Wooden circus stilts – 1.8m

Posted by jerry on December 16th, 2008 — Posted in DIY, Woodwork

This is probably about the tallest you can make them without seriously sacrificing strength or weight – any taller and you really want properly engineered metal or carbon fibre stilts.

This is basically making new legs for old stilts. You can read how I made the original pair here.

Here is the upper strap arrangement with padded shin/knee cup. The screws holding the shin cup go through the webbing for the straps – which are made from high quality seat-belt material.


The boots give the best support and hold for the feet, if the stilts are for one person and you can sacrifice a pair of sneakers or boots – boots are better for ankle protection.


Here is the underside of the foot plate – as you can see the main leg shafts are directly beneath the ball of the foot and quite central so the forces are mainly vertical.


And here is the finished set. The timber is finished with one coat of orange shellac and then wiped over with orange oil to feed the wood and keep out moisture. They are made from straight grained pine with no knots, and are 1.8m tall to the base of the foot plates. The leg timbers are 32mm x 42mm x 1800mm (1.5″x2″x6′)



British steam car – Inspiration – takes its first run

Posted by jerry on December 7th, 2008 — Posted in Journal, Steam, Technology

The British steam car challenge – dubbed ‘Inspiration’ – has taken a further step forward with dynamic tests of the car running independently entirely under its own …um… steam. This is a video of one of its first ever runs – a low speed dynamic test to ensure all the components function together to make a drivable car.

In the process the support team is learning new skills, including how to ‘launch’ the car. A team of 6 people is involved. The sequence of operations involved in checking, filling and starting the car requires coordination, timing and teamwork. Each step is a step closer to achieving the ten-year goal of this team to break the world’s speed record for a steam car, last officially set in 1906 at just over 127mph.

This team has displayed remarkable tenacity and overcome enormous financial and engineering difficulties to come up with the turbine-driven car seen above. They hope to establish a new world record next year.

Moon smiley – conjunction of venus, jupiter and the moon

Posted by jerry on December 1st, 2008 — Posted in Journal

Tonight, despite some cloud I managed to get a rough shot of the conjunction that made the moon into a smiley face. This evening at 21:22 (9.22pm) the moon lined up with venus and jupiter to present a mouth and two eyes overhead just to the south looking from Canberra Australia.

Photo was taken at 1/5th second on f5 on 400 ISO – and the shot was hand held using a canon EOS 1000D and a 300mm zoom.

moon smiley

David J of the Brisbane Blog also posted a photo of the moon smiley


Woodworking – make a zero clearance saw table

Posted by jerry on November 27th, 2008 — Posted in Journal, Woodwork

Many of you would know I’ve been busy lately making a mandolin. Today I encountered a slight obstacle. I was cutting some thin strips for the ribs out of Tasmanian blackwood and got partway through the first cut when there was a thud and suddenly the saw was working very hard. I hit the stop button and assessed the situation. It was a classic mistake. I hadn’t considered the width of the gap between the saw blade and the table – which is quite wide on the triton mark 3, and the thin strip dragged itself down between the blade and the tabletop.

I pondered this for a bit and remembered the solution – make a zero clearance sacrificial table. I had some 3mm MDF (medium density fibreboard) and found a piece about the right size – enough to cover about half the triton saw table. I set the blade to the height I wanted for the cut, then I removed the guard – note if you do that you need to be absolutely focused on your safety. I positioned the MDF above the blade, started the saw, and with one edge braced against the riving knife I lowered the MDF onto the blade, making sure that my hands were well clear of where the blade would cut. I then stopped the saw and there was the false tabletop with zero gap between the saw blade and the MDF. I clamped cut a slot for the fence bolts, then clamped the MDF in position and set the desired gap between the fence and the saw blade.

At that point I replaced the blade guard and made a trial cut in a pine offcut before going back to the precious Tasmanian blackwood, ready to make the thin strips that will eventually become the sides of the mandolin.

zero clearance saw table


Canon EOS 1000D – the Moon

Posted by jerry on November 12th, 2008 — Posted in Journal, Technology

Tonight is close to full moon, so I thought I’d give the camera a go. I set it on the tripod at f5.6 and 1/125 on ISO100. And here is the result


I suspect there is still room for great clarity and focus, but it’s not too bad for a quick go – what do you think? More importantly, what do you think I can do to improve the shot?