Topic: Snort help (Read 13460 times)

Subculture · « **Reply #25 on:** May 06, 2012, 05:42:55 pm »

Basically what you have described is the system used for years on the Darnell boats, and in latter years used in smaller boats by U.S modellers owing to the availability of smaller diaphragm based pumps and the acronym RCABS was coined.

This system doesn't have the same ability to finely trim a boat as the peristaltic system, because your bag should be completely empty with boat at neutral or close to neutral buoyancy.

If you leave air in the bag, it will compress as the boat dives deeper. In practice in shallow ponds this makes little difference to the boats behaviour, but if you dive deeper e.g. in a swimming pool your boat will likely end up negatively buoyant.

bbdave · « **Reply #26 on:** May 06, 2012, 08:24:54 pm »

So the other way is to have the bag in the WTC and pump water in?

Does the TT board control fwd/rev of the pump? so i need a pressure switch does this go in the feed to the pump and shut it off at a given pressure only allowing it to reverse?

Dave

Subculture · « **Reply #27 on:** May 06, 2012, 08:52:18 pm »

Correct to the first two questions, the pressure switch goes to a special port on the control board. The chap that sells the board also does the pressure switch, and also supplies the pump head used in the Neptune. The latter may prove a tight fit in a 70mm module however. You can use geared pumps for this system too, cheaper and faster pumping speed, but you need a pinch valve as they're not self sealing against pressure like the peristaltics.

bbdave · « **Reply #28 on:** May 06, 2012, 09:56:49 pm »

I could use a pump from the other site the TT bits look good though so a deffinate option there.

I just printed the relevant pages of the manual off not sure what voltage the pcb runs off though.

Dave

Subculture · « **Reply #29 on:** May 07, 2012, 07:00:45 am »

It's designed to run a 12 volt system.

bbdave · « **Reply #30 on:** May 07, 2012, 10:06:45 am »

Thats good as i plan to use 11.1v i just wasn't sure if the distribution board reduced the voltage. This seems to have evolved beyond the snort idea

.

Dave

Subculture · « **Reply #31 on:** May 07, 2012, 10:32:43 am »

Not sure how it will work with 3S lipo- the board has a voltage monitor which may trip out early on the lower voltage. Might be okay, would defintiely be good on 4S LiFE battery (12.8 volts).

Various ballast systems have their pros and cons. With a peristaltic pump, the main disadvantage is the slow pumping rate. If your boat needs more than a quarter of a litre displacement, it's probably a good idea to look at either using a geared pump or fit a different kind of system.

I think a diving time of 30 seconds or less is about right. Any more than that and it can get a bit laborious waiting for your boat to submerge.

With a Welman, I wouldn't think you'll need anything more than about 100ml volume.

U-33 · « **Reply #32 on:** May 07, 2012, 11:29:57 am »

Before y'all get too excited over these Thunder Tiger boards, beware that they are not the early versions, these had several faults in them. (Been there, done that, returned the boat. I'm now on my 3rd...and it's perfect.)

A pretty good way to determine which is which to check the main power wires...stiff cables that are a *** to bend are the early versions and best avoided. Those with flexible cables are more than likely going to be the later boards with the new uprated components fitted to them, and are to be recommended.

Maybe a phone call/email to the supplier prior to giving the flexible friend another good work out might be a good idea....

bbdave · « **Reply #33 on:** May 07, 2012, 05:07:15 pm »

Well i'll get the hull built then go from there and find out what sort of ballast is needed.

If finances stretch i'd go for a small Engel system as i am used to them. But i'm considering all options

Dave

Subculture · « **Reply #34 on:** May 07, 2012, 06:25:58 pm »

An Engel tank won't fit in a Welman unless you make it bigger than the John Lambert plan.

bbdave · « **Reply #35 on:** May 07, 2012, 07:29:56 pm »

I've enlarged it roughly 1.5 times so i could get a 90mm Wtc in if needed but it all depends on what i can afford when the time comes.

Dave

Subculture · « **Reply #36 on:** May 07, 2012, 07:59:51 pm »

Ron Perrott had some new Engel tanks he was looking to sell on. You would need to trim one down for the Welman I think. He had a set of 500ml tanks and was looking for about £150 for the pair, which is a big saving over buying them from Engel. Sell one on and you're in business.

bbdave · « **Reply #37 on:** May 08, 2012, 04:40:34 pm »

Thanks but i have tyres to buy this month first

Dave

Subculture · « **Reply #38 on:** May 08, 2012, 06:06:21 pm »

They don't work well on subs!

bbdave · « **Reply #39 on:** May 18, 2012, 08:00:33 am »

Is this a peristaltic pump?

http://www.cornwallmodelboats.co.uk/acatalog/graupner_1951.html

Dave

U-33 · « **Reply #40 on:** May 18, 2012, 09:19:04 am »

No mate, that'll be a common or garden geared type pump.

The image shows a diagram of a perilstaltic pump...do a google search, there's thousands of 'em out there.

Rich

Subculture · « **Reply #41 on:** May 18, 2012, 09:26:23 am »

Williamson do a comprehensive range, and the ebay links mentioned before.

http://www.williamson-shop.co.uk/series-200-mini-peristaltic-pumps-215-c.asp

The geared pump you linked to causes a few problems. This was used in a French submarine kit called the Galathee, and unfortunately the gear on the motor tends to lose its key. Some people have replace them with Kavan pumps, which are bigger, but have brass gears and don't suffer this fate.

bbdave · « **Reply #42 on:** May 18, 2012, 03:43:21 pm »

I have been looking but was trying to find cheaper ones as £40 seems high but i guess i'll have to bite the bullet

Dave

Subculture · « **Reply #43 on:** May 18, 2012, 04:07:04 pm »

You can buy just the head and add a geared motor, which you can get cheaply on ebay ( e.g. about a tenner). That'll work out at about a score- not too bad.

bbdave · « **Reply #44 on:** May 18, 2012, 06:07:49 pm »

Do you happen to know the shaft dia. needed i can email them if not. i have seen the 300rpm motors on the bay.

Dave

Subculture · « **Reply #45 on:** May 18, 2012, 07:05:13 pm »

I don't I'm afraid. The company should be able to help with that one though.

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Author Topic: Snort help (Read 13460 times)