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Topic Summary

Posted by: kit
« on: 15 June 2015, 19:59:11 »

Hi Tolly

Joe is spot on with the basic principles.

Like Andy I let my ballast be the batteries as much as possible - my Tribal has 19AA NiMH's in there and I still had to add lead.

Lead wise I use motorbike wheel weights - they come in 60g strips but can be broken down into 5g bits.  Self adhesive and the glue is obviously waterproof.  I got 3Kg on eBay from a tyre dealer for about £20. 

One other thing to add - try to avoid adding ballast in either the bow or the stern.  Having weight at either extremity makes the boat less manoeuvrable as the inertia will resist the boat turning so try to keep the ballast as central as possible.

Oh yeah, one other thing with my Zulu - the waterline on my plan was not straight so best to check before you get busy with a paintbrush.... 

Initially I just measured the bow and stern waterline heights then joined the dots but the waterline was far too high amidships.  In the end I measured the waterline height amidships and then stretched it for and aft to the bow and stern which I think gives the right height.

Cheers

Kit
Posted by: radio joe
« on: 11 June 2015, 13:54:39 »

Quote from: Anatole3 on 10 June 2015, 23:16:38
hi guys

just a quick question how much ballast (lead) do you have to put in these
and where do you put it .
ta in advance.
tolly

Hi Tolly           
There is no definitive answer to your question, the batteries / running gear components you have used and where you have placed them will have a bearing on the amount of ballast and where it is placed, only a flotation test of your near completed boat will tell.
Once you have got the boat to near completion ie. With all the weighty bit's fitted and the water line marked try the hull in water without the superstructures on, add bits of lead keeping them as low and near the centre line as possible till the hull is floating level near the water line and upright, (no lists), now try the superstructures on and check the water line if it's ok carefully lift the boat out making sure not to move the lead now tack the ballast in place with spots of glue, I use PVA in case I ever want to move the ballast, I will say if this is your first boat you will be surprised just how much lead it will take. ::DD
Posted by: andy
« on: 11 June 2015, 04:33:03 »

Quote from: Anatole3 on 10 June 2015, 23:16:38
hi guys

just a quick question how much ballast (lead) do you have to put in these
and where do you put it .
ta in advance.
tolly

I let my main Batteries be my ballast.  This gave my a very good run time.  A single charge lasted most events I went to.

You find a picture showing he location of my batteries in my HMS Nubian on this web link

http://www.wmunderway.8m.com/cgi/yabb2/YaBB.pl?num=1187739060

Andy
Posted by: Anatole3
« on: 10 June 2015, 23:16:38 »

hi guys

just a quick question how much ballast (lead) do you have to put in these
and where do you put it .
ta in advance.
tolly
Posted by: Anatole3
« on: 06 June 2015, 11:27:07 »

Hi
just found a wasp and Bofors same site
try here                    http://www.shapeways.com/search?q=1%2F96+bofors  Bofors  guns

here for the wasp   http://www.shapeways.com/product/TW3LULPQ6/westland-wasp-helicopter-kit-1-96

hope this helps
Posted by: Anatole3
« on: 05 June 2015, 19:51:33 »

 :smiley1:HI Guys
I have been beavering away at my Zulu the bottom deck now is in the hull it is square the prop shaft
is in just a bit of filling and sanding to do motor is attached and the rudder is in the method in the manual is too fiddly to support the brass shaft if you drill the hull then get a piece of 3/4 inch dowel rod
about half an inch long drill a hole in the centre put it over the rudder shaft and epoxy it in does the reinforcing and looks neat.
just finished printing some decals for F119 on clear inkjet paper look good
will finish the electrics tomorrow.
my other half thought id emigrated went down the shed at about 7 30 last night came back up to the house and it was nearly 1 o'clock.
time flies when you are having fun
Posted by: radio joe
« on: 01 June 2015, 16:37:29 »

Hi guys, I'm not saying the half template method is a perfect fit,  with the varying surface of the glass lay up etc. But it's close enough with a little trimming to get a good enough fit to tack in place with Cyrano, I then bond in with a small fillet of P38 round the edge of the bulkhead. :wink1:
Posted by: kit
« on: 31 May 2015, 16:32:20 »

I like Joe's method, makes sense and I may retrofit mine with with bulkheads - not too worried about the hull flexing but I would like to build in some watertight compartments as flotation chambers.

One small point in Joe's post - Joe has obviously managed to suss a symmetrical hull but I doubt that any of mine are even close   :-\.  Anyway, if you have any doubt about hull symmetry, make the template for both sides as flipping won't work
Posted by: Anatole3
« on: 31 May 2015, 16:12:25 »

Thanks guys
The method you use makes sense it  stiffens up the hull which
is quite floppy.
will try  your method Joe let you know how it goes

tolly
Posted by: radio joe
« on: 31 May 2015, 13:41:42 »

Hi Tolly   I like to use bulkheads especially on non planted hulls like Zulu where the sides tend to be quite flexible so bulkheads act as stiffners
Once you have the bottom plate bonded in decide where you want the bulkheads check the  beam measurement at each bulkhead position with the plan, place a strut across the beam to the correct measurements and hold in place with masking tape or similar once all the positions are correct make a cardboard template of each bulkhead, I usually mark a centre line in side the hull that way you only need to make a half template and transfer to ply by marking one side of a centre line then flip over and mark the other, hope all this makes sense.  ::DD
Posted by: kit
« on: 31 May 2015, 10:23:10 »

Hi Tolly

I used brass instead of wood to flatten out the hull as it keeps the centre of gravity lower but that's just personal preference.  There is also a chain here on how to straigten hulls using a hair dryer at http://www.deansmarine.co.uk/index.php?topic=738.msg6079;topicseen#msg6079. 
 
Never tried it myself but that was only because I hadn't seen the thread.

I don't bother with bulkheads and I haven't had any problems with any of my builds but Joe is the expert for Zulu.  And others I suspect!

Cheers

Kit
Posted by: Anatole3
« on: 30 May 2015, 21:33:00 »

 :smiley1: Hi Joe

Just a quickie I have just been through my kit
and have the same problem as you had with
the hull being concave so I am going to make a
ply bottom to straighten it out .
Maybe I am stupid I have looked through all the docs
for a template to make the  bulkheads but cant find one
the ply decks I can transcribe from the plan  onto a sheet of ply.
but I am  at a loss to how I can make these if it was an aircraft id know what to do
maybe I can use a rule and compass and white card to make a template.
how did you do it
help
tolly
ps yours is a great build if mine turns out half as good I will be pleased.
Posted by: Anatole3
« on: 28 May 2015, 19:31:04 »

Hi
I was a radio electrical mechanic for three years on Eskimo
my job was maintaining all the radar systems
I wish I could have stayed in.

regards
tolly 
Posted by: radio joe
« on: 28 May 2015, 19:16:59 »

I bow to your knowledge Tolly, is just I never came across any mention of a 293 radar when researching HMS Zulu.
Posted by: Anatole3
« on: 28 May 2015, 17:59:14 »

Hi Joe
in 67/78 before conversion to Seacat the Tribals had 4 radars the big bedstead on top was the 965
long  range air radar  metric radar the small cheese scanner half way up the main mast was the nav radar 978 very high definition (for those days) the one on the small mast was the 293 this was the GP radar last but not least was the 903 this was the gunnery radar linked to the MRS  3 targeting system.
sometime after I left her they changed the 293 to the 993 changed the nice cheese scanner to that horrible offset triangular thing spoilt the clean lines when they were lined up fore and aft.
 all the best
tolly