Acrylic Snowman

While the MDF snowman worked out nicely, and it looked ok painted up, I wanted to get back to trying my hand at making some models from acrylic.

Given that Christmas is rapidly approaching, I thought I’d tackle the snowman again, and see just how well the CNC, along with a new set of router bits specifically for plastic from toolstoday.com would work out.

Just an aside for a second.  I have just gotten an iPad Pro, and while writing the article, have used one of the pro’s features of being able to run a second program simultaneously, and on screen at the same time.  Awesome feature! 

  
I also found a better supplier of plastic sheet goods, so that will be great (and dangerous to the wallet).  They also sell acrylic ‘glue’, and it is a vast improvement over using Superglue.

I still have some processes to work out to make things run smoother on the CNC process of working with acrylic, but for the most part it went very well.  Acrylic is pretty flexible when it gets thin, even worse than MDF it seems, if that is even possible.  So I found myself supervising the whole job while it was machining.  I was using an upcut bit, and perhaps that also has a lot to do with it.  While chip clearance is important (especially with a material that can melt), lifting the piece is not the best way of ensuring it is stable.  I still don’t have revolution speed control, so am still running the bits slower than I would like, and again that is probably a real factor.

Still, the result is a great snowman. Looks awesome (especially with Kara Rasmanis wielding her camera)  

 Next one to tackle – an acrylic AT-AT (Imperial Walker) in greys and black plastics. And there will be video, just once I have a better idea of just how to manage this material!

Xmas is here already?!

No idea where that year went.  Good grief.

My wife and daughter have been having a bit of fun painting up the Santa’s Workshop (from MakeCNC)

My first time, I hit a bit of a snag, as I used the 6mm plans by mistake and still cut it from 3mm MDF (which is the model above).

Since then however (and despite the warning to the contrary), I’ve been quite successfully making the workshop from 3mm MDF, using a 1/16″ router bit from Toolstoday.com.

It is a fun kit to assemble (and paint if you have the patience).

As you can also see in the first photo, I gave Frosty a treatment as well, using an airbrush for the most part (he was already fully assembled that made it a bit tricky).  My suggestion for him would be to assemble the hat, then paint it, but then paint the rest of the snowman while still in pieces.

I used acrylic paint for this job, which goes on quite well on MDF, although MDF is like working with rough cardboard.  Doesn’t pay to rush the painting either, but seeing as the year has finished before I realised it had begun, I did anyway just to get the job done.

I am still in two minds about painting the models – they do look good painted, but equally, they offer a different quality in their raw state.  Like looking at a scene and deciding if it is better depicted in a colour photograph, or a black and white one.

Certainly for the Xmas decoration aspect, the painted model wins hands-down.  Next time I’ll have to think about how to run some fibre optic lighting through the place!

I obviously have a young daughter – while painting Frosty, I kept getting an adapted line running through my head from a certain movie

“Do you want to paint a snowman?”

 

The Multimaterial Dragon

From the recent video, here are a couple of images of the dragon, cut from acrylic, aluminium, corian, carbon fibre, brass, copper, MDF, ply and melamine (and the assembled dragon is acrylic and aluminium).

Design from MakeCNC.com

Just been to the aluminium merchants, and picked up another $600 worth of aluminium sheet, from 1.5mm to 6mm thickness for some upcoming projects.

For Numismatists, Notaphilists & Coin Collectors

Here is my latest project, ready for the next edition of The Shed magazine.

It is a coin storage cabinet, with spaces for 1200 individual coins, stored in acrylic trays.  It has a curved top (using kerfing) and tambour door.  By replacing a 6mm thick tray with two sheets of 3mm clear acrylic, bank notes could also be stored and displayed.

Each tray has a tab with a descriptor of the tray engraved in it, such as “Australia 50c Commemorative”, and each coin slot is sized to the specific coin that it is to house.

When the edition of The Shed comes out (soon), the article goes into detail how it was made, using both CNC and non-CNC techniques.

A birthday present

A 70th birthday present for my Uncle.

Happy birthday Peter!

Acrylic pen, turned on the Nova Comet II.  With the drill press out of action, it took a couple of seconds to remember that I now had the Nova Pen+ Jaws from Teknatool

They worked perfectly, and worked with the pen mill as well mounted in the chuck.

It was nice not to rush this job – I had time to take my time.

Pen sanded to 12000 grit with micromesh acrylic sanding pads.

Acrylic Wizard

Wanted to see how well acrylic blanks can be machined by the Beall Pen Wizard.

Biggest frustration is you can’t just jump into a project. You have to go through all the steps to turn a pen beforehand. Not a problem (unless you are impatient to try an idea out!)

This was very much a test- I wasn’t so worried about the end result, so long as there was a reasonable degree of confidence that it could be achieved.

The blank is probably too (colour) detailed to also be machined, so I’ll look at plainer acrylics for when I plan to use the Wizard to finish the pen off.

In this case, I used a side-mill bit, and ran a spiral flat on 4 sides of the pen. Then did 4 additional lighter passes in between each of the other 4.

Remounted the resulting pen on the lathe (not turning), and tried the Dremel buffing wheel. Point to note- the heat generated exceeds the melting point of the acrylic!

Then tried the traditional acrylic sanding pads, which worked better, although rounding over and softening the result.

So another successful experiment, with more lessons learned. For one, don’t load up the cutter on the workpiece if the gearbox is in reverse- you are likely to undo the spindle!

Again, experienced a bit of flex and play in the jig, but a decent result (for a beginner!) was still achieved.

The Camera is (still) Mightier than the Pen

There is a pen style to suit everyone, from the thinnest slimline designs, through to the bulkiest, heaviest ones.  The price can vary from a few dollars to $100 or so, simply for the mechanism.  You’d certainly want to be on your turning game when working with the expensive models.

Elegant Beauty Kit

There are stacks of different pen kits out there, from slimlines, through sierras, sedonas to emperors and on and on.  Some require one turned section, some 2, either the same diameter, or with lids, or other sections.

Sedona Kit

Some are more complicated than others!

Blank Drilling Vice

A blank drilling vice holds the blank steady, and parallel to the drill bit.  Until recently, I used a standard metalworking drill press vice which was ok, but this style of dedicated vice eliminates the problem of ensuring the blank is actually vertical.  It also makes it easy moving from one blank to the next, or to remount a blank for redrilling.  Changing to a larger or smaller blank is easy – certainly no harder (and I’d say easier) than a standard screw vice.  The quick-action lever is a definite boon.

Tube Inserter

This simple tool is a tapered shaft, and allows the brass core to be inserted without you directly coming into contact with the finger -joining Superglue!  I tend to find it also prevents over-insertion, where the brass tube sticks out the other side (and the speed the glue sets typically prevents a fix).  However, it is a rather gentle taper, so is not as effective for the larger tube diameters.

Pen Mill

Once the tube is inserted, and the glue set, it is time to dress the ends so they are flat, and perpendicular to the tube (and therefore the components).  Some mills have different diameter central bores for the different pen types.  This helps keep the mill accurately aligned, and also cleans out any glue (etc) that happens to have gotten in where it shouldn’t have.  However I still haven’t found a mill that I am happy with.

Pen Mandrel

Have a couple of pen mandrels here – the top one is variable (ie has variable length with a chuck)  The mandrel is critical as it supports the blank as it is being turned, and given that the finished pen can be as thin as 0.5mm, providing decent support is rather important.  A knurled knob at one end holds the blank firm as it is turned.

Bush

Different pens have different diameters, both outside to match the components, and inside – the diameter of the brass tube.  Rather than have a mandrel the right diameter for each pen type, bushes are used to fit inside the brass, centering the blank on the mandrel, and the outside of the bush provides a reference for the final thickness the pen needs to be turned down to.  These are a consumable – they do get worn so occasional replacement is necessary.  However, they are only $5 – $8 for a set, so it isn’t too expensive.

Live Centre

Instead of my normal live centre, (or my new Nova one) both of which are too sharp and have too thin a cone end to fully support the end of the mandrel, I found this cheap chinese one, which is hopeless for the job it is designed for, but perfect for pen turning.

Centre matching Mandrel

The short, wide angle and blunt/rounded tip is useless as a live centre, but matches the end of the mandrel surprisingly well.

Sandpaper

Getting the required finish requires sanding (unless you are an expert turner, and even then I imagine they use sandpaper too!), and you always need to work through the sandpaper grits to ensure there are no scratches left to ruin the finish.  This pack provides a convenient storage, and to keep it all in order.

Cyanoacrylic & Accelerator

Other than glueing the tube into the blank, I also use CA glue as a finish, typically with 18-20 coats to produce a very durable finish.  To apply so many layers, the accelerator is necessary.  If one layer is not fully set before the next one is applied the finish is ruined with a milky layer under the surface.  I prefer the aerosol can applicator – a fine, even application.

There is no different between the CA glue here and the Superglue in the small 2g tubes, other than convenience.  A 2g tube will do about a pen, including the finish, give or take.

Acrylic Sanding Pads

Getting a really fine finish requires going to an increasingly fine abrasive, and the acrylic sanding pads are excellent for this, especially when used on acrylic pens, or CA finished ones (you don’t need to CA finish an acrylic pen!)  These pads are coloured based on the grade of abrasive, so it is easy to move from one to the next.  They can be used dry, but they are superior when kept soaked in a bowl, and used wet. This cools the finish, which is important for both types – they are easily destroyed if they get too hot with the friction of sanding, leaving no option but to strip back to bare wood (if a CA finish) and start again, or if an acrylic to drop right back to a rough grade and work you way up again, hopefully the heat affected zone is not too deep.

The pads themselves are also damaged if they get too hot.  A simple rule of thumb is: when used wet, watch out for any dry spots that form which will quickly indicate an area where the temp is rapidly rising.  Watch out for any steam, and feel with your fingers too.  Keep wetting the pads down (dipping them back in the water) – not only will this keep them wet and cool, but also washes off any abrasive particles that have come loose.

The finish these pads do achieve is superb.

Hut Pen Wax

There are other finishes out there, including Hut Wax PPP (Perfect Pen Polish).  These look great straight off the lathe, but I have found them very disappointing with their lack of durability.

Ubeaut Shithot Waxtik

This is a wax by Neil Ellis of Ubeaut, and as you can see I haven’t used it yet (bought it for the name first and foremost!) It got its name from wood turners though, as each when asked how the wax stick was, remarked that it was……., and the name stuck!

Ubeaut was originally going to be called Shithot, but the business licensing organisation cracked it.  At least the product itself, with a typically Aussie approach to naming, made it to the market.

Pen Press

Finally, when it has all been finished, the final assembly can be done.  I used to use a Superjaws for this step, but a dedicated pen press is a much better solution.

Perfect Pen Presentation

Finally, it is imperative that the finished pens are displayed proudly, which leaves only one problem – deciding which one to write with!

It’s in Disguise!

Had a chance at part two – to finish off the Mont Blanc camo pen.  This is the top, with the initial turning completed and ready for finishing.  Although the difference in diameters at either end looks quite severe, it is nowhere near as pronounced when the pen is assembled.  So with Paul Kelly cranking out of the stereo about making gravy, I started working on the finish.

Finishing the Acrylic

Running the lathe near flat out (it is after all a very small diameter, so the edge speed is pretty low even at maximum RPM), it is important not to allow the temperature to rise.  Acrylic will melt very easily, and timber has a tendency to blow out.  You can often get away with it with timber, but it is better practice to keep the temp down.

When working with acrylic, the acrylic sanding pads work extremely well, and have the benefit of being used wet, so they are good for keeping the workpiece cool.  If the water runs out/evaporates off, the temperature can spike very quickly, so constant vigilance is the order of the day.

Acrylic Polishing Pads

The pads are colour coded (and again I’m getting that wiggly red line telling me that I’m wrong spelling it that way)

The pads are colour coded, so you can easily identify each grit and work up through them – do not be tempted to skip any, otherwise you are almost guaranteed to have scratches in the finish.  The other thing is to make sure the workpiece, and the abrasive are flushed regularly (or in the case of the workpiece, at least carefully wiped down), particularly when dealing with the large grits.  If any have become dislodged, they can cause significant scars in the finish.

Scoring the Shoulder Width

This pen design has a sleeve that fits on the top half of the pen, so a shoulder needed to be cut.  It was meant to be 7/32″, which means nothing to me – I’m sure it should but I can’t picture what it is.  So with the FastCap calculator, it converted to 5.55mm.  Setting the digital caliper to this, I then used the inside diameter points to become a set of accurate dividers, and to then score the line.

Forming the Shoulder

Using a parting tool as a scraper, it formed a sharp shoulder ready for the sleeve. I originally bought the shoulder down to the diameter of the bush, but it turns out it was not very accurate.  At least it was too large, so I was able to still work down to the right diameter.  It did result in me having to test the fit almost a dozen times, but when it got there, the fit was perfect – no glue required. Slow and steady – if you are in a rush, or impatient, pen turning is a chore rather than meditative, or whatever you get out of it. Again, the digital caliper worked very well, allowing the sleeve internal diameter to be accurately measured, and compared to the forming shoulder.

Top Assembled

Using the new pen assembly press, it all went together very easily.  The press worked well, but it has way too much flex in the base. Not hard to fix – I will simply attach it at a number of points to a heavy, straight (probably wooden) base.  Other than that (which is an easy fix), having a dedicated pen assembly press is a definite bonus.  And a lot more convenient than setting up a SuperJaws which is how I’ve done it in the past.  A bit more of an appropriate sized tool for the job too!

Polishing Pads

Polishing the lower half – the pen is currently turning (3000 RPM) – the flash of the camera has mostly frozen the pen.  Again, working through the grits to get the required finish.  I started with 180 grit sandpaper (dry) to compensate for some irregularities in the surface caused by my less-than-perfect turning abilities.  This sends the acrylic an astonishingly opaque white, but have faith, it all comes right fi you diligently work through the grits of the acrylic finishing pads, with plenty of water to keep the surface cool and clean.

Pen Supplies

Just before I finish, this (for those who haven’t seen it) is my pen turning box – full of different pen kits, some of the tools of the trade, bushes, etc.  It is double sided, so lots of interesting bits n pieces in there.  Found a couple of kits that I forgot I had, so more to try out in the near future.

The Finished Pen

The resulting pen – I haven’t made a decent pen-photographing setup, but I think it comes across ok here anyway.  Has a very nice feel, not as heavy as some (I discovered I like heavy pens after making some Sierras and EBs (Elegant Beauty)), but still closer to what I like than the slimlines, which just seem too thin and too light to me these days.

And the camo makes for a very interesting design as well.

Invisible Pens

I know it is hard to see anything in the photo below, but you’ll just have to trust, that like on the battlefield, the pens are actually there.

This is a collection the “Roving Reporter” did as a commission to some currently serving personnel. The acrylic is made locally and is skillfully colourmatched to the actual current camo used in the field.

Camo Pens & Keyrings

The Results

A couple more results

These are the resulting two pens from the evening.  The pen on the left is again a Sierra, with a black acrylic body.  I’ve had this pen blank for a couple of years, and hadn’t found a project to use it on, until I saw the black components of the Sierra, and that made it a no-brainer.  I don’t think I expected the white to remain thin tracks through the pen – I though they were going to be large facets of white, revealed as the blank turned round.  I guess not!  Overall I am very happy with how it came out.  The pen would be even better if I was a Collingwood supporter!

The pen on the right is actually the same pen as the previous one.  I decided I really wasn’t happy enough with the fit and finish I had achieved, so took the pen apart, remounted the body in the lathe and turned the original timber off (ie turned it into toothpicks).  I was then able to start again with a new blank.

This time I am much happier with the results.  I don’t know what the timber is though unfortunately.

The finish on the right pen is CA, and given it is my first CA finished pen, I’m not exactly an expert.  However, I will make a pen video very shortly, and will attempt to show how the CA finish is applied.