Farfle joins the MENS club

woot! lams are stacked!
aaand it's 11 pm. Im headed out.

2012-07-27224914.jpg
 
Farfle said:
woot! lams are stacked!
aaand it's 11 pm. Im headed out.

2012-07-27224914.jpg
Click to expand...
hehe start winding! :wink:
 
Some evcalc shots with some different gearing. With 3.3 kw of waste heat, I don't think that speed is sustainable for long. :twisted: :twisted: :twisted:

75mph.png

888mph.png

95mph.png
 
New swingarm is almost done! Just have to make some gussets, mounts for the motor, shock and dropouts.

2012-07-30233731.jpg



2012-07-30233742.jpg
 
epic.

Mild or Cromo? and dimensions of the swingarm material be good if you can, cheers!
 
Its 3/4x1.5" and 3/4x3/4" .045 wall high-tensile. One step above mild steel, and one step below chromo. I cant find chromo in rectangular tube that doesn't cost ten bucks a foot. :? :? .
 
That thing is looking pretty mean for sure. Motor makes my 3220 look more than a bit anemic. Nice werq so far looks like it's going to be a fun one.
 
Very nice build so far. Excited to see ur motor come together, we need more motors built by us. !!!!!!!!!! lams look sexy :mrgreen:

now go! Really show the kids what ElEcTrIcKs can do!!!!!!!!! :mrgreen: :mrgreen:

Great work!
 
Yikes, that motor is a beast! Bike looks great as usual! Unbelievable craftsmanship!
 
Question for those more educated than I, since this motor has 18 teeth and 16 mags, would it be wound AaA BbB CcC, twice over? or something different?
 
Thanms much for the winding diagram. Progress made today, dropouts are done, when nomex paper shows up, it's winding time.

2012-08-02134231.jpg


2012-08-02134313.jpg
 
Miles said:
Looking good.

Perhaps a slightly darker shade of pink, though? :)
Click to expand...

Thanks AJ, and it does look pink in that picture... its supposed to be red-orange, but looking back thru my pics it shows up pink in a few of them :lol: :lol: .
 
About to start winding, and have a few questions. the origional wind made 480 rpm at 48v, so 10 rpm/v. Im aiming for 30rpm/v, the original wind was 31 turns of 2 paralell strands of 18awg in delta. so, to get about 3x the kv, ill need 12 paralelled strands with 5 turns 6x less turns to get 3x the kv as the stator is twice as wide. BUT, that's in delta, so in wye that would be 3 turns of 20 paralelled strands :shock: that's a phase wire that's 5awg :shock: im worried about the lack of resistance and inductance this beast will have.
 
Did your controller have field weakening (or over speed) before?

If not you might want to increase your turns back up to 5 turns

If you want around 3000 RPM maximum and plan on using field weakening controller, like the Sevcon Gen4, I would target spinning 2500 No-load without field weakening, if you are planing on running the Sevcon Gen4, the max nominal voltage you will have is 104V, and you want to run that if you want the best performance out of that controller, so I would target 2500RPM/104V is about 24RPM/V or only about 2.4x the KV of the original Motor.

To follow your original math, you had 31 turns, and you doubled the thickness of the stator so you would need 15.5 turns to get the same KV, you want 3x the kv so 5turns, then switching to Wye decreases by 1.73x which would end up with 1.8x the Kv of the original Motor

4 turns WYE shoudl give 2.2x the Kv of the original Motor

3turns WYE should give 3x the Kv of the original Motor.

Based on that I woudl go with 4 turns.

Lets look a the torque numbers though and see what you really want
In other threads you can find that Kt (Nm / A) is equal to 9.549/kv , so a 4 turn WYE,double wide motor with 2.2x the original KV would in theory have 22RPM/V = 0.434Nm / A. I know that RMS amps and DC Volts and stuff are all confusing, but from what I have experianced that conversion works pretty good at predicting Torque / Phase RMS apms as reported by a Sevcon controller. So a Size2 with 250RMS phase amp limit gives 108Nm of torque. With a 20" OD rear tire, you would get about 120kph at 2000 RPM, which sounds about right, maybe a little high for most of the kart tracks and be fun on the road. So you would want a 2:3 ratio on your gearing so 3000 motor RPM = 2000 Wheel RPM, that would multiply your torque at your rear wheel by 3/2, so rear wheel torque is 150Nm. With a 20" OD tire 10"radius (0.254m) that woudl be 590N of force to the ground .. 590N is about 130pounds force. I imagine you and your bike will weight something like 260lbs all up, so that would only give you about 0.5G acceleration. at 1/2G acceleartion your theoretical 0-60 time is around 5.5Seconds, which isn't bad, but it won't make you crap your pants which I think is what you are going for. To do that you would need to upgrade to a larger controller, or go to more turns, maybe 5, and sacrifice power available at top speed, or gear a little shorter which would be easier on your motor / controller, but would certainly limit your top speed.

All this math was done quickly so I could surely have made a mistake .. please check it over and tell me what you think.

-ryan
 
Biff said:
Did your controller have field weakening (or over speed) before?

If not you might want to increase your turns back up to 5 turns

If you want around 3000 RPM maximum and plan on using field weakening controller, like the Sevcon Gen4, I would target spinning 2500 No-load without field weakening, if you are planing on running the Sevcon Gen4, the max nominal voltage you will have is 104V, and you want to run that if you want the best performance out of that controller, so I would target 2500RPM/104V is about 24RPM/V or only about 2.4x the KV of the original Motor.

To follow your original math, you had 31 turns, and you doubled the thickness of the stator so you would need 15.5 turns to get the same KV, you want 3x the kv so 5turns, then switching to Wye decreases by 1.73x which would end up with 1.8x the Kv of the original Motor

4 turns WYE shoudl give 2.2x the Kv of the original Motor

3turns WYE should give 3x the Kv of the original Motor.

Based on that I woudl go with 4 turns.

Lets look a the torque numbers though and see what you really want
In other threads you can find that Kt (Nm / A) is equal to 9.549/kv , so a 4 turn WYE,double wide motor with 2.2x the original KV would in theory have 22RPM/V = 0.434Nm / A. I know that RMS amps and DC Volts and stuff are all confusing, but from what I have experianced that conversion works pretty good at predicting Torque / Phase RMS apms as reported by a Sevcon controller. So a Size2 with 250RMS phase amp limit gives 108Nm of torque. With a 20" OD rear tire, you would get about 120kph at 2000 RPM, which sounds about right, maybe a little high for most of the kart tracks and be fun on the road. So you would want a 2:3 ratio on your gearing so 3000 motor RPM = 2000 Wheel RPM, that would multiply your torque at your rear wheel by 3/2, so rear wheel torque is 150Nm. With a 20" OD tire 10"radius (0.254m) that woudl be 590N of force to the ground .. 590N is about 130pounds force. I imagine you and your bike will weight something like 260lbs all up, so that would only give you about 0.5G acceleration. at 1/2G acceleartion your theoretical 0-60 time is around 5.5Seconds, which isn't bad, but it won't make you crap your pants which I think is what you are going for. To do that you would need to upgrade to a larger controller, or go to more turns, maybe 5, and sacrifice power available at top speed, or gear a little shorter which would be easier on your motor / controller, but would certainly limit your top speed.

All this math was done quickly so I could surely have made a mistake .. please check it over and tell me what you think.

-ryan
Click to expand...

that is good info right there, it may appear hard going but well worth a few re-reads to soak it up, quite impressive to begin with just a couple of bits of data about a motor that doesn't exist yet and end with a good ballpark 0-60 time -it all adds up right to me. fine work biff!
 
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