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[marmoi]

Some more pics of the props and bow thruster

[marmoi]

This is the completed rudder assembly, minus the arm. The bottom support has a Bronze bush in it. The rudder tube is Brass and will be bonded into place.

[marmoi]

Work has now started on the remainder of the engine room. I propose to build an Aluminium frame for the motors that will support the prop shaft bearings as well. Adjustments will be made with shims under the motor support and bearing blocks.

Engineers have started dismantling the test bed in preparation for the move.

[marmoi]

Oh, and if you are wondering, work has been gong on with the conning tower and the detailed drawing is nearly complete. Sorry about the resolution, it's a bit difficult to squash an A0 drawing down to fit on here!

Something to build during the winter! 

[dreadnought72]

 

Marmoi, the motors look identical to the big Buhlers I have for my Dreadnought. In yuor model it seems like they're all going to be mounted the same way around. Do you thinnk that two of them running in reverse is ok? I'm not 100% sure about this, and was thinking of turning a pair of mine around.

Just curious.

Andy

[marmoi]

Hi Andy,

I have been running them on the test bed for some time now and have had no problems. I also use the in my Dreadnought and have had no ill affects running them in this format.

Mark

[marmoi]

If all goes to plan I hope to have the hull on display at the Birchwood and Leamington shows this year. 

[dreadnought72]

Hi Andy,

I have been running them on the test bed for some time now and have had no problems. I also use the in my Dreadnought and have had no ill affects running them in this format.

Mark

Thanks Mark, brilliant answer. I ran a pair of mine for several hours in forward and reverse to measure the voltage/current over time, and this suggested there was no real bias, other than slow "beats" at full revs (unloaded) pointing to a very slight - handful of % - difference in revs.

Ok. That makes installation easier!

Andy

[marmoi]

I have done a few multi motor models over the years and have never found any noticeable effect from running the motors in two different directions. The Buhlers are such a nice multi pole motor and they run so smoothly I have been very pleased with the fine control that I have achieved so far.

Mark

[marmoi]

Had a few more spare moments at the weekend so got on and machined the motor mounts. Very happy with the result, both just slipped onto the ends of the shafts without any adjustments.

[marmoi]

Work has now started on the supports.

[marmoi]

Managed to get the rest of the support frame built and assembled into the hull, only minor change was to reverse the aft feet as the rake of the hull was too much to get them in.

[Prophet]

Impressive build i must say, those brass props look the dogs kahunas! i have a question on you ships construction, are you putting any supporting bulk heads in to aid in the GPR hull support? your model is extremely long i would have though that you need an internal frame work to stop the hull warping, flexing (to much)?

[marmoi]

I am just building/assembling all the components at the moment so I can arrange them in the hull, once happy I will know where all the bulk heads and braces can go and what shape they will need to be, once done I will cut and fit.

I have gone down the road of fitting bulkheads and strengthening the hull first and it always ends with me trying to make a hole or try a squeeze something in.

[marmoi]

With the bad weather during the week, I was back in the workshop and decided it was time to make another of the large components to go into the hull - The speaker box.

Now after some research a few years ago I found that to get the best results from a speaker you should mount it in a round case. Luckily Ikea sell them, although they call them wooden fruit bowls (strange these Ikea people). Having purchased the new speaker case, I marked the cutout for the speaker and mounted a cutting blade in the milling machine and sliced the top off.  To my delight the speaker dropped into the hole with a delightful plop. The case will be drilled and sprayed Black to match the speaker.

[marmoi]

Another glorious day and a chance to get the hull out and this time I thought I had better put the edging on the upper sides of the hull. This has two purposes 1. to stiffen the moulding as the weight was starting to cause deflections and 2. to add backing to the port holes for when I drill them out (How many portholes!).

Had to drain my resources to find enough clamps for this job and even then had to do one side at a time.

[marmoi]

The bow thruster is now fitted in the forward torpedo tubes as can be seen in the pictures above.

[RaaArtyGunner]

Had to drain my resources to find enough clamps for this job and even then had to do one side at a time.

Nice bit of lateral thinking, caulking guns as clamps 

[marmoi]

Sorry same principal, but defiantly one handed clamps.

[marmoi]

I would just like to say it was good to meet some of you at the Birchwood show over the weekend and the comments and advice were all welcome.

With the bit of sunny weather on Monday and with the holes on the hull now filled and sealed (well almost all), I decided to try ballasting the model to find out what was required to get the correct displacement.

After marking the waterline in a few places the hull was placed on the test tank and gently loaded until it reached the correct level. My estimation of 16-18 kilos of ballasting turned out to be pretty close, so I can now look at building some ballast boxes into the hull.

[marmoi]

Before I go any further I felt it was time to glass fibre over the plastic padding areas.

So with the shortening evenings I set to cutting the mat.

[marmoi]

Once I was happy that the patches would cover the areas correctly I mixed the resin and following the advice given on this forum added some talc to the mixture.

Those who have not read this thread, the talc is added to stop the resin from being sticky after curing and believe me it works 

Once the resin had set, I just had time to stick the rudder servo board in place. This is realised I did not take into account when trialling the ballast, so I will need to look at this area again.

[marmoi]

With the unexpected good weather last week coinciding with a weeks holiday it was straight into the garden and a massive amount of wood cutting, screwing and gluing!

I have cut all the bulkheads now and fixed them in place, ballast boxes have been built and fixed. The battery box has been built a support strips for the terminal added along the side. The two under deck formers have been cut (but not stuck down) for the fore and aft decks. I also took the chance to build a box around the bow thruster to one contain any possible leaks and two deaden any sound.

[marmoi]

When the weather turned wet it was into the workshop and work began on the bilge keels. The G3 has 4 bilge keels and I decided that they should be made of Aluminum as the boat is so heavy i.e.e they will survive a scuffing better than wood would.

I cut and drilled the four keels before machining the general profile, then it was of to the linisher for several hours of hot metal and burnt fingers! 

The keels will now need some gentle forming to fit them to the hull before screwing on.

[dreadnought72]

Once again this build is producing a mine of useful information.

Aluminium for the bilge keels = inspired choice! I've been wondering about wood ones for my Dreadnought, even cartridge paper ones filled with resin, and I've been stymied on this for ages. Like yourself, they're going to need some serious strength when (in my case) I hit something at a metre a second with a 50+kg hull, and while I'd not thought of metal, I think your decision to go down this route is excellent.

Fabulous work, Marmoi!