Chucks Prototype Double Capstan (3D print and laser cutting group)

[Chuck]

This is my start of the Capstan Project prototype.   This Log will be locked Initially so I can get all of the content up here for the entire project....

Folks can participate and ask questions in my log once I finish writing and creating all of the instructions.

 

[Chuck]

This project is primarily based upon the contemporary draft from the NMM for Neptune below.  Some changes and additions were designed into the project from other sources but its a pretty close representation.  

 

 

This type of small project was a popular modeling subject back in the day.  There are countless examples out there (including contemporary period models) and so I thought it would be a fun object to build.  Here are some examples.  The displayed varied and some were very decorative. Their size and scale varied as well.

 

Our project will be made at 1/2" scale.

 

 

 

 

 

 

 

[Chuck]

The plan sheet

This is an plan overview to scale...which you can download.   All other parts and files can be downloaded from their respective tabs at the top of this club page just below the banner photo for the group.

 

Capstan project plan sheet.pdf

 

[Chuck]

Even though this is a small project and model there are still quite a few parts to be laser cut as you can see below in this low res file..   We will discuss the color coding and techniques and materials I used later as the build log proceeds.

[Chuck]

There are also plenty of 3D printed parts for this small model.   Here is a look at them all in the chitbox slicer.

 

[Chuck]

Before we even start making sawdust allow me to offer up some advice.   For any of of you who have known me for any length of time, the two most important things to remember when building any model are....and they should be carved onto my tombstone.

 

1.  SLOW DOWN...It always amazes me how folks just rush through each and every step.  It is not a race.  You dont get extra points if you finish first.  Its the opposite actually. I have taught workshops and studied many build logs from folks at all levels of experience.  Some of these guys just rush through the projects and I end up seeing glue joints with big spaces and gaps, way too much laser char on everything, and surface qualities that would defy expectations with glue globs everywhere.    If folks would just slow down and enjoy it and complete each step as if it were a model unto itself they would take their models from a 5 to an 8 almost instantly.   Just slow down.  Appreciate every step in the process.

 

2.   Use a light touch...we are building delicate and elegant works of art made from sometimes very thin and delicate parts.  We are not carving a bear with a chainsaw.   Handle your model and parts with care and keep your hands and fingers clean as you build.   You will take your models from an 8 to a 10 in short order.

 

To begin building the model, start with these two laser cut pieces for the bottom base.  The part on the left is 1/16" thick and the one on the right is 1/4" thick.   

Depending on what wood you select (I am using Alasken Yellow Cedar) your laser settings for speed and power will vary.   Most of this project has all of the wood parts painted.  At least the version I chose to create.  

So you can use virtually any wood from Cedar to even basswood as it is readily available and easy to laser cut.  But yes you can use Boxwood or Swiss Pear too.   It just depends on if your laser cutter can cut through 1/4" thick material.  That will be the thickest material we will be cutting and only a few parts including this base.  

 

The part on the left is actually upside down.  Just shown so you can see the engraved logo I added which wont be seen unless you look under the base.  This is the perfect area for you to add your name and the date you completed the model...hopefully you will also leave my Syren logo, LOL.  

 

Other parts will have laser etched lines like the part on the left.  I will discuss my laser parameters more directly in the laser cutting tab and section of this group. As this is just the build log area let us continue.

 

 Glue the 1/16" thick piece directly on top of the thicker base part.   Make sure your etched lines face up so you can see them.   Also remember to adjust the direction of the grain so the layers are at 90 degree angles to each other on both layers for strength.  The engraved logo of the bottom layer faces down.  Also try not to have any glue squeeze into the small square slots where the 3d Printed columns will eventually sit.   This will effect how they sit in those slots if there are glue blobs in those.   Clean them out soon after applying the glue.

 

There are also laser etched wooden sides that must be added and are laser cut from 3/64" thick material.  You may opt for the Black and Gold sides instead but I know some folks like the natural wood look.  Either way you must use the wood sides and the can be covered up with the black and gold pieces later.  But for now just add these as the omission of these parts will effect how the black and gold versions will fit later on.  

 

Glue a section on opposite sides first and then glue the remaining two in position next with the top edge being flush with the top edge of the base.   Clean off the laser char from the top and bottom edges first though.

 

Above you can see the 1/8" thick base which can be glued in position next.  It is the part marked LB-1.   The LB stands for Lower Base.  Unlike the base itself this is not a perfect square so it only fits in one direction and corresponds to the laser etched square on the top of the base.

 

Clean of the laser char and light sand the top with some 320 grit paper to make it nice and smooth.  I do this to all parts by the way to prepare for final finishing.  In this case some satin wipe on poly.

 

I also knocked off the top edge all around this piece that represents the capstan partners.  You dont want a hard edge here.   Just soften it up a little bit.  You can the laser etched lines that represent the individual timbers and the bolts.  You could always drill out the bolts and add some real or simulated versions if you like.  It is up to you.

 

 

 

 

[Chuck]

 

Above you can see how I added the side letters all around the base.  This is laser engraved on very thin plastic sheets.   They are self adhesive.  So just peel off the backing and stick them to each side.   Remember to use the correct order so it makes sense when you turn the base.   Place the panels on two opposite sides first.  They are cut slightly longer than need so you can trim the ends flush with the base.   Then repeat with the remaining opposite sides.   Place them right on top of the wood lettering if you prefer this finish.   

 

Try and avoid sanding the gold letters with any abrasive.  You want them nice and crisp and shiny.   You can however sand the black underlayer.  Try and get nice clean corners.

 

Then paint the top of the base black as well with acrylic paint.   I also applied a Wipe on Poly finish to the capstan partners.

 

Chuck

[Chuck]

 

Next you can glue the 3D printed pawl base on top of the capstan partners.   It will fit right in the laser etched circle on the top of the partners.   Its orientation doesnt matter but just center in that etched circle.  I used CA glue for this.  It does a great job gluing the resin parts to the wood parts.  But you do have to position it quickly before the glue sets.   So keep this mind.  Dont dilly-dally with getting it centered.

 

 

[Chuck]

 

You can now glue the four 3D printed legs to each corner of the base.  You will have noticed by now that the width of the lettered sides is wider than the base.  This creates a lip around the entire bottom when upside down.  This make positioning the legs so easy in each corner.   Just but them against the lip in each corner.

 

 

[Chuck]

You will need parts A and B next.   In addition you will need a 1/8 x 1/8" strip.   Any wood will do but I am using a cedar strip.   Just cut a small length for now.   Maybe an inch long or slightly longer.   You will need a few more of these for various assemblies on this project.  So cut a nice 12 to 15" strip and keep it handy for the entire model.

 

 

[Chuck]

Using the strip insert it into the 3/16" thick part B.  Then take part A  (3/64" thick) and insert that so the laser etched letter A is facing the laser etched B.   Glue the two layers together.  BUT....IMPORTANT.

 

Dont glue the two layers to the center strip.  You will be removing it later.  This is just for registration.

 

The two layers should be a press fit in that center square hole.   You dont want it too loose.   If its too loose it will fly off in the next step but there is an east remedy for that.   Mill a slightly larger strip....or if the strip is too tight.  Sand it smaller so its a nice press fit.   Dont force the thinner layers onto a strip.   It will certainly split along the grain.   You can just laser cut another should that happen but its better to adjust the size of your strip if needed.  

 

Now the fun part...

 

Chock the strip in your cordless drill.   Then on a speed that is comfortable for you, use a sanding stick to remove the char from the edge of part  A ONLY.   Just a light sanding.   You will notice that part A is larger in diameter than part B and that is what you still want after you remove the laser char from Part A.   Dont over sand it.   This happens quick so use a light touch.   My sanding stick is a 160 or even finer grit.

 

 

 

 

[Chuck]

You will need part C and the 3D printed ring....

You will notice the little rectangles with holes along the edge of the ring.   They are closer to one edge than the other.  Slip this onto part C up against the lip created by part A.   Just slide it on there!!!  No glue is need.  This should be a nice press fit also.  If not and it is too loose then add some glue.   That just means that your laser Kerf was to large and your laser cutter settings were set too high when you cut that disc.  This made your part B slightly too small.  Its an easy fix and not a huge problem.  Cut another on lower power or just use some glue.

Then take part C and slide that onto the stick.  On the other side that doesnt have a thin disc yet.   Face the etched letter C towards the center so you cant see it although it doesnt really matter.  See below.

 

We are not going to sand any laser char off the edge of part C.   The only thing you might have to remove is the small sprue tab that supported it in the laser cut sheet.  Just a few swipes to remove that nub.  Glue the disc C to part B as before remembering not to glue it to the stick!!

 

Sand teh stick flush to the bottom of side of part C as shown.   Leave a little bit of the stick standing up on the other side for later.  It also creates a built in handle for the next step.

[Chuck]

Lets add some pawls....

 

You will need a brass bar that is 3/64" dia.   

 

Cut the brass round wire into four small lengths.  Maybe 1/4" long.  Take your 3D printed pawls and glue one of those brass pins into the hole of the pawl.  Those holes are should be a nice press fit.   If its too tight then your 3D printer settings were too high.  Your exposure setting is too high which makes the hole smaller because of over curing.  You can glue the brass into the holes.   Remember this is going to be a working capstan model.   

 

You need to drill holes through the ring and into the 3/16 middle layer.   Use a 3/64" drill bit or very slightly larger.   The brass pins of each pawl are inserted into those holes.  If you want this to be a working capstan model dont glue them in the holes.   Again they should be a press fit so the pawls actually move and pivot.  I blackened the ends of the brass pins.   I also added a light coat of weathering powders to taste to give all the metal parts a look that I prefer.   I used some browns and rust colors....very light.  Dont over-do the weathering.

 

 

 

NOW...if everything works out correctly....

You should be able to place this assembly into the capstan pawl base.   You glued this to the base already but I am using an extra one here for the photo.   It should just sit in there.  It should not be too loose or even too tight.   Basically part C should be the exact size you need to sit in the center of the pawl base.  This will NOT be glued in position.   You want it to rotate and for the pawls to engage along the sides.  Give it a test.

Testing....below.

 

Then just set the base and this lower assembly aside so we can start building the lower capstan.  Note the small length of that center stick still sticking up from the pawl assembly.   Keep that there as you will use that to mount the finished lower capstan.

[Chuck]

In this photo I am testing that pawl assembly on the model.  Remember no glue as it needs to turn.  I am also testing the fit of the four 3D printed Columns although we wont need them yet.   They fit pretty darned good in their respective square holes.   Those will be added much later.

[Chuck]

Ok lets start on the lower capstan...

 

You will need LD 1 and LD 2 parts.  There are two LD1 parts which are 1/16" thick.  LD2 is the gear-like part (1/8" thick) that when sandwiched together will make up the center of the lower capstan drum.  Slide these onto another short length of 1/8" strip as shown below.   They can be glued together but once again, dont glue it to the strip.

Chock it your drill again and sand away the laser char from the edges.  But in addition to just removing the char, the profile of this assembly is rounded.  Check the plan.  You can see how the edges were rounded off.  Now if you plan on painting the capstans red like I did you can rest a little with the sanding.  But if you want to go with a natural finish, really make sure you get the char off.  Especially remove the char from the end grain areas.  You might want to apply a thin coat of wipe on poly just to see if it gets really dark.  Then you know you have to sand more off.   While still on the drill use some fine sandpaper (320 grit or even 400 grit)  to give the wood a nice surface for painting and finishing.

 

Then get parts LD3 ready.  LD stands for lower drum by the way.  Glue those onto the assembly.  One on each side.  These are very thin so dont force them or they will break along the grain.  Then chock it up again and start sanding and shaping.  These discs are larger in diameter with some extra size on them.  Dont be afraid to remove the char and reduce the diameter.   Sand the edges and soften them.  They are indeed also rounded off a bit.  Refer to the plan to see the profile of each layer you add as you proceed.  

 

 

Below you can see how the previous discs were sanded smaller and profiled.  Next up is LD5.  This is 3/64" thick and on what is the bottom of the drum.  You know the drill...literally.  Glue it to one side of the assembly and insert back into the drill.  Sand to match the plans.

 

 

Examine my progress below.   Now its time for LD4.  I since removed some of the reference lines but it looks pretty much the same.  Glue this on to form the top.  Only this time, you must make sure those small holes are lined up with the square opening in the drum.   These are the holes for the capstan bar pins.  

 

Same deal with this layer.  Glue it on and then chock it up and sand it.  Dont be afraid to reduce the diameter.  Check the plans to see the final profile of the entire drum.  NOTE that the this piece is 5/64" thick.  But as you sand it with your sanding stick, you can reduce the thickness along the outside edges.   You need to create more of a slight dome shape to this layer.  Use the plan as a guide to determine teh final thickness along the edge.  

This completes the lower drum.  But I decided to paint at least the first few coats of red paint at this stage.  Also get your 3D printed center column ready.   You have 3 of these.   This is the shortest and most interesting of the three.

 

 

 

 

 

[Chuck]

I have added the top central column piece and painted that red as well.   you should have a small length of that 1/8" strip hanging out of both sides of the lower drum.  The 3d printed columns simply slide onto it.  The one I painted red is placed on top.  The orientation doesnt mater.  But make sure the top is correct and dont add it upside down.  See pic below.  Then I took one of the remaining 3D printed central column parts and glued it onto the bottom of the drum.  Make sure you pick the right one.  Its the one WITHOUT the small round section on it.   Make sure that you sand the bottom of both sides of these 3D columns flat.  Sometimes they have some extra cured resin on them and the small nubs from the supports.  So use a sanding stick to make them flat.  

 

You can also glue the laser board black ring to the top of the drum.  No laser etched reference for this ring.  So just do you best to center it using the center column and outside of the drum as a reference guide.  Its starting to come together nicely.

 

 

[Chuck]

Time to add the whelps...Parts for the lower capstan.  I mention this because the whelps for the upper capstan are indeed different.   So take care when finding them among your laser cut parts.

 

These are pretty straight forward.   They are laser cut and 1/4" thick.  They have engraved slots for the chocks on both sides.   Before you even punch these out of the sheet, sand both sides with 320 grit to clean them up and prepare the wood surfaces for final finish.   Then punch them out with a sharp number 11 blade and sand the edges free of laser char.  Now the laser engraved slots can sometimes be a little rough.  So take a file and just give them a few passes.  You dont have to go crazy here.  But sand the sides and bottoms of the slots a bit smoother.  But dont make them any wider.  That would be bad.

 

I will also mention that although I am using 1/4" thick whelps, if you are laser cutting your own pieces, you could swap out the thickness with 7/32".   The actual is somewhere in-between and after testing with 1/4" whelps I determined they looked just fine.  But really, the same would be true if I used 7/32" thick whelps.

 

Then glue them to the faces of the center column.   They may be slightly wider than the faces on the center column but that is ok.   Just add them all around the column and evenly space them.  As you go, note how those slots should be even from one whelp to another.  This is where you will be sliding your chocks into in the next step.  If the slots are higher on one whelp then the one next to it, that is not good.  It means you over sanded the top edge of the whelp.  No worries there are extras.

 

NOTE...the bottom of the whelps should be flush or nearly flush with the central column.   If they are not.  No need to worry just yet.   Wait until after you add the lower chocks and we can access and move forward.  Its not that big a deal.  Especially if they are shorter than the column.   

 

[Chuck]

Time to insert the chocks...

 

These are different thicknesses.  The upper chocks are thinner than the lower.   But they are same for both the upper and lower capstans.   So there are plenty of extras.  

 

The lower chocks are concave along the outside edge...with the upper chocks being convex or rounded outward.   see below.  

 

These chocks are cut oversized both in length and in width.  This is probably the most time-consuming part of the project.  But it is also one of the most important.  Especially if you plan on going with an unpainted capstan.  You want to show nice tight joints here...and properly shaped chocks.  It could start looking sloppy really quickly.

 

So first,  sand a chock on its small edge to knock off the sprue nub.  Not a lot.  but just flatten it out.   Then sand both sides so its a nice pie shape and your chock can slide all the way into position.  The back edge should touch the column.  The two sides should be nice clean and tight fit in their whelp slots.   No gaps.   Take you time.  There is plenty of meat on these.   You will be sanding them and testing them and then sanding and testing more.   Test fit them until they slide in with a nice fit.  You will grow accustomed to how much to remove and where after the first few chocks are completed.

Below you can see one of the chocks test fir in the slots.  note how far it still sticks out.  This is by design.   Take a sharp pencil and mark the sides where it meets the front edge of the whelps.  Do this on both sides.

These are complex little buggers with some crazy angles.  But if you proceed like this it isnt difficult at all.  And it will look like it should, with the chocks mortices into the whelps.  A detail at this scale that you cant omit.

 

Remove the chock at this point and use your pencil marks as a guide.  Sand that angle into the front edge of the chock.  Make it concave or convex depending on if it is an upper chock or a lower chock.

 

But dont sand it all the way to your pencil line.  Just in case you remove too much.  This is when it is a good time to test it again and glue it into the whelp slots.  Then carefully finish sand the outside edge flush with the whelps...and create the final finished concave or convex shape.  Use a fine 320 grit sandpaper or file.  Be careful not to round off the bottom corners of the whelps.  keep the whelps the shape they should be.  Its all too easy to be impatient and rush this with sloppy final results.

When you are finished....apply some wipe on poly and paint it red.   Take your time.   Its very easy to leave a lot of paint globs.   Thinner coats and many of them.  I used acrylic paint from a tube.

 

Below you can see how I tested its fit on the base.   Just slide it onto the stick you left in the base with the pawls.  Note how the capstan still turns and the pawls engage.\

 

In the photo below you can also see the small bolts that I added.  For the bolts on the whelps and chocks I used 40lb black fishing line.  I pre drilled the holes so the fishing line was a press fit.  No glue is needed.  Just push in some fishing line and use a sharp #11 blade to slice off what sticks out.   Slice off the excess so that just a small amount of the line stands proud of the surface.  This does a great job of simulating bolts.  The columns are being tested again just to see how they look as well.

 

This is when you should examine the bottom of the capstan.   Does it sit flat on the base.   Note how the bottom whelps and chocks are all flush and even,  I sanded the bottom of the capstan just a bit to make it all flat and even so it would sit right on the capstan base.  No gap between the capstan and the base here.   When you are satisfied,  you can glue the capstan onto the base and the center stick used to align it.