Humminbird Side Imaging Forums

Other Interest => DIY - Side Scan Sonar and towfish => Topic started by: Rorofr on July 21, 2011, 03:27:07 PM

Title: My first towfish
Post by: Rorofr on July 21, 2011, 03:27:07 PM
It is not finished yet but it looks like this :

(http://img819.imageshack.us/img819/9468/towfish.jpg)

Since the picture has been taken, the weight has been melted inside the tube. I will also cut it to make it shorter., it's a bit too long for my small boat.
Title: Re: My first towfish
Post by: Rickard on July 21, 2011, 03:38:49 PM
Clean, simple and smart, this fish will work fine! Don't make it shorter, the longer the more stable.

Rickard
Title: Re: My first towfish
Post by: Roddy on July 22, 2011, 12:02:46 AM
Dito Richard!

Rorofr; Looks good, nice job. best of luck. Roddy :)
Title: Re: My first towfish
Post by: Jolly Roger on July 22, 2011, 03:22:30 AM
Keep us posted how the fish performs rorofr!

I'm looking forward to see your results.

Regards / Harry
Title: Re: My first towfish
Post by: Rüdiger on July 22, 2011, 03:34:41 AM
Hey :D

Simple but good solution !!
What cable do you use?

mvh
Rüdiger
Title: Re: My first towfish
Post by: Rorofr on July 22, 2011, 09:02:08 AM
The square shaped section of the tube makes all easy !

For the cable, which is not yet ready, I plan to use a 30ft cable extender from Humminbird and to glue it. I'm not sure it will work but looking to the connectors, I think it is possible.

My plan is to have my towfish operate at 5m (~16ft), so I might need another extender, I'm not sure. I'm currently building a kind of "wing" that will help the fish to stay deep (picture to come...).
Title: Re: My first towfish
Post by: Jolly Roger on July 23, 2011, 01:39:42 AM
Good rorofr,

I'm looking forward to see your depressor wing, because I was thinking about building one for my fish too.

Regards / Harry
Title: Re: My first towfish
Post by: abraquelebout on July 23, 2011, 03:29:16 AM
hi roro
i'm in france too
rickard said right, a long towfish is stable, i get two towfish, one for salt water with 60m cable
it measure 1,20 m and one for river, 1 m and 20m cable
waiting for picture
Title: Re: My first towfish
Post by: Rorofr on July 23, 2011, 02:33:30 PM
Hello abraquelebout,

I'm from Normandy, and you ?

By the way, our american friends should now how special normandy beaches are. We have here one of the world biggest shipwreck area, most from WWII and D-Day landing. All these wrecks are loaded with dramatic history. I hope to be able to bring you some nice scans of these wreck.

Concerning my towfish, I made some adjustments. Weight has been melted inside the tube and I put the probe in the front :

(http://img812.imageshack.us/img812/9028/dsc04632gp.jpg)

I also added this small wing that should help to maintain the fish deep when pulling :

(http://img708.imageshack.us/img708/8894/dsc04633e.jpg)

This is the expected position when dragged by the boat :

(http://img703.imageshack.us/img703/476/dsc04634qx.jpg)

I did not receive my 30ft cable extension yet, but I will  test the fish anyway tomorrow with the small 15ft original cable. It will not go very deep by it will show me the behavior of the fish when dragged and especially the effect of the wing. Weather forecast announce 4bft and 1m waves ... good test for a fish !

Regards,

Ronan.
Title: Re: My first towfish
Post by: abraquelebout on July 23, 2011, 05:15:34 PM
hi ronan
i'm in Ile d'Oleron, between 2 days there's a nother recent wreek at 35 m depht and 11 miles of my coast
[attachment=1]
it's a cargo, 87 m lengh it sunk a day before
i'm waiting for your first job with you towfish
what's the depht of your location?
for working at 10 m the ducer cable is ok for my towfish, with 60 m cable i must scan at 30 - 35 m
if there's no current
i think making an additional ballast at 10 m than towfish to go on more depht
good luck for your thirst job
Title: Re: My first towfish
Post by: Vik3 on July 30, 2011, 12:49:52 AM
....
 I'm currently building a kind of "wing" that will help the fish to stay deep (picture to come...).

I am from Kazakhstan. :) It looks like a good idea to use the “anti-wing”  instead of heavy weights, but I think the wing needs to be adjusted to certain angle of attack (like kites) otherwise it will not go down. The one more piece of rope and the hole behind the wing might be used for that.
Title: Re: My first towfish
Post by: Roddy on July 30, 2011, 04:24:20 PM
Be carefull, wing's can put a lot stress on the tow wire/cable/rope. Roddy
Title: Re: My first towfish
Post by: nediver on October 29, 2011, 06:05:11 PM
Is it me or is the transducer mounted backwards in the pictures???

If this transducer is mounted correctly, how can you have guide fins pointed in the direction of travel? They be at the rear-to the left-pf the transducerin the pictures,
Thanks
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