Advice on first RC bike project?

Hi guys,

I'm new here and have spent the last few evenings reading around old threads.

I've decided to dip my toe with a Kepler-style friction drive (fantastic work) to assist my pedalling. It'll be mainly for short journeys so I'm looking for plenty of power. I'd like to get 30mph if I can. Of course, it should also be cheap

I've given up trying to find parts in the UK, so I'll likely order from Hobbyking (unless someone recommends a better supplier)

The thing I could use some help on is recommending parts. I've noted below parts recommended by Kepler, but the list is nearly two years old, links no longer work, parts get discontinued. I get the impression this technology moves fast.

The only motor I can find is the Turnigy 80-100 motor.

Is it still the case that I should stick to 6S because higher voltage controllers are much more expensive? My concern is that a 6000W 12S motor will be only 1500W on 6S.

I need a motor, controller, servo tester/throttle pot, a charger and some 5ah Lipo's.

Any advice would be very greatly received. I don't want to order parts that end up not working well together (like sync problems), especially since postage costs will be significant.

Thanks,
Tony

You sound to be in pretty much exactly the same boat as me, except I am more interested in a mid mount chain drive solution. The joy of RC type motors is they are a cheap money investment, on the other hand they are a massive time investment since you need to fabricate a two stage reduction system.

I found this turnigy clone with a UK distributor

http://www.giantcod.co.uk/xyh80100a-130kv-brushless-outrunner-7055-p-404608.html

It says they are moving warehouse at the moment though so will be interesting to see if they get them back in stock soon.

Hi Guys,
Welcome to es , couple of tips dont go for the 6kw motor for your first projects these motors are very hard on controllers and cause more trouble than they are worth. A good place to order motors from is leaderhobby I have ordered around 10 motors from them and they have always arrived in a good time. If you want to go for a friction drive setup get a motor with a skirt bearing but for a chain drive system then try to get a motor without the skirt bearing. the 3kw 63mm motors is a very good starting motor and will push a bike upto 40mph and they are a little kinder on controllers. where abouts in the UK are you guys? if you get the lower kv motors ( 180 ) and only run them on 6s then there are some very good e-bike sensorless controllers that will do the job for around £25 these can be upgraded to provide the power you need at a minimal cost.

Thanks for the advice, I will probably end up lurking for another six months before trying to build anything! I'm in Nottingham or there abouts. I'm tempted by the RC route because time and a little manufacturing skill I have, money? not so much...

Do you mean like this? I will start saving my meagre pennies!

Just had a completely none related thought. I used to work for a CNC manufacturing firm who specialised in Go-Kart parts but also dabbled in making bits for Pashley, I wonder if we could capitalise on that expertise for non hub e-bike manufacture? Hmm

zogworth said:

Do you mean like this? I will start saving my meagre pennies!

Just had a completely none related thought. I used to work for a CNC manufacturing firm who specialised in Go-Kart parts but also dabbled in making bits for Pashley, I wonder if we could capitalise on that expertise for non hub e-bike manufacture? Hmm

Click to expand...

Thats the very motor I have been using for the past 2+ years for many projects, there is another ( same spec ) but its red and cheaper http://www.leaderhobby.com/product.asp?ID=9394001224349.

Go-Kart parts there would be a demand for sprocket carriers for sure for BB drives and for direct drive :wink:

Gwhy, the 63-74/170-kV you linked to ($42), does it have a skirt bearing? Have any of the shell-drives (Kepler/Adrian) worked out OK with a non-skirt bearing motor?

I'd also like to know that as well.

One issue might be (assuming I've worked this out right) 6S at 170KV (assuming 80% of no load speed) gives 35.6kph = 22.1mph.

Is there anyway to sort the motors listed on Hobby leader? There are 24 pages of brushless outrunners and I'm not sure where to start looking...

Doing some more reading this evening, I've realised I also need something to monitor the pack voltage. I'd be happy with a simple voltmeter, unless and inexpensive cycle comp./watt-meter is available?

I've just read in another thread that USPS will be refusing to carry LiPos from the 15th may, so I'd like to get my order in asap...

Hey guys, the Leaderhobby 6374-180 looks physically identical to the Hobbyking Turnigy 6374-170 (older SK series) which does NOT have a skirt bearing. However, I have been running one of these on my wife's bike on a Kepler Mk1 Drive over the past year, around 500 km on 5S with no motor problems. Speed is around 30 km/h.

I have also purchased a Hobbyking SK3 Series 149 kV motor, which DOES have a skirt bearing, but haven't run it on anything yet. Looks like much better build quality, windings are tighter with thicker copper wire than older SK series.

Punx0r said:

I'd also like to know that as well.

One issue might be (assuming I've worked this out right) 6S at 170KV (assuming 80% of no load speed) gives 35.6kph = 22.1mph.

Is there anyway to sort the motors listed on Hobby leader? There are 24 pages of brushless outrunners and I'm not sure where to start looking...

Doing some more reading this evening, I've realised I also need something to monitor the pack voltage. I'd be happy with a simple voltmeter, unless and inexpensive cycle comp./watt-meter is available?

I've just read in another thread that USPS will be refusing to carry LiPos from the 15th may, so I'd like to get my order in asap...

Click to expand...

The 2 motors linked do not have skirt bearings. The best way to look through leaderhobby is to use there search option and enter 6374 this will list all that size motor, I think they do a 200kv motor @3kw that size but you can also run them with higher voltage for more speed but this requires either a hv rc controller or a better e-bike controller and fit hall sensors to the motor, the option of running 24v is just to keep it all as simple as possible even a 120A 24v rc controller can be very cheap ( £20) but there is no form of current limiting and I was seeing peeks of around 180A when I was playing around with 24v 100A rc controllers and I dont think a rc controller over shooting its rating by this much will last very long so some form of current limiting will have to be incorperated.

Thanks for the tips

Which controller is this cheap 120A one?

Searching through some of Adrian_sm's posts has thrown up some links to 6374 motors:

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=18182

http://www.hobbyking.com/hobbyking/store/__18184__Turnigy_Aerodrive_SK3_6374_149kv_Brushless_Outrunner_Motor.html

I reckon the screws around the end of the can indicate a skirt bearing on this one:

http://www.leaderhobby.com/product.asp?ID=9394001220805


I'm going to have a closer look at the specs for each later and have a search about for any issues/problems with them.

I'll avoid the 6Kw motor



I've also seen a cheap Turnigy wattmeter: http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10080

Punx0r said:

Thanks for the tips

Which controller is this cheap 120A one?

Searching through some of Adrian_sm's posts has thrown up some links to 6374 motors:

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=18182

http://www.hobbyking.com/hobbyking/store/__18184__Turnigy_Aerodrive_SK3_6374_149kv_Brushless_Outrunner_Motor.html

I reckon the screws around the end of the can indicate a skirt bearing on this one:

http://www.leaderhobby.com/product.asp?ID=9394001220805


I'm going to have a closer look at the specs for each later and have a search about for any issues/problems with them.

I'll avoid the 6Kw motor



I've also seen a cheap Turnigy wattmeter: http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10080

Click to expand...

Yes normally the screws indicate a skirt bearing, as for a cheap rc lv controller look through ebay I have been running a mystery 100A lv controller with some of the stuff I have been playing with lately but the one that is better at starting up and have been overshooting is a boat rc lv 120A controller ( I replaced the watercooled heatsink with a normal heatsink ) I think the boat controller was around £30 delivered from ebay but the mystery controllers are around £20 for a 100A one something like this for 6s max http://www.ebay.co.uk/itm/TUR-120A-Brushless-Motor-Speed-Controller-RC-ESC-BEC-/300556010887?pt=UK_ToysGames_RadioControlled_JN&hash=item45fa88c587#ht_2287wt_756 ( I havent tried this one so dont know how good it is ) . The watt meter is a very good investment for setting up the bike, most of the people who dont have a CA have one of these watt meters ( I have 3 of them and they work very well ).

Nice one

I don't mind spending $60/$70 on a controller if it's going to be more reliable. I appreciate this is still cheap for a controller, though.

I think it's all coming together now

One thing I'm stuggling to find search results for is a thumb throttle. Are these commercially available? From what I gather it's just a case of replacing the pot on the servo tester with a throttle pot.

Tony

Punx0r said:

One thing I'm stuggling to find search results for is a thumb throttle. Are these commercially available? From what I gather it's just a case of replacing the pot on the servo tester with a throttle pot.

Click to expand...

4QD have the 50 deg. pots: http://www.4qd.co.uk/accs/pots.html#pots

I have some 4QD pots and metal levers in a box somewhere...

I could add a return spring to one, but I was hopping for a less DIY option.

I see some inexpensive ICE thumb throttles (for mini bikes) on ebay that could perhaps be adapted to operate a pot. Perhaps even a linear/slider pot...

I'm getting close to ordering, anyway :lol: