Holy CRAP! 125V@102A into a cromotor, Video

zombiess

10 MW
Joined
Jan 31, 2011
Messages
3,048
Location
Oklahoma City
Ok, that's about the only way I can describe the experience I just had. Yeah so 125V, and 102A battery / 74A phase fed into one of these motors with a 21.5" tire is total holy crap territory (*edit 95% sure on the amp settings now that I found the correction factor for my shunt mod*). My bike has a swing arm that has been extended 8 inches / 20cm and looks like this

ebike-11-22-11.jpg


and from 26mph (40% throttle) if I flip the switch to position 2 (70% throttle) the bike will pull the front wheel off the ground for over a foot and carry it about 20 feet if I'm not leaning over the handle bars! Leaning over the bars it will still pull the front wheel for a few inches for a couple of feet :shock: ! The first power wheelie actually scared me because I just wasn't ready for it.

This thing is a suicide machine at these settings if I'm not careful. Going to be doing some tweaking for sure. For the first time ever I got my 18 FET 4115 controller warm after playing around on these setting for about 4 miles in the neighborhood doing some low and high speed abuse (I'm just asking to pop an FET, I know). I'm going to back off the settings so I can get video this weekend before I hurt my controller.

You guys with 24" and 26" wheels will have zero problems with torque. I rode back to back on the same settings with my 9C 2806 then with this beast installed and it's a HUGE difference in power. Top speed seems about the same but I'll have to wait until daylight in full safety gear with GPS to check out how fast this thing really goes. I got to 55mph on several of the streets with room left to stop and none of them are longer than a 1/4 mile. I'll double check my top speed with GPS but it was within 1mph previously with this tire.

I might have to rephrase my amp settings because I'm on the 2nd phase of calibrating my shunt after adding a piece of 12 awg copper in parallel to the 3 shunts already installed. First calibration put me around 0.53 mOhms, batteries are charging now so I should have a better idea of what the shunt is. I'm probably going to remove it for more granular control since without it I was around 1.2 mOhms but installed it for trouble shooting purposes to see if current limiting was causing me a problem.

This thing is epic.

************************************************
Video can now be seen in this thread
http://endless-sphere.com/forums/viewtopic.php?f=6&t=35925

minimonster2.jpg

borghub1.jpg

borghub2.jpg
 
WOW man - glad you finally unleashed the beast. WTB Video cant wait to see it.

Be safe tho your pretty valuable to this forum (and others I am sure ;) ).
 
Urrnnnggg.... I think I just had a man accident.... 55mph without trying? :shock:

That sounds just awesome. Hmm, this or the new scooter hubbie coming up shortly- wonder which will be the winner...
 
:shock: :lol: :lol: :twisted:

Effing awesome dude. Video is sorely needed :).. wheelies at 26mph is insane..
 
Controller kicks ass! Just re calibrated the shunt for the 2nd time. 1st time around I got a value of 0.52x mOhm (wrote it down for reference) but I thought that was a little low so I set it for 0.763mOhm and figured I'd give it a 2nd go, just measured how much I put back in the pack vs how much I pulled out and after the correction got 0.523 mOhm again which means my current ratings are off by a factor of 1.457x So I wasn't pulling 70A from the battery,I was pulling 102A from the battery :) I'm thinking I should remove the extra shunt since it's an easy mod to undo with just a few seconds using my soldering iron + the time to uninstall and reinstall it, no wonder this thing pulled so damn hard, I was stuffing around 12KW into the controller which means I was putting at least 10KW into the motor even after 8V of sag from 125V down to 113V... all on my little Lyen 18 FET IRFB4115 controller that I've been tweaking and it was only warm to the touch after 4 miles of this but I used up almost 20% of my battery capacity in 4 miles based on how much I put back into it and that was with probably 1.5 miles of coasting now power LOL. It's a 30S3P pack made from 20C Turnigy packs.

Need to edit the title to reflect the newer numbers. Makes me wish I had my thermometer meter hooked up so I could watch the FET temps to see what they peaked at. Motor was barely warm. Will do that this weekend, but probably with the power dialed back a little. At 70% and 105% throttle it's really easy to power wheelie it sky high at anything under 25mph if you aren't careful and leaned over the bars.

Read mine and MarkCycles threads on how to mod these controllers to make them live at crazy power levels. Run all 8 gauge power and phase wires and mod feed/pull power from the FET tabs instead of the PCB, makes a HUGE difference + adds lots of additional copper to each bank for heat sinking and current sharing. Gotta get rid of that thermal strip for better material. I used mica, but that's time consuming. I'm building another 18 FET just like this but I'm going to match the FETs in each bank. I also have a 12 FET water cooled IRFP4568 add on module I made that I have to test out next.
 
Stevil_Knevil said:
Dang, already drilled holes in it! Wait a minute.. is that a CroMotor?

That's a picture of my bike with a 9C 2806 showing the geometry, not the motor. You'll have to imagine a Cromotor in it's place with a Pirelli ML75 2.75" wide 21.5" diameter tire until I take an updated pic in the daylight.
 
andynogo said:
Urrnnnggg.... I think I just had a man accident.... 55mph without trying? :shock:

That sounds just awesome. Hmm, this or the new scooter hubbie coming up shortly- wonder which will be the winner...

I've been 50+ for a while now on my 9C 2806, just can't do it for too long before the motor gets nice and toasty, gotta be careful. It's because I'm running high voltage high amps, makes going fast a walk in the park, just need to monitor what you are doing and have a bike that is stable and you trust. Next up is the rear brake install. This bike needs it bad, regen is great but I want regen + my hydraulic 203mm rear brake.
 
excellent thanks for sharing! 102a is a lot of amps! :mrgreen: that is 12kw peak!!!!

cant wait installing it on my velomobile!
 
I guess im going to have fun at 24s lipo using a 17 moped rim.

Zombies dont be shy... why not 24kw?????????
 
Bwahhhahahaha! Done right this time! Wear the leathers to ride it. 8)
 
gensem said:
I guess im going to have fun at 24s lipo using a 17 moped rim.

Zombies dont be shy... why not 24kw?????????

You are going to have a blast, especially if you feed it amps. I now understand why the Croatian guys all say the never lace it in less than a 24" bicycle wheel. This thing just pulls hard. I never thought I'd have an issue with wheelies from 15+ with an 8" over swing arm unless I was trying to do them.

I need to re weigh the bike but the old 9c setup with me on it in normal upright riding position was something like 45% front 55% rear, leaning forward front biased the weight. I have a Pirelli ML75 2.5" wide that's going on the front and I might switch the rear to the same 2.5" tire to see if it fits this wheel better. The 2.75 is hard to get lined up just right during install on this rim which I don't think is wide enough for it.

24KW.... yeah, not on this frame/wheel size after feeling what this does. Dropouts are DoctorBass torque arms welded to the extended swing arm as drop outs.
 
zombiess said:
You are going to have a blast, especially if you feed it amps. I now understand why the Croatian guys all say the never lace it in less than a 24" bicycle wheel. This thing just pulls hard. I never thought I'd have an issue with wheelies from 15+ with an 8" over swing arm unless I was trying to do them.

I need to re weigh the bike but the old 9c setup with me on it in normal upright riding position was something like 45% front 55% rear, leaning forward front biased the weight. I have a Pirelli ML75 2.5" wide that's going on the front and I might switch the rear to the same 2.5" tire to see if it fits this wheel better. The 2.75 is hard to get lined up just right during install on this rim which I don't think is wide enough for it.

24KW.... yeah, not on this frame/wheel size after feeling what this does. Dropouts are DoctorBass torque arms welded to the extended swing arm as drop outs.


I dont plan on going over 45mph, and also dont want to go over 8, maybe 10kw on my commuter. I want the bicycle to be reliable. :)
Controller has 24 4110 mosfets, so amps shouldnt be much of a problem.
 
gensem said:
I dont plan on going over 45mph, and also dont want to go over 8, maybe 10kw on my commuter. I want the bicycle to be reliable. :)
Controller has 24 4110 mosfets, so amps shouldnt be much of a problem.

Your setup will be dead reliable and climb any hill according to Accountant. He told me that's what this thing was designed for, dead on reliability and climbing power. I need to find a good hill to test this on, I doubt it's even going to notice there is a hill.

Your controller will let you run lots of amps, top speed is determined by voltage. I'll get official top speed numbers this weekend during the daylight.

What is your final tire diameter and fully charged voltage going to be, I now have enough info to estimate some numbers for those who want to be a bit more sane than me.
 
zombiess said:
Your setup will be dead reliable and climb any hill according to Accountant. He told me that's what this thing was designed for, dead on reliability and climbing power. I need to find a good hill to test this on, I doubt it's even going to notice there is a hill.

Your controller will let you run lots of amps, top speed is determined by voltage. I'll get official top speed numbers this weekend during the daylight.

What is your final tire diameter and fully charged voltage going to be, I now have enough info to estimate some numbers for those who want to be a bit more sane than me.

I do have a long 10 mile hill close to me... should be close to 8-10% and I ll climb it when I get a new swing arm (i was stupid and broken mine).

Voltage ll be close to 90v nominal, 100v fully charged (24s zippy 8ah 2p) outerdiameter is pretty close to 24" maybe 23.5"
Im really not that worried about top speed I just want to go from 0 to 35mph in under 3 seconds. :)
 
Zombiess.
For you to be impressed that says alot!!!!
I mean I was impressed with you riding the 9c at 50++ mph. Now that you are saying this baby has scary torque.
Can't wait to see some wheel spinning roster tail dirt kicking vids.
 
gensem said:
I do have a long 10 mile hill close to me... should be close to 8-10% and I ll climb it when I get a new swing arm (i was stupid and broken mine).

Voltage ll be close to 90v (24s zippy 8ah 2p) outerdiameter is pretty close to 24" maybe 23.5"
Im really not that worried about top speed I just want to go from 0 to 35mph in under 3 seconds. :)

0-35 in under 3 seconds no problem... if you have good geometry/suspension setup/skills/can ride a unicycle hehe. 45mph will be no problem but you'll probably find yourself going to 24S3P like me because the amps are so addictive.

Since you will be running that controller near it's max voltage keep your battery wires as short as possible to the controller, use 8 gauge and possibly twist them to help minimize the inductance. Oh yeah, hold on tight and be ready to back off the throttle if you see sky. My suggestion is to start off at lower amps and work your way up unless you are already there now like the rest of us nuts :)

I'm turning mine down for commuting because it's too much to ride without accidentally looping right now + I want my controller to stay alive.
 
Video in action please :)
 
Same for me, I like torque and accelaration from 0 to 40mph. I will also run mine at 24s. My setup will be 12 bricks of 6s 5ah Turnigy lipos Wired in a 24s 3p config. I have the Lyen 24 fet «freeway controller» that is rated at almost 8kw. My wheels are being built as we speak by JRH = 17 inch moped rims, 12g spokes with 2.5 gazelle tires. Outer diameter is about 22.5 inches. I bought some harnesses from Icecube = mix of 8awg and 10awg with 4mm bullets, precharge resistor, fuse, ...etc. I also got some of Method's LVC/HVC boards to dumb proof the whole thing. Man, I look at the bike and the parts sitting in my basement everyday and I dream about riding it when the snow is gone!!!!
*** What kind of performance will I get with 22.5 inch OD wheels?
 
He, we are still waiting for a vid of this motor powered with big amps.

I just received the spokes for mine, to lace in a 24 in bicycle wheel. Not ready yet to ride it, for we are n the snow here. The build is for the spring, so I rely on you guys who have nice weather, to inspire me. :D
 
Congrats zombie!

Glad to see it up and running. :D

-JD
 
hillzofvalp said:
Id like to try this motorin my 29er.. (700c). Wht phase amps/battery amps u running?


A large part of why this bike rips is because of the small wheel.

You would have roughly 45% less torque and 45% less power for any given speed in a 29" wheel vs the 21" wheel.

That would likely still be great for most applications, but do keep in mind that using a 29" wheel with this motor would perform about like putting a 300lbs rider on the bike rather than a ~180lbs rider.
 
Back
Top