Strongbow type tug

[Paddlemex]

....you will also sleep better knowing

- even when only the craftsman notes the failure...

Right guys. I would have always seen the lack of concentricity and kick myself for not having fixed it on time.

[Paddlemex]

Got some work done last (long!) weekend.
Made the second paddlebox and started the superstructure.
A picture of my superstructure "kit". I went together quite well, but I had not considered the slight camber of the roof. Since I glued the side walls perfectly square to the roof the walls now tilt slightly inwards. I guess I can correct that with a frame. Should be easy … I hope.
Begins to look like a paddle tug.
Also was able to find the 4mm brass and assembled the second wheel. Actually I had to buy 5/32" brass, but the 4mm-5/32" dimension is about the only measure where metric/inch dimensions are identical within 3/100 mm so i won't matter.
I made a picture of the completed wheel and the wheel kit for No. 2.

Jurgen

[Hankwilliams]

Excellent - go on Jurgen!

[Paddlemex]

Thanks Thomas.

I am now working on the shaft bearing/seal solution. Still have no final design for that.
I have seen that many of you use bronze or brass bearings with lubrication devices.
I am considering ball bearings of the sealed type, the 2RS type. What would speak against this?
I think if the seals keep the grease in, they will keep the water out. Are there indications against this?

Jurgen

[derekwarner_decoy]

Jurgen...

Inexpensive bearing housings in aluminium with a 12.5 bore body bore

They are available with a stainless steel ZZ [stainless double shielded, all stainless steel {400 Series}  ball bearings ] to suit common bore sizes.....4mm    6.35mm as shown here

If a pair are mounted just by the hull, they will provide accurate alignment [low rotational friction load] & support for the paddle shaft

The Beaings are lisited low cost, and as ZZ [2RS], so are are not water resistant, but splash proof  only

Pretty sure they are originally from SPD/SI in America....about AUD$20.00 each complete


The relatively low speed of the application and the duty cycle involved also favors bronze bush & compact  [o-ring] sealing for the paddle shaft

Derek

[Paddlemex]

Those are nice housings, Derek. But they would be kind of over-engineerd for my ship. I thought of a flat plywood housing attached to the hull. Or maybe made of aluminum.
However I didn't consider the water proof against splash proof difference. Is the splash(??) inside the wheel housing more than industry splash level?
Maybe I shall go back to the bonce bearing solution. I have some 5/8" bonce bar in stock.

Jurgen

[Paddlemex]

No bearings yet, but the rudder is installed.

Does it only happen to me? You have a whole day to work on your model. You make a (wish-) to-do list and if you actually get 30% of the list done it's been a good day.

The rudder design is not to the drawing. I took the look from a series of pictures of the John H Amos in Flickr https://www.flickr.com/photos/jf01350/sets/72157617231943410 Scroll down.

To be able to have it removable I installed a piece of 7mm brass tube in the hull which allows the 3mm rudder shaft to enter tilted and then align with the hinge pins. The space between the the shaft and the tube is then filled with removable bushing inserted from above.
The pictures tell the story.

First I drilled the bushing only to 1.6mm and used a 1.6mm piano wire to align the hinge bases. Hinges glued with epoxi.
Then the hinge pins are glued with superglue and the bushing bore is enlarged to 3mm.
The rudder blade is silver soldered to the shaft and the hinge strips are soft soldered to the blade.

Jurgen

[derekwarner_decoy]

Those rudder pintals look very strong & the supports against the rudder blade prototypical Jurgen

I am not a fan of epoxy/superglue on such small size/diameter components, however fully understand the forces will be in shear against the 1.6 diameter wire pin joints.......

My preference would have been all brass construction with 1/16" diameter brass hard drawn wire and brass pintal support brackets and all soft soldered

The captive method/design for rudder removal is also is also quite unique 

Derek

[Hankwilliams]

Really admirable kind of building and precision! May be, you will get a model of really museum quality, Jurgen!

[Paddlemex]

Thanks to my crowd of followers of 2.

Derek, maybe the pictures suggest that the supports are flat glued to the hull. Not so. The visible brass part is a 6mm square brass rod which has been machined to 3mm dia. 12mm long. All that now invisible 3mm part is glued into the stern. The 3mm drill is still in the Dremel in the second picture. Unfortunately I have no picture of the parts.

Then I needed the support without the pin so I could align with the 1.6mm piano wire. I agree solder would be better, but I didn't want to solder on the glued part, it would have softened the epoxi and ruined the alignment.
An option would have been to cut a thread on the 3mm diameter and screw the supports into the stern, but - no - the epoxi is fine.

Thomas, I know myself and the final finish is not my strength. Museum quality is too high, let's aim for a good stand-off (1.5 m distance) model.

I still want to imitate 3 or 4 rivets on each hinge strip. My thoughts go from a simple dot of glue to drilling and actually riveting. Come time come rivet.

Jurgen

[DamienG]

 

[Paddlemex]

Thanks Damian.

I correct myself: Crowd of followers of 3. 

[derekwarner_decoy]

Jurgen......could I suggest that many more of our PD members  view your postings than just the 3 you suggest

We also see that this your #build thread has been opened & viewed 2242 times so......  

I have caught a snapshop #70  here of your thread today, and also a snapshot of members visiting our site today

So if you see no one has looked at your #build thread for say any one week....then take up a cooking thread

Derek

[Paddlemex]

I'm sorry Derek, the cooking thing is not gonna happen. I have an agreement with my wife: I don't mess up the kitchen and she doesn't build models.
Seeing the views now.

[Hankwilliams]

Really a very good agreement...