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[Phil22]

Overall results

[Phil22]

The epoxy approach when putting together the railing sections has proved much easier for us than using solder.

For our build we wanted something a little unique, we extended the rear cabin a touch to create a (theoretical) platform to access to the funnel mounted ladder.

[Phil22]

A couple more of the brass details




Radar and guard

[Phil22]

Hey MBM,

For those interested. A colour version of the Banckert 516 build instructions can be downloaded here:

https://www.billingboatsusa.com/experienced/42-516-banckert.html

Size: 874 kb

[Phil22]

Steady work on the handrails has continued over this past week. They’re almost done bar buttoning up a few small areas.  Daunting at first, but with thought and some trial and error we are happy with the results for a first effort.  We’ve picked up a few new skills and tips along the way ; )


Port and starboard handrails from the deck to the bridge








A cutting mat provides a great visual aid when putting bends in the required spots





The ladder is supported by a small piece of ply under the top step - helpful during mockup as for each rail there is only one point of contact at the stanchion





As not to have open joints on the stanchions these extra details were fitted





The full set of brass parts





The instructions have the rails of this section (left side) going into the rear cabin wall. For ease of fitting and for something different we made them this way (right side - pre-trimmed 'P' shaped part)





--










The intention so far was to go with a brushless motor (like this: https://hobbyking.com/en_us/turnigy-aerodrive-dst-700-brushless-outrunner-motor-700kv.html?___store=en_us) but I’ve since read that brushless struggle a bit a low revs. Would a brushed motor be more suited for this build?


Thanks for reading and any information shared.

[Subculture]

I’ve since read that brushless struggle a bit a low revs. Not wishing to build a speed-tug, would a brushed motor be more suited for this build?

They're referring to cogging at very low rpm, which applies to sensorless set-ups. This is pretty much eliminated on modern brushless esc's.

On a boat this makes little to no difference, as the prop is essentially a fluid clutch e.g. it slips. Cogging can cause issues on model cars that like to run slow e.g. rock crawlers, where lots of torque is required and lots of sensitivity at low throttle settings.

In short I wouldn't let it concern you.

[Phil22]

Hey Subculture

Thank you as always for the helpful clarification and insight. We'll be getting to grips with the electronic components in the near future as the structure nears completion.

[Mark T]

There's some really nice work that the two of you have carried out there.  Its looking very nice indeed 

[Subculture]

Whilst on the subject of epoxy, I find a coat of epoxy resin on wooden parts, mixed with a little bit of talcum powder, seals and strengthens everything beautifully before priming. Once the epoxy is lightly cut back (the talcum powder is optional but helps the sanding), it seals and smooths the grain giving a smooth surface more like the plastic parts

[JimG]

Instead of talcum powder I use Microballoons, costs more but I find it sands better and gives a really good finish. (won't smell as good when sanding though)
Jim

[Subculture]

I once used some microballoons as a substitute for fumed silica when thickening some epoxy to use as a gelcoat- that was an experiment, but a big mistake. When I was post finishing the mould I ended up with lots of tiny pock marks, which I believe were the microballoons so I only tend to use them for areas which won't be sanded back.

[JimG]

Sounds like you were using a lot more microballoons than I would use to seal and fill the surface of wood. Some of the earlier microballoons (especially the brown phenolic type) were larger than those available today (the white type seem to be very small) so could have lead to a pock marked surface. When I have used them to produce a sanding sealer only a small quantity was needed as they are there to fill the grain of the wood not to give a thick layer. When sanded I have not seen any pock marks on the surface, with the surface  ending up as smooth as styrene sheet.
Jim

[SailorGreg]

I once used some microballoons as a substitute for fumed silica when thickening some epoxy to use as a gelcoat- that was an experiment, but a big mistake. When I was post finishing the mould I ended up with lots of tiny pock marks, which I believe were the microballoons so I only tend to use them for areas which won't be sanded back.

If you could see the pock marks with the naked eye then it was probably air bubbles in the mixture.  Microballoons are, as the name implies, very small indeed and you cannot distinguish them in the epoxy matrix.  However they do stiffen the mixture, which makes it a lot harder to get air bubbles out, so you need to be quite gentle mixing them in.  But they do make sanding so much easier, and with care and good luck you can get a baby's bum finish as witnessed by Jim.

[Phil22]

Any excess epoxy on the handrails easily came off with a scrape from a craft knife, while leaving the joint intact. There are 5 or 6 more details to go on for the rigging then its on to hull strengthening and prep for the electronics.

Thanks to all for your input on working with wood surfaces. Good info to know

[Subculture]

Wasn’t air. The little marks showed once I compounded the tools. Only the part of the tool which had the micro balloons showed the marks. On something that is going to be painted it’s no big deal, but this was a tool to mould from. It was still usable, but I made a mental note not to use microballoons for that purpose.

[Phil22]

Well, we thought the brass bits were all wrapped up. Not quite, but it’s okay as they’ve turned out to be real fun to make.

The last parts (watch this space….) are for the mast rigging. Puzzling on how best to attach the lines, a few ideas were tried out including creating various hooks and looping the wire back on itself. None of which looked particularly neat. Finally we settled on chopping up unused stanchions and soldering the trimmed hole sections to the ends.







To stop the nano-bits from moving about while soldering they where each threaded onto some spare wire then taped down like so.




They should hold well.







Lastly got an initial undercoat on and some surface leveling.

[Phil22]

After 3 months away from the build and out of winter hibernation, the Banckert has officially been pulled back out from under the bed. Game on!

First off, I put together a list of everything that still needs doing (that I’m aware of). This I’m sure, will fall into some kind of clearer order as the work continues. Secondly, I took stock of the remaining unassembled and unused parts. It is starting to look more like the box - on the outside ; P

 

[Phil22]

Been working on the wooden deck rails and moorings this week. Some tapering of the bollards is required to allow for vertical fitment against the hull.









For the curved pieces, we tried lightly scoring the underside of the rails then applied a coat of wood glue.



This seemed to work ok but the scores are kinda visible and not sure on their durability. Previously other members have mentioned heating or soaking. What are some recommended processes to setup for each approach?



Thanks in advance.

[SailorGreg]

The scores can probably be filled with a small amount of wood filler and if your glue is good then the curved bits should be as durable as the rest of the rail.

However, if you want to try something else, you can steam small pieces like this in a microwave.  Wrap the piece in a few layers of kitchen towel then soak in water. Pop it into an unsealed plastic bag and put it in the microwave for 2 minutes. Take it out (it will be HOT - wear gloves) and push into place and clamp it there until dry/cool.  The grain will have been raised a bit but some gentle sanding will get rid of that.

Another alternative is to laminate several layers of veneer.  Make up a blank with the same profile as the rail and cut as many strips of veneer as it takes to build up the right thickness.  Lay them in place with glue, clamp down and leave to dry.

I still think this is an outstanding first build.

Greg

[Phil22]

Hey Greg,

Thanks very much for the reply and information. Will give the microwave approach a few tries and see what type of results can be had. I guess there might not be another build for some time after this one, so we're enjoying taking our time with it.

[Phil22]

Hi All,

We'd really appreciate the help of the forum members with guidance on the stuffing tube and prop setup. Looking around we've not yet found many answers as we are still in fact unsure of the questions. We understand that all builds are unique and have their own requirements. I think what we are needing is a crash/sink course (hopefully not lol) in what is what.

The Banckert kit contains:

- Brass stuffing tube 98mm x 6mm (5mm inside diameter) x 1
- Brass prop shaft 135mm x 3.5mm diameter (3mm thread diameter - 10mm of thread) x 1
- Brass nut x 1
- Plastic prop x 1 (not intending to use)
(Think the second small brass nut shown is a detail part)










:: Stuffing Tube - Propeller Shaft ::

We want to put in a 40mm brass prop (4 blade), the one we've seen online here in Tokyo has a 4mm (M4) thread.

- Is the kit's stuffing tube 98mm x 6mm (5mm inside dim) suitable to take a prop shaft connected to a 4mm prop?
- Is there a minimum gap or internal clearance needed within the stuffing tube and the prop shaft?
- Should the stuffing tube be any longer?

:: O-rings :: Warning REAL NEWBIE Q's here

- (Hesitate to ask this one) Are they required on both ends of the prop shaft?
          Does the nut next to the prop work with the grease to stop water ingress?
- Where are o-rings placed and how are they kept in place?

:: Play ::

I've read various things about play in the prop shaft. Some articles say a bit is needed, others warn of it as the prop hull or both may be damaged especially when reversing.

The hull is still intact, we'll keep it this way until we are certain we know how to proceed on with this area.




Unsure of the name of this part below. It has a 6mm internal diameter






The skeg (right terminology??) is around 5mm wide at the point where the stuffing tube should exit.




There's a lot in this post and probably the most crucial thing to get right. Your experience on how to tackle this part of the build would be sincerely welcome.

Thank you for any info or advice shared.

[SailorGreg]

The first thing to discuss is that there don't appear to be any bearings in the end of the stuffing tube.  Your shaft is clearly smaller than the internal diameter of the tube, so you need a bearing at each end of the tube.  If you haven't already done so, can you search through your fittings and see if there are two brass/bronze collars that look like they would be a tight push fit in each end of the tube and are a snug fit around the shaft?  If you try and fit things as they stand you will end up with a very noisy, leaky arrangement (o-rings notwithstanding).  If you cannot find any bearings, I suggest you buy a ready made tube with bearings included (which will almost certainly include a new shaft, but that's better than no bearings at all).  There are plenty available on the internet, such as these.

On the subject of o-rings - no, you don't need them.  Assuming you get some bearings of the right size in each end of the tube, a little bit of waterproof grease will see you home and dry (!).  You could usefully put a brass washer between the locking nut and the end of the tube, and similarly on the inboard end for when you run in reverse.

Play in the propshaft - you need a tiny bit of play, enough that when you push and pull you can feel there is a little movement, but not so much that you can actually see it move.  You are looking for as tight a fit as you can without there being any binding as the shaft rotates.

And this hardware should be fine with a 40mm prop.  If you get the bearings in place.

Hope that all helps.

Greg

[tica]

HI
There should be 2 brass/bronze collars looking like that one in this photo (Taken from my fittings bag for Banckert) the shall be pressed into the tube.
R
Carsten

[Phil22]

.

[Phil22]

Our huge thanks to @SailorGreg and @tica

The info which you both shared has helped in our understanding enormously!!!! You've also raised our confidence with this aspect of the build.

As you mentioned Greg and as Carsten pointed out in the photo, those 2 bearings are present in the kit for the stuffing tube. We had no idea as there are many little brass details not listed in the manual. All good now ; )

For the prop-shaft requiring a tiny bit of play. I image this could be something we can hear more than see when assembling the components. A kind of small "knock" maybe?

Now that we understand more about what is what, we are thinking to go with a smaller size (M3) prop and use the kit's parts unless we can find a brass 4 blade (38~40mm) on a 3mm thread.


Thank you again you've really helped a lot.