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so after coming home from the energy conference in november and burying my self in a charge management circuit project for the monopole kit i recieved (yes its working without me hovering over it and no i am not going to discuss it on this forum so PM me if you have questions because its off topic here) i have now decided to take a peak at this forum.... 17 pages
allready quite the activity. it took a chunk of a day to read through it! i noticed the predictable reaction to the dvd to start trying to reproduce the literal lockridge device, i appreciate the change in direction and focus on seeking to understand/teach some principals via the "torque enhanced motor" that Peter has started, and the results to Matthew Jones work is fasinating!! i guess i have some catching up to do!
so to start with i do have a motor collecting dust on my shop shelf it came out of an old electic lawnmower. i had a bunch of specs on it saved on a harddrive that later crashed quite awhile after i junked the rest of the mower components so now all i have to work with is a sticker on the motor that says 24v and 971051-001(serial number?/part number?) google didnt turn anything up in a quick search. i think i remember reading on the mower deck houseing that is was 1hp but thats only from memory. the permenent mag stator is very strong i really had to pull hard to seperate it from the rotor.
motor specs i could measure
some pictures i attached below
some beginning questions to consider before "passing the point of no return" when i strip the original winding off
motor length via shaft length end to end 8"
motor diameter 3 7/8"
shaft diameter .675" (just under 11/16th)
iron stator housing length 4.5"
iron stator housing thickness .2" (or a little more than 3/16")
magets are .5" thick 3 1/8" long
2 pole stator 1 north 1 south magnet
inside stator diameter 2.479" (little more than 15/32)
rotor iron is 2 3/8" long, diameter is 2.4"(.4 is shy of 13/32")
rotor iron brush width is 13/32", gap between brushes .143"(just under 5/32")
rotor iron has 14 brush secions
air gap 2.479-2.4= .079" (a little under 8 thousands of an inch?)
existing wind diameter is .045"
awg gauge table shoes this to be closest to 17 gauge (who sells/uses 17gauge?)
16 gauge 0.0508
17 gauge 0.0453
18 gauge 0.0403
turns and length per winding section i wont know untill i unwind one
i "think" i was able to count 7 or 8 turns on 1 winding section? i could have missed some turns
copper comutator has 14 segments an even number so 1 section at 180deg apart is satisfied but 14 is not evenly divisible by 2 so i dont think i can do 4 pulses per rev but that might be too many anyway for this motor so i will focus on 2 windings and 2 pulses per rev.
comutator diameter is 1.165"
1 cumutator section is .692" long .235" wide(note width measured from a caliper does include curvature of section)
comutator circumference is c=d*pie c=1.165*3.14=3.658"
so 2 sections divided by 14 sections is .1428 or 14% duty cycle
(.235*2) divided by 3.658 is .1285 or about 13% might be more accurate.
existing carbon brushes
width(side occupying part of the circumference) .35"
depth(side occupying length of comutator section) .412"
length(whats left of the carbon brush life time) .521"
plastic brush/comutator/bearing endcap housing length 1.5"
i think theres just enough room for me to add 2 more brushes for recovery
nice ball bearings smooth no slop or rough action
test run unloaded/idle
@ 12.84volts input about2.5amps(0 to 30 gauge hard to read precision) 1690rpms
@ 25.19volts input about2.5amps 3430rpms
the next test i did was to spin up the rotor in my vertical mill at 3 set rpms and record the voltage output, this would be the BEMF
1155rpm 8.3v 1155/8.3=139.157 rpms per volt
1871rpm 13.4v 1871/13.4=139.626
2821rpm 20.15v 2821/20.15=140.0
here are some questions i would like to consider before starting
1.these ratios appear to be really close. either my readings are a little off and this trully is a linear function or its not a linear function and the math is more compilcated. does anyone have the math formula for calculating generator output useing variables like stator field strength, rpms, airgap interactions, wire gauge, number of turns..... am i missing anything? is it a linear equation?
2. can i use this calculation to find the magnet field strength(in gauss) of my existing motor so i can use that gauss variable for future winding calculations?
i was thinking for the first test i could leave the last 2 existing windings on the rotor and wire them in series to the to comutator sections that leave the N/S poles of the windings perpendicular to the n/s poles of the stator like was shown in the drawing in post 279.
3. because as the rotor spins the first pulse is 1 polarity +/- on the comutator sections then the second pulse the polarity flips -/+ then in order for there to be opposing poles pushing against each other the direction of each winding in series must be important (cw or ccw) is this correct? and if so should the direction of each winding if in series be the same (ie cw/cw) or opposite (cw/ccw) my guess is its the same (cw/cw) because the 2 windings in series act like 1 coil with a north and south pole that flips its poles as the comutator sections flip there polarity. would this be the same case if i were to make the 2 windings parrallel instead of series?
4. this zig zag winding idea is very interesting it looks like really a big loop thats folded in half? does this mean that 1 pole (say the south pole) is folded in on it self and only one pole (say the north pole) is facing out toward the stator magnets?
if so would that mean that since the magnets are N/S that this would be a push/pull type of action? and would that work on a motor type like mine where each magnet occupies half the stator instead of 1/4 the stator?
could this be why matt has had to use a diode on his winding and use 1 pulse per rev instead of 2 where the polarity would flip?
it would seem to me that if a push/pull action is whats happening than not having the diode in the winding which would allow a polarity flip would also reverse the push/pull to a pull/push and depending on where the rotor is oriented when the power is engaged(timing) would cause a magnetic dragging action instead of a motoring action. after all if we run the motor in its "stock" configuration and switch the power wires(polarity) the moter runs in the other direction.
anouther way to look at it would be if matt used a bifilar winding each winding useing 1 diode but the ends of the second winding would be soldered to the reverse commutator sections of the first winding and without the diodes this would basicly be a magnetic short doing us no good. but with the diodes only 1 winding would fire at a time. in fact if it was wired
this way could the inductive collapse (since the polarity flips at the moment the power is disengaged) fire into the second winding before the next pulse? if so would we need the second set of brushes for recovery if we can "deal" with the colapse and subsequent sparking internally on the rotor?
5. continuing with the consideration of the inductive collapse if i just want to deal with it on the rotor and not use recovery brushes other than other bifillar(or seperate winding) possibilities could i just mount a diode in series with a light bulb or block resistor or maybe some sort of controlled sparkgap(like the ne2 neon bulb in a bedini system only bigger accross the winding contacts(so long as the resistance is higher than my winding so i dont create a short that prevents my winding from powering up) and safely "dump" the collapse and eliminate brush sparking allowing us to stick with just the 2 brushes further simplyifing the mechanical alterations of the motor?
7. understanding some maximum design peramiters. and building a comparison
we know that at 25.19 my test motor idles at 3430rpms, half that is 1750rpms, thats really close to my 1871rpm BEMF test run if i use 1871/13.4=139.626 than 1750/139.6=12.536volts(eerrrgg!!! making the assumption that BEMF is linear) so (guessing again). if my motor is 1 hp than all that output comes from 25.19-12.53=12.66volts times whatever the amps are at that loading rpm... i dont have a safe way to break it to that rpm yet.
but the point i will make here is that the work is being done continuously for the entire dutycycle. in the "torque enhanced motor" mode the power comes from the 13% duty cycle.... this means the power involved(volts-BEMF*amps) in that 13% has to accomodate the load+(drag losses when freewheeling).....so i have 3 questions pertaining to this 13%
1.max limits for the commutator for the on pulse
i guess i would look at the brush size and comutator size first to consider how much amps for the amperturns we can give it during the 13% window.
so if i have the dimensions for the carbon brushes and the comutator sections how would i find out how much current would be considered a safe max level for the on time? is there a rating chart for what dimensioned carbon can take and is that for continueous duty/can i push higher for a 13% timeframe
2. after knowing what amps i can cummute, next would be winding type vs voltage and what might harm the stator magnets..... in the standard mode with 14 sections that means the brushes move to 7 different serialed coil pairs per rev right? so each pair of coils delivers 1/7th the total power per rev minus the BEMF and inductive discharges in the winding.
so if i use 2 of the existing coils in series and recovery brushes and keep the rotor braked to 1750rpms and i use 8 times the effective voltage minus the BEMF 12.66*8-12.53=88.75volts then divide by 2 since i have 2 pulses per rev 88.75/2=44.37volts would this then give me 2 pulses in amperturns equivilent to or bigger than the 7 pulses in the stock motor at its "effective" voltage? i see this as the highest voltage senario (if we are talking about keeping same amperturns as the stock version compressed into a smaller time window).
the other direction is to rewind with bigger gauge wire same number of turns to lower the BEMF and increase the amps per volt untill this will run into the comutator amperage limit. this would be the lowest voltage senarieo.
so far i have tried to consider reshaping the motor so the magnetic stators still see the same amperturns per rev just compressed into 2 pulses at a 13% duty cycle. in terms of what the magnets see there should be no change in amperturns per rev
but suppose i increase the turns in the winding and/or shoot for higher voltages how would i look for some upper limits that might harm the magnets are there any symptoms/observations that might point to "overdriving the magnets" or is the upper limit so high i need not consider it.
3. rest time in between pulses for the coils to demagnetize?....
it seems there needs to be a rest period so our coils dont turn into crispy critters. are there any symptoms/observations to look for that might show that the rest time is to short? power drop off? larger amps accompanying some heat? magnetic drag?
ummm ok i think i have spent too much time thinking about what to put in this post and then typing it up..... i should just throw it out there and and see where i go from here.
thanks for your patience if you got all the way through this post.
Eric
so after coming home from the energy conference in november and burying my self in a charge management circuit project for the monopole kit i recieved (yes its working without me hovering over it and no i am not going to discuss it on this forum so PM me if you have questions because its off topic here) i have now decided to take a peak at this forum.... 17 pages
allready quite the activity. it took a chunk of a day to read through it! i noticed the predictable reaction to the dvd to start trying to reproduce the literal lockridge device, i appreciate the change in direction and focus on seeking to understand/teach some principals via the "torque enhanced motor" that Peter has started, and the results to Matthew Jones work is fasinating!! i guess i have some catching up to do!
so to start with i do have a motor collecting dust on my shop shelf it came out of an old electic lawnmower. i had a bunch of specs on it saved on a harddrive that later crashed quite awhile after i junked the rest of the mower components so now all i have to work with is a sticker on the motor that says 24v and 971051-001(serial number?/part number?) google didnt turn anything up in a quick search. i think i remember reading on the mower deck houseing that is was 1hp but thats only from memory. the permenent mag stator is very strong i really had to pull hard to seperate it from the rotor.
motor specs i could measure
some pictures i attached below
some beginning questions to consider before "passing the point of no return" when i strip the original winding off
motor length via shaft length end to end 8"
motor diameter 3 7/8"
shaft diameter .675" (just under 11/16th)
iron stator housing length 4.5"
iron stator housing thickness .2" (or a little more than 3/16")
magets are .5" thick 3 1/8" long
2 pole stator 1 north 1 south magnet
inside stator diameter 2.479" (little more than 15/32)
rotor iron is 2 3/8" long, diameter is 2.4"(.4 is shy of 13/32")
rotor iron brush width is 13/32", gap between brushes .143"(just under 5/32")
rotor iron has 14 brush secions
air gap 2.479-2.4= .079" (a little under 8 thousands of an inch?)
existing wind diameter is .045"
awg gauge table shoes this to be closest to 17 gauge (who sells/uses 17gauge?)
16 gauge 0.0508
17 gauge 0.0453
18 gauge 0.0403
turns and length per winding section i wont know untill i unwind one
i "think" i was able to count 7 or 8 turns on 1 winding section? i could have missed some turns
copper comutator has 14 segments an even number so 1 section at 180deg apart is satisfied but 14 is not evenly divisible by 2 so i dont think i can do 4 pulses per rev but that might be too many anyway for this motor so i will focus on 2 windings and 2 pulses per rev.
comutator diameter is 1.165"
1 cumutator section is .692" long .235" wide(note width measured from a caliper does include curvature of section)
comutator circumference is c=d*pie c=1.165*3.14=3.658"
so 2 sections divided by 14 sections is .1428 or 14% duty cycle
(.235*2) divided by 3.658 is .1285 or about 13% might be more accurate.
existing carbon brushes
width(side occupying part of the circumference) .35"
depth(side occupying length of comutator section) .412"
length(whats left of the carbon brush life time) .521"
plastic brush/comutator/bearing endcap housing length 1.5"
i think theres just enough room for me to add 2 more brushes for recovery
nice ball bearings smooth no slop or rough action
test run unloaded/idle
@ 12.84volts input about2.5amps(0 to 30 gauge hard to read precision) 1690rpms
@ 25.19volts input about2.5amps 3430rpms
the next test i did was to spin up the rotor in my vertical mill at 3 set rpms and record the voltage output, this would be the BEMF
1155rpm 8.3v 1155/8.3=139.157 rpms per volt
1871rpm 13.4v 1871/13.4=139.626
2821rpm 20.15v 2821/20.15=140.0
here are some questions i would like to consider before starting
1.these ratios appear to be really close. either my readings are a little off and this trully is a linear function or its not a linear function and the math is more compilcated. does anyone have the math formula for calculating generator output useing variables like stator field strength, rpms, airgap interactions, wire gauge, number of turns..... am i missing anything? is it a linear equation?
2. can i use this calculation to find the magnet field strength(in gauss) of my existing motor so i can use that gauss variable for future winding calculations?
i was thinking for the first test i could leave the last 2 existing windings on the rotor and wire them in series to the to comutator sections that leave the N/S poles of the windings perpendicular to the n/s poles of the stator like was shown in the drawing in post 279.
3. because as the rotor spins the first pulse is 1 polarity +/- on the comutator sections then the second pulse the polarity flips -/+ then in order for there to be opposing poles pushing against each other the direction of each winding in series must be important (cw or ccw) is this correct? and if so should the direction of each winding if in series be the same (ie cw/cw) or opposite (cw/ccw) my guess is its the same (cw/cw) because the 2 windings in series act like 1 coil with a north and south pole that flips its poles as the comutator sections flip there polarity. would this be the same case if i were to make the 2 windings parrallel instead of series?
4. this zig zag winding idea is very interesting it looks like really a big loop thats folded in half? does this mean that 1 pole (say the south pole) is folded in on it self and only one pole (say the north pole) is facing out toward the stator magnets?
if so would that mean that since the magnets are N/S that this would be a push/pull type of action? and would that work on a motor type like mine where each magnet occupies half the stator instead of 1/4 the stator?
could this be why matt has had to use a diode on his winding and use 1 pulse per rev instead of 2 where the polarity would flip?
it would seem to me that if a push/pull action is whats happening than not having the diode in the winding which would allow a polarity flip would also reverse the push/pull to a pull/push and depending on where the rotor is oriented when the power is engaged(timing) would cause a magnetic dragging action instead of a motoring action. after all if we run the motor in its "stock" configuration and switch the power wires(polarity) the moter runs in the other direction.
anouther way to look at it would be if matt used a bifilar winding each winding useing 1 diode but the ends of the second winding would be soldered to the reverse commutator sections of the first winding and without the diodes this would basicly be a magnetic short doing us no good. but with the diodes only 1 winding would fire at a time. in fact if it was wired
this way could the inductive collapse (since the polarity flips at the moment the power is disengaged) fire into the second winding before the next pulse? if so would we need the second set of brushes for recovery if we can "deal" with the colapse and subsequent sparking internally on the rotor?
5. continuing with the consideration of the inductive collapse if i just want to deal with it on the rotor and not use recovery brushes other than other bifillar(or seperate winding) possibilities could i just mount a diode in series with a light bulb or block resistor or maybe some sort of controlled sparkgap(like the ne2 neon bulb in a bedini system only bigger accross the winding contacts(so long as the resistance is higher than my winding so i dont create a short that prevents my winding from powering up) and safely "dump" the collapse and eliminate brush sparking allowing us to stick with just the 2 brushes further simplyifing the mechanical alterations of the motor?
7. understanding some maximum design peramiters. and building a comparison
we know that at 25.19 my test motor idles at 3430rpms, half that is 1750rpms, thats really close to my 1871rpm BEMF test run if i use 1871/13.4=139.626 than 1750/139.6=12.536volts(eerrrgg!!! making the assumption that BEMF is linear) so (guessing again). if my motor is 1 hp than all that output comes from 25.19-12.53=12.66volts times whatever the amps are at that loading rpm... i dont have a safe way to break it to that rpm yet.
but the point i will make here is that the work is being done continuously for the entire dutycycle. in the "torque enhanced motor" mode the power comes from the 13% duty cycle.... this means the power involved(volts-BEMF*amps) in that 13% has to accomodate the load+(drag losses when freewheeling).....so i have 3 questions pertaining to this 13%
1.max limits for the commutator for the on pulse
i guess i would look at the brush size and comutator size first to consider how much amps for the amperturns we can give it during the 13% window.
so if i have the dimensions for the carbon brushes and the comutator sections how would i find out how much current would be considered a safe max level for the on time? is there a rating chart for what dimensioned carbon can take and is that for continueous duty/can i push higher for a 13% timeframe
2. after knowing what amps i can cummute, next would be winding type vs voltage and what might harm the stator magnets..... in the standard mode with 14 sections that means the brushes move to 7 different serialed coil pairs per rev right? so each pair of coils delivers 1/7th the total power per rev minus the BEMF and inductive discharges in the winding.
so if i use 2 of the existing coils in series and recovery brushes and keep the rotor braked to 1750rpms and i use 8 times the effective voltage minus the BEMF 12.66*8-12.53=88.75volts then divide by 2 since i have 2 pulses per rev 88.75/2=44.37volts would this then give me 2 pulses in amperturns equivilent to or bigger than the 7 pulses in the stock motor at its "effective" voltage? i see this as the highest voltage senario (if we are talking about keeping same amperturns as the stock version compressed into a smaller time window).
the other direction is to rewind with bigger gauge wire same number of turns to lower the BEMF and increase the amps per volt untill this will run into the comutator amperage limit. this would be the lowest voltage senarieo.
so far i have tried to consider reshaping the motor so the magnetic stators still see the same amperturns per rev just compressed into 2 pulses at a 13% duty cycle. in terms of what the magnets see there should be no change in amperturns per rev
but suppose i increase the turns in the winding and/or shoot for higher voltages how would i look for some upper limits that might harm the magnets are there any symptoms/observations that might point to "overdriving the magnets" or is the upper limit so high i need not consider it.
3. rest time in between pulses for the coils to demagnetize?....
it seems there needs to be a rest period so our coils dont turn into crispy critters. are there any symptoms/observations to look for that might show that the rest time is to short? power drop off? larger amps accompanying some heat? magnetic drag?
ummm ok i think i have spent too much time thinking about what to put in this post and then typing it up..... i should just throw it out there and and see where i go from here.
thanks for your patience if you got all the way through this post.
Eric
The other 24 volt motor does have a threaded end and it came with a left handed thread nut. I tried to find an extra one, its not standard size, I thought it was metric but know one has any that I can find.
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