Weighing in scooters

jluttichau · September 20th, 2006, 03:40 PM

Hi,

I wanted to trim and balance my scooter the other day so i put it in the bathtub and had it in and out about ten times before i got tired of it. Are there any tricks on how to do this quick and painless? I was thinking of attatching a bag on the outside of the scooter so i didn't have to take it out and open it to adjust the amount of led weight.

Cheers
Jonas

caverkevin · September 20th, 2006, 04:04 PM

Don't know if I am giving away industrial trade secrets here. This is the trick I learn at SUEX.

Take a circle of cave line, little bigger than the diameter of your scooter. Place it around you scooter while it is floating in the water. Hang lead weights on the string. Add enough weight to get your buoyancy the way you like. Move move the position of the string up and down the body to get the trim the way you like. This will give you a idea of the amount and location of the ballast you need.

Since the lead is out side you scooter, it has changed the overall amount of displacement. Take the weight of the lead you hung on the string, divide that amount by 1.1 and that number will be very close to the amount you have to put inside your scooter.

Then remember how you position the batteries and ballast off the center line of the scooter will control how much it want to roll back to the keel position. Farther away, the more it wants to roll. Closer to the center line, less effect.

Cheers!!

Kevin

TobinGeorge · September 20th, 2006, 04:17 PM

Quote: (Originally Posted by jluttichau)

Hi,

I wanted to trim and balance my scooter the other day so i put it in the bathtub and had it in and out about ten times before i got tired of it. Are there any tricks on how to do this quick and painless? I was thinking of attatching a bag on the outside of the scooter so i didn't have to take it out and open it to adjust the amount of led weight.

Cheers
Jonas

Just install a fixed pitch prop and all your troubles will fade away

Seriously, what machine do you have? With my X the quick start guide got me pretty close, close enough to be able to dive it. After 2-3 dives and very small adjustments it was perfect.

I do have access to a digital scale with 1/100 gram resolution.

If you have an unknown combo, i.e. differnt machine, new battery etc. I'd be tempted to try Kevins approach, but I think you will deeper waterr than your bathtub.

Tobin

jluttichau · September 20th, 2006, 04:27 PM

Quote: (Originally Posted by TobinGeorge)

Just install a fixed pitch prop and all your troubles will fade away

Uuuh uuuh.. where can i get one??

Quote: (Originally Posted by TobinGeorge)

Seriously, what machine do you have? With my X the quick start guide got me pretty close, close enough to be able to dive it. After 2-3 dives and very small adjustments it was perfect.

X-scooter

well you have to do a really bad job if you were unable to dive it.

I guess i'll have to have a look at the manual then.

Cheers

jluttichau · September 20th, 2006, 05:04 PM

Quote: (Originally Posted by TobinGeorge)

Seriously, what machine do you have? With my X the quick start guide got me pretty close, close enough to be able to dive it. After 2-3 dives and very small adjustments it was perfect.

ok i just had a look at the manual, those numbers are definately too heavy for our waters. So i guess i'll try the caveline approach.

Cheers
Jonas

Michael-Fisch · September 21st, 2006, 09:18 AM

Quote: (Originally Posted by caverkevin)

Don't know if I am giving away industrial trade secrets here. This is the trick I learn at SUEX.

Take a circle of cave line, little bigger than the diameter of your scooter. Place it around you scooter while it is floating in the water. Hang lead weights on the string. Add enough weight to get your buoyancy the way you like. Move move the position of the string up and down the body to get the trim the way you like. This will give you a idea of the amount and location of the ballast you need.

Since the lead is out side you scooter, it has changed the overall amount of displacement. Take the weight of the lead you hung on the string, divide that amount by 1.1 and that number will be very close to the amount you have to put inside your scooter.

Then remember how you position the batteries and ballast off the center line of the scooter will control how much it want to roll back to the keel position. Farther away, the more it wants to roll. Closer to the center line, less effect.

Cheers!!

Kevin

Thanks Kevin,

your method is easier, faster and better than the method that I have been using in the past, I'll now use your method in the future.
Michael

Eirik Kjos · September 21st, 2006, 01:18 PM

Quote: (Originally Posted by jluttichau)

ok i just had a look at the manual, those numbers are definately too heavy for our waters.

Hi Jonas!

So you bought yourself an X. Congrats. It`s the conversion from imperial to metric that is wrong in the X manual, just do it yourself and you`ll be pretty ok for normal saltwater. 3,5% salinity that is. If you like an engineering approach: Any less salt, just adjust the amount of lead accordingly.

Eirik Kjos

jluttichau · September 21st, 2006, 03:48 PM

Quote: (Originally Posted by Eirik Kjos)

Hi Jonas!

So you bought yourself an X. Congrats. It`s the conversion from imperial to metric that is wrong in the X manual, just do it yourself and you`ll be pretty ok for normal saltwater.

Hi Eirik

Do the conversion or do the weighing?

Salinity today varies from 0,7% - 2,5% depending on the divesite. So I would love a matrix of how much lead i have to stuff in the scooter depending on the salinity in percentage.

Cheers
Jonas

September 20th, 2006, 03:40 PM	#1 (permalink)
jluttichau(Offline) Custom User Title Join Date: Nov 2005 Location: Denmark Posts: 437	Weighing in scooters Hi, I wanted to trim and balance my scooter the other day so i put it in the bathtub and had it in and out about ten times before i got tired of it. Are there any tricks on how to do this quick and painless? I was thinking of attatching a bag on the outside of the scooter so i didn't have to take it out and open it to adjust the amount of led weight. Cheers Jonas

September 20th, 2006, 04:17 PM	#3 (permalink)
TobinGeorge(Offline) New Member Join Date: Nov 2005 Location: Southern California Posts: 566	Quote: (Originally Posted by jluttichau) Hi, I wanted to trim and balance my scooter the other day so i put it in the bathtub and had it in and out about ten times before i got tired of it. Are there any tricks on how to do this quick and painless? I was thinking of attatching a bag on the outside of the scooter so i didn't have to take it out and open it to adjust the amount of led weight. Cheers Jonas Just install a fixed pitch prop and all your troubles will fade away Seriously, what machine do you have? With my X the quick start guide got me pretty close, close enough to be able to dive it. After 2-3 dives and very small adjustments it was perfect. I do have access to a digital scale with 1/100 gram resolution. If you have an unknown combo, i.e. differnt machine, new battery etc. I'd be tempted to try Kevins approach, but I think you will deeper waterr than your bathtub. Tobin __________________ http://www.deepseasupply.com

September 20th, 2006, 04:04 PM	#2 (permalink)
caverkevin (Online) Doing It Caverkevin Join Date: Nov 2005 Location: North Kackilackie Posts: 360	Don't know if I am giving away industrial trade secrets here. This is the trick I learn at SUEX. Take a circle of cave line, little bigger than the diameter of your scooter. Place it around you scooter while it is floating in the water. Hang lead weights on the string. Add enough weight to get your buoyancy the way you like. Move move the position of the string up and down the body to get the trim the way you like. This will give you a idea of the amount and location of the ballast you need. Since the lead is out side you scooter, it has changed the overall amount of displacement. Take the weight of the lead you hung on the string, divide that amount by 1.1 and that number will be very close to the amount you have to put inside your scooter. Then remember how you position the batteries and ballast off the center line of the scooter will control how much it want to roll back to the keel position. Farther away, the more it wants to roll. Closer to the center line, less effect. Cheers!! Kevin

September 20th, 2006, 04:27 PM	#4 (permalink)
jluttichau(Offline) Custom User Title Join Date: Nov 2005 Location: Denmark Posts: 437	Quote: (Originally Posted by TobinGeorge) Just install a fixed pitch prop and all your troubles will fade away Uuuh uuuh.. where can i get one?? Quote: (Originally Posted by TobinGeorge) Seriously, what machine do you have? With my X the quick start guide got me pretty close, close enough to be able to dive it. After 2-3 dives and very small adjustments it was perfect. X-scooter well you have to do a really bad job if you were unable to dive it. I guess i'll have to have a look at the manual then. Cheers

September 20th, 2006, 05:04 PM	#5 (permalink)
jluttichau(Offline) Custom User Title Join Date: Nov 2005 Location: Denmark Posts: 437	Quote: (Originally Posted by TobinGeorge) Seriously, what machine do you have? With my X the quick start guide got me pretty close, close enough to be able to dive it. After 2-3 dives and very small adjustments it was perfect. ok i just had a look at the manual, those numbers are definately too heavy for our waters. So i guess i'll try the caveline approach. Cheers Jonas

September 21st, 2006, 09:18 AM	#6 (permalink)
Michael-Fisch(Offline) New Member Join Date: Jul 2006 Location: Germany Posts: 264	Quote: (Originally Posted by caverkevin) Don't know if I am giving away industrial trade secrets here. This is the trick I learn at SUEX. Take a circle of cave line, little bigger than the diameter of your scooter. Place it around you scooter while it is floating in the water. Hang lead weights on the string. Add enough weight to get your buoyancy the way you like. Move move the position of the string up and down the body to get the trim the way you like. This will give you a idea of the amount and location of the ballast you need. Since the lead is out side you scooter, it has changed the overall amount of displacement. Take the weight of the lead you hung on the string, divide that amount by 1.1 and that number will be very close to the amount you have to put inside your scooter. Then remember how you position the batteries and ballast off the center line of the scooter will control how much it want to roll back to the keel position. Farther away, the more it wants to roll. Closer to the center line, less effect. Cheers!! Kevin Thanks Kevin, your method is easier, faster and better than the method that I have been using in the past, I'll now use your method in the future. Michael

September 21st, 2006, 01:18 PM	#7 (permalink)
Eirik Kjos(Offline) New Member Join Date: Dec 2005 Location: Trondheim, Norway Posts: 8	Quote: (Originally Posted by jluttichau) ok i just had a look at the manual, those numbers are definately too heavy for our waters. Hi Jonas! So you bought yourself an X. Congrats. It`s the conversion from imperial to metric that is wrong in the X manual, just do it yourself and you`ll be pretty ok for normal saltwater. 3,5% salinity that is. If you like an engineering approach: Any less salt, just adjust the amount of lead accordingly. Eirik Kjos

September 21st, 2006, 03:48 PM	#8 (permalink)
jluttichau(Offline) Custom User Title Join Date: Nov 2005 Location: Denmark Posts: 437	Quote: (Originally Posted by Eirik Kjos) Hi Jonas! So you bought yourself an X. Congrats. It`s the conversion from imperial to metric that is wrong in the X manual, just do it yourself and you`ll be pretty ok for normal saltwater. Hi Eirik Do the conversion or do the weighing? Salinity today varies from 0,7% - 2,5% depending on the divesite. So I would love a matrix of how much lead i have to stuff in the scooter depending on the salinity in percentage. Cheers Jonas