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[colin-stevens]

i am using one suppled by Sub-tech. the 1/8th with 4mm adaptor.
just tried her out again in the bath with a extra air box. think it did the trick, well till the battery went flat, lost servo movement, and the pump jammed on, over inflating the bag and it burst. Water sure got in then.prepare yourselves and cover any young innocent ears. *********, ***********,!!!!!!!!!!!!.
just as well the receiver is in a balloon. dont seem to be getting very long out of the battery, wonder if it is becuase it is sitting in water? may try Sheerlines idea. but wil use a cycle inner tube, sealed. any venting will then inflate the tube, indicating there is a problem, what do you reckon?
goint to try a smaller air box.
any way, till then i think that no water got in. never turned the motor on though.
oh why did i ever start this, and there i am thinking of doing an X-Craft. thats on the back burner till i sort this wee beasty out.
brace yourselves, hoping to get up to Black Park this sunday. expect to find an empty pond now i have said that.

[Subculture]

If you mount the bag in some sort of support/cuff, like a cylinder with holes drilled around it to allow it to vent, this will offer a lot of support to the bag, and will help to prevent it splitting in the future (this is covered in the book 'Model Submarine technology).

A good type of bag for your model is the type used for medical applications like these-

http://cgi.ebay.co.uk/10-500ml-URINE-LEG-BAGS_W0QQitemZ320027778369QQihZ011QQcategoryZ36440QQssPageNameZWD2VQQrdZ1QQcmdZViewItem

Also for air pumps, try this place-

http://www.respotec.de/shop/index.html?motore_pumpen_ventile_luefter_pumpen.htm

For water pumps, try a car breakers and look at recent cars with centrifugal pumps, these can move a lot of volume at reasonable pressure and are usually designed to remain wet for long periods.

[cbr900]

SUBCULTURE,

I have disposed of the subtech seals, and replaced with the ones sent to me, can you suggest a grease for smooth running and waterproof.


Roy

[Subculture]

I use silicone grease. Waterproof and doesn't tend to harden like vaseline etc.

I use the Servisol brand, which i purchased from Maplin electronics, but you can also purchase silicone grease from a good plumbers merchants.

What was wrong with the subtech seals?

Andy

[Mankster]

I use the same silicone grease but I find it need more topping up than vasline. My subtech push rod seals leaked under vacuum until I replaced the seals with o-ring's.

[Subculture]

Did you ever try turning the seal the other way round so the lip faced the opposite way?

Andy

[Mankster]

No, I'll give that a go  :)

[cbr900]

Good idea with the seals will try that myself, it's amazing how some thing are to simple to fix that they are overlooked,
Surely there must be a waterproof grease that will stay where it is put, someone must have this knowledge,   HELP



Roy

[Subculture]

There is Renolit CA-LZ, that Norbert supplies, which is based on tacky calcium soap. Haven't tried it myself, but Norbert doesn't tend to sell rubbish.

http://www.modelluboot.de/Zubehoer/Dichtungen.html#Haft

(Bottom of page)

I don't know of a UK supplier, try googling.

Andy

[magpie]

I use the same silicone grease but I find it need more topping up than vasline. My subtech push rod seals leaked under vacuum until I replaced the seals with o-ring's.

The other thing is what Dave Welch does now. The aft part of the WTC is isolated from the rest so it doesn't vacuum when you inflate the bag. You lose a bit of volume, but you can increase the size of the WTC to compensate. This also keeps the majority of you electrics safe from the leaking water if there's any.
My 2c
Jason