Topic: Perkasa to Brave Swordsman, a long overdue conversion. (Read 11058 times)

unbuiltnautilus · « **on:** February 03, 2018, 08:31:39 am »

I have wanted to build one of the Royal Navy Brave Class FPBs for many years, the spark kind of evaporated when Brave Borderer was mass produced a few years ago. However, I had the opportunity to obtain a fellow club members Perkasa a couple of years ago. Last year I used it as a brushless testbed ( much useful data to follow! ), now it is time to convert to HMS Brave Swordsman, the under appreciated little sister of Brave Borderer. She was fitted with a modified superstructure, not as pretty as Brave Borderer, but an interesting prototype none the less.

unbuiltnautilus · « **Reply #1 on:** February 03, 2018, 08:37:41 am »

Work starts with the fitting of a smaller gas turbine duct on the rear superstructure. This well built part of the model needed removing, to give me a clear deck to rebuild from, out with the hammer!

unbuiltnautilus · « **Reply #2 on:** February 03, 2018, 08:43:31 am »

...and then back up again...

A hole cut in the deck is to help my rather annoying JJC Gas Turbine sound module to annoy the neighbours to its maximum effect. 1/32" ply is being used extensively to save a bit of weight.

unbuiltnautilus · « **Reply #3 on:** February 03, 2018, 08:48:11 am »

This 1/32" ply is a really nice material to work with. Smooth surface finish and easy to work with. Used with balsa square to stiffen up joints and structures, is resulting in a light but stiff superstructure. I need to save weight wherever possible, big heavy speaker going in at some point..

SteamboatPhil · « **Reply #4 on:** February 03, 2018, 05:17:13 pm »

Nice conversion, I agree with you I use 1/32 ply in all of my boats construction.
Will keep watching the progress

ballastanksian · « **Reply #5 on:** February 03, 2018, 06:07:48 pm »

That is a good sized turret you have there as well! Are you using superglue to stick the parts with? I have a model that is partly made from thin ply and the joins keep splitting. It is an older model that I am restoring and wonder if the ply needs wiping or rubbing to remove any natural wood oils etc???

unbuiltnautilus · « **Reply #6 on:** February 03, 2018, 06:51:24 pm »

Cheers for the responses chaps

I am using a medium viscosity cyano in combination with a spray activator to kick off the joint. The balsa strips were pre-glued on one flat edge, slid into place quickly, then given a quick squirt of activator. The ply to balsa and ply to ply joints had a run of cyano chased along the joints with a cocktail stick, left for about thirty seconds to wick in properly, then zapped with the activator. The joint then cleaned up with either permagrit or a decent file.

I would doubt if your old ply is expelling some sort of oils, I would expect the opposite, with the ply being properly dried out, due to old age (!). The other suggestion, stick to big bottle cyano brands, rather than the cheap mini tubes. These seem to be troublesome, producing crystal laden joints on occasion. Other than that, I shall remain comfortably clueless on your problem!

Now, the big gun.....

unbuiltnautilus · « **Reply #7 on:** February 03, 2018, 07:23:29 pm »

Regarding the big turret,I shall quote from a paper published by The Royal Institution of Naval Architects, Jan 7th 1960.

'The gun armament of coastal force craft had for many years been a combination of automatic weapons up to 40mm calibre and some larger guns such as the twelve pounder and 4.5" of greater hitting power, but doubtful accuracy when used from the poor gun platform provided by a fast moving boat in a seaway. After the war, attention was directed to the design of a gun, mounting and control system suitable for coastal forces from which the Coastal Forces System 2 ( C.F.S.2 ) was evolved. The gun used in the C.F.S.2 is a 3.3" calibre high velocity gun which, together with stability and prediction equipment, is carried in a turret mounting.'
' Trials of the prototype mounting on HMS Bold Pioneer demonstrated very high accuracy and rate of fire could be maintained even at high speed in a seaway. This considerable achievement brought its penalty in weight, power and complication. The weight of the mounting is 5 1/2 tons, while the all up weight, including ammunition, magazine fittings, and directing gear is 8 1/2 tons.'

Unfortunately for us modellers, the further development of this gun was abandoned. However, its size and weight penalties resulted in the gun position on the braves being relatively further aft than on other sister classes, such as the Perkasas. Resulting in the rather cool, 'go faster' look of the two Braves.

The drawings show the original layout of Brave Borderer, the optional variants that could be fitted to the basic design, and finally my attempt at overlaying Brave Swordsman over the original Brave Borderer drawings ( so take nothing on Swordsman as gospel, it is close enough to keep me happy, but has been the result of 'near enough' interpretations of the few photos of my chosen vessel..still, it gives an idea of the differences between these two sister vessels.

unbuiltnautilus · « **Reply #8 on:** February 03, 2018, 07:52:19 pm »

The big turret was started last year, with the basic shape being a combination of 3/16" ply for the base and 3/16" and 1/4" balsa sheet for the sides. Now is the time for 1/32" ply skins to be applied.
As before, medium viscosity Cyano glue was used throughout. Cyano on the balsa, while activator was pre-sprayed on the plywood. This meant getting it right first time, no room for errors or it would be scrap! Luckily all ( almost all! ) went fine. The slots for the gun were cut in the ply first, the sanded with a drum sander in a hobby drill to get the top and bottom curves.
Once everything was glued on, I began hacking the balsa inner cores away from the slots. Using the hobby drill again with a combination of Permagrit and sanding drums, much mess was made. Kept the sawdust in a tub for filler powder later on in the build.

unbuiltnautilus · « **Reply #9 on:** February 03, 2018, 07:57:02 pm »

The gun and breech were a mix of a 1/35 scale Tiger tank turned aluminium barrel which I had already, and a single piece of teak, chopped to match the only photo I had of the turret. A bit of plasticard added to the look of the breech mechanism and should look good once painted grey.

unbuiltnautilus · « **Reply #10 on:** February 03, 2018, 07:58:30 pm »

THEN I found another photo of the turret, which I already had, but didn't seek out cos I forgot I had it....so a bit more detailing work will be in order

unbuiltnautilus · « **Reply #11 on:** February 03, 2018, 08:06:36 pm »

Final job, bringing us up to yesterday evening, was infills in the deck hatch that would otherwise be big holes when the new, slightly smaller superstructure goes on. This time using 1/8" ply, cut to a tight fit, then filled and blended in to the existing deck

So far so good. The old superstructure will no longer fit now, therefore no turning back....Looks fast standing still!

Capt Podge · « **Reply #12 on:** February 03, 2018, 08:52:39 pm »

Quote from: unbuiltnautilus on February 03, 2018, 08:06:36 pm

This time using 1/8" ply, cut to a tight fit, then filled and blended in to the existing deck

...and you have made a fine job of this too!

This is a fascinating refurb and refit - keep it up, you're doing great.

Regards,

Ray.

unbuiltnautilus · « **Reply #13 on:** February 04, 2018, 09:59:08 pm »

Not much doing today. Too busy at B&Q purchasing upholstery nails ( Steampunk demands their use for rivets!! ). So I finished of sanding the filler flat first. I used Deluxe Materials Perfect Plastic Putty for this. I was unsure of this product at first, and still wont use it on the hull, but above deck, and suitably Sanding Sealered, should be fine. It spreads out easily with spatula or offcut of plywood. Drying time is slower than a two part filler, but patience is my middle name....
1/8" x 3/8" spruce coamings have replaced all the originals round the modified front hatch, thereby restoring the splashproofing up front..followed by me hacking the coamings off the rear hatch, ruining all those good intentions! The Braves did not have the slightly raised centre deck running all the way aft like the Perkasa. Instead, the deck was flush aft of the ducting. So a suitable piece of !/8" birch ply is now cut to fit. All I have to ponder is how to make it removable for rudder and servo access if needed, while keeping the water out. A Job for tomorrow I think..

mudway · « **Reply #14 on:** February 05, 2018, 08:10:58 am »

Is this a 1/32 Brave? I was curious as to which outrunner you were using.

derekwarner · « **Reply #15 on:** February 05, 2018, 08:46:13 am »

UBN....following on with interest

....& as you say, this is not a true scale conversion.......

These scale vessels even at scale speed can produce a stern wave much higher than the stern.......so

....a complete stop of engines could awash the stern

So you could consider taking Refit Builders Licence

& elevate the stern Quarter Deck by continuing the 1/8 x 3/8" combing to cover this area.....all of your original images depict this with the elevated plinth & the 40/60 Bofor mount at the stern

This would certainly assist in a water proofed stern

Derek

unbuiltnautilus · « **Reply #16 on:** February 05, 2018, 09:35:03 am »

Quote from: derekwarner_decoy on February 05, 2018, 08:46:13 am

UBN....following on with interest ....& as you say, this is not a true scale conversion.......

These scale vessels even at scale speed can produce a stern wave much higher than the stern.......so ....a complete stop of engines could awash the stern

So you could consider taking Refit Builders Licence & elevate the stern Quarter Deck by continuing the 1/8 x 3/8" combing to cover this area.....all of your original images depict this with the elevated plinth & the 40/60 Bofor mount at the stern

This would certainly assist in a water proofed stern

Derek

I had to renew my Refit Builders Licence earlier this year, it had got a bit dog eared! The good news, following extensive trials last year, driving it like I stole it, did not result in the stern wash problem. It did highlight the 'sidewash' problem, as visible in the first photos at the top of the post. This created some water on deck issues. If I just piloted the vessel in a responsible manner, this would not happen, where is the fun in that!
Anyway, walnut 'D' section is going round the hull/deck edge to improve the looks and hopefully divert some of the side spray away.

unbuiltnautilus · « **Reply #17 on:** February 05, 2018, 09:37:44 am »

Quote from: mudway on February 05, 2018, 08:10:58 am

Is this a 1/32 Brave? I was curious as to which outrunner you were using.

Yup, this is the 1/32 model. I have carried out a series of brushless trials with the model, using two different motors and a variety of prop sizes and voltages. With a watt meter in line, I have actual data, which I shall share soon ( When I find the notebook! ).

ballastanksian · « **Reply #18 on:** February 05, 2018, 08:37:58 pm »

This is becoming a gem UBN. The use of a tank gun barrel is ever so logical and saves loads of time whittling or machining as well.

unbuiltnautilus · « **Reply #19 on:** February 26, 2018, 05:44:05 pm »

Guess what, the NEW superstructure will not fit! So, more mods required.

smudger1309 · « **Reply #20 on:** February 26, 2018, 05:50:42 pm »

this is a nice conversion / build, been joy to read and look at the photos

thank you for sharing.

i just managed to get hold of a type 45 destroyer last week and she sailed for first time with me yesterday its nice to get back into navy boats / ships

unbuiltnautilus · « **Reply #21 on:** February 26, 2018, 08:04:54 pm »

Quote from: smudger1309 on February 26, 2018, 05:50:42 pm

this is a nice conversion / build, been joy to read and look at the photos thank you for sharing.

i just managed to get hold of a type 45 destroyer last week and she sailed for first time with me yesterday its nice to get back into navy boats / ships

Thank you, much more to follow as always.
What Type 45 have you got 1/96 or 1/72 ( or 1/32! )?

unbuiltnautilus · « **Reply #22 on:** February 26, 2018, 08:25:57 pm »

A bit of CAD for the next part of the build, Cardboard Aided Design!
With the different superstructure profile of Swordsman, there are no plans existing, showing the layout from the top, sides or front/rear. I have estimated a side view but have had to 'learn the ship' to aid me with designing the intakes protective cowling. The photos can be contradictory at best, regarding angles and the like. The best I have been able to do up till now is use Brave Borderers design as a guide to Brave Swordsmans design.
It seems fair to assume that the layout of the two hull structures are the same. The flying bridge seems to be in the same place, and the big intake cowl is in the same place. These all help to anchor the unknown parts of the design. The big front cowl serves a specific purpose, this is to ensure sea water spray is deflected away from the engine intake cowling, over the three Proteus gas turbines at the aft end of the ship. Brave Borderer displays something of a streamlined aerofoil profile. To carry that through to the shorter profiled cowl on Swordsman, could be as simple as angling the cowl down slightly, towards the aft end. Drawings of Brave Borderer indicate that this cowl also tapers aft, when viewed from above. All I need to do is incorporate all that into a pre-existing model...easy.
Incidentally, the difference between the two sister ships is never commented on, but it seems more than likely it was a trial between two designs of cowlings. The more sexy curved cowling seemed to have won out, as it appeared in all the following variants of these designs. However, the less attractive squared off cowl design did appear in the Swedish Spica 1 missile boats in the mid sixties.
Anyway, less chat, more cardboard.....
Starting with the obvious and easy end, I mocked up the forward bridge structure, first just taped together, but then hot glued for a bit more strength.

unbuiltnautilus · « **Reply #23 on:** February 26, 2018, 08:39:46 pm »

The main reason for all this 'CAD' is to get the interior structure worked out in my head. For some reason I have had a total mental block on this one. Usually I can 'see' what the interior structure etc, needs to be before building...not this time though. Therefore, the cardboard is a good substitute for thinking about stuff!
The aft cowl and doorways into the structure were next. One plus of doing this, is being able to argue that the bulkhead position usually modelled in this type of model, is too far aft. The whole reason for all these curved bits on the Vosper FPBs, was to allow the vast amounts of air needed by three gas turbines, to be safely sucked into the engines, without sucking in half of the English Channel at the same time ( also somewhere to scoff a sly sandwich, sheltered from the elements apparently! ). If the bulkhead was modelled where it normally was, this would severely restrict any ability to suck air. What it does do is make the structure easier to assemble. Leave it out and the whole thing gets more complicated to build...which is fun!

unbuiltnautilus · « **Reply #24 on:** February 26, 2018, 08:48:13 pm »

The weird shaped part that fits flat on the hatch will probably be the first part I build. Attaching and assembling up and forwards from that part. This has made the whole exercise worth it, as this was what I could not visualise with just coffee and doughnuts alone!
The final task was shaping and fitting the top structure, followed by standing back and comparing to old photos and video. So far I am happy, but boy is it ugly!!
Motors next

News:

Author Topic: Perkasa to Brave Swordsman, a long overdue conversion. (Read 11058 times)