Reconnecting some wires, a beginner's journey

arthurtuxedo

100 W
Joined
May 16, 2017
Messages
111
Location
San Francisco, CA
Hi all,

I finally got the project bike that I posted about a few months ago into rideable shape. It rides like a dream, I love the gear hub, and the hydraulic disc brakes I installed the front allow braking distances that could probably beat most cars. However, all the part swapping and jostling has knocked a few wires out of their sockets, particularly the connection between the battery box and controller, so I'm going to have to learn to solder. I also routed the wires incorrectly installing the battery box, giving them less slack than they were designed for.

My first two questions for this project are...

1) Any tips and caveats on buying the equipment? I was just going to get a 60W soldering kit, heat gun, shrink tubes, spiral wrap, hook & loop fasteners, and rosin core solder on Amazon. I also wanted to get some spare lengths of wire to add slack but don't know where to get them or what kind to look for.

2) Would it be easy to combine the two connectors shown in the picture into one, particularly a type of connector that would allow me to get rid of that plastic box on the fork but retain the waterproofing?

IMG_1033.jpg

Thank you!
 
Soldering technique is different on different types of joints so it's difficult to give exact advice, but as a general rule, keep the soldering iron tip on the joint from before until after you add the solder. With big joints, give plenty of time to allow the joint to heat up so don't be in too much of a hurry to remove the iron. I taught kids to solder for 10 years. The biggest mistake they made was waving the iron around like a magic wand.

When buying solder, get the 60/40 tin/lead, not the lead-free. The lead-free doesn't work as well.
 
You can avoid the soldering by learning to crimp, then using a connector that crimps, like Anderson power poles. 45 amps type.

Or, a good plug for solder connections is the gold plated 4 mm bullet connectors. Get those were RC hobby stuff is sold. To solder those, you need a way to keep then stood up, like a board with holes drilled, and a solder iron with a big fat tip. Power not crucial, the big heat holding tip is what you need. Like they use for stained glass.

Other tiny connectors on the bike will need the fine tip iron. Or crimp well.
 
Replace that bulky O.E.M. connector w/ a slick 9-pin connector from Luna Cycle;

https://lunacycle.com/parts/hub-motor-parts/ebike-kit-extension-cable/

Cut the extension and graft in on.

I too like 4 mm bullet connectors and use them where ever I can. Use only the quality Turnigy pieces and order a couple of packs, they are good to have;

https://www.ebay.com/itm/5-Pack-5-Turnigy-HXT-4MM-Bullet-Connector-Plug-Housing-Sets-for-Lipo-ESC/230987162835?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649


But I don't solder them w/ an iron. I place them solder cup up by using the holes in my wire stripper pliers layed flat on my table. Then I fill the cup w/. solder by heating it w/ a sm. torch, butane or propane and then dunk the stripped wire end into the cup and hold it there for a couple seconds. Don't put too much solder in the cup ior the wire end will push it out. I have found that the first time the cup fills up, it's really only 2/3 rd.s full and this is good. Test that the connector is secure by pulling on it.
Now the plastic protector that you have already pushed up the wire before soldering the connector(unless the other end is bare). It has a little ridge inside, that when the cover is pushed over the brass connector and locks it on. I usually gently heat the base of the cover until it just starts to get soft and push like Hell and it will snap on. To get it all the way on, place the opposite connector(male on female, female on male), so it will push all the way on.
All this might sound complicated, but once you start practicing, you will quickly see what I'm talking about and after several, you will be putting them on like a pro.
Rather than soldering wire 14 ga. and heavier, I will usually use the bullets w/out the covers and cover w/ shrink fit for a more or less, perm. connection.

Get your silicone wire from Hobby King, along w/ most of the other little stuff. I wouldn't bother w/ the hook and loop fasteners, but instead secure wire bundles to the frame w/ soft velcro straps(don't use Zip ties on wires).

SAM_1185.JPG

Hope this helps
 
motomech said:
Replace that bulky O.E.M. connector w/ a slick 9-pin connector from Luna Cycle;https://lunacycle.com/parts/hub-motor-parts/ebike-kit-extension-cable/

Shame there are no specs for those plugs.

Presumably the 3 bigger pins are for the phase wires; but what ampage can they handle?

It'd also be nice to be able to buy the plugs individually so that you can put one directly onto the motor wires, rather than having to cut a pre-made cable in half and then graft the ends onto existing wires..
 
Besides being water-tite, the 9-pin connectors are small enough that the axle hardware slides right over housing. A BIG PLUS.
I "graft" wires all the time, done right, one can hardly tell.

The 9-pins come on some larger motor Kits, like the Bafang BPM. That's a motor that regularly sees 2000 watts or more.
 
Thanks for the advice! Now I am trying to decide whether to proceed by ordering soldering or crimping gear.

Here is a pic of the disconnected wire from the battery to the controller. Is this the sort of thing that can be crimped? It looks like it would be hard to solder since it's attached to the bike and I would probably drip molten solder all over the floor and frame.

IMG_1040 (1).jpg
 
fixing that existing connection is a solder job for sure.

Must have been a good crash eh? That's pretty jacked up.
 
I bought it from a crazy guy who lives on a boat. I figured the price was right and it would be a good project to learn to work on Ebikes, but now I know that I bit off more than I could chew and I should have spent the extra money on one that actually worked and acquired the mechanical skills more gradually. Oh well, we all make rookie mistakes in the beginning!
 
Oh well, we all make rookie mistakes in the beginning!

I've blackened my fingers a few times and I recently tossed out my "box of shame", full of toasted controllers.
But 8 years and a half a dozen builds later, I have a pretty good handle on this ebike building stuff.

You really should consider doing your the wiring in the manor I have out-lined. I've tried most every kind of connector, from XT's to Andersons, and for lower powered systems, the 4 milimeter bullets are the easiest to install and the lkeast costly.
 
I wouldn't crimp anything on the motor phase wires or the battery wires. It can work in theory, but only if done absolutely perfectly. The best connector is no connector. I've built many electric bikes and I've never found a need to disconnect a controller once I've installed it, so I tend to solder battery and motor phase wires directly, which saves many problems. The only connector you need is the one that allows you to remove the motor wheel. Most have a connector near the wheel, so you don't need/want another one at the controller.
 
d8veh said:
I wouldn't crimp anything on the motor phase wires or the battery wires. It can work in theory, but only if done absolutely perfectly.
Crimping does require some skill but I think it is easier to learn and quicker to do then soldering, especially on the big wires. From what I know almost all connectors in the auto and aero industry are crimped
 
I received a couple hundred bucks earlier than expected, so I'm thinking that I'll go ahead and order a Cycle Analyst v3 if I'm going to be messing with the wiring anyways. Will the c2013 eZee controller have a plug for it or will I need to do the shunt mod?

I also have my eye on the TDCM torque sensing bottom bracket from ebikes.ca. Does it matter which spindle length I get?
 
Turns out the wires in the second pic are just to the ignition key, not connecting the battery and controller like I thought. Received my 60W soldering iron and 60/40 core today so I'll make the attempt soon.

I can't see any way to route the wires properly through the bottom of the frame without cutting and reconnecting them since the controller is too big to fit. I understand why I routed them incorrectly the first time, since I really didn't have a choice. This leaves me torn between cutting all the wires and re-soldering them to get the proper routing or just leaving it as-is and adding some extension to the ones that don't reach due to the bad routing. The second route would certainly be easier!

The controller is pretty small and has some apparently custom screw holes to hold it to the battery box. It only has two large wires coming out of it and no obvious way to hook up a Cycle Analyst so I probably won't try to do further upgrades once I have it working again. Maybe I'll just get it working so I can sell it and do a custom build from the ground up like I probably should have in the first place. Either that or just lay off Ebikes for a while. I'm a lot more used to riding uphill now and no longer have knee pain on my daily route so a pedal-only bike might serve me just as well for now.
 
After a very helpful e-mail exchange with Lyen, I got the motor working again by twisting the ignition wires together! I guess the only thing the ignition key did was complete a circuit, so now I can take my time watching tutorials and still have E-power in the mean time. The power in this thing really puts my old bike to shame, and even though it maxes at 20 MPH, it's almost too much speed for the streets of SF, especially when I am also pedaling in the highest gear. I'll still probably upgrade the cells to 52V someday, but for right now I'm more than satisfied with the boost at 36V, 20A. The slow-wind eZee motor (which is basically a BMC, IIRC) climbs hills like a champ, too!

I also learned that my controller is not compatible with a Cycle Analyst, so I'll need a new one if I'm ever going to add one, install a torque sensor, and / or use the PAS that came with the frame. TBH, I kind of like the lack of pedal assist. It forces me to either be a total bum and lean on the throttle all the time or ride it like a regular bike and only use the assist for hills. Hopefully I'll choose the latter!
 
arthurtuxedo said:
I also learned that my controller is not compatible with a Cycle Analyst, so I'll need a new one if I'm ever going to add one, install a torque sensor, and / or use the PAS that came with the frame.

ALL controllers are compatible with a CA, at least as a monitoring device.

Use the CA-SA version, with a separate speedo sensor, and you can use it on ANYTHING that is DC-powered.

If you want to use the CA as a limiting/control device as well as monitoring, you just have to modify the throttle and ebrake connections on the controller and/or CA to connect them as needed, per the UUG by Teklektik and/or the other documentation on the Grin Tech site and/or ES threads about it.
 
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