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[oldiron]

  Not trying to flog a well rode horse, but I've got one of the ubiquitos Smit Nederlands on the go. I though I'd share a little different construction technique for this popular vessel as opposed to that described in Billings instructions..
  I'm building this tug for towing competition and as a result wanted the deck to be solid and sealed to prevent water ingress to the hull. Billings designs the boat to have the majority of the deck lift off. This leaves a problem of sealing the vast seam against water. To get around this I made the only opening underneath the deckhouse with all access to and from the hull through there. In so doing I also relocated the battery and motors to provide ease of access. This shifted the design weighting of the vessel to be more central to the hull displacement, so the vessel doesn't take the head down apporoach in the water requiring a great amount of weight in the stern.
  The vessel is still under construction but I'll follow up as I go.

oldiron

[Martin (Admin)]

Interesting looking motors!

[oldiron]

Interesting looking motors!

  The motors are old Dumas motors I picked up from an estate sale. They had an extra sheet metal covering over them. Not sure what it did, but I removed it and the extra space was just enough to allow the battery to slide out between the motors uninterrupted.

oldiron

[Martin (Admin)]

Sometimes DC motors had an extra sleeve to enhance the magnetic field and act as a bit of a heat sink.....

[banjo]

 :)

I shall watch to see how you balance that fore and aft with the motors and batteries as illustrated.   I am working on my Nederland rebuild but took a slightly different approach to the waterproofing issue.

Regards,

banjo

[banjo]

Sometimes DC motors had an extra sleeve to enhance the magnetic field and act as a bit of a heat sink.....

I think they are called "Stator" rings, usually an intergrated part of the motor performance design.....

[oldiron]

Sometimes DC motors had an extra sleeve to enhance the magnetic field and act as a bit of a heat sink.....

I think they are called "Stator" rings, usually an intergrated part of the motor performance design.....

  I was wondering if they had anything to do with reinforcing the magnet field of the stator. Sounds like that may be the case based on what you're saying. I can slip them back on again if needs be.
  The battery is pretty well right in the center of the vessel. When i lift it up it feels well balanced for and aft. I'll be putting it the bathtub shortly to check out the water line and level. I post how i make out.

oldiron
 

[oldiron]

:)

I shall watch to see how you balance that fore and aft with the motors and batteries as illustrated.   I am working on my Nederland rebuild but took a slightly different approach to the waterproofing issue.

Regards,

banjo

  Just tried the Nederland in the water with the batteries and motors as shown in the pics. She is light in the bow, however, there is lots of room fwd. for weight, plus the pilot house and radio gear haven't been added yet. The radio gear is going in the bow. With those additions I expect her to come level then add weight for final depth to waterline.

oldiron

[Shipmate60]

oldiron,
The sheet metal coverings on the motors are called "Flux or Torque" Rings.
The theory is it reduces the "stray" magnetic field and keeps it within the armature windings and increasing the torque of the motor.
As I said that is the theory, in a model I have not found much difference with or without.

Bob

[oldiron]

oldiron,
The sheet metal coverings on the motors are called "Flux or Torque" Rings.
The theory is it reduces the "stray" magnetic field and keeps it within the armature windings and increasing the torque of the motor.
As I said that is the theory, in a model I have not found much difference with or without.

Bob

  bob:

 Thanks for the information. It makes sense......in theory. However, as you say, on a model motor I expect the noticed difference would be fractional at best. Almost seems like an after thought in the construction of the motor as if they were trying to correct a perceived deficency in motor design.

oldiron

[banjo]

 

I also had an issue with the rudder servo and access to the linkage.  How are you solving that?

[bigford]

harbor models sells a cable and pully set up that would work great for this set up

[oldiron]

harbor models sells a cable and pully set up that would work great for this set up

 Great idea, thanks for the tip. I was thinking along the line of a brass tube under the deck, with a steel rod through it, clevises at each end (one for servo an one for rudder). I'm going to look closer at the cable idea too.

oldiron

[bigford]

here's the pic and info from harbor

 
The Steering Solution is an effective means to control steering through the application of a unique cable and pulley system attached to the rudder posts. A servo, not supplied with steering solution, powers the cable. For large props of 3" or larger, the use of a high torque is suggested for overcoming strong prop wash. The rudders can be smoothly turned 90 degrees without the steering mechanism locking up as can occur with piano wire and bell cranks. Snapping the rudders a full 90 degrees on a kort nozzle set will allow the boat to walk sideways for tight maneuvering.

[banjo]

 :)
The query I had about rudders was that the deck appears to be secured but on the bath test I couldn't see the rudders installed.......

[oldiron]

:)
The query I had about rudders was that the deck appears to be secured but on the bath test I couldn't see the rudders installed.......

  For the test I had installed the hull fittings for the rudders, but left the rudders off. The deck wasn't permanenly fastened down at that point.

oldiron

[banjo]

 :)
Just for a moment..........
There was a guy on RC Model Boats Forum who made a beautiful barrel back 1930s model, and everyone was watching his progress, double skinned mahogany, etc etc...... he had forgotten the rudders.....
Will you be going with the "Becker" rudder system?

I wish you every success with this build and hope you will continue to post your progress....

[oldiron]

:)
Just for a moment..........
There was a guy on RC Model Boats Forum who made a beautiful barrel back 1930s model, and everyone was watching his progress, double skinned mahogany, etc etc...... he had forgotten the rudders.....
Will you be going with the "Becker" rudder system?

I wish you every success with this build and hope you will continue to post your progress....

Banjo:

  Thanks very much.
Yes I'm using the Becker system. I got the Billings fittings kit when I purchased the hull and the rudders came with it. However, the Kort nozzles didn't come with it, so I'm going to have to scratch build them. Been thinking about the best way to do it. My first thought was plastic water/drain pipe, however I don't think it has a thick enough wall to allow me to turn down the taper. My other thought is to roll it in copper or brass, at least them I can get the correct angle on them.
  Took a look at a barrel back on that group.....beautiful work. Would that ever be annoying (and embarrasing) to forget the rudders.  Every summer, for one day in July, we have an antique and classic boat show in Gravenhurst with a large number of full size mahogany runabouts, such as that, on display and running. Makes for an eye popping day.

oldiron

[Martin (Admin)]

here's the pic and info from harbor

 

That looks a huge servo load!

[banjo]

 :)
This could well be your lucky day!

I have a pair of Korts for a Nederland going spare....

Now the hard sell...

You can have them for what they cost me....

[banjo]

here's the pic and info from harbor

 

That looks a huge servo load!

And totally un necessary with "Becker" rudders"

[oldiron]

:)
This could well be your lucky day!

I have a pair of Korts for a Nederland going spare....

Now the hard sell...

You can have them for what they cost me....

Thanks very much. Most appreciated. I'll contact you off line to arrange payment and postage etc.

oldiron

[banjo]

 :)

As I said your lucky day....

They didn't cost me anything!!

You pay postage thats all.....

 

[OMK]

Way to go, Banjo. What a neat gesture.

Like you, I'm absolutely smitten with this build. Mr. Oldiron is obviously a man with an eye for quality workmanship.

[banjo]

 :)
PMK

I was a bit miffed at first when I saw this thread.  I thought I had bragging rights on re-decking Nederlands,,but being a few cannon balls short of a broadside myself, and seeing the Gent short of Korts, I came to my senses and in the Mayhem spirit made the magnificent offer you remarked upon!!!!

Besides....he is from Canada....