Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[sub john]

Reply#224
HI Mike  Got your servo AMP through the post today will have a look as soon as i can, you said that you had heard that WIFI could course interference to radio control on 2.4 GHZ yes it could but it would have to be pretty close by to course a problem  as they don't knock out much RF

One of the things i was going to say a while ago i know you are in to mechanical things more than electronics you might find this interesting when i made the compressor for the sub i converted a 10CC model boat engine water cooled job to take the roll of a compressor in the sub when i pressure tested  the air tanks for storing compressed air  the 10CC engine put in 340 PSI in to the air tanks and was still going, one thing i should say is all this test was done with air tanks and every thing under water to see if there was any leaks and if some thing went bang the water would absorb it as these sort of pressures are dangerous once this test was done air tanks would be set so air tanks would only be filled to 140PSI  the sub sits at this pressure all the time even as it sits in the garage. Compressor has got auto loob injection meaning when compressor first starts up it takes a few drops of oil from a oil storage tank with one way valve and flow controll valve, this is sucked up by air intake on compressor which is on a timing circuit and then switches back to air in take  after oil has gone through compressor it is separated off  by catching chamber and clean compressed air is feed to air tanks. As it seems to have worked for  20 years what more could you ask, as i think it is quite reliable
    John

[Subculture]

Don't you need a boiler cert to run those sort of pressures?

[MikeA]

you got the package today?? If i remeber rightly i sent that first class monday morning, it should have got to you by tuesday.

ah good im please you got mechanical i know what your talking about now. what are you using as air tanks john?

[sub john]

Reply #226
 Hi Subculture, The air tanks that are in the sub have not been welded in any way they where made from hydraulic ram cylinders with pistons took out these units will take a lot more pressure than i can put into them, these units bolt together there is two of them inside the sub and i would not won't to have to take them out to have them pressure checked and tested as i would end up taking the sub a part as these was one of the first things to go in it next thing to go in was central ballast tank which holds two gallons of water and it would be a pain in the neck to take it out. As i can not see these air tanks going BANG in the for see able future, all fittings are industrial type including all values and regulators. You must admit that if it has stood like this for 20 years and still works the same as it did when it was first made it's got to say some thing
   John

[MikeA]

hydraulic ram cylinders eh? bet their heavy lol, what they from?

[sub john]

hi mike here is a picture of the autopilot thats going to go in to the sub you will be able to set waypoints so the sub will do the preset course on the water the garmin unit is picking up saterlite link for data

[MikeA]

wow awesome. Theres more technology in this sub than the real thing, will the signals from the satelite reach the sub underwater or this only for surface use?

[Subculture]

Can the satellite signal transmit through water? Or do you revert to compass heading for underwater.

[sub john]

Reply #231
HI Mike,    Yes it is starting to get hitec no you will not be able to pick up satellites GPS under water what you will Babel to do is have patch antenna under the floor of the conning tower even with having decks are  under water you will still be able to pick up GPS link, then once sub submerges it will run on  auto compass unit for navigation

You asked where the hydraulic rams heavy that i used for the air tanks the answer to that it NO they are made of some special  grade alloy. A friend of mine got them for me if i remember right they was going to be scraped

Other thing that i was going to say about compressor one of the main problems that i had was trying to fine an electric motor that could take the constant hammer ever motor i tried it gave up and went bang, the motor that i found in the end to run it was off a industrial photo copier machine, was meant to run on 48Volts but it runs in the sub on 24Volts it has worked very well. Motor is linked  with  positive drive belt, has still got the same belt fitted from when i did it many years ago
   All the best John

[MikeA]

will the gps be able to find its position using the compass, obviously it wont be able to gauge distance though just direction. im suprised there weret many motors out there that couldnt cope witht the demand of the pump 

did you manage to get that amp board i sent you working in your esc circuit?

[sub john]

Reply#234
HI Mike,   Trouble was trying to find motor that didn't pull much currant but had got high talk and had got to be small, when compressor is running only pulls  2AMPS at 24VOLTS

Have not tried your AMP board yet will get around to it as soon as i can
     John

[MikeA]

you know for my last boat i bought a 12v car tyre pump, it had a 540 motor in it and the pump cost 4 pound from bargain madness. I stripped the 540 motor out of it but kept the pump in my tool box im sure ill find some use for it some day. it pumps up 150 psi i think and has a reduction gear box and pressure guage fixed to it. It seems like a good find if i ever need a supply of compressed air. pulls a bit more than 2 amps i think though, dont know really.

do you mind me sharing my new found knowledge of esc making on here?

[sub john]

Reply#236
HI Mike,  Going back to picture of GPS unit that i stuck up the other day on hear, one of the other things you will be able to do is send data back from the sub through radio link and would link up to the laptop or PC with the soft ware that i have got you would be able to bring up on screen of laptop the lake or what ever water you was on and all the data would be displayed on the screen where the sub is in the water doing its thing, plus would leave trail on the screen telling you the route which it has come from and where it is going. Its a good job i have got big battery's in the sub to run all this
   
Circuit for speed controller for drive circuit H bridge not really bothered what you do with it Mike but need to make sure it works first on your servo amp  board
    John

[MikeA]

so what i gather this can only be used on the surface, if the compass works underwater and send back live data of its angle it wont be able to say its actual position, because without the gps it cant measure distance.
Could this be done with sonar? With 4 sensors on the sub. 1 at front 1 at back and 2 on either side. Then using sound to gauge the coordinates of the sub on the lake by the pings bouncing off the banks?

[sub john]

Reply#238
Hi Mike,  Yes once the sub is under the water you won't no where it is because you have lost satellite down link. But what you said about sonar having four sensors one to front one to back and one on each side of the sub I'm sorry to say that the sonar side of it is all new to me at the moment but i have been looking up a lot of stuff on it as i won't to get in to playing about with sonar as it would get the brain matter going. Have a look on the net under SDR radio that is some thing that you would be able to use linked to sonar as it is soft ware controlled radio program lots of radio hams are using it for different radio bands as it can be used right down to a few KHZ. And if you used a soft ware package which you can get and can be set up to take out back ground noise so you are just left with the frequency that you won't to listen in on.

I think you would have to use a thing called a passive sonar head which i would make to have a look at 360 degrees all round vision got a few ideas but will keep quite about that one
    John

[MikeA]

well get the sub on the water before you start upgrading it too sonar navigation. Would be cool though

i suppose you could strip a cheap fishfinder to see how they work and incorperate their technology:
http://www.ebay.co.uk/itm/GARMIN-FISHFINDER-400C-COLOUR-DUAL-TRANSDUCER-FF400C-UK-/220904128188?pt=UK_SportingGoods_FishingAcces_RL&hash=item336ee97ebc

obviously this one is silly money but you know what i mean.

have you ever built a radar before?

oh another thing how can you use passive sonar to locate the postion of your own sub?? ideal for listening to other subs yeah but thats all does is listen youl need the ping of the active sonar for it to bounce off the banks of the lake to gauge the subs position.

[Davy1]

Steady on Mike - you are on a "technological roll here"!

And ideas are easy - it is getting them to work that is hard!

As far as sonar is concerned, what is more useful perhaps is to have the active "sonar" on the bank and a "transponder" on the sub. Return pulse can then give you range and bearing.

[MikeA]

oh yeah suppose that would be easier. I dont know how to make it work, that johns job. 

[sub john]

Reply#241
HI Davy 1    You could be right about having transponder on the sub and active sonar on the bank side, but like you said Davy its easy to have the ideas but its hard to get them to work thats the hard bit. But sonar is new to me i don't think it is going to be easy to get it to work, this is some thing i will do a lot later on. One of the problems is having transponder on the sub its going to have to knock out a lot of power i would say to get the range, I know that you have been using sonic sound to find lost models in the water.

If i tried to work on sonar now i don't think i would get the sub in the water for a long time and i won't to get it on the water next year
      Is the giro thats been modded to level control working OK
     All the best John
              PS HAPPY CHRISTMAS /HAPPY NEW YEAR  TO EVERY ONE ON THE FORUM

[MikeA]

just got to link up video now eh john, not much point in having sonar when you can see where your going. you off work for christmas?

 merry christmas and all that 

[sub john]

Reply#244
HI Mike    Its got to cold to mess about with antennas in the canal to test video link  going to have to wait till it gets a bit warmer, any way i have got loads to do on other bits. I have not had to go to work for about 4 years now so i get loads of time to play and mess about with electronics if i had to go back to work i would not have had time to rebuild the sub, it would have took a long time to get it back together

That speed controller that you won't to do i had to design a servo for rudder control the mechanics in it are out of electric window motor and gear box from a car and that has got a H bridge drive circuit working off servo amp board unit is very powerful to work the rudder and is digital proportional control the same as you would have for what you would use in your model boat.
     John

[MikeA]

theres a bloke on here that posted the other day his servo:

http://www.modelboatmayhem.co.uk/forum/index.php?topic=34532.0;topicseen

thought you was still working, you ready for crimbo?

[sub john]

Reply#246
HI Mike   Had a look at link you posted on the servo  H bridge  it's using transistors basic problem is transistors run hot on high currant because they loss .6 of a volt through junction of transistor if you did the same circuit using fets the voltage drop from drain to source on the fet  would be so low that it would not generate much heat so you would not have to use a heatsink to keep the fets cool when under load. The junction of a fet the lose they call RDS

Other problem is if you use a servo amp out of a normal servo  you normally would have to use a resistor about 560k from off one side of motor back to timing circuit on servo amp especially if you was trying to make a fast moving servo if you don't get this right then servo would hunt and over shoot on movement of the servo arm, it can get quite involved to get it right the one in my sub sits on custom made PCB.

 BA-HUMBUG  DOES THAT TELL YOU ANYTHING
                                        JOHN  PS Pauline has got me more electronic bits for Christmas

[Subculture]

Has the ghost of Jacob Marley been around yet then?

[MikeA]

I thought fets were a type of transistor have to do more study. looks like you did allright for christmas. i got lots of smellys, i think people are trying to say something.