RE: semi submersibale ship
OH that type of ship. there is always a part of the ship above water. this means it just changes the waterline. what you have to do is to take in water as ballast. and find a way to get rid of it again. I would say either pumping water or pumping air can do that for you. while you are filling/emptying the ballast tanks, you must prevent the water from sloshing in the tank too much because that might cause a list or even capseize the boat. just as a precaution I would advice to make some sort of waterproof box for the electronics. Success with the project !
Posted on: 10/7/2009 3:22 PM by Author "raalst" in the forum "RC Submarines"
http://www.rcuniverse.com/forum/fb.asp?m=9154272

RE: semi submersibale ship
if you type readable english maybe I answer.
Posted on: 10/7/2009 6:09 AM by Author "raalst" in the forum "RC Submarines"
http://www.rcuniverse.com/forum/fb.asp?m=9153200

RE: wtc end caps
I lubricate my o-rings as standard procedure, but I have no clue what others do. I still think that your o-ring is too large to fit in the tube of the WTC. but it is easy to quickly try the grease. let us know if it solved the issue.
Posted on: 9/26/2009 4:02 PM by Author "raalst" in the forum "RC Submarines"
http://www.rcuniverse.com/forum/fb.asp?m=9125715

RE: wtc end caps
the orings must be of an exact size, a few tenths of a millimeter larger outer diameter than the innner diameter of the wtc you put them in to. they must also sit snug against the bottom of the end caps' groove it is lying in. what you say sounds like an o-ring that is too large or too thick. having said that, a bit of grease is probably required to have the thing sliding at all. some grease attack the rubber, not good. I know for sure that silicon grease will not attack rubber. same for the grease used for faucets. all you ever want to know about o-rings (and then some) : [link=http://eriks.nl/documentatie/afdichtingen/o-ringen-en-overige-ringen/precision-o-rings-technnical-handbook.pdf]eriks' o-ring handbook[/link]
Posted on: 9/26/2009 3:51 AM by Author "raalst" in the forum "RC Submarines"
http://www.rcuniverse.com/forum/fb.asp?m=9124871

RE: wtc end caps
do you have access to a lathe ?
Posted on: 9/24/2009 3:52 PM by Author "raalst" in the forum "RC Submarines"
http://www.rcuniverse.com/forum/fb.asp?m=9120899

RE: It started with the Graupner U-16..
inbetween RTR and a kit ? that's a perfect fit for a ThunderTiger Neptune. that kit is screwed together, not much more is needed. it looks like a research sub. [link=http://www.youtube.com/watch?v=uosbypxcBKU]youtube film of it [/link] otherwise, do not forget to check out european sellers like www.modelluboot.de and www.lecma-rc.com to get a feeling what is involved/available.
Posted on: 5/6/2009 6:18 AM by Author "raalst" in the forum "RC Submarines"
http://www.rcuniverse.com/forum/fb.asp?m=8743210

RE: It started with the Graupner U-16..
you can also consider the Trumpeter SeaWolf and Trumpeter Kilo for conversion. Because they are round, the water tight compartment is easier to build/cheaper to purchase standard round WTC's can be bought from e.g. Big Dave Welch. I made one for the Kilo from drainpipe. I do not have ota's conversion kit, but the Revell VIIc is very small to build the needed equipment into. Ota is a very gifted modeller. For a first boat, you should keep things as easy as possible. another possibility is the Conrad/Robbe Seawolf, a fantasy model, fairly cheap. can be made into a static diver as a phase II, after you have succesfully completed the kit out of the box. good luck !
Posted on: 4/29/2009 5:56 AM by Author "raalst" in the forum "RC Submarines"
http://www.rcuniverse.com/forum/fb.asp?m=8725097

RE: How to improve underwater RF reception?
this link may answer a few questions about under water RF transmission. fasten your seatbelts and brush up your electronics skills first. As far as I understand from this, the antenna underwater will need to have another length as the air-antenna and putting the antenna in the water saves the effort to penetrate the water from the air, so it IS a good idea. [link=http://www.qsl.net/vk5br/UwaterComms.htm]http://www.qsl.net/vk5br/UwaterComms.htm[/link]
Posted on: 4/1/2009 3:51 PM by Author "raalst" in the forum "RC Submarines"
http://www.rcuniverse.com/forum/fb.asp?m=8638964

RE: Watertight servo linkage: idea
this solution was used on small Japanese models. I have seen it on a japanese site somewhere. no need for the spring either. the servo is quite able to move the piston both ways
Posted on: 8/9/2008 11:25 AM by Author "raalst" in the forum "RC Submarines"
http://www.rcuniverse.com/forum/fb.asp?m=7826648

RE: Any experience with piston systems?
ok, the servo potmeter is fixed in the middle so that if your stick (on the transmitter) in is the middle, the servo does not move. as soon as you move the stick up or down, the servo starts turning in some direction and it keeps on turning as ong as the stick is held out of the centrer position. the servo was modified to be able to rotate freely. that is also why the potmeter is outside the servo package. the servo turns the threaded rod. The white thing on the tube that is the piston arm is basically a nut. it moves along the threaded rod when the servo turns. each servo turn means the nut moves a millimeter. the threaded rod disappears into the hollow tube piston arm. switches must be added to make sure the servo stops when the piston reaches the extreme ends of the syringe. (shameless plug mode on) If you really want to know all, I have written an article about such a setup in the next SubCommittee Report, available to members of the Subcommittee.
Posted on: 7/29/2008 5:10 PM by Author "raalst" in the forum "RC Submarines"
http://www.rcuniverse.com/forum/fb.asp?m=7785545

RE: Any experience with piston systems?
I use my limit switches to short the potmeter signal wire to ground or it's positive lead. that is the same as when ou would yank the potmeter to it's extremes. That way you do not have to switch big currents. and you can leave out the diodes. as for force : the previous version ued asmaller servo and during development destroyed my wtc. it pushed it apart. do not underestimate the gear ratio of the thread/nut combo. as said, the price is relative slow movement. each servo full turn (servo was modified to do multiple turns) will advance the piston about a millimeter. that's about 1/25 of an inch. the thread is M5.
Posted on: 7/25/2008 4:28 PM by Author "raalst" in the forum "RC Submarines"
http://www.rcuniverse.com/forum/fb.asp?m=7771736

RE: Any experience with piston systems?
as for syringe systems, I'm building a new one after operating a first one with succes for over 3 years. this version features a more coarse thread than the first, causing the piston to move faster (well, okay, less slow). It requires limit-switches, which I have not yet tinkered out for this version. it is 60ml (2 oz, I'm told) "big" meaning it can lift 60 grams out of the water [image]http://www.modelbouwforum.nl/forums/imagehosting/27254888e69747826.jpg[/image]
Posted on: 7/25/2008 3:52 PM by Author "raalst" in the forum "RC Submarines"
http://www.rcuniverse.com/forum/fb.asp?m=7771622

RE: dynamic diver delima
maybe there are a few idea's in these links (especially a diy seal for a pushrod) : [link=http://home.vianetworks.nl/~raalst/kilo/kilo.html]my kilo build[/link] since all action happens on the aft end of the wtc, a bottle of sorts made from sturdy plastic with a plastic lid should be usable (then you do not need these end-caps) and a film about current performance. please note
Posted on: 1/2/2008 6:11 AM by Author "raalst" in the forum "RC Submarines"
http://www.rcuniverse.com/forum/fb.asp?m=6840708