Hillzofvalp's 29er Thread... now with custom 63T (cromotor)

[rui_fujino]

your build is looking very good. how fast do you do? i believe you can hit 40mph no problem...and if thats the case, surely your battery and controller isnt stable with vibration?
Also i noticed you wanted +55 chainring with 11t? thats quite crazy setup...I've got 52T - 11T setup and I can pedal 35mph no problem...when you hit beyond 40mph your not suppose to pedal
i think the best solution to single freewheel is to get your self creative double to triple chainset setup so that you can pedal wide range of speed especially when your battery is down...

[hillzofvalp]

Yeah I can get up to 40 on the flats. got it to 44mph on a slight down hill grade once.. but I didn't want to go any further.

I can get up to 35 on pretty steep hills... I'm pretty happy with this figure. Though that's pulling 2500-3000W the whole hill. I'm seeing practical efficiency around 36Wh/mile, with very little pedaling.

In regards to vibration, the controller is heatsinked and screwed on to the enclosure, which is in turn attached to the frame very securely. Should the controller sit on bushings? The batteries are very snug.... there is not much room for things to jiggle around. critical gaps receive some old intertube rubber, and the sub packs are velcroed together. The 8S on down tube is sitting on .1" thick, 2" wide rubber.

Yeah, one of the reasons why I'm considering making my own gear is that I like to sit around 25-35mph, and the lowest the high quality white industries freewheels go is I think 15T or 16T. The cromotor can't accept a multi speed freewheel, and I'm not interested in the complexity of a derailleur system. My current crank is a very high quality one that I don't really need, but I can't justify getting rid of it just to put on a larger ring. I think the largest I can buy for this 108-115bcd (can't remember) is around 50T. It might actually be fine for my purposes, cause you're right in saying that ebikers generally should pedal less over 30mph so as to prevent loss of control.

A side benefit is that a CNCed gear is about 5 hours of my time and about $40 for the 12x12x.125" 7075 sheet... which could be less than a commercially available chainring.

I also may be milling a spacer to get optimum chain alignment with the cromotor. I don't have my hands on it yet to know

I just got a spell check telling me that cromotor should be cremator! Maybe that is more appropriate....

[hillzofvalp]

I just ordered a mtx 33 dh rim in the 700c size. I'm hoping that the wider rim will lower my rear end a bit (with the 2.35" big apple tire) to match the new front ebike-rated schwalbe energizer pro (1.75").

[Tommy L]

Good day!

I just built a 9C 2810. Started with 38v nom then 76.8v nom now at 89.6v nom.

at 76.8v I was at 36amps. at 89.6v I turned the CA down to 28amps to keep the max wattage the same.
It's a whole new beast.

Add 4 more S to your rig. You won't be disappointed!

Tommy L sends....

[hillzofvalp]

With this size wheel high voltage doesnt make a lot of sense... Especially with 9.3kv motor. I don't want to go too fast and I don't want to deal with hIgh voltage in general. There is also maybe enough room for a single 26650 cell.. I have 100 cells in there.

[Tommy L]

With this size wheel high voltage doesnt make a lot of sense... Especially with 9.3kv motor. I don't want to go too fast and I don't want to deal with hIgh voltage in general. There is also maybe enough room for a single 26650 cell.. I have 100 cells in there.

Nice clean build!

Tommy L sends... \\m//

[hillzofvalp]

I had an epiphany last night after I realized the 12FET really wasn't going to cut it for the cromotor (especially after ruining the 12FET when beefing up traces (don't ask how)). I will build my linear bms boards and 400-600W charger into the main enclosure, with all the electronics for temperature sensing, rfid features, as well as include an auxiliary battery. I will put an 18FET on the down tube and give it some better cooling.

[hillzofvalp]

all I can say is wow. I'm not even up to full power yet at 80/120A settings on my new 18FET. Strangely, controller doesn't get warm much at all.

The weird thing is I get better efficiency and better regen and overall performance than my 2807. I ran the same 60/80A settings that I ran on my 2807 last night, and normally the controller would be very warm if it was my 9C.. but not if it's this cromotor. Strange how it works that I'm going much much faster and yet still being easy on the controller and still getting the same if not better efficiency than my 2807 at the same settings. THis is a 29" wheel, but I am launching like a motorcycle!


More pics, vids, details after I get more time with it.

[Samd]

Video would be awesome.

[Alan B]

Regarding your possibly weakened magnets, if you can't see a difference in unloaded speed, you won't find a difference in torque either. If the torque has gone down by some percentage, the unloaded speed should go up by the same percentage.

[hillzofvalp]

"100% throttle setting actual speed but NO LOAD is actually what I'm topping out at with the 115% setting. I am still investigating the issue, if one even exists. Might've been a hard day (I can't even remember when this happened even though it was so recent) and maybe the motor wasn't cooling down between charges so it got sluggish. At this point, let's keep this stuff in my own thread and I will post here once I have a more definitive answer." -cromotor sales thread

So, the motor seems to sound a bit better and maybe even feel better, but I'm not sure why. The KV should be around 9.3 but I'm measuring around 8.0 with the 100% setting and 10.3 with the 115% setting with no load spin up. I will take it out again with the 100% setting to see if I can actually get up to top speed (which is around 45mph). I've reached the point where controller switches from pwm to full on many times with the 115% setting and that is about 45mph.

In case everyone is wondering, my CA is calibrated. I am calculating the rpm of the wheel using the cycle analyst and working backwards. should be within a few percent of actual kv if my logic is correct. THis is a 18FET lyen controller programmed with the compatible hall angle setting in keywin.

[zombiess]

It might be worthwhile for you to get a laser RPM meter. I think hobby king has some cheap, probably some on ebay too. Should make measuring the KV much easier. It always needs to be measured at 100% throttle at a given voltage and no load. You will have a tiny bit of load from the wheel and tire, but it shouldn't skew the results much. Good news is you said you are only seeing around 2.5A no load current I think which is right around where it should be. At 125V no load I see 3.3A current with my 20.2" tire.

Here is a copy of all the data I collected and sent to Justin to update his simulator, maybe some of this will help you figure it out.

OK, here is the data I collected at the different voltages. I think this is about as clean of data as I'm going to get without using a cycle analogger. I reprogrammed the controller so position 3 was 100% throttle which is where all my testing was done. What I did was make a pass in one direction in a mild tuck until the amps stopped dropping, then turned around and made the pass coming back staying in the same tuck position and averaged the 2 results to help eliminate error from any grade on the road. After each pass I added another 6S 17AH pack in series to the ones already there, that's why you see the voltage dropping a little each time. I didn't want to do a full recharge for this and figured the data was still relevant since the start voltage was given.

It's hard to tell exactly how much sag I had once I was at speed because of the surface charge of the cells burning off but typically on a 125V pack that settles down to 123V I'll see around 3-4V of sag going 55mph. On the 49.9V pull I saw about 0.3V sag at speed I think, it might have just been the surface charge dropping.

Code: Select all

volts                Unloaded MPH         Unloaded Amps        Loaded MPH           Loaded Amps
49.9                  28.0                     1.7               24.5                18.5
74.5                  41.7                     2.3               36.1                32.6
99.0                  55.4                     2.9               45.9                44.6
123.5                  ???                     3.3               54.8                60.1


I need to do the cap mod to get the CA to read higher MPH for the unloaded speed but you can probably predict what it is from the previous data points, based on the data it should be 69.1 MPH since there is a 13.7 MPH difference in unloaded speed between the other 2 data points.

Wheel size is programmed for 1612mm which is what I had to enter to get it to match my GPS speed to within 1mph. Bike plus me weighs in at 270lbs.

[hillzofvalp]

I'm going to make sure that my throttle is set up right in the cycle analyst. I did make some changes for this controller for my current throttle, but it may still need some tweaking. THis may explain the hesitation getting into FULL ON state when I give the throttle full twist.

Thanks for all your patience and advice.

[John in CR]

Forget the 115% speed setting, and no load at anything other than 100% is meaningless. That's the kind of stuff that causes controller and motor problems. If you need more top speed after properly tuning your controller to your motor and load, then increase the voltage. Doing crap like > 100% speed settings is like pushing motors way into saturation to get more power. Bad Bad Bad. You have a high power motor now, so learn to walk before you start trying to run. Don't do repetitive hard launches like in that parking garage, especially with a big wheel like you have. Hard launches are fine. Just ride around some afterward to give the extra heat of launch a chance to dissipate. Back to back to back etc hard launches if done enough times will melt any motor without some kind of active cooling. Just spread the fun out some more, and learn the limits of your motor.

The Kv of your motor is fine, so there's nothing wrong with it. You owe Zombiess a big apology, and need to go clean up the mess you made in his motor sales thread. You also owe an apology to everyone whose time you wasted responding to your nonsense about your motor being broken.

[hillzofvalp]

Please do not parent me? There is no mess in zombies thread. I have not confirmed that the motor has been damaged, and this could be a learning experience for all.


It doesn't make sense that 115% would be faster, but I could be wrong. At this setting, I reached 45mph on the flats. At 100%, this is my no load speed. There is probably an issue with my cycle analyst throttle parameters if I'm not reaching 45mph.

If this motor is fine, then ive proven it can take 120C+ bursts and, with care, can power a 2280mm wheel up a 4-8% (never measured) grade at nearly 40mph.

At one point John, I'm sure you made a mistake in the forums. I'm very sorry if someone publicly scolded you about how to behave.

[nicobie]

. I'm very sorry if someone publicly scolded you about how to behave.

No worries hov, John is just being John (which is fine by me).

I get this all the time, and could care less about it. Gotta have a thick skin.

[Alan B]

My understanding of the 100% settings is they advance the timing in the controller to "field weaken" the motor by having the electromagnets oppose the permanent magnets somewhat. This creates greater speed by raising the Kv, but it does so by wasting power and creating more heat. Seems like a bad thing to do in a larger wheel.

[MattyCiii]

"Cromoted" - love it.

Sounds like "promoted", and I suppose that's the point, since a cromotor is basically an upgrade from just about anything else, isn't it

[John in CR]

. I'm very sorry if someone publicly scolded you about how to behave.

No worries hov, John is just being John (which is fine by me).

I get this all the time, and could care less about it. Gotta have a thick skin.

So Nicobie, do you think it's ok to go into a multiple items for sale thread of a valued member/vendor trying to bring a new product to us and claim a faulty product when there's nothing wrong with the item? The guy needs more than schooling. He needs some sense knocked into him if he thinks a clean up of the mess he made isn't warranted.

Out of pity I refrained from delivering a deserved full LFP treatment, but if I'm going to get grief over it then I regret holding back. It's one thing to point out a product problem to the group, but the problem needs to be real not imagined, because public announcement of imagined problems can cause harm. In this case, Zombiess will surely lose sales unless HOV cleans up the mess he made, not to mention the grief he was put through thinking there might be a magnet problem with those motors. Whether the contact is only online or not, everyone should be held accountable for their actions.

There's a difference in being blunt vs abrasive, and someone being blunt doesn't require anyone needing to have thick skin, so take my jackhammer prose at face value and avoid interpreting it otherwise. I call it like I see it without sugar coating, but I do have an open mind enough to admit if I'm wrong, and if I've wronged someone I certainly apologize.

John

[gensem]

If it was me with a "problem" that was found not to be a problem I would also clean my posts to avoid confusion later bogging down Zombiess sales.
Hillofzval sometimes John tone looks a little harsh but he is really a nice person.

[John in CR]

If it was me with a "problem" that was found not to be a problem I would also clean my posts to avoid confusion later bogging down Zombiess sales.
Hillofzval sometimes John tone looks a little harsh but he is really a nice person.

Thanks Gensem. To me it's just being blunt. Only clients and my wife get the sugar coated a$$ kissing side of me. Friends such as you guys get blunt. If I was being harsh then I'd mix in some choice words, something I try to avoid. I try to say whatever I would say in person, including a bit of sarcasm sometimes, but that's hard to pull off well with the written word, at least for me, and things end up misinterpreted. Aussie Jester was mad at me for a long time, and I never understood what happened there, but that's resolved. I hope there's nothing hanging out there other than me wanting to chop a hand off of the thief SangesF, but there's no misinterpretation there, and harsh would be an understatement.

John

[hillzofvalp]

Im only getting to about 40mph on this setting. Idk if thats in line it's what you'd expect.

(66V 77A/145A)


I will work on zombies thread this weekend when i have a moment.

[zombiess]

Im only getting to about 40mph on this setting. Idk if thats in line it's what you'd expect.

(66V 77A/145A)


I will work on zombies thread this weekend when i have a moment.

When I simulate 66V@77A with the model of the motor I've created I get a top speed of 41.7 MPH (tucked), 29" tire diameter with the controller pulling 50A to hold that speed which is 2586W output. Motor is at 86% efficiency.

[hillzofvalp]

My wheel is about 28.6 when under load, which may explain the small disparity. That power seems about right but I will double check tomorrow.

Thanks man

[Alan B]

This is modelling, don't expect 1 mph accuracy. The drag at these speeds is not that consistent from one setup / rider to another, among many other variables.