Took a couple pics of the batts today, this is about 38 out of 40 8 cell packs total, so from the pics there is just 2 missing. Quite a bit of power sittin there. The one black thing you see there is a completed 48 volt pack minus the connecting wires. In total there will be 8 of those black 48 volt packs.
high rpm's for what?! the beauty of series wound motors is down low... hehe, besides if you look at any dyno graph of this kind of motors you will see that as rpms go high power comes down.
johnws6 i have one of those motors in my father's "scrapyard" the drum is a brake, the one i have is rated at 36V 60A 2,6Hp 2800rpm's what are the ratings on the one you have?
oh and something have just crossed my mind, you will feed your motor with 48V rigth? if your motor was built to work with 36V theres no way that the motor will use 600Amps once you start moving... using my motor as an exemple:
if i feed it with 48V, at 2800rpms (nominal speed) the motor will pull +-80A from the batteries
now ASSUMING that the motor efficiency and a crap load of constants dont change
at 1400rpms (half the nominal speed) the motor would pull 160A from the bateries
at 700rpms, 320A
at 350rpms, 640A
to make this motor pull 600A from the batteries at nominal speed you woul need a 270V batterie pack, this means that you're gona leave the line very hard but after a couple of yards the acceleration would not be so spectacular... i think you would be better with more volts and less amps, better for your ET and much better for the motor :S
Last edited by bhp Hunter; 07-13-2007 at 08:09 AM..
talk is just talk.. this guy is trying to build a drag bike so you should give him credit for spending the time money and the effort... it may not reach 80mph but it will be something he can be proud of.. any of us building something would be proud of their creation no matter what the results...
now he got a nice motor that was meant for folklift or something like that(too lazy to go back and read what that motor came out of)... anyway the motor was hauling or was meant to haul heavy loads... let's just say 800 lbs. by the time his bike is done it may weigh 150lbs. and say he's 200 lbs. that motor will move him with not problem... now if he gears it down to a 1.2:1 ratio their's his 80mph... the motor will pull some big amps but it is possible..as long as he stays in that rated 2800rpm range he may have a couple hp pulling him across the finish line. how fast down the 1/8 mile, i guess once he gets his bike together we will see... i hope he does set a record
im not trying to disencourage him... on the countrary, i've thinked of something that could be a problem for him and presentet what i think that could be the solution, to go 80mph he needs a certain amout of power, he can obtain that power by gearing low as you said and pull lots of amps from the batts and beat the hell of the comm and brushes and 600A for 10 secs is a lot for a motor of that size, or he can feed more volts to the engine gear a bit higher still have neck breaking acceleration out of the line and good top end without beating the engine so hard.
you're right about the feeling of building things by ourselfs, even if it doesnt work has we expected its something done by us and no one can take that from us