Skipjack Kathryn by Mahuna - FINISHED - 1:32 - Based on HAER Drawings

[druxey]

I've seen ones as small as 0.5mm at:

 

minitaps.com

[Mahuna]

Thanks for the link, Druxey.  You're right - they are quite expensive.  I'll stay with the swivel idea.

[HIPEXEC]

Amazing work! 

[Mahuna]

6 hours ago, HIPEXEC said:

Amazing work! 

Thanks Rich.

[jhearl]

When I built my buyboat model last year, I too was faced with the challenge of making turnbuckles. I took a slightly different approach. Let me mention right up front that the scale of my boat is 1:24 so this may be more difficult at your scale but perhaps it's worth consideration.

 

As seen in the pic below. I used some 1/16" brass tubing cut to short lengths. I soldered pieces of square brass solid rod to each side of the tubing. I did not attempt to tap threads in the tubing - as you've discovered, small, left-hand taps and dies are expensive or unavailable. I did thread both rods using a right-hand die. Even at my larger scale, it's pretty much impossible to tell which direction the threads run but you can tell they are threaded at least. I simply epoxied the rods into the turnbuckle bodies.

 

Cheers -

John

 

[Mahuna]

Very nice turnbuckle, John - thanks for sharing it.   I just took a look at your Buyboat - very nice! You have a real nice website as well - I plan to spend some time looking at your other models.

[mtaylor]

Frank,

What about using John's design but put a nut inside the turnbuckle and use threaded rods....????  Just thinking out loud.

[Mahuna]

Hi Mark:

 

I do have a set of jewelers taps and dies, so threading is really not an issue.  The problem is that I only have right-hand threading capability and for the turnbuckles to actually work one end needs to be left-hand thread.  This is the reason why I'm planning on using a swivel at that end.  This will allow me to tension the shrouds using the turnbuckles.  Since the shrouds will be made of wire (Kathryn's shrouds are steel wire) I'm a little concerned about adjusting the tension without using the turnbuckles.

[mtaylor]

Ah... valid point.  Hmm.... <thinking cap>  Just one end needs to be threaded, the other has to pivot.  If I can find some free time tonite, I do a quick drawing and see if it'll work.

[PETERPETER]

Something like this ?  

Edited December 6, 2017 by PETERPETER
Add clarity.

[JerryTodd]

A couple of sources for functional turnbuckles/bottle-screws

 

Model Yacht Fittings: http://www.modelyachtfittings.com/Pages/default.aspx

RBModel:  http://www.rbmodel.com/index.php?action=products&group=019

[Mahuna]

Hi Peter.  Yes, your illustration is what I plan, except that instead of a small washer there is a plug soldered on the end of the swivel to secure it inside the turnbuckle.

 

Jerry - thanks for those links.  It appears that the turnbuckles from Model Yacht Fittings are also made with a swivel instead of LH thread (the hook end).  This photo appears to be their smallest size, which would be too big on the Kathryn.

 

[PETERPETER]

I was certain you would come up with a working solution for turnbuckles.

[Mahuna]

3 hours ago, PETERPETER said:

I was certain you would come up with a working solution for turnbuckles.

Thanks Peter.  I think the approach will work.  It will be a while before I need the actual turnbuckles, so I'm working on other things now.

[Mahuna]

Part 45 – Kathryn’s Wheel

 

Again it has been a while since the last post, but Happy New Year everyone – I hope 2018 brings everyone health and happiness.  The last month has been filled with holiday activities that have slowed down the modeling on Kathryn, but there actually is some progress to report.

 

Most of the time has been spent on making Kathryn’s wheel, which turned out to be a quite complicated milling job.

 

Kathryn’s wheel, shown in the following photos, is all metal (except for the wooden hand grips).  The rim of the wheel is fairly thin, exceeding the diameter of the spokes by only a small amount.  There are bumps on the rim whenre the spokes pass through – I’ll call them ‘spoke seats’.  The spokes are held on the hub by nuts.

 

                         

 

The diameter of the wheel was measured from the HAER drawings.  The photo was imported into TurboCad, and the diameter of the wheel was used to scale the photo so that the other wheel measurements could be determined.  The following drawing shows those dimensions (blue used for actual dimensions, while red was used for the scaled dimensions for the model).

 

                        

 

A 1-inch diameter brass rod was used to mill the wheel rim and hub.  After mounting the rod in the 3-jaw chuck, the first step was to face the end of the rod and to reduce the end of the rod to the final diameter.

 

                        

 

The chuck and rod combination was transferred to the rotary table on the milling machine, and the rim and hub were milled.

 

                        

 

The next step was drilling the spoke holes.  The chuck was removed from the rotary table and the rotary table was installed on the vertical attachment.  A dial indicator was used to ensure that the rotary table was squared to the milling machine and that it was perfectly vertical.

 

                        

 

A center drill was used to start a hole at the spoke location.

 

                        

 

A carbide drill was then used to drill the spoke hole in the rim.  The spokes will be made from 1/32 brass rod, so a #66 drill was used.

 

                        

 

When the hole was drilled through the rim the drill was fed through until a corresponding hole could be drilled in the hub.

 

 

The chuck and rotary table combination was removed from the vertical attachment, and 1/32 brass rods were used to check the proper alignment of the holes.

 

                        

 

The rotary table and chuck were returned to the mill, and the 5/64 center hole for the shaft was drilled.

 

                        

 

The rim was then milled to a depth of .016 between the spoke seats.

 

                        

 

As can be seen in the first photo showing the actual wheel, the rim narrows between the spoke seats.  This narrowing was performed on the model using a 1/16 end mill held in a collet.

 

                        

 

After this last operation was completed, the milling of the wheel was finished.

 

                        

 

The milling sounds relatively simple, but it took the better part of the last month (and six wheels) to get it right.  It was a good learning experience – dealing with backlash, centering the mill over a rounded surface, improving the accuracy between steps, etc.  Along the way I needed to document the sequence of steps, and a copy of the sequence is attached for anyone interested in seeing the details of the process.

 

                        Making Kathryn's Wheel.pdf

 

After the milling was completed there was still a lot of work required on the wheel.  That’s the subject of the next post.

 

Thanks, everyone!

[druxey]

A tricky bit of machining! Looks good, Frank.

[mtaylor]

I can believe you had a steep learning curve on the wheel, Frank.  The end result makes it worth it.   Beautiful!!!!!

[cog]

A happy, and healthy New Year to you too.

And that was merely one side ... I think I would have taken the easy way out: Use a file ... lovely piece ofwork and  machine prowess

 

[thibaultron]

Great machining Frank! Quite a small and complex part.

[Mahuna]

16 hours ago, druxey said:

A tricky bit of machining! Looks good, Frank.

Thanks Druxey.

 

15 hours ago, mtaylor said:

I can believe you had a steep learning curve on the wheel, Frank.  The end result makes it worth it.   Beautiful!!!!!

Thanks Mark.  It was quite a challenge, but worth it.

 

8 hours ago, cog said:

A happy, and healthy New Year to you too.

And that was merely one side ... I think I would have taken the easy way out: Use a file ... lovely piece ofwork and  machine prowess

 

Thanks Carl.  Filing certainly is an alternative.  Even with milling there's a lot of file work ahead.

 

2 hours ago, thibaultron said:

Great machining Frank! Quite a small and complex part.

Thanks Ron.

[EdT]

Ah, lovely work on the wheel Frank....and Happy New Year.

 

Ed

[Mahuna]

Thanks Ed, and Happy New Year to you as well.  

[Mahuna]

Part 46 – Kathryn’s Wheel cont’d

 

After the milling was completed, there was still quite a bit of work left on Kathryn’s wheel.

 

With the wheel still in the chuck, the spoke seats were filed to the round shape, and the areas between the spoke seats were cleaned up.

 

                       

 

                        

 

The nuts that hold the spokes to the hub were simulated using 3/64” brass tube, since this tubing had an interior diameter of 1/32” that would accommodate the spokes.  Small pieces approximately 3/64” long were parted from the tube using a micro saw.  The burrs that resulted from sawing off the individual piece were cleaned up using a miniature reamer, and the reamer was then used to hold the piece for some light filing.

 

                        

 

The following photo shows the ‘nuts’ test fitted to the spokes in the wheel.

 

                        

 

The wheel eventually would need to be parted from the workpiece, and the back side of the wheel would need to be finished.  The chuck with the workpiece was returned to the lathe, and a light line was scribed using a pointed lathe cutting tool.  This line would be the border of the wheel rim.  The parting tool was then used to cut a deeper groove at the high point of the spoke seats for the backside of the wheel.  The forward edge of this line would be used as a sawing guide.

 

                        

 

The handles of Kathryn’s wheel are made of wood.  On the model, these handles are a maximum of 1/16” thick and are 3/16” long – too small for drilling and shaping wood.  I have some aluminum tubing that measures 1/16” OD and 1/32” ID – perfect for the handles – so I decided to use the aluminum tubing and paint it an appropriate wood color.

 

The first step was to lightly scribe a line for a 3/16” length of tube for the handle.

 

                        

 

Using a WW collet, the tube was then mounted on the lathe with the line scribed in the previous step used to designate the exposed length.  A piece of brass 1/32” rod was inserted in the aluminum tube to prevent it from collapsing.

 

                        

 

A parallel barrett file was used to shape the handle.  Because of the blank side, this file could be rested against the collet without damaging the collet.

 

                        

 

A hobby knife was used to part off the handle by using slight pressure while rotating the tube.  Again, the 1/32” brass rod prevented the tube from collapsing.

 

                        

 

The following photo shows the wheel with the spokes, nuts, and handles test-fitted.

 

                        

 

Once all components fit properly, 5-minute epoxy was used to glue the spokes and nuts in place.  Excess glue was wiped off using a small artist’s brush dipped in isopropyl.

 

The chuck and workpiece was then mounted back on the lathe to provide a secure platform for parting off the wheel.  The lathe was not turned on, it was simply moved by hand while a jewelers saw was used to part off the wheel.

 

                        

 

A piece of brass rod was inserted in the center hole of the hub to prevent the wheel from falling off once the hub was sawn through. 

 

                        

 

A small triangle file was used to scribe the boundaries for each spoke seat on the unfinished side of the wheel.

 

                        

 

The rim was then filed to the scribed line to reach the proper thickness, and the spoke seats were rounded to the final shape.

 

                        

 

The clamp shown in the prior photo is a jewelers ring clamp.  The jaws on either end are leather lined, and holding pressure is achieved by pushing a wedge into the end opposite the workpiece.

 

                        

 

The wheel is essentially completed, but still needs final finishing, painting, and mounting – this work will be posted in the next day or so.

 

Thanks everyone for the ‘likes’ and comments.

Edited January 6, 2018 by Mahuna

[mtaylor]

Beautiful work, Frank.  Too beautiful to paint, in my opinion.

[Mahuna]

On 1/5/2018 at 8:51 PM, mtaylor said:

Beautiful work, Frank.  Too beautiful to paint, in my opinion.

Thanks Mark.  I'm going to try some alternatives.

[Thistle17]

Incredible work on one of my favorite work craft. Certainly a candidate worthy of a museum home!

Joe

[druxey]

A very labor-intensive job well done, Frank!

[popeye the sailor]

very nice looking wheel Frank!   

[Mahuna]

On 1/7/2018 at 8:28 AM, Thistle17 said:

Incredible work on one of my favorite work craft. Certainly a candidate worthy of a museum home!

Joe

Thanks Joe.  I also like the working boats of the Chesapeake, and think they make interesting models.

 

On 1/7/2018 at 11:38 AM, druxey said:

A very labor-intensive job well done, Frank!

Thanks Druxey.  Yeah, lots of labor, especially with the many false starts and re-do's

 

On 1/7/2018 at 12:56 PM, popeye the sailor said:

very nice looking wheel Frank!   

Thanks Popeye.  I'm pretty pleased with the wheel.  The photos show a lot of things that could have been done better, but it's time to move on to something else.

[Mahuna]

Part 47 – Kathryn’s Wheel cont’d

 

Kathryn’s wheel required some buffing to get rid of the file marks remaining from the shaping exercises.  This buffing was accomplished using cloth buffing sheets (similar to emery cloth) from a kit sold by Micro-Mark.  The sheets range in grit from 1,200 to 12,000, and I’ve used the kit to get a nicely polished lacquer finish on the base of some bird carvings.  It worked quite well on the surfaces of the wheel that could be reached.

 

                        

 

                        

 

I’ve experimented with various paints, including Testor’s steel and aluminum colors, but wasn’t happy with the appearance of a painted surface.  I found that the Flemish Black from JAX Chemicals gave a very nice finish when diluted with 5 parts water to 1 part of the chemical.

 

                        

 

The spokes in the area of the spoke nuts didn’t take the finish well, most likely due to the epoxy that was used for the joints.  I had tried to clean up the epoxy with isopropyl, but it seems that it didn’t clean up well enough since the brass color still showed.

 

                        

 

                        

 

The handles shown in the above photos were painted and temporarily installed to get a feel for how the color (Testor’s wood plus a little dark brown) worked.

 

The handles were epoxied in place, and the openings at the end of the handles were filled in with modeling paste.  The color for the handles was darkened slightly and the handles were then touched up.

 

                        

 

The shaft for the wheel, along with a collar over the shaft, were cut and then darkened with the Flemish Black solution.

 

                        

 

                        

 

The wheel was mounted in the steering box, and the box was temporarily mounted on Kathryn’s deck to check its appearance.

 

                        

 

                        

 

The steering box needs to be positioned to ensure that the cabin doors can be opened, but before it can be permanently mounted the Sheet Traveler and associated blocks needs to be mounted behind it.  That will be the subject of a future post.

 

There are many shackles used in Kathryn’s rigging, and it will require some testing of various approaches to making and installing those shackles before any serious rigging can be done.  So it may be a little while before the next post.

 

Thanks everyone!