Xiongda 2-speed motor

[IdleMind]

This a clever mechanism and thanks d8veh for reporting your evaluations. I was wondering if you have any concern about using just one bearing on each of the planet gears. Could this allow the planet gears to tip out of Parallel and cause the noise you noted or premature gear wear.

 

[d8veh]

It seems to be very rigid. I guess that they're roller bearings or double ball races. I'm still trying to understand what causes the chattering at low speed and high torque. Greasing seems to stop it.

 

[endlessly_ending]

My guess is, that its simply the slightly coarser modul (1,5 versus 1,0 normally) that causes the noise in combination with the double gearing thats engaged all the time: the diffential speeds (1/1.8 ) may cause a new set of spectra accordingly.

As for the hill climbing ability I was very impressed by the XiongDa plus stock controller on a 10s battery: roughly 120kg up a 10% hill - without any pedalling !



As can be seen in the charts this equals to about 40Nm in a 26" wheel.

Given the lady in the sales video uses almost half the wheel size (17") and also might have roughly half the total wight to pull up, its not that unrealistic that she might go up a 27% hill wiht ease

 

[turbo1889]

18% and 27% hill grade, yes, I can see that could be with a light weight rider especially with small drive wheel and/or pedaling and it might be that steep from the video.

But that isn't the same thing as a 18-degree and 27-degree hill. They don't look that steep and I think the person who made the video has the two different forms of measurement confused.

From the calculations I've done (see the post I just made on the bottom of page 5 on the other thread) in Low this motor laced into a standard 26" wheel should be capable of just barely dragging my heavy @$$ up a 10% hill without pedaling but I really should pedal to keep the motor from overheating. While at the same time being capable of some pretty respectable speeds on the flat when in High.

That's not bad at all. Not quite what a mid-drive running through a wide gear range is capable of but not shabby in the least especially for a small low wattage hub motor !!!

 

[d8veh]

The motor is able to drag 135kg (all up weight) up a 14% slope with 15 amps and 36v. If you increase the current to 20 amps or the voltage to 44v (12S), it does it easily. With reasonably hard pedalling, I got it up 31% - still 135kg. In low gear, it's just like a 250w crank-drive in bottom gear.

 

[endlessly_ending]

d8veh

Whats the wheel size you had the motor in and what winding has that motor?

I did a test with 10s Lipo plus 2s LiFePo uphill recently and was very pleased with the results too. The motor barely got warm, maybe 10-15K above ambient.
Went up with roughly 15km/h in low gear, without any pedalling.

This test translates roughly into 1000meters of climbing each hour .
From the chart belo we see that this equals roughly 300W mechanic power needed (120kg, 5-10% grade)- not that shabby at all.




Another 100W or so has to be added for tractional resistance - so in total the mechanic output of the 2-speed XiongDa was in fact around 400W here.

Controller got hot though but was in a bag - still quite impressive for its small footprint.
On a rough guess the stock controller was workling close to its ampere limit, on voltages under load of 43-48V

 

[teslanv]

So from where or whom could a person buy this motor?

 

[docnjoj]

The motor is able to drag 135kg (all up weight) up a 14% slope with 15 amps and 36v. If you increase the current to 20 amps or the voltage to 44v (12S), it does it easily. With reasonably hard pedalling, I got it up 31% - still 135kg. In low gear, it's just like a 250w crank-drive in bottom gear.

I am trying to order one now. I have asked for it laced in a 20" wheel, 135mm rear motor kit with controller (preferably sine wave). It will be stressed on my trike as it weighs in at about 150 kilos with me and tools. I just don't go very fast (< 20mph). Will only be using 36 volts.
We will see what happens.
otherDoc

 

[d8veh]

d8veh

Whats the wheel size you had the motor in and what winding has that motor?

It's a 26" wheel. I've no idea of the winding, but it does about 12 mph in low gear at 36v.

 

[docnjoj]

So proportionally in a 20" it will do about the same, since they decrease the winding numbers. This could be way cool! All I need is 18 mph max in high and to make a 5% 2 mile grade. This sounds reasonable @36 volts, yes?
otherDoc

 

[endlessly_ending]

So proportionally in a 20" it will do about the same, since they decrease the winding numbers. This could be way cool! All I need is 18 mph max in high and to make a 5% 2 mile grade. This sounds reasonable @36 volts, yes?
otherDoc

As long as you dont ask for doinng all at the same time, you should be fine IMO.

If you intend to wind up your 130kg a 5% grade by 15mph/ 30km/h you are asking for about 550W plus lets say another 150W for rolling resisctance.
700W mechanical output will be too much to throw on this hub size for any extended period of time IMO. From what I have seen, about 500W real output might be about the limit for the small footprint of such hub motors.

 

[docnjoj]

Thanks Endlessly_E.
Right now I go up at about 8-10 mph and pedal like crazy. If I can get similar performance, I'd be thrilled. The gearing and the 20" wheel should allow fewer amps than the current 9C, I hope. Oh well, that is what Early Adapters face! I gotta check those graphs again. The 18 mph is as fast as I can go now on level ground. We are not speed demons.
otherDoc

 

[docnjoj]

Oh yeah! What diameter spokes should I use? I like the 14 gauge ones cause they are easy to lace and stay tight. Does this motor need bigger diameter on a 20" wheel? I'm guessing one cross should do it? Rhino-lite rim.
otherDoc

 

[d8veh]

It can produce a lot of torque, so I use 13g 2-cross.

 

[docnjoj]

I just ordered spokes from John Holmes and it dawned on me . Will the 135 mm rear motor need dishing?
Thanks in advance.
otherDoc

 

[d8veh]

It might be OK if you have a front onr, but if you have a rear one, it'll need dishing. It should be OK with the same length spokes on each side. To avoid a substantial dish, you can stretch your frame further and use spacers on the disc side and on the caliper. I wrote something about it here:

http://www.pedelecs.co.uk/forum/threads/rocky-mountain-conversion-with-xiongda-kit.17654/

 

[docnjoj]

It might be OK if you have a front onr, but if you have a rear one, it'll need dishing. It should be OK with the same length spokes on each side. To avoid a substantial dish, you can stretch your frame further and use spacers on the disc side and on the caliper. I wrote something about it here:

http://www.pedelecs.co.uk/forum/threads/rocky-mountain-conversion-with-xiongda-kit.17654/

Yep it is a rear but I don't use rear brakes on the trike. 2 front 185 BB7's stop me on a dime with change. It is not critical to exactly center but I will mess with the spokes for dishing just to make it look good. Thanks again d8veh for clear, accurate advice.
otherDoc

 

[turbo1889]

Okay, I've got all the pictures of the gears and clutch assembly and the provided tooth count info along with the posted diagrams in the first page of the other non-tech section thread and the magnet count.

I'm trying to figure out the motor to wheel reduction ratios the gearing provides for the two gears so I can then use the wheel RPM info (in high gear at 36v the standard motor winding configuration for 26" size wheels does about 233-RPM free spinning no load, and in low gear about 130-RPM free spinning no load) to figure out what kind of electronic RPM levels the controller would have to deal with when running this motor at higher RPM's.

I think the reduction ratios are:
----- High Gear = 4.444444 to 1 (A string of 4's continuing to infinity to the right of the decimal.)
----- Low Gear = 8 to 1 (Exactly.)

That being calculated as:
----- High Gear = 18t steel motor output gear turns 32t composite planetary gears on axle fixed mount plate and these are shaft coupled to 12t steel planetary gears on opposite side which turn the inner 30t composite final output gear on the double clutch assembly output plate. Reduction Ratio = (32t/18t)*(30t/12t) = 4.444444
----- Low Gear = 18t steel motor output gear turns 32t composite planetary gears on axle fixed mount plate and these are shaft coupled to 12t steel planetary gears on opposite side which turn the outer ring 54t composite final output gears on the double clutch assembly output plate. Reduction Ratio = (32t/18t)*(54t/12t) = 8

Thus with 20 magnets the electronic RPM would be 80 times the wheel RPM in low gear and 44.444444 times the wheel RPM in high gear?



This sound correct to all of you?

Reason I need to know this is because I'm looking to use a controller on one of these motors other then the manufactures paired controller for it. The one I'm looking at is a fully programmable controller with a very wide voltage operating range of anything from 18v to 90v that has provisions for a motor direction reversing switch (which is all one needs to change between low and high gear with these motors if you do your shifts manually and are willing to sacrifice the auto shift function the factory paired controllers for them have). But it can only handle 40,000 electronic RPM though unless I pay extra for a high RPM model. With such a controller with such a wide voltage range and programmable amp limit I could really figure out what these motors are capable of across a wide range of voltage and amp levels.

 

[d8veh]

Your estimates of speeds in each gear don't look right to me. I posted the actual no load speeds somewhere. With a 36v battery and 26" wheels, it does about 12mph in low gear and 20mph in high gear on the road. That equates to approximately 160 rpm and 270 rpm on the road.

 

[docnjoj]

I thought I asked this already but my brain has failed again. To take this little motor apart there are 3 screws to remove (no problem). Then you need to replace one of the screws with an Allen screw . Does this only go part way in so the outer plate can be rotated or does it need to go the full depth of the screw hole? Thanks
otherDoc

 

[endlessly_ending]

The thread is in the clutch beyond the plate, screw in roughly a 10-12mm 1/2" and you will be able to unscrew the plate plus clutch.

 

[docnjoj]

Thank you very much! Now all I need is the motor.
otherDoc

 

[turbo1889]

Your estimates of speeds in each gear don't look right to me. I posted the actual no load speeds somewhere. With a 36v battery and 26" wheels, it does about 12mph in low gear and 20mph in high gear on the road. That equates to approximately 160 rpm and 270 rpm on the road.

Hmmm, since your the original "discoverer" of this motor I hate to contradict in any way but aren't those your 44v pack numbers not your 36v pack numbers? Or at least that's way I thought from your original thread on the UK forum.

I mainly took the "Wheel RPM vs. Voltage" numbers off of the motor test table image at the bottom of this alibaba.com listing:

http://www.alibaba.com/product-detail/Double-Speed-Motor-Electric-Bike-Conversion_1195155734.html

Which I should note they seemed to have used an EXACTLY 36v (+/-0.02v tolerance) stable power supply for that test and it is notable that most "36v" e-bike batteries usually pump out a bit more then just 36v at least for the top half or more of their capacity.

If the motor is wound a little faster then that table indicates then that is good to know although if I've got the gearing ratios correct even with your faster RPM numbers for 36v its still only about 13,000 electronic RPM at 36v so I should be able to at least take the voltage all the way up to the 72v level without having issues with the 40,000 electronic RPM limit the controller I'm looking to use is limited too.

So do I at least have the mechanical gearing ratios correct even if the wheel RPM for voltage numbers are a little too low? Just trying to confirm the gearing works the way I think it does and those are the correct gear reduction ratios.

 

[turbo1889]

And, yes, I realize I'm going to run into iron core heating issues running that high of voltage and RPM. It's just if I can run this motor (actually probably a pair of them front and rear) off of this wide voltage range programmable controller which can use any battery voltage between 18 and 90 volts then I should be able to try a variety of configurations and figure out exactly how high you can take it with upping the voltage and RPM and keeping it at 15-Amps limit before the core eddy current heating issues become a problem.

For my own personal application and also for future reference in this Tech-Section thread on this motor it would be nice to have:
----- The physical gearing ratios of this motor.
----- The Kv of the standard winding configuration(s) of this motor.
----- The practical limits of over volting and/or over amping of this motor.

I think I'm at least part way on my way to figuring out the first two from the data others have provided and if I can make the controller I'm looking at work with this motor I should be able to put a solid dent in figuring out the last one on that list.

For my particular application I am currently of the mindset of going with the wide range controller I'm looking at and then progressively pumping up the voltage with a strict motor phase amps limit in effect to protect the motor on the bottom end (the more you increase pack voltage even with the same battery side Amp limit in effect the more Amp multiplication you can get on the bottom end of the motor unless you put an amp limit into effect on the phase side of the controller as well, the controller I'm looking at is capable of that functionality) until I run into overheating issues on the top end and then backing back off one notch on the voltage and calling it good and and then open up the bottom end by increasing the phase amp limit until I run into overheating issues on the bottom end and then back off the phase amp limit a notch and call it good again. Thus effectively max out both my top and bottom ends. So if that is how it works out I should be able to provide some answers as to the practical limits of this motor both in terms of over amping for bottom end torque and over volting for top end speed. I have no plans to make any attempt to both over volt and over amp together at the top end so that question won't be answered and I will stick to a battery side Amp limit of no more then 15 Amps or maybe a little less if necessary to prevent overheating in the motors mid-band due to running higher voltage and only set-up to allow over amping on the bottom end on the motor phase side through bottom end amp multiplication effect. Basically I want to build a "stealth", "sleeper", "extreme cheater" e-bike where people can't tell its an e-bike unless they look and or listen really close that goes as fast as I can make it go both on the flat and up hills and still limit myself to using small stealthy little hub-motors like these and these two speed motors have the advantage over all similar small stealthy hub motors in being able to have both a good top end on the flat and good hill climbing capability as well in the same package.

 

[d8veh]

Your estimates of speeds in each gear don't look right to me. I posted the actual no load speeds somewhere. With a 36v battery and 26" wheels, it does about 12mph in low gear and 20mph in high gear on the road. That equates to approximately 160 rpm and 270 rpm on the road.

Hmmm, since your the original "discoverer" of this motor I hate to contradict in any way but aren't those your 44v pack numbers not your 36v pack numbers? Or at least that's way I thought from your original thread on the UK forum.

I mainly took the "Wheel RPM vs. Voltage" numbers off of the motor test table image at the bottom of this alibaba.com listing:

http://www.alibaba.com/product-detail/Double-Speed-Motor-Electric-Bike-Conversion_1195155734.html

Which I should note they seemed to have used an EXACTLY 36v (+/-0.02v tolerance) stable power supply for that test and it is notable that most "36v" e-bike batteries usually pump out a bit more then just 36v at least for the top half or more of their capacity.

If the motor is wound a little faster then that table indicates then that is good to know although if I've got the gearing ratios correct even with your faster RPM numbers for 36v its still only about 13,000 electronic RPM at 36v so I should be able to at least take the voltage all the way up to the 72v level without having issues with the 40,000 electronic RPM limit the controller I'm looking to use is limited too.

So do I at least have the mechanical gearing ratios correct even if the wheel RPM for voltage numbers are a little too low? Just trying to confirm the gearing works the way I think it does and those are the correct gear reduction ratios.

The measurements that I did at 46.6v equate to 136.6 rpm and 224 rpm at exactly 36v, so you seem to be correct. I would estimate that my 36v battery runs at about 40v on the road, which would increase the rpms to 151 and 250. I need to check again my speedometer in case it's a little too fast.