Monday, 30 July 2012

Wheel Jig – Part 2

Cart Wheels Part I

Today I made some improvements to the wheel rim jig, I marked out the outer rim using a transom arm protractor. That is, a protractor that is made by fixing a batten to the centre of the circle and then rotating the batten through 360 degrees marking a line at the end of the arm. This gives you a circle. Then I cut along the line with a jigsaw to leave me with a circle. I still need to rasp down some high spots and fill some low spots, but it gives me the shape that I need.

I drew a line through the centre of the circle to give me the starting point. This line passes through the centre point in the circle, the line gives me 0o and 180o. From there, I marked off points at 36o, 72o, 108o, 144o and back to 180o. As the circle is divided by an even number, I can simply draw a line from each of these five points to the opposite side of the circle to give me 10 equal divisions.

Next, I marked out a point on each of the division lines about 1 and a half inches back (2.5cm) from the perimeter and drilled holes through for the jig clamps. Turn the jig over and clean up the slight tear-out from the drill and, presto, a wheel rim jig is made.


You should be able to draw a straight line between each opposing pair of jigs and they should all meet in the centre of the circle.

I may need to fix another layer of fence palings to the jig to make it thick enough. Otherwise there will be a tendency for the laths to warp because one side or the other of the clamp will be off-set.



The threaded bar that is used in the clamp has been left quite long so that I can have enough clamp to make a rim up to about 15cm.

In the top photograph, I have put the topmost clamp all the way through and brought the next two clamps all the way forward so that I can use the clamp as a hanger to hang the clamp off the ground. I have also got a hole drilled through that was at 45o from the first hole. This will be where I can hang the jig up in my workshop. Hanging the jig means that I can have bench-space cleared up while I wait for the epoxy to cure. The epoxy that I will be using is a two-part marine epoxy. This epoxy has a little bit more flexibility in it than other woodworking epoxies and the wheels will take a bit of bumping around when under load.

One of the reasons that I have made this jig with 10 jig clamps is that I intend to make my wheels with 10 spokes. The clamps also provide me with a guide for making the spokes.

Anyway, that’s it for today. I hope you enjoyed it.

Read Part I here

Friday, 27 July 2012

Making Cart Wheels

Cart Wheels Part II

I need to make some cart wheels for my planned goat cart. Some time ago, I had some jig clamps made (to my design) by a local engineering company, they are simply a pair of round bar of equal size and diameter. The bottom piece is tapped so that a bolt can be passed through it, while the top piece has a hole for the bolt to pass through. When the bolts (2) are tightened, the two pieces are brought together.


The idea is that you have a timber form and you drill a hole through the form and pass the tapped clamp piece through the hole. The work piece that needs to be clamped is then put on the form and the top piece of the clamp is added with the bolts (I have fixed nyloc nuts to the ends of the threaded rod to make my bolts). I have 10 of these clamps.

On another project that I was working on, I made some crude timber wheels (using fence palings).


The wheel was only being used in a “proof-of-concept” so I never actually used the wheel. The next part is to mark up the wheel and put in the holes for the jig clamps. There are 10 clamps, so 10 holes around 360o means that they will be at 36o from each other … well I can work with that. First, drill one hole and put the clamp in.


Here you can see what I mean, one part of the clamp is fixed in the jig, while the other is able to move in and out by turning the bolts top and bottom. The only real drawback with this design is that it is easy for the piece to skew, so I have to be careful when tightening the bolts.

So, to prove the concept for you, here is a piece of Huon pine that I cut from a larger piece, this is called a lath. I cut many of these laths to make laminated longbows from (another story for another time).


I’ve placed another jig clamp at 45o (because it is easier to measure with what I had at hand. I will put the rest of the clamps at 36o).

You can see how the clamps are pulling the Huon pine in to the shape of the former.

For this to work properly, I will need to steam the lath (and the lath will need to be much longer). I will be cutting many more laths on my table saw from Tasmanian Oak since that’s a fairly easily obtained timber in the widths and lengths that I need. I also need to refine the timber wheel that I am using as a form. It is not a perfect circle. For that I need to set up my router on a swing arm from the centre of the wheel. I’ll use a straight cut router bit so that the wheel is cut cleanly from the centre.


The lath will be set on the forming jig while pliant from steaming and then taken off the former. When the lath has cured, I will then use epoxy to glue it to another lath until I have a wheel rim that is approximately as high as it is wide.

In between laminations, I will leave the progressing wheel rim on the jig as the next lath will need to be formed to the wheel rim as it goes.

The above lath is about 3mm thick and 30mm wide, so I’d need about 10 laths to make a wheel. Also, each lath needs to be about 3mm longer than the previous one to account for the increase in thickness.

So, there you go. Apart from a bit of tidying up in the workshop that was my playing around in the workshop.

Tomorrow I have a Goat Judging course to attend, so I won’t be doing any more work on this project until Sunday.

Thursday, 26 July 2012

Loooong weekend

This weekend is a long one for me. I am taking this Friday and Monday off for some much needed rest and recreation.

Now that the forge is completed, I can start planning some other stuff that I’ve been wanting to do.

A while back I made some wooden wheels that were going to be used on a water rocket carriage. The water rocket project went into hiatus (mostly because of time and cost issues), but the wheels were completed. I am thinking of using the wheels as a forming jig for making spoked wheels for a goat cart. I’ll need to drill some holes into the perimeter of the wheel so that I can attach the steamed wood to the jig using some clamps. I’ll need to rip-cut some timber that I have in the feed shed (blackwood, sassafras, Huon pine, leatherwood … etc.) and then I’ll steam and bend the wood around the jig. After the wood has “formed” I’ll bend another and then glue it to the previous lath. I intend to make each wheel from about 7 x 3mm thick laths. This will make each wheel about 21mm thick and about the same width.

I’ll make the rims for the wheel using steel hoops (made on the forge). I need to make some hubs and spokes as well … but I’ll get around to that later, for now, the wheel rim is the target project.

I will make one wheel rim and see how that goes. If it all goes pear-shaped, then I will rethink the plan.

When the wheel rim is crafted, I will need to cut it up into sections so that it can be hammered onto the spokes … but that is probably thinking about it a bit too early.

Also, I am picking up some aluminium roofing from a friend on Friday, so I will also need to do something with that. The aluminium roofing is intended to be the roofing of a new goat shelter that I am building in  the bottom paddock. I will need to buy some timber posts for the frame and some stud timber for making the wall and roof structure. Ideally, the new goat house will be only about 1.8m high. The goats won’t be able to use it until I have sorted out the fencing in the bottom paddock … but that is still a job for later when I have enough spare cash for fencing material.

Sunday, 22 July 2012

More work on the Forge

So the plan for today was to fix the gap in the hood and to put the flue on the forge.

I started to cut a hole in the roof of the lean-to for the flue to go through, but all of the water on the roof from the dew came sluicing down on me … so I’ll leave that for later on (when the dew has finally evaporated off).

I cut the steel from the piece I cut out of the body to make some patches for the hood and fixed it on. It’s none too pretty … but then I don’t suppose that a forge is intended to be aesthetically pleasing … is it?


The hood will now direct smoke and ash upwards without getting in my face. Yay!


Like I said … it’s none too pretty. But I can always “hide” some of this mess with some pot-black, it will be less obvious if it is of a uniform colour. Also, the pot-black will help to reduce the amount of rusting that will affect the hood. Heat will make the rust flake off, but it’s better to have no rust in the first place.

You can see where the hole is going in the roof for the flue to go through.

Fitting the flue will be an exercise in expanding the bottom of the flue to go over the top of the hood, and then screwing it in place.

I got up on the roof of the lean-to and cut the hole through for the flue, then dropped the flue down and over the opening at the top of the hood. Fired it up and voila … chimney.


Still a lot of smoke coming out of the forge, but then I was burning straw. I need to cut the bottom of the flue into tabs, spread the tabs and screw them on to the top of the hood to make it nice and secure. That should also help with the smoke … a little bit. A good fire, when it is burning a better fuel will not smoke as much as this, so I am pretty happy with the outcome.

Now the flue has been attached to the hood and I’ve fired it up.


I’m burning a bit of straw and some old fruitwood cuttings. When the straw burned off and the wood was burning well, the flue drew most of the smoke as planned, so it was working.


With the air pumping into the forge from the old vacuum cleaner through the tuyere, I was getting a reasonably fierce burn in the middle of the forge. Of course, the fuel was used up pretty quickly as there wasn’t much of it, so it only burned for about 10 minutes. With some decent fuel in the forge, it should get quite a good heat going. I may need to put a grate over the top of the tuyere so that the burning coals don’t just drop through to the floor. I need to keep some coals banked to keep the heat going and so that I can get a good burn happening.

Anyway, that’s pretty much it. There may be some tinkering required as I increase the heat, but the forge is now ready to go into service.

Saturday, 21 July 2012

Hood goes on

Today, I fitted the hood onto the top of the forge. Well, almost.

It would seem that I am at two with measurement. I didn’t take the overlap into account, so the hood has a gap of about 10 centimetres. Looks like I have some patchwork to do.


Fixing the hood on to the top of the forge body, I went around the hood with drill and screws: drill a hole, screw the hood; drill a hole, screw the hood. Slowly pulling the hood into shape around the forge body.

The scale of the gap wasn’t clear until I was about 3/4 of the way around the hood. By then, I needed the able assistance of my lovely wife and daughter to push the hood down to the body while I drilled and screwed.

I’m going to use the panel that I cut out of the front of the body to patch the hood.

I couldn’t resist firing the forge up to test the tuyere. It worked brilliantly. With the vacuum on blow and the tuyere open, the forge fired up nicely … with the tuyere closed, the thing got hellishly fierce. The flames from the forge started licking the roof of my lean-to, so the flue is going to be critical if I want to keep a lean-to and not just work in a pile of ash.

I also did some clay patching around the base of the forge body. The clay that I laid in the base had shrunk by about 2cm, so I pushed more clay into the gaps and increased the angle of the incline of the internal dish shape. I also made a bit of a clay shelf at the front of the forge for more heat reflection and protection for me.

As the forge gets used, the heat rising from it will anneal the steel hood, so I am expecting this to pop and creak a bit while I use it for a while. When that has stopped, I will replace the screws that hold it onto the body, with bolts with spring washers.

I may need to cut another aperture into the other side of the forge so that I can put longer stock into the forge and heat it in the middle. Well, that can wait for now, it won’t stop me from using the forge, nor will it really limit what I want to do … for now.

Well … I’ll get onto patching the hood tomorrow. It shouldn’t take me very long. Then I need to put the flue on and through the lean-to roof.

Sunday, 15 July 2012

No work this weekend!

This weekend, our daughters had skipped off to sleepovers so my lovely wife and I had a pleasant weekend of liberty … mostly.

Apart from escaping goats and sheep, we had virtually all of the weekend to ourselves. We indulged ourselves with a night out at a nice Thai restaurant (Suwan Thai at Salamanca, in Hobart). We didn’t have to worry about ordering for a vegetarian or for a chilli sensitive child. What a luxury!

After that, we came home and vegetated, watched whatever we wanted and didn’t have to chase children off to bed.

In the morning, we farted around the house until we went out to buy some new fish for our aquarium. We bought some (5) new Lake Malawi cichlids. They are all very young and we certainly can’t put them in with the Jewel cichlids until they have grown up a bit. But, they are sure purty lookin’.


Next weekend, I’m going to do more work on the forge, and hopefully even fire it up. This weekend was more about forging a better relationship with my wife.

Sunday, 1 July 2012

Not much time …

I didn’t get as much spare time this weekend as I would have liked to. Still, I got some of the shaping done of the hood of the forge.

I started with a circle of steel and cut a chord out with the section length equal to the circumference of the forge body.

Next, I started shaping the cone from the chord. I was going to make a simple tool to bend the steel, but in the end, I didn’t have time to fart around with such a short lived tool. Instead, I used an old hardwood pallet and belted the steel along some radial lines that I marked on the steel.

This meant that I had a number of segments with sharpish lines.

Then I went around the partially bent piece and started rounding out the cone. There was a lot of stress in the steel at the point, so it took a lot of correcting the edge.


I drilled six holes in the steel (three holes per side) and used fencing wire to hold the edges together, twisting the wire to cinch the edges closer together.

The cone is still quite flat (more of an oval at the base rather than a circle), so I still need to bash it some more to get it even and … useful.

When I have the edges matching properly, I will weld the edges together.

To get the hood working properly as a cone, I will need to heat it and then do some more bashing. The heat will be used to relieve some of the pressure in the steel as it is only bent, rather than shaped with heat.


The point of the cone will be cut off and joined to the flue. The cone will also be used to make the cap for the flue.

When this is done, I will be drilling and bolting the hood onto the top of the forge body. The bent over top of the forge will be bent back to match the angle of the hood.

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