sheepjeep
NAXJA Forum User
- Location
- Boston, MA
Re: THe NAC Lots-O-Post Thread
i give you a dog pooping bubble gum bubbles
i give you a dog pooping bubble gum bubbles
THe NAC Lots-O-BFG KO2 Thread
- Thread starter ROBZ95Xj
- Start date
themangeraaad
NAXJA Forum User
- Location
- Halifax, MA
Re: THe NAC Lots-O-Post Thread
And now I think I'm ready to go to work.
And now I think I'm ready to go to work.
Dundy
NAXJA Forum User
- Location
- Taunton, MA
Re: THe NAC Lots-O-Post Thread
"I am working on a water crossing propulsion system with prop and flotation so she can cross anywhere as we have a lot of water in our area?
"I am working on a water crossing propulsion system with prop and flotation so she can cross anywhere as we have a lot of water in our area?
MoparManiac
NAXJA Forum User
- Location
- Amherst, NH
Re: THe NAC Lots-O-Post Thread
I'm ready to leave.
Thankfully I only have a halfday today.
I'm ready to leave.
Thankfully I only have a halfday today.
themangeraaad
NAXJA Forum User
- Location
- Halifax, MA
Re: THe NAC Lots-O-Post Thread
I'm also taking a half day but only so I can head to the north shore and run some errands w/o getting stuck in too much rush hour traffic.
I'm also taking a half day but only so I can head to the north shore and run some errands w/o getting stuck in too much rush hour traffic.
- Location
- Rainy side of Washington
Re: THe NAC Lots-O-Post Thread
Im about to get the third degree from my boss for the spectacular failure of a test. Everything that failed is crummy consumer level stuff he told us to use instead of actually designing a proper solution to the problem. Time to tell him what broke (all the stupid shit he forced us to use, usb connectors from china ain't milspec and neither are shitty ham radio products), who put it in the design (him), and what I am going to do to fix it today instead of retesting and failing again like he wants... this is gonna be fun and I will either be successful or jobless and happy in massachusetts by tonight.
He literally wants us to burn another whole day and a few grand in jet fuel after monkeyXXXXing a solution to a problem that shouldn't exist instead of simply building it right. There isn't time to build it right (a few weeks for the whole system) but there has been time to duct tape it back together repeatedly since august because that is faster.
Can't wait! If you ever get an offer from a small business owner please realize that all small business owners are insane in some way or another. Make sure they are insane in a good way. This one isn't.
Im about to get the third degree from my boss for the spectacular failure of a test. Everything that failed is crummy consumer level stuff he told us to use instead of actually designing a proper solution to the problem. Time to tell him what broke (all the stupid shit he forced us to use, usb connectors from china ain't milspec and neither are shitty ham radio products), who put it in the design (him), and what I am going to do to fix it today instead of retesting and failing again like he wants... this is gonna be fun and I will either be successful or jobless and happy in massachusetts by tonight.
He literally wants us to burn another whole day and a few grand in jet fuel after monkeyXXXXing a solution to a problem that shouldn't exist instead of simply building it right. There isn't time to build it right (a few weeks for the whole system) but there has been time to duct tape it back together repeatedly since august because that is faster.
Can't wait! If you ever get an offer from a small business owner please realize that all small business owners are insane in some way or another. Make sure they are insane in a good way. This one isn't.
themangeraaad
NAXJA Forum User
- Location
- Halifax, MA
Re: THe NAC Lots-O-Post Thread
So watching that video and reading the description I learned a couple things. First of all his snorkel system was apparently successful and second, if I drive through deep water and have problems I must need bilge pumps.
And I wish I had the money to build a WK just to beat on.
So watching that video and reading the description I learned a couple things. First of all his snorkel system was apparently successful and second, if I drive through deep water and have problems I must need bilge pumps.
And I wish I had the money to build a WK just to beat on.
vetteboy
NAXJA Forum User
- Location
- morganville, nj
Re: THe NAC Lots-O-Post Thread
http://www.pirate4x4.com/forum/showthread.php?p=13827113#post13827113
$10 says he pays no attention to what I said.
Also makes me laugh because he and I don't get along online at all, yet he seems to be content with modeling his front coilover mounts after mine.
http://www.pirate4x4.com/forum/showthread.php?p=13827113#post13827113
$10 says he pays no attention to what I said.
Also makes me laugh because he and I don't get along online at all, yet he seems to be content with modeling his front coilover mounts after mine.
MoparManiac
NAXJA Forum User
- Location
- Amherst, NH
Re: THe NAC Lots-O-Post Thread
Well his exhaust doesn't hit or rattle after driving it for 20 feet, so YOU'RE WRONG.
Well his exhaust doesn't hit or rattle after driving it for 20 feet, so YOU'RE WRONG.
ktm racer 419
NAXJA Forum User
- Location
- ROW DIALIN
- Location
- Rainy side of Washington
Re: THe NAC Lots-O-Post Thread
Apparently he rethought things overnight the same as we did, and agrees we should build this right. XXXXing finally.
Time to be a real engineer instead of a professional duct taper of random junk.
Apparently he rethought things overnight the same as we did, and agrees we should build this right. XXXXing finally.
Time to be a real engineer instead of a professional duct taper of random junk.
themangeraaad
NAXJA Forum User
- Location
- Halifax, MA
Re: THe NAC Lots-O-Post Thread
I just walked past a couple guys talking in the hall who were, apparently, discussing compatibility between several systems. I just happened to catch the line "it shouldn't matter, cause chariot-V and chariot are the same thing, they're just different".
I think I understand what he was trying to say, however the guy he was talking to didn't look like he had the same level of comprehension.
I just walked past a couple guys talking in the hall who were, apparently, discussing compatibility between several systems. I just happened to catch the line "it shouldn't matter, cause chariot-V and chariot are the same thing, they're just different".
I think I understand what he was trying to say, however the guy he was talking to didn't look like he had the same level of comprehension.
themangeraaad
NAXJA Forum User
- Location
- Halifax, MA
Re: THe NAC Lots-O-Post Thread
Anyone know of a good way to break the bead of a tire while the tire is still on the vehicle? I planned on using a 2x4 w/ the high lift jack under my bumper but it would save some time if I could do it w/o pulling the wheels/tires off the Jeep if there's an easy way to do it...
Anyone know of a good way to break the bead of a tire while the tire is still on the vehicle? I planned on using a 2x4 w/ the high lift jack under my bumper but it would save some time if I could do it w/o pulling the wheels/tires off the Jeep if there's an easy way to do it...
vetteboy
NAXJA Forum User
- Location
- morganville, nj
Re: THe NAC Lots-O-Post Thread
Might be able to brace something against the frame and/or control arm and use the power steering?
Still sounds like way more trouble than removing 5 lug nuts.
Might be able to brace something against the frame and/or control arm and use the power steering?
Still sounds like way more trouble than removing 5 lug nuts.
- Location
- Rainy side of Washington
Re: THe NAC Lots-O-Post Thread
I'm pretty good at it, but it involves wheeling my jeep like a maniac. It may also damage the tire in the process.
I'm pretty good at it, but it involves wheeling my jeep like a maniac. It may also damage the tire in the process.
vetteboy
NAXJA Forum User
- Location
- morganville, nj
Re: THe NAC Lots-O-Post Thread
Remove the valve core, attach a straw to the valve stem, and start sucking.
Remove the valve core, attach a straw to the valve stem, and start sucking.
themangeraaad
NAXJA Forum User
- Location
- Halifax, MA
Re: THe NAC Lots-O-Post Thread
Odds are I'll pull the tires to do it but it was worth asking in case someone had a trick to get it done faster.
That's why I was asking for something easy. I didn't know if there was some trick like "pull the valve core and drive the tire up onto a specifically placed brick" or something that would save me time.
Odds are I'll pull the tires to do it but it was worth asking in case someone had a trick to get it done faster.
ktm racer 419
NAXJA Forum User
- Location
- ROW DIALIN
- Location
- Rainy side of Washington
Re: THe NAC Lots-O-Post Thread
apparently my lazy trolling is too hardcore for ProJeep
apparently my lazy trolling is too hardcore for ProJeep
vetteboy
NAXJA Forum User
- Location
- morganville, nj
Re: THe NAC Lots-O-Post Thread
Reis et al. (1) showed the remarkable way by which cats lap fluids. A cat extends its tongue to the surface of the fluid and lifts a slender column to its mouth by adhering the tip of the column to the dorsal side of its tongue. Afterward, without shifting its head, the cat rapidly closes its mouth, enabling it to capture a portion of the fluid column, and then repeats this cycle with a lapping frequency f = 3.5 ± 0.4 s^−1. To understand this mechanism, and to explain this lapping frequency, Reis et al. performed a fluid dynamics experiment that simulated the cat’s mechanism and provided a scaling analysis, explaining that “the column dynamics are set by a competition between inertia and gravity.” Their scaling relations, however, are based on an incorrect application of the principles of fluid dynamics, and, as expected, it does not provide a quantitative agreement with their observations. For example, their theoretical prediction for the lapping frequency is f ~ (gH)^(1/2)/R, where H is the length, R is the radius of the cat’s tongue, and g is the acceleration of gravity. But for H = 3 cm and R = 0.5 cm, corresponding to their cat’s tongue dimensions, f ~ 108 s^−1, which is a factor 31 times larger than their observation. An analysis that does agree with their observations is given here. Although dogs lap by a more elaborate mechanism, curling the tongue backward to scoop some of the fluid, my analysis shows that their lapping frequency is similar to that of cats.
The scaling analysis of Reis et al. is based on two incorrect premises about the physics governing the flow in the fluid column under consideration: (i) that the fluid pressure is the hydrostatic pressure p = ρgz at height z, corresponding to the pressure of a confined column of fluid of density ρ, where g is the acceleration constant of gravity, and (ii) that the balance between fluid inertia and gravity is determined by the relation ρv2R ~ p, where vR is the radial speed at z. The fluid in this column, however, is not static but instead flows freely under the action of gravity, and, therefore, in a first approximation, the difference of fluid and atmospheric pressure can be neglected. Hence, the relevant time that determines the lapping frequency is the characteristic time tG for the fluid in the column to descend back into the bowl. The mean axial velocity of the fluid in a column of height H is vz = (gH/2)1/2, and tG = H/vz = (2H/g)1/2, which is the Galilean time for an object to fall from height H. For a lapping height H = 3 cm, tG = 78 ms, which is close to the observed 70 ms taken by Reis et al.’s cat to lift the milk by its tongue. Also, the predicted cat’s tongue mean velocity, H/tG = 38 cm s−1, corresponds to the observed value UMAX/2 = 39 cm s−1. Finally, the predicted lapping frequency f = 1/(4tG ) = 3.2 s−1 is in good agreement with their observation [an additional factor of 2 in the time between laps is based on the data of Reis et al. in figure 2 in (1) that shows that the tongue rests for a time of order 2tG].
It should be pointed out, however, that a column of fluid confined only by surface tension is unstable. This instability, which was ignored by Reis et al. in their analysis, was first studied experimentally by Joseph Plateau (2) and later described theoretically by Lord Rayleigh (3) who determined the characteristic time scale tR for collapse of the column. Neglecting the effect of gravity, Rayleigh found that tR ~ 3(ρ/σ)1/2R3/2, where ρ is the density, σ is the surface tension of the fluid, and R is the radius of the column. Initially, R decreases with time, as can be seen also in Reis et al.’s simulation, and after tR < tG, corresponding to R < Ro = [(2Hσ)/(9 gρ)]1/3, the Plateau-Raleigh instability takes over, leading to the break-up of the fluid column observed by Reis et al. For milk at room temperature, σ = 44 g s−2 (4), ρ = 1 g cm−2, and Ro = 0.311 cm.
Assuming that the lapping height H scales approximately with the size or mass M of the animal according to the relation H ∝ M1/3, it also follows from my analysis that the lapping frequency f ∝ H−1/2 ∝ M−1/6. This dependence appears to be in agreement with Reis et al.’s observations for the lapping frequency of large felines. After the first submission of this article, Crompton and Musinski presented a high-speed x-ray video demonstrating how a dog ingests a column of liquid adhering to its tongue (5). They found that it took their dog 110 ms to trap the liquid, in excellent agreement with my own observations and prediction that for H = 6 cm, tG = 111 ms.
Reis et al. (1) showed the remarkable way by which cats lap fluids. A cat extends its tongue to the surface of the fluid and lifts a slender column to its mouth by adhering the tip of the column to the dorsal side of its tongue. Afterward, without shifting its head, the cat rapidly closes its mouth, enabling it to capture a portion of the fluid column, and then repeats this cycle with a lapping frequency f = 3.5 ± 0.4 s^−1. To understand this mechanism, and to explain this lapping frequency, Reis et al. performed a fluid dynamics experiment that simulated the cat’s mechanism and provided a scaling analysis, explaining that “the column dynamics are set by a competition between inertia and gravity.” Their scaling relations, however, are based on an incorrect application of the principles of fluid dynamics, and, as expected, it does not provide a quantitative agreement with their observations. For example, their theoretical prediction for the lapping frequency is f ~ (gH)^(1/2)/R, where H is the length, R is the radius of the cat’s tongue, and g is the acceleration of gravity. But for H = 3 cm and R = 0.5 cm, corresponding to their cat’s tongue dimensions, f ~ 108 s^−1, which is a factor 31 times larger than their observation. An analysis that does agree with their observations is given here. Although dogs lap by a more elaborate mechanism, curling the tongue backward to scoop some of the fluid, my analysis shows that their lapping frequency is similar to that of cats.
The scaling analysis of Reis et al. is based on two incorrect premises about the physics governing the flow in the fluid column under consideration: (i) that the fluid pressure is the hydrostatic pressure p = ρgz at height z, corresponding to the pressure of a confined column of fluid of density ρ, where g is the acceleration constant of gravity, and (ii) that the balance between fluid inertia and gravity is determined by the relation ρv2R ~ p, where vR is the radial speed at z. The fluid in this column, however, is not static but instead flows freely under the action of gravity, and, therefore, in a first approximation, the difference of fluid and atmospheric pressure can be neglected. Hence, the relevant time that determines the lapping frequency is the characteristic time tG for the fluid in the column to descend back into the bowl. The mean axial velocity of the fluid in a column of height H is vz = (gH/2)1/2, and tG = H/vz = (2H/g)1/2, which is the Galilean time for an object to fall from height H. For a lapping height H = 3 cm, tG = 78 ms, which is close to the observed 70 ms taken by Reis et al.’s cat to lift the milk by its tongue. Also, the predicted cat’s tongue mean velocity, H/tG = 38 cm s−1, corresponds to the observed value UMAX/2 = 39 cm s−1. Finally, the predicted lapping frequency f = 1/(4tG ) = 3.2 s−1 is in good agreement with their observation [an additional factor of 2 in the time between laps is based on the data of Reis et al. in figure 2 in (1) that shows that the tongue rests for a time of order 2tG].
It should be pointed out, however, that a column of fluid confined only by surface tension is unstable. This instability, which was ignored by Reis et al. in their analysis, was first studied experimentally by Joseph Plateau (2) and later described theoretically by Lord Rayleigh (3) who determined the characteristic time scale tR for collapse of the column. Neglecting the effect of gravity, Rayleigh found that tR ~ 3(ρ/σ)1/2R3/2, where ρ is the density, σ is the surface tension of the fluid, and R is the radius of the column. Initially, R decreases with time, as can be seen also in Reis et al.’s simulation, and after tR < tG, corresponding to R < Ro = [(2Hσ)/(9 gρ)]1/3, the Plateau-Raleigh instability takes over, leading to the break-up of the fluid column observed by Reis et al. For milk at room temperature, σ = 44 g s−2 (4), ρ = 1 g cm−2, and Ro = 0.311 cm.
Assuming that the lapping height H scales approximately with the size or mass M of the animal according to the relation H ∝ M1/3, it also follows from my analysis that the lapping frequency f ∝ H−1/2 ∝ M−1/6. This dependence appears to be in agreement with Reis et al.’s observations for the lapping frequency of large felines. After the first submission of this article, Crompton and Musinski presented a high-speed x-ray video demonstrating how a dog ingests a column of liquid adhering to its tongue (5). They found that it took their dog 110 ms to trap the liquid, in excellent agreement with my own observations and prediction that for H = 6 cm, tG = 111 ms.
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