TongXin (a.k.a. Nano) motor project

[cody]

I will report my findings once the design built and is tested. If somebody is interested I'll post the controller as well.

I'm interested. Can you post the controller design? Thanks.

 

[cody]

I've tried contact Diana at Tongxin a couple of times, but I got no response. I tried the email from their website and the hotmail address that has been posted too. How long did anyone wait before the got a response? It's been about 2 weeks so far. Thanks.

 

[bogmonster]

For thise of you with a Tongxin and on the question of the Tongxin motor drag, what constitutes near zero? I now have tongxin (not yet in a wheel) and I am surprised by the resistance turning it by hand? Almost appears to be turning the motor?

I don't yet have a battery so can't try with power. I have mounted the motor in my forks and spinning it by hand the motor stops after not more than a single revolution. Not the near zero drag I had hoped for? I don't want to get this built into a wheel if this is not right?

Maybe my expectations of near zero drag were too high or maybe it's duff?

Cheers, BM.

 

[flecc]

I'd say wait until you have it up and running BM, it could be just new assembly stiffness that instantly disappears in use when the drive engagement frees up.

Spinning by hand is always misleading, Any standard hub motor bike wheel feels free to a hand spin, but their epicyclic drag when cycling without power is very real as many of us know to our cost when the battery runs out. That's where the Nano uniquely scores since nothing is engaged when freewheeling.
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[bogmonster]

I'd say wait until you have it up and running BM, it could be just new assembly stiffness that instantly disappears in use when the drive engagement frees up.

Spinning by hand is always misleading, Any standard hub motor bike wheel feels free to a hand spin, but their epicyclic drag when cycling without power is very real as many of us know to our cost when the battery runs out. That's where the Nano uniquely scores since nothing is engaged when freewheeling.
.

Yeah, that sounds good advice. First I think I will get a battery before I get it into a rim so I can at least spin it up and see what happens. If that goes OK I will put it into rim and give it a proper test.

I think the drive is engaged at the moment due to the resistance so hopefully it is just because it is new.

Won't know for sure for a few weeks until I get a battery.

Cheers, BM.

 

[Tiberius]

BM,

I have a test jig and a suitable power supply if you want to run it up.

Nick

 

[frank9755]

It is hard to tell before it's built up.

To reassure you, when I spin my Tongin motor by hand (by the wheel rim with the bike upside down) it actually doesn't spin for as long as the suzhou bafang in my wisper does. But it certainly has negligible resistance when ridden.

 

[bogmonster]

BM,

I have a test jig and a suitable power supply if you want to run it up.

Nick

Tiberius,

Thanks for the kind offer. I have just ordered a battery from Ping so hopefully I will be in a position to wire it up myself soon.

Cheers, BM.

 

[bogmonster]

It is hard to tell before it's built up.

To reassure you, when I spin my Tongin motor by hand (by the wheel rim with the bike upside down) it actually doesn't spin for as long as the suzhou bafang in my wisper does. But it certainly has negligible resistance when ridden.

Frank,

Yes that is reassuring. I suspect that it is just new and will sort itself out with some use. Also, on further investigation there appears to be an initial friction that reduces at higher RPMs. I guess just a feature of how the drive mechanism works. I am quite looking forward to getting it installed. I have a 10ah Ping battery on order and hope that will be large enough. I think it should be OK if I charge at work as well. People are claiming 25miles from the 4.5ah battery on the Cytronex and that uses the same motor.

Only planning on using it on the hills but there are quite a few of those around here. That is why I am running a 175rpm motor in my 700c wheels. Hope the battery delivery does not take too long over the festive period.

Cheers, BM.

 

[Barnowl]

Frank,

Yes that is reassuring. I suspect that it is just new and will sort itself out with some use. Also, on further investigation there appears to be an initial friction that reduces at higher RPMs. I guess just a feature of how the drive mechanism works. I am quite looking forward to getting it installed. I have a 10ah Ping battery on order and hope that will be large enough. I think it should be OK if I charge at work as well. People are claiming 25miles from the 4.5ah battery on the Cytronex and that uses the same motor.

Only planning on using it on the hills but there are quite a few of those around here. That is why I am running a 175rpm motor in my 700c wheels. Hope the battery delivery does not take too long over the festive period.

Cheers, BM.

Yes I've had 25 miles out of the Cytronex. It depends on loads of factors, (hills, weight, headwind etc) but never had less than 20 out of a full charge.
Also no problem with the freewheel. I was concerned about mine when I first had it and tried spinning it by hand. It made a slushing sound and there does appear to some drag. However out on the road no issue at all.

 

[wotwozere]

Hi

Is this the same motor has the brompton bike uses?

My friend was going to buy one

thx

Bob

 

[bogmonster]

It is the same. I think the Brompton kit uses the 260rpm version.

BM