Ball & Socket Armature - Double Ball Joint

Double Ball Joint 

This is going to be a monstrously long post so you might want to get comfortable.
In this post I'll be demonstrating how to make a ball and socket joint. Its quite a complex process so bare with me.
Ball joints are a more advanced method of making armatures. Unlike wire armatures, ball and sockets joints can be manipulated over and over again without wearing out and breaking. Another positive it that individual joints can be loosened or tightened to your desired tension. The down side to using ball joints is that they are time consuming and complicated to make. In the past I've made ball joints out of brass and used them in the necks of my puppets.You can read about my old ball and socket joints HERE.

I plan to make new armatures for the characters 'Roy' and 'Elle'. This will hopefully give them a greater range of motion and I won't have to worry about wearing out the aluminium wire armature. I plan to achieve all the articulation with an mix of steel ball joints and hinges. I'm quite confident that my home made ball joints work, the challenge is making them small enough to fit inside my characters.

If you want to see some great examples of ball and socket joints then I'd recommend John Wright. His ball and socket joints are super high quality and used for many professional productions. John Wright Ball Joints can be found HERE. 

Tools & Machinery

Here are some of the tools that I will be using. Firstly a bench drill press. I recently invested in this specifically for making ball and socket joints. Its quite small so it doesn't take up too much space.

The bench drill gives a lot more control that a hand drill and most importantly it drills strait down at 90 degrees every time. This is crucial as any wobbly holes will reduce the quality of the joint. I also use a range of different sized drill bits. Its important that they are HSS (high speed steel) as they will be drilling into steel.

Above you can see a small vice I use for holding materials while I drill. Its screwed into a small  wooden base so I can move it around while I'm working.

Finally, I use this rotary tool quite often at various stages. I have a collection of accessories that fit into the tool. pictured above is a reinforced cutting wheel.

Sandwich Plates

I start by making the plates that will hold the steel ball bearing. The size of the materials will vary depending on the size of the joint. Here I'm making a 5mm joint.

Above are the material for the plates. I use 6mm x 3mm steel bar (sold at B&Q in 1 meter lengths). The nuts and bolts are M2 (2mm). The bolts are called socket cap bolts and on the right is the Allen key that is used to tighten them.
I started by cutting 2 small identical lengths of steel bar with a hack saw. 
Its easier to make the plates in batches so I've marked one of the bars to show where it will be divided. I will be focusing on the left section.

Next I  mark where holes will be drilled. In the left hand section you can see that there will be 3 holes. the middle hole will be for the bolt and the holes either side of it will hold the ball bearings. Its best to keep all the holes central. If they are too close to an edge the joint could be wonky or weakened. I usually measure all the marks to make sure everything will line up OK.
When I'm happy with the positioning of the holes I use a center punch to put a little dent into the steel. This acts as a guide for the drill bit and locates it to the right spot. Without the center punch the drill bit would skate on the surface and drift off course.

I then clamped the two bars together making sure they lined up and the edges were flush. The blue vice holds the bars steady and the red G-clamp will stop them from separating when they are drilled.

I used a M1.5 HSS drill bit to drill a pilot hole into the steel. Its best to take your time and drill in short bursts, removing any metal filings. Its also a good idea to use cutting lubricant. After drilling the first 3 holes I re drilled them, expanding them to M2.

Once the holes where drilled I attached some of the nuts and bolts. These help to hold the 2 bars together. You don't want the bars to slip or the holes won't line up and the joint will be ruined.

I then drilled the holes for the other joints using the same method.I kept the G clamp on until all the holes where finished and I could bolt them together. The next stage was to separate the 3 joints.

Above are the 3 joints after they where cut with a hack saw. Its important not to mix up or rotate any of the plates or you might mess up the alignment. I draw black marks on the outside of each joint so I can remember how they line up. From now on I will just be showing the 3 hole joint that's at the front of the picture above.

Next I round the ends. I secure the plates in the vice with one nut and bolt tied in the middle hole.

The reinforced cutting wheel is great for cutting into the steel and shaping it. I use it on its fastest speed. Small sparks and metal specs fly from the metal so I recommend wearing goggles and a mask. ( I haven't mentioned any health and safety stuff before, but you should always take the necessary precautions when using tools and machinery).

After finishing one end I flipped the joint and rounded the other end. The rounded ends make the joints easier to handle and will give the joint more freedom to move.

Finally the plates should be complete and ready to hold some ball bearings. Above you can see the two plates loosened and separated.

Drilling & Soldering Ball Bearings

Now that the plates are ready the next stage is to drill some steel ball bearings to go in them.

For this I use 5mm stainless steel ball bearings and 1.5mm steel rod. The hardest part of this whole process is drilling ball bearings. Drilling straight into a sphere is tricky, and doing it at this scale can be a nightmare.

To hold the bearing steady I use some brass bar that has holes drilled into it. Much like the sandwich plates I just made, these will be used to clamp the ball on either side. If I tried to hold the bearing in a vice without the bars the ball would get scratched and likely spin loose when you try to drill it. Because brass is softer than steel it won't scratch the bearing.

To make the ball easier to drill I flatten the top edge. A flat surface is much easier to drill into than a curved surface. I use the cutting wheel but you could also use file.

Next I make a small dent in the centre where the hole will be drilled. This will guide the drill much line a centre punch would. To do this I use a small, pointed diamond cutting bit in the rotary tool.

Next I expand the dent using a 1mm drill bit in the rotary tool.

I then drill the bearing using a M1.5 HSS drill bit and the drill press. I once again drill in short bursts. I try to drill about 60% of the way through.

Finally I check to see if the steel rod fits. If the hole is too shallow I drill some more.

Soldering

Next the ball bearing needs to be soldered onto the steel rod. The join needs to be really strong as the ball and rod will be under huge pressure when secured in the joint.

 Above are the tools I use. On the left is a tub of flux which is used to help the solder fuse with the metal. At the top you can see some helping hands (small metal clips) that holds things in place while I work. The yellow reel holds Silver Solder wire. Mine is an acid core solder thats designed to be used with metal. Silver Solder is much stronger than soft solder (which is designed for electrical soldering.) My solder isn't ideal as its a little bit thick. The thinner solder is best for making ball and socket Joints. You can find Solder and Flux HERE
At the bottom of the picture is a small butane torch that's used for heating up the metal and melting the solder. Finally you can see that everything is laying on grey brick. This acts as a heat proof surface that I work on. I don't want to burn down my desk.

First I roughed up the surface of the areas that will be joined. This helps the solder stick the the metal and gives it something to grab onto. To do this I used a file. You don't want any grease or dirt on the metal or it might prevent the solder from sicking.
I then applied flux paste into the hole of the bearing and onto the end of the steel rod. I pushed the two parts together and used the helping hands to hold the parts on the surface.

Its difficult to take pictures while your soldering as my hands are busy holding the torch and the solder wire. I start by heating up the ball all around and keeping the flame moving. The white flux paste will fizz and turn clear. As this happens I dab the solder wire onto the join. The solder should melt and move around the flux into the join. The flux helps the solder to move and sometimes you can direct the solder using the heat.
The bearing will start to glow a cherry pink. Once this happens I dunk the ball into some water and quench the heat.

After drying it down it should be cool. You can see in the picture above that the metal is darker and has fire scale on it.

I use some wire wool to clean of the dirt and shine the bearing up. Now that I've completed the first ball  I repeat the process to make the second ball.

Above you can see the two balls ready to be assembled between the sandwich plates. After testing if everything works I usually solder the nut onto the outside of the sandwich plate to stop it from rotating. this will mean the joint can be tightened using just the Allen key in the socket cap screw. To neaten things up I cut off the excess bolt and give everything a quick polish.

Finally the ball and socket joint is complete and ready to be played with. It's wise to test the function of the joint before incorporating it into the rest of the armature and building a puppet around it. you wouldn't want to discover that one of the soldered parts was loose after all that work.
I will be using this kind of ball and socket joint for the waist of my new armatures. Using these basic methods I will be making several different joints and I'll post details about them soon. I will probably continue with hinge joints.( Hopefully it will be a shorter post)

I hope people find this useful.
Thanks for reading.

SETS part deux

In this post I will continue talking about the creation of the alleyway set. In my last post I showed how the basic wall structure and brick effect was made. Now I'll show how I added more details and finishing touches.

 In the picture above you can see that there are a few more details added. A stage door was cut from MDF and painted purple. We used piano hinge to allow it to swing open. The steps under the door are also made from MDF and sprayed with a grey speckle paint ( like this one LINK ). The spray paint gives a great stone texture and is much quicker than trying to create the effect by hand.

 The door surround was cut from funky foam, sprayed with texture paint and stuck on with PVA glue. Next to the doorway is a mail shoot that the Mail Man will use to deliver a package into the theatre. The door for the shoot was cut from a sheet of aluminium. The handle and hinges are aluminium rod.

The picture above shows how the shoot opens. The stone frame for the shoot was made from funky foam in a similar way to the door. The only difference is the green corner sections that were sprayed with a different texture spray.

GARBAGE 

In the design art you will notice that there are garbage cans, boxes and  and other items in the alley way LINK. These will help to dress the set and make things look more interesting. Because these are background items, I didn't want to spend too much time making them.

Most things are made from cheap materials and recycled parts. The trash cans are made from a thin plastic tray that held old paint brushes. The tray ways sprayed silver and wrapped around a plastic cup. The lids where made from funky foam and sprayed silver. The dumpster is made from foam board and another black plastic tray.

The garbage bags are made from garbage bags, wrapped and tied around scrunched up paper. Finally, the box was made from thin corrugated card.  Most of these props wouldn't hold up well to scrutiny, but luckily they'll be in the background. They might look rubbish but hey, there meant to be garbage.

The Lamp

Above the stage door is a spherical lamp. It was a bit of a challenge trying to figure out how to make this match Josh's designs and function correctly. First I decided to power the lamp using a 9volt battery. The down side to using batteries is that they can run out of power during animation, resulting in the light getting dimmer and dimmer. Replacing the batteries mid shot would cause the light to suddenly get too bright and would be very noticeable in the final animation. To avoid this I will have to turn the light off between the time I take each photograph. this will conserve the battery power and give a steady glow of light in the animation.
Another alternative would be to power the light off the mains using a dc power adapter with the correct voltage. I've done this before to power the headlights of the truck in STUMPED.

For the bulb I used a small incandescent Christmas tree light. Incandescent bulbs give a warm glow that matched the look we were hoping for. LED's tend to give cooler colours.
The round cover for the bulb is made from a ping pong ball. The bulb fits through a hole in the top. The sphere and bulb are supported by aluminium wire and a milliput wall mount. (both painted black)
The electrical wiring runs along the aluminum wire and through the wall to the battery. The on/off switch is located on the right hand side of the wall to give me easy access while animating.

Above you can see all the parts assembled together. The door and mail shoot have text painted onto them using a stencil.

One of the final details to be added to this wall are some Theatre posters. Josh designed some nice little posters using some images of my Elle puppet. Above are the poster frames made from balsa wood.

Finally the balsa frames were painted red and the posters were stuck in place. these will be placed on the wall in the alleyway and in other locations around the theatre.

Recently I've been making new armatures for both the Elle (Actress) and Roy (Mail Man) puppets.

There's nothing wrong with the aluminium wire armatures that they currently have, but now that I've got a little more spare time, I've been getting creative and done something that I've wanted to do for a long time. So stay tuned to see how I've made full steel ball and socket armatures.

SETS!

Hi, sorry I haven't posted any updates in a while. The last few weeks have been pretty busy. I finished my third year at Uni, went on holiday, had my graduation ceremony and I'm currently interning on a film in London. But don't worry, 'Opening Night' hasn't been abandoned, it's just on hold for a few weeks, and we will continue production soon.

Until then I have lots of pictures documenting the construction of the sets that I can share. I'll be starting with 'The Alleyway' set. This is the first scene in the film and takes place in an alley next the the Theatre. This is where the stage door is located and a mail shoot.

 

Above is a concept image made my Josh. It shows the look we're trying to achieve. The Mail Man will need to walk down part of the alley and interact with the door and mail shoot.

The alley is very long and narrow with several tall buildings in the distance that would take a lot of time and money to make. Since we don't have much time or money, we cheat.

Above is a picture of the stage I made earlier. As you can see we don't have a huge ground surface to work with. The amount of work space is an important factor to consider when designing sets. Our solution was to make a small section of alleyway and digitally extend it later using green screens. I'll explain more about that later. In the limited space we do have, we made the parts of the alley that our Mail Man Puppet will need to interact with.

We started by cutting a large MDF flat that will represent the wall of the theatre. We cut out a doorway and a square hole for the mail shoot, making sure they were in scale with our puppets. (we need our puppets to be able to fit through the doorway). To create the brick texture we spread a thin layer of  multi purpose filler over the surface of the MDF.

When the whole board was covered with a 3mm layer we pressed lines into the surface to represent bricks. We used rulers to ensure the lines were straight and had to work fast because the filler is air drying. While we were working we used a water spray to keep the filler damp. After about 3 hours the filler had set.

The next stage was to paint the wall. We sprayed the whole surface with grey primer to create the grey concrete colour between bricks. Next we mixed up a terracotta colour in cheap poster paints and sponged it onto the surface in a 'dry brushing' technique. The idea was to colour the top surface of the bricks while leaving the gaps between them grey.

Finally we painted lighter and darker colour variations to select bricks to make them look more diverse. These were painted with a brush in a random pattern. While painting we made sure the colours looked ok while they were under the studio lights. Different lights and bulbs can change the perceived colour of the wall. That's why is some of these pictures the bricks seem to change colour

Here is the wall after it was painted. as you can see it has a purple-ish tint, which matches our design art. There is still a lot of details to add to the wall at this stage such as the door, door frame and mail shoot. I'll continue with that in my next post, as well as the wall on the other side of the alleyway.
P.S I'll try and get Josh to update his blog too.

That's all for now,
Until next time.