Author Topic: New Towfish Project  (Read 3966 times)

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Offline bob

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New Towfish Project
« on: January 06, 2010, 11:41:03 AM »
  I posted a towfish question in the xumba.scholleco forum and have received no replies. Hopefully, I can some opinions here - My plan is for an experimental shallow running towfish, and a couple of questions.
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  I am in the process of building a simple towfish with a 1" thinwall PVC body. The plan is to make a short 1' nose section filled with concrete coupled to a 3' hollow (water filled when submerged) body. The inexpensive PVC will allow me to experiment with various lengths, weights and balance. The transducer will be attached below (outside) the tubing. I plan to have it run only about 5' deep until I get it working. My questions are about balance - at what position should I attach the tow point, and whether it should be slightly nose heavy, tail heavy, or balanced when suspended in the water? I have a spare SI transducer and just placed an order for a transducer switch. Thanks,

bob baldwin
bryan, texas
997c SI
1197c SI
AS GRHA GPS


Offline keizerh

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Re: New Towfish Project
« Reply #1 on: January 06, 2010, 01:31:17 PM »
Built one.

Movable diving leads for the weight.
Tow eye at about 1/3 from front, but movable.

Holes in the 80mm tube to let water in and out.
Hollow skirope around the cable.
262/455 ducer.
Looks good in the water, but didn't scan yet.

Used to have a Imagenex sportscan, with equal construction

hendrik



hendrik

Offline bob

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Re: New Towfish Project
« Reply #2 on: January 06, 2010, 02:02:25 PM »
Sounds good on that 1/3 back for the tow position. Should it be balanced at that point, or slightly nose/tail heavy? I expect to spend some time experimenting before getting it correctly set up. Thanks for all the information Hendrik.

bob baldwin
bryan, texas
997c SI
1197c SI
AS GRHA GPS

Offline Rickard

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Re: New Towfish Project
« Reply #3 on: January 06, 2010, 03:27:49 PM »
Hi Bob,

I built one and have done a lot of scanning at depths from close the surface down to 45 meters. The towfish is described at the other forum in the thread you tried. My fish is rather heavy compared to the fish you plan but I think the same general rules apply in your case too. It should be balanced but you can make it a little bit noseheavy if you wish.

Rickard

Offline keizerh

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Re: New Towfish Project
« Reply #4 on: January 06, 2010, 03:34:10 PM »
Mine is a little noseheavy, just like the sportscan was.
hendrik

Offline bob

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  • Software: 4.750
  • Accessories: AS GRHA GPS
Re: New Towfish Project
« Reply #5 on: January 06, 2010, 04:04:26 PM »
Thanks Rickard and Hendrik - that's all I need to know to get started on the prototype. I had read all the towfish posts on the forums, but just had a couple of details I wasn't sure about. Thanks, again.

bob baldwin
bryan, texas
997c SI
1197c SI
AS GRHA GPS


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