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[Turbulent]

After seeing the success of the Sheerline Type II I've decided to refit my Traf' to accommodate Nimhs under the WTC.

As well as freeing up space in the bow & lowering the centre of gravity, centre of bouyancy is raised.

[Turbulent]

With raised WTC, I've had to shorten the Prop shaft & add an additional UV joint.

[ajg141]

I will be watching your progress with a great deal of interest and if it doesn't look too difficult might just try it myself. It's changing all the universal joint gubbins that's been putting me off. Good luck - and I'll be intrigued to hear how it performs after the re-fit.

Andrew

[colin-stevens]

are you putting the batteries in the wtc or the free flood area. if in the wet area do they need sealing? youre answer could solve on of my problems, unfortuantly, only one of them. oh well.

[Mankster]

NiMH in general can be run wet, no troublewith mine in 3 years .

[colin-stevens]

ta.

[Turbulent]

My batteries are in the wet under the WTC, they are encased in shrink tube & both ends have been filled with mastic to keep them dry.

The whole conversion has taken about three evenings, hardest job, making new mountings to take the WTC, the metal strap has been replaced with velcro.

Put her in the pond this morning, sat up on a much better waterline, testing next weekend, the boat is a good few pounds lighter as well.

[colin-stevens]

assuming you are using Ni-cads. with the more traditional lead acid batteries i sealed the pos+ve terminal with thick glue to stop, cant remember what, but it was something i read , made sense at the time so did it. is this the same for  Ni-cad, and the new generation of hydride etc batteries.
just about to make a new radio box for my See-hund, dont reckon that i have made the ballast area big enough. if other battreies apart from lead acid can go in the wet area it means i can move the dry boxes further forward increasing the size of the ballast area. then i can get in the air bag as reckomended by Ramesh. what a wonderfull chappie he is, answered my ballast queries nicely. it was simple realy, explained in words of one sylable and succintly(had to look that up).
thanks gyus this site is proving realy usefull.

[Turbulent]

Gave her another test in the pond today & after ballsting her up, final trimming for diving took about 10 minutes, with the batteries at the bottom of the hull, stability is vastly improved as is diviing & surfacing, will post pictures after further trials at the weekend.

[ajg141]

Just wondering how the last set of trials went. I see you have you found an improvement in the stability - but what about the turning circle? And how's the additional CV doing? If you've a pic of the final set-up for that I'd love to see it. Many thanks.

Andrew

[Mankster]

I thought it performed better that any Sheerline Trafalgar I've seen. Turning circle was impressive for a boat with a propulsor. Very little roll too now that the cylinder is higher up. No foam anywhere either  :) Even with a double U joint, with those angles you will get more frictional losses and lose a some efficiency but it is of little consequence with battery capacity these days.

[ajg141]

Looks like I've got yet another re-build job on my hands then before I get started on that Resolution. Lol. Thanks for the info.

Andrew

[sheerline]

Hello all. The modifications I originally carried out on Trafalgar produced astonishingly good results and transformed the boat's performance. The idea was to rid it of upper weight, raise the height of the buoyancy and stick all the lower weight directly under the dive unit. This set up is the submarine ideal and in Trafalgar it works superbly well. To this end, I have created a lighter, reinforced upper hull, re-designed dive unit cradles and a new NiMh  waterproof battery pack. These are the three main ingredients which make all the difference although I have been right through the boat and modified almost eveything else to make it so much easier to build as a new kit.
Older boats can be retrofitted using the new ideas and components and Turbulent is getting stuck into his as you have seen, his mods so far have already made drastic improvements to the performance of his boat.
There are some  older Trafalgars out there running with the nylon gearboxes originally supplied and for those, moving the motor lower down on the backplate to create a more accurate alignment of the drive/ propshaft would be problematical. For those fitted with the later all metal motor/box units, the single hole mounting can be plugged and a new hole drilled lower down, allowing  the shafts to align. If you have to leave your motor output shaft where it is, you will end up with a double cranked driveshaft, so shorten the output shaft on the dive unit to allow the coupling to butt up against the dive unit gland and shorten the propshaft to 5 inches in length. With a second coupling fitted to the propshaft, you  will need a length 4mm brass or stainless rod to link the coulpings together  This setup will reduce the angles on the couplings and thereby allow them to run freely.
If anyone is interested in any of the new components or needs advice on mods, give me a call and I will be happy to help out.
Best regards.. Chris     

[ajg141]

Many thanks for the info Chris. I'll have a delve round inside over the next few days and be in touch. From what I've heard it would be a mod well worth doing.

Andrew

[magpie]

Hi Turbulent

I see your using the Sanyo 3600s. I put them in my u-boat and I'm very happy with them. I use dual rate on my throttle at 50% mostly with the odd blast on full and get an hour or more before she slows a bit.
Jason

[colin-stevens]

Sheerline, a question. if you are making the batteries watertight, they must be air tight, so can i ask about venting? i am led to beleive that this is important in charging, discharging batteries. i have mine siting totaly exposed to the elements, including the plug. no intention of going into salt water, so am a little happy, but not convinced.
colin

[sheerline]

Hi Colin, I sleeve the batteries with heat shrink and machine up an end cap which carries a pair of rubber bellows through which the cables pass. Before shrinking the sleeving, I apply a sealant at each end to seal the whole lot up. Should these batteries ever build up any pressure, it will find its way out through the sealant or the bellows .I do not recommend any kind of fast charging forthese NiMh packs and only the delta peak charger should be used. These cells do vent, especially if you try to extract current as they are reaching a low state of charge. Oxygen is generated within the cell and I have witnessed it escaping from an almost exhausted pack. It is not recommended these cells are abused in this way but if you are running one of my boats, you will notice it's reluctance to dive as the pack runs low. If you cease operating the boat at this point, you will not have flattened the pack completely and therefore not built up any kind of pressure within. It all seems to work out quite well.
Hope this helps.......... Chris   

[Turbulent]

An update on previos posts, ran her again today for about 1 1/2 hours in total, the stability afforded by the batteries low down really is superb, I run at slow speed practicaly hands free with only an inch of periscope and even in the turn there is no loss of stability, if you've not modded your Traf's yet, make it a winter project. I'm sure Chris will be able to supply the battery packs pre made if you ask him nicely!!!!

[ajg141]

My mods are also now almost complete  :). The only thing that's needed now is for the wife to disappear for the afternoon so that I can reclaim use of the test tank (without her knowledge) and do some re-ballasting. Fortunately she's booked a day at one of those health spa places in a couple of weeks time (not that I am convinced it will help!) so the solution is imminent. I must say that the work involved has been fairly straightforward thanks to Chris's considerable help.

Andrew