 on ebay close by. I think il use a turnigy 130kv with a lyens controller like gwhy suggested.
Does anyone know the amp draw of this or similar motors when fitted to a bike?

Welcome to the chopper club. :wink:

Heres mine...

I'd like to go RC but thats a long way of yet.

Regards
Tom

 

[Alster370]

They are great lookers arent they? Ive been viewing your thread Topcat, looking very good I have to say.

 

[AussieJester]

ive had a think over and decided that maybe a road e bike would be best, and since im a fan of American chopper I thought why not give it a chopper frame?

One adevantage is the 'chopper' stlye frames are open for alot of packs to be mounted within
the frame... While my bikes not technically a "chopper" the feet forward cruiser frames
also perform well as e-bikes when it comes to fitting the electrics...best of luck

KiM

 

[LI-ghtcycle]

Welcome to the board!

I must say, if you start with an RC build, I dare say you will never want to go back! Trust these guys explicitly, I thought I knew what I was doing when I got my first motor and ran a simple friction drive (Kepler).

I was warned by many here not to use the 295 KV E-Flight 110 with 8S (30V) as it was waaay too small and had too narrow of range (8S only). Guess how long it lasted on the first hill climb attempt I made?

TWENTY SECONDS!! :lol: :lol:

In twenty seconds I turned a $120 motor and $120 ESC into useless junk, and I have a VERY limited budget.

Don't trust specs alone, go with the specific motor/esc combos that are suggested for the voltage you run, or you will most likely "Let out the Magic Smoke" much more than you will ride.

If you're a electronics guy and know your way around RC motors, maybe I'd say go ahead and experiment, but if your like me with a limited budget and a very rudimentary knowledge of these things, I highly recommend two things in particular: BEST and I do mean BEST battery you can possibly afford. (I went for the Turnigy 25 - 50C Nano Tech batteries in 6000 mah (6 AH) ) I have seen scores of posts about batteries being hot, puffing up and going dead on low powered RC builds, and most of those threads have this in common: cheap LiPo, and little AH's. Let me ask you this, which is cheaper, a $40 LiPo pack that is run ragged and lasts 300 charge cycles because it's flogged with-in an inch of it's life, running at max discharge, or a $60 LiPo pack that can last years since it's only being run at 30-50% of it's rated capacity?

The second thing, and I know I am repeating here, but it's worth repeating, buy the BEST ESC you can possibly afford, save up, collect cans, pan handle, what ever! Just don't buy a ESC that looks good on paper (Turnigy 200A ESC you mentioned earlier is a PERFECT example) that will give you endless headaches over sync issues, blown caps & crappy throttle response, when you can buy an ESC that will do everything you want out of the box for $60 more!

If you are now shifting gears to a street ride, I'd suggest you check out the various single stage and friction drive set-ups here. I think one of the most tried and true combinations involves a Turnigy 63-74 -200 KV http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=3890 motor paired with a Castle Creations Phoenix Ice ESC. (About $120 shipped or same at local hobby shop) http://www.castlecreations.com/products/phoenix_ice.html Sure you can get a cheap HK for $60, but will it allow you all the programing to protect your LiPo with LVC and Amp limiting? There are both friction and single stage belt drives using these with great success (notice that not only is the motor large, but it's designed to run all the way down on 3S (11V) on up to 8S (30V) so it's not likely to get hot going at low speeds and up hills. That's $180 and another $25 for a castle link that will let you plug into your computer to not only check the data log after running your bike, but customize the LVC, Amps limits, and other very usefull items to keep your batteries happy. $205 VS $150 might sound like a lot, but for me, it's peace of mind!

It's the amps especially at low speeds like carrying a heavy load or going up hill that kill the most, I have been running this motor/esc combo on just 4S and three parallel of the turnigy nano techs (18AH's) and I have not once while going up even a 12% grade at 9 MPH with pedaling (I am being cautious as my LiPo's are still breaking in) has the motor or ESC become even slightly warm! The batteries on this climb for the first time had just the slightest warmth so faint I had to check several times to be sure they were actually getting warm. Notice that I am regularly pulling 60 - 80 amps starting on a steep hill like that with pedaling, and then it settles down to around 20-30A, but I have once peaked on 118A! Not a good idea on just 4S, but again, nothing has even got warm! If you're wanting to do some of the cheaper packs, just make sure you're using a good amount, 10AH's I think should be the absolute minimum, but 15 AH's (5AH packs) is MUCH better, will last longer and we won't see any posts about how you accidentally killed a cell. The other thing is chargers. You can have your batteries charge in a couple hours, or a couple days (ok over-night :wink: ) just depends how much you want to pay. Don't skimp here either, if you can't afford a 10A charger, get a good 2A one and make sure you balance them or you're liable to over discharge a cell or 2 in the pack at some point. Also, all the crazy videos you sell of LiPo blowing up usually (90%+?) involve improper charging, over-charging is what generally makes them go boom, just check out LFP's LiPo disctruction video http://www.youtube.com/verify_age?next_url=http://www.youtube.com/watch?v=dree0rTr1HM

I did the same hill that killed my original motor on the Kepler Drive (Eboost) today at 15MPH with pedaling, and NO EVEN WARM! I will plan on using 6S (22.5V) next with this build, and I am using a 700c Hybrid with skinny roadie tires, and it rocks! My bike is 41lbs with all my Batman gadgets, batteries and drive. The lightest I could get a similar build with a DD was 65lbs on a 26" Trek 830 MTB. I like to pedal, so I don't mind the friction drives, and just as long as you start with pedaling, you're not likely to have any problems, particularly the EV Todd version with a metal roller, with tire wear.

Don't let me talk you into anything you're not looking to do, I'd just like to say I was EXTREMELY lucky that both Castle and E-Flight warrantied the motor & ESC that I burned up, otherwise I might not be riding much now.

Keep the bike light and close to a normal bike and I think you will be happiest on your current budget. If you have money to spend, by all means get a X5304 and $2,000 worth of beefed up bike, batteries, and plan on melting things on your quest to best Dr. Bass and his 67 MPH beast! If not, then do a 9c Hub motor (I like the 9 x 7) and plan on it being 20 - 30lbs heavier than a comparable friction/belt drive (check out the MkII RC Drive! My next project is making something similar! http://endless-sphere.com/forums/viewtopic.php?f=28&t=10635&start=15

 

[Alster370]

would a belt drive be possible for this project? I know the torque can snap them in half from these motors but I really like the noise of an outrunner and don't want chain noise interrupting that.

 

[gwhy!]

would a belt drive be possible for this project? I know the torque can snap them in half from these motors but I really like the noise of an outrunner and don't want chain noise interrupting that.

I dont see why not. The problem would be getting a pulley big enough for the back wheel. I think AJ had a complete belt drive at one stage and he made his own rear pulley. Chain noise is not really a problem on the final stage though its the initial reduction from the motor that can be noisy so I would defo use a belt for the first reduction stage.

 

[Alster370]

Im currently building some portable speakers that can be strapped onto the bike. Just had everything ordered.