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History's Hinge - 'Ain Jalut

[Cornelius]

This is my homebuilt ROV . Tried and tested and considered as good as a commercially built one . More fun when you do it yourself though .  Cornelius

[divetech]

hi Cornelius

look good

her are some pice of my rov.

[Cornelius]

Kristian . My ROV is 70 cm  x  60 cm  x 45  cm high . It is purposely built to fit in a suitcase  ( when taken apart ) . I travel quite a bit by myself and a too big unit would not do me any good . Besides size has nothing to do with the result . The purpose of a ROV is to bring a good high resolution camera down to the level you want it to go . It has to be built so you can direct it in any position you want  to look . In other words it has to go left and right and up and down . The speed has to be variable . Mine is doing all that and I am perfectly happy with it . I also can add a recorder so I can look back at  where I have been .   Cornelius

[divetech]

hi

mine is bigger than that it has a deptrating of 720m with the TMS.
when it is fitted with to manipulators one 4 function and a 6 function the weight is around 230 Kilos.

it is ok but it needs a bigger boat with a small crane to lunch it

best regards
Kristian

[Jesus of Lubeck]

Hello Cornelius and welcome to you Divetech,

Cornelius and/or Divetech: are either of you able to post anything on the history of the ROV in marine archaeology/research?  Additionally, what problems does one encounter with the DIY approach?  I assume the cost effectiveness of the home-built device might say it all; however, does the vehicle you have built have any distinct design advantages, aside from the obvious portability factor?  Bravo - nice photos.

Best Regards,

Lubby

[Cornelius]

Lubby . One of the weak parts of an ROV is the driveshaft - propeller connection . Any seal there is bound to leak at greater depth .  Or ...if you tighten the seal so much the shaft cannot turn anymore .  Basicaly an ROV is an ROV regardless of size . All it has to do is drop your camera to a certain depth . If you have a high resolution camera you got what it takes to get a clear picture .  Lighting is another factor that will need some attention . The color of the lights should be blue and green  ( one on each side ) . With the new led-lights it is not difficult to get proper lighting . I enclosed the motors completely so that no water will ever reach them . I used a magnetic coupling to drive the propeller shaft . So leaking is not my problem anymore regardless of the depth I am working in .  Since most normal dives are around the 100-120 Ft there is no use in going any deeper unless you are equiped to do so . So if you want to devide ROV's in groups I would still say an ROV is an ROV regardless of size  but the USE of the ROV will devide them in the two sections , deep or shallow use .   Cornelius

[Jesus of Lubeck]

Thank you Cornelius. Very informative.  I am curious about one further aspect of home built ROVs: most of the plans I have seen for these devices suggest mounting a color camera.  Is there any advantage to using, say, an infrared camera or some other sensor?

Again thanks for the response.

Best Regards,

Lubby

[Cornelius]

Lubby . The most important part of the ROV is the camera . It should be a low light high resilution camera with the possibility at low light to automatically switch on the infra red lights . Usually now there is a series of infrared leds mounted around the camera lens .  The rest of the ROV is just a means to bring the camera down to the desired level . So size is not important afterall . I would say the smaller the better . If you want to investigate a certain area it is not to your advantage if you have to bring a crane to transport your ROV . This is just my idea though . There may be advantages in size but I cant think of any .   Even a simple steel housing with a camera in it would work . You can make it as strong as you want to to reach any depth . You dont even have to have propulsion since the weight of the unit will help it go down where you want . The boat will move the unit and a simple rudder will keep it going straight . You do need a thin but strong wound steel cable though to lower and retreive the unit .   Cornelius

[ole.Grubstake]

Nic Picture of the ROV Corny. Glad I was able to see it.
Grubby

[Jesus of Lubeck]

Hello again Cornelius,

Well I am going to venture into the realm of the DIY ROV.  I have settled most of the technical issues for the prototype with the exception of the thrusters.  Are you able to give any guidance on this subject?

Best Regards,

Lubby

[Cornelius]

Lubby , As thrusters you can use a tablefan . The type that is sold by  Walmart  ( in the USA )  . It is a standard 12" fan . You can use the bearings also ( I did) and you can knock out the shaft and use it . The only thing you have to do is reduce the thrust to half the propeller blades  ( cut half of it away ) . Be sure to leave the bottom of the blade alone so it does not become too weak . The motors I used are the heater motors out of a Mercedez car . Under normal condition they use about 2 - 3 amps  . Go on with this project , you will enjoy it .   Cornelius  ( ps  . Dont use seals , use a magnetic coupling ! )

[Jesus of Lubeck]

Hello Cornelius and thank you for the advice (again).

I will continue with the project - I my locality is surrounded by water on three sides.  As the project progresses I will post material on the junior archaeology area of the forum and under this topic as well.  Have no fear about the magnetic coupling lesson; I have taken it to heart and will employ the device.

Best Regards,

Lubby

[liquidmusic]

You have the most elegant looking home brewed ROV I've seen online, Cornelius.  If you don't mind my asking, or if anyone else has advice, I'm having trouble finding information on how one might go about building a magnetic coupling as you describe.  The concept is very simple, but I don't have any experience building such a thing, so I'm trying to find a source for more description about how one actually constructs a magnetic coupling.  Any suggestions?

[Cornelius]

Liquidmusic . Although it is a simple item  , it is a little harder to explain if you have no notion at all about magnetic couplings . Why do we use magnetic couplings ? Well we do because we than can enclose the motor without being scared of water shorting out the circuit .  You enclose the motor in a ( in my case ) PVC tube with just a little larger diameter then the diameter of the motor  . Here you need a motor with a double shaft  9 mercedez Benz  heater motor is such an item ) . Why the double shaft ?  Well you need an trust bearing on one side to counteract the pulling of the magnet on the other sisde of the shaft . Without the trust bearing the rotor of the motor would be drawn too much to one side and eventually dammage the bearings of the motor . On the other side of the motor you mount a disc with radially afixed magnets  ( in my case 8 magnets ) . You mount them in a north -South position  ( so N-S-N-S-N-S -N-S )  . The magnets have a diameter of 15 mm and are 8 mm thick .  The cap of the PVC pipe on the trust bearing side can be glued on while the cap on the magnet side has to be glued in such a way that when it is in place the magnets just clear the cap and turn free . Now if you start the motor the disc will run inside the PVC pipe without any obstruction .  The wire supplying current from the battery to the motor can be afixed water tight with silicon glue or by a professional feed through fitting .  The propellor should be mounted to the PVC pipe ( with bearings and shaft )  while a second the disc ( same as one on the motor ) should be just running free  of the PVC cap  ( of the motor housing ) This part can run in the water . This unit is called a magnetic coupling because the one disc when turned by the motor will take the other with it and turn the propellor .  It is not as easy as I wrote here but this is only to give you some kind of idea  .  Have fun trying it out .  Cornelius