Prototype build of ELLIE

[Bob Abell 2Participant @bobabell2]

Sorry for not commenting sooner, chaps, we've been out all day, braving the ferocious storms in Wales

I'm a bit surprised at the exotic stuff being recommended

Will wait a few days, pending further "easy to get" suggestions

Bob

[Peter FitnessParticipant @peterfitness34857]

Bob, as I said in my earlier post, I use an outboard motor grease which is waterproof. It's available at any marine supply shop here, and I would guess that the same would apply elsewhere. I like the sliding bush idea, that's called thinking outside the box

Dave, I have not found any noticeable restriction on the motors using this grease, and my motors are the common garden variety 540 type can motors, with the odd 600 or 700 thrown in, depending on the size of the boat. I use a 6v power supply from SLA batteries, of varying capacities depending on how much ballast I need. As you said, everyone has a different solution, and the funny thing is that they will all work, it boils down to personal preference. My main concern with oil is that it could leak past the outer bearing into the water, potentially causing pollution, especially in enclosed waters where most of us sail. It does create pretty colours on the water in sunlight, though

Peter.

Edited By Peter Fitness on 02/11/2013 21:08:17

[Dave MilbournParticipant @davemilbourn48782]

Peter
"Oyl" is just a part of the name. I've never seen any snail trails of pretty colours from the back end of my models.
If you say that outboard motor grease is OK with smaller electric motors like ours then I won't argue the point – you've used the stuff, after all.
Dave M

[Paul TParticipant @pault84577]

Dave

I have to admit that viscosity can be a problem if the tube is fully packed with grease and that under this condition something like a 5cc engine would have to work hard to turn the cold shaft.

The secret is to only apply the grease to the moving parts of the shaft that actually come into contact with the tube, for example on a 20in propshaft I would coat the bearings and the adjoining 15mm of shaft with grease and the rest of the shaft and inner face of the tube would merely be wiped with grease to prevent rusting.

The shaft rotating in the tube doesn't produce sufficient frictional heat to melt the grease so it stays where you placed it and the small amount of grease in the tube produces the same level of viscose drag as a tube filled with oil.

I should add the caveat that these findings come from experiments and experience gained with shafts at a maximum pitch of 8 degrees and as such I cant account on the effects that gravity will play on propshafts with working angles greater than 10 degrees.

Paul

[Dave MilbournParticipant @davemilbourn48782]

Paul
You'd better send me a dollop, then! I may not have 20 years left………..
Dave M

[Bob Abell 2Participant @bobabell2]

Retro fitted a lube pipe to the propshaft…..A bit late in the day!

Used a brass sleeve with the lube pipe soldered to it and slid it over the propshaft

Having drilled a hole in the proptube first of course

 

The lube tube allows for easy lubrication at the pond side

 

Bob

Edited By Bob Abell on 03/11/2013 13:53:14

[Dave MilbournParticipant @davemilbourn48782]

[Bob Abell 2Participant @bobabell2]

It's a gadget for joining wires together

Often used for recycling old plugs and sockets?

I take it, it doesn't meet with your approval?

Please explain the dramatics!

Bob

[Dave_PParticipant @dave_p]

Eeeeeeeeeeeek!!

[Dave MilbournParticipant @davemilbourn48782]

They are designed for clamping single copper (solid) wires. Terminals for stranded cable have proper clamps built in which avoid the screw from tightening against the thin strands and severing them. The screws also can push aside many of the strands when tightened down hard and result in very small contact area which increases resistance > heats up the conductor > melts the plastic and sets fire to your boat.

I've seen this happen.

Dramatic, as you say.

Avoid.

DM

[ashley needhamParticipant @ashleyneedham69188]

There is a little Blue thing just to the right of THAT THING. What is this?? I hope its not one of those clamp-on fuse thingies.

Perhaps Bob has soldered all the little strands together before inserting them in THAT THING thus emulating the intended use. Perhaps Bob SHOULD solder all the little strands together??

I confess to using THESE THINGS on and off, but not for anything carrying much current.

Ashley

[Bob Abell 2Participant @bobabell2]

I can understand the dramatics for household wiring, but for a model boat running on 12v……..

Gerraway with yer!

Don't forget……….the ends have been tinned!

Bob

[Dave MilbournParticipant @davemilbourn48782]

Better than nothing, but which bit of "I've seen this happen" was unclear? I can't recall what voltage the system in question was using but I'd have remembered if it was at all unusual.
Yeah – so I'm a smart-alec know-it-all kinda geezer, but I try to eliminate all possible risks in my models when it comes to electrickery. They take a lot longer to build than they do to burn or sink.
Suit yourselves.
DM

[Tony HadleyParticipant @tonyhadley]

Don't you find that when the ends are tinned, a weak point in the cable occurs between where the tinning finishes and the strands start? This weak point is liable to break if subject to flexing, much better to use the red or blue crimp-on ends.

Tony

[Tony HadleyParticipant @tonyhadley]

Whilst working away on one of my models a thought occured – would it be possible to use through-crimps in this situation? In the unlikely event the joint needs to be moved, they are cheap to replace.

Tony

[Peter FitnessParticipant @peterfitness34857]

Dave, I'm fairly sure that the reason you don't get "snail trails" from using oil is that the bearings in your boats are properly made, unlike some I've seen.

Paul mentioned the viscosity of grease – as it doesn't really get cold where I live it hasn't been a problem for me. After all, if the temperature drops below 15C we think it's cold, on the other hand, 30C is a nice warm day

While the discussion is still on shaft lubrication, I have heard it said the the water alone is sufficient lubrication for most model applications. Does anybody have thoughts about that? Obviously it would only affect the outboard bearing.

Peter.

[Dave MilbournParticipant @davemilbourn48782]

Peter

Over here I've found that there are two quite different types of material used for shaft bearings. One is a sintered bronze type which will take up oil as a lubricant, while the other is a plastic which is said to use water as the lubricant. I try to use the second type wherever possible but the running gear on Sea Spray has the other type.
The other issue – quite separate in my view – is what to fill what our American buddies call the "stuffing tube" with to prevent ingress of water. I'm on record as using Waxoyl. On small models like Sea Nymph I haven't bothered with anything at all and had no problem.
Liz would agree with you about 15C being cold! I guess that's just one of the many drawbacks you have living in a place like Tazzie…………… ;o)

Oh yes – almost forgot those connections. If a cable isn't long enough then I replace it with one that is. No need to get complicated about things, is there?

Dave M

[Peter FitnessParticipant @peterfitness34857]

Dave, I actually live near Lismore, in the far north eastern corner of NSW, over 2000km north of Hobart, Tasmania. Our climate is classified as Sub-Tropical and, while we can get frosts in the low lying areas, they are almost unheard of where our house is.

As I mentioned in an earlier post, I make my own prop shaft assemblies, and turn the bearings up out of bronze round bar. The grease in the tube stops any water ingress. I agree about cable length, the fewer connectors the less likelihood of problems. Speaking of connectors, I have standardised on Deans, all wired the same so motors and ESCs are interchangeable throughout my models. That doesn't mean I can put a motor where an ESC should be, I use male plugs on the motors, and female on the ESCs and batteries.

Peter.

[Paul TParticipant @pault84577]

Is it safe to come out of the bunker yet?

I have been waiting for the peacekeepers to be deployed especially as the question of Bobs connector has been raised in the UN. David Cameron has called a meeting of Cobra and is on the verge of declaring martial law in Nottingham whilst sending warships to patrol Etherow lake.

Meanwhile I have been busy with the brush and shovel as the path is knee deep in toys and dummies.

Paul

[Bob Abell 2Participant @bobabell2]

A very amusing reply, Paul…….That's what was needed!……..Oil on troubled waters!……..Lol

It's that Milbourn's fault!……..Using too many exclamation marks!

And my fault for showing my ignorance of wire connectors

As a matter of fact, his scathing attack has highlighted possible danger in the home, which I will certainly bear in mind on future home wiring lash ups!

So many thanks go to Dave M!

Bob…….With more egg on his fizzogg!

[Dave MilbournParticipant @davemilbourn48782]

Bob
You are easier to wind up than one of my grandson's toy cars – and far more fun to watch! No offense intended whatsoever, m'duck (it's only a toy boat after all)..

Peter
Sorry, mate. We had so many customers over there that I confuse one for another from time to time. It's impossible for any two places on mainland UK to be 2000km apart, so the scale of the place is often underestimated. BTW I have done exactly the same as you i.e. standardised on Deans connectors.

Tony
Agree about the weak spot in tinned cable but it’s only significant IMHO where the wire is subjected to constant moving and is less than about ten strands.You'd have a helluva job snapping 14AWG! I too favour crimped ferrules for terminating cables like this (as I pointed out in my article).

Paul
You are one bad dude, Doc.

Sea Spray glazing is now fitted into frames and frames painted, Will post some piccies once they’ve been glued into position on the model.

DM

[Aestus57Participant @aestus5782081]

Off Topic….

Dave,

You're quite correct….the traditional distance from Lands End to John O'Groats by road is 874 miles (1,407 km) and takes most cyclists ten to fourteen days; the record for running the route is nine days. Off-road walkers typically walk 1,200 miles (1,900 km)

On Topic….

Its amazing how much I'm learning from following this build, I've used those connectors for years without thinking about the problems they can cause and I consider myself a fairly experienced modeller. I will certainly bear your comments in mind in the future. Thanks to you and everyone contributing to this build.

Peter (15 miles from John O'Groats)

[Tony HadleyParticipant @tonyhadley]

Posted by Dave Milbourn on 03/11/2013 23:11:50

Over here I've found that there are two quite different types of material used for shaft bearings. One is a sintered bronze type which will take up oil as a lubricant

Dave,

Does this sintered bronze go under the name of Oilite? which was used in car dynamos before the change to alternators. A few drops of lubricating oil are applied (which are absorbed by the bearing) on a regular basis. I have also seen it used on model woodworking lathes with an internal spiral lubrication groove (obviously not extending to the end of the bearing). Can't understand why the shaft manufacturers don't favour its use.

Tony

[Dave MilbournParticipant @davemilbourn48782]

Tony
That's my understanding, although the manufacturers don't use that term these days. Model Boat Bits – who supplied the shafts for Sea Spray – just call them 'hard-wearing bronze'. Interestingly they also supply 'propshaft grease' for filling the stuffing tube. Link here **LINK**
Dave M

[Bob Abell 2Participant @bobabell2]

Well that`s the wiring done, chaps

Now back in the paint shop to finish off the décor and a few more coats of varnish

Not much to do now, the windows need finishing off and the glazing……Then the Maiden voyage, just in time for the cold weather!

Bob

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