Broad Ambition - The Model

[Wildfuzz]

8 hours ago, JennyMorgan said:

Re splicing, anglers use a thing called a baiting needle, ideal for splicing fine strands on models, you won't need a fid. Will the splices be tapered? I suppose you could use an ordinary darning needle but baiting needles normally have bigger eyes and are made of finer wire.

How about someone who has the vice and skills for fly tying, very similar sizes and construction methods which may be employed in splicing.......

[JennyMorgan]

11 minutes ago, Wildfuzz said:

How about someone who has the vice and skills for fly tying, very similar sizes and construction methods which may be employed in splicing.......

Suspect that a fly tyers vice would not be needed, just masking tape holding a fend-off to a suitable something. However the dexterity of a fly-tyer would be useful. Any handy fly-tyers on the forum? In my opinion the suggestion of using waxed whipping thread is a sound one.

[Polly]

I could crochet you some fairly fine chain in whipping thread?

[grendel]

how did we progress to whips and chains so quickly  

Cant trust you lot any further than we can throw a mudweight.

[grendel]

now lets be realistic, how many people are going to spot if a splice is tapered at the size they will be, maybe I will just use a blob of glue.

[Polly]

Nothing wrong with chains, they give a lot of scope!

[BroadAmbition]

Talking of realistic - a working centrifugal bilge pump is a step toooooo far imho.  As you quite rightly point out the full size version with that flared bow does fine in a swell so no reason for the mini-me's to fare any different.  Besides I can't see me using the model in any sort of chop or overly busy river come to that

Griff

[ExSurveyor]

I suppose the obvious question is would it actually sink even if it did flood.  I suspect the amount of wood versus the motors and gears means it should float,  although I survey houses not boats 

Perhaps some shaped polystyrene inserts for when the models are afloat. 

[BroadAmbition]

The weight of the battery bank will be the heaviest inboard Item, this will also be needed for the ballast so the models sit down in the water to the proper depth.  Peter may even have to add ballast.  Polystyrene inserts sounds feasible though

Griff

[grendel]

spot on Charlie, there will be some space inside for added flotation if necessary, we had the batteries in on the test float, and the model was still sitting high in the water

[grendel]

tonight we have glued the last plank shaped, and work continues on smoothing the fenders. they are then painted with acetone to slightly melt the plastic and smooth and bond the layers together - ready for painting.

 

 

[Polly]

Actually if you are letting Griff loose with this masterpiece, it's going to need to be swan proof. Just ask him what he did to my birthday present speed boat on Sutton Staithe! 

[tjg1677]

Go on Polly, do tell............please!!!

[Polly]

Noooo confession is good for the soul....ask Griff 

[grendel]

well last night I had a search for a centrifugal pump as a bilge pump, I was looking for a 3d print file to save me some time, and I found a couple, one was quite small, designed for a motor from a pc cd drive, and the other was tiny. as I hadnt got a spare cd potor handy, I first tried with the smaller one, this is only about 19mm in diameter (3/4").

So now to test it and see how much water it can pump. this run from a 3.7v camera battery.

all that is needed now is a water activated switch and some tubing  

[grendel]

Here are some close up pictures of the pump.

[grendel]

the fender by comparison is just 2" (50mm) long

[grendel]

Ok a few more tests done, we are pumping at a rate of 1.5 litres a minute

[MauriceMynah]

Earlier in the thread someone mentioned floating key fobs. It occurred to me last night that if mini BAs life ring were to be securely attached to the model on a long line, and the ring itself would easily detach from the model, should the unthinkable ever happen for whatever reason, the ring would float to the surface with the model at the other end of the line.

As I say, just a thought.  

[grendel]

Well this afternoon I am multitasking, earlier I was doing some design work, and just now I have steamed and shaped another plank.

The design work was to re-design the anchor winch I made a while back, now I have a 3D printer I can do bespoke designs and create my own solutions in a smaller footprint than the one I previously made. I have a small but powerful motor scavanged out of a computer CD drive, its the one that opens and shuts the drawer, round this and with the help of a pack of gears I already had, I designed an anchor winch, this is currently printing, so we will see if I got the gear spacings right.

[grendel]

well I have just been outside and brought in the washing - well not exactly the washing, but it was strung up across the greenhouse door, half of the fenders have now been primed and painted white.

[grendel]

3 hours ago, grendel said:

, so we will see if I got the gear spacings right.

well no I didnt, the spacings were imperial, not metric, so I was 0.4mm too tight between the worm and the takeoff, so a redesign and reprint, also the vertical supports need beefing up a bit.

[grendel]

I have now redesigned the housing, the supports are beefed up wider and thicker, plus I am printing it in a different orientation so the weakness of the laminates isnt across the arms, but now running along them, hopefully this will give me the part I want. just another couple of hours to wait for a new one to print, the good thing is that this is only just over £1 to produce, the new part is more solid too, but still less than £1.50.

[grendel]

meanwhile one blue end has been added to the fenders, now hung up to drip and dry, they were just dipped into the paint pot then hung up.

[JennyMorgan]

On two models that's four and a half fenders per side!