Home Brew – Temperature managed fermenting cabinet

When home brewing beer, it is important to keep a constant and cool temperature. I like to aim for around 19 degrees C (66F) for ales (references) and 4 degrees C for lagers but in New Zealand the general yeasts sold or packaged with kits for lagers are really ‘lager style’ top fermenting (ale) yeasts; also I don’t have the budget or equipment to go for a lager style ferment anyway.

So I wanted to build something that would smooth out daily temperature variations and could potentially have some temperature management (eg peltiers in the summer, incandescent light bulbs in the winter) to assist in smooth and appropriate temperature management.

Total Cost: $2
Tallboy: Recycled
Scrap Wood: Recycled
Polystyrene: Recycled (Sometimes you can find large sheets on the roadside in industrial areas)
Masking Tape: Already had a roll.
Screws: Already had
Adhesive Insulating Foam Tape: $2 a roll
Hinges: Already had

Tools Needed: Screwdrivers, Drill, Hammer, Torch or other light source


I had a tallboy waiting to be junked so I removed all the drawers, stripped the front panel off them and attached them together to form a solid pseudo wall/door. I also drilled a 8cm hole and installed a fan although currently I am not using it.

After creating the front ‘door’ I removed the drawer sliders, mounted it on hinges, and placed a small block on the bottom of the door so it would fit into the cabinet and stay closed. Then I glued polystyrene to the sides, floor, roof and back panel. The back panel sheet is on the rear of the cabinet otherwise there would not have been enough room for the fermenter.

I did the torch test (put a light inside and close the door, if you see light there is a leak) and found quite a few flaws. I also thought that there might be some problems with gaps between the sheets in the corners etc so used duct tape to try and seal it up a bit. I also got some door seal padding strips and lined the door where it was appropriate.

The twisted pair cable you see in those pictures is the temperature probe to test the effectiveness which I graphed and will explain here.

This is the raw temperature data for 20 days from 4 probes. (The second graph is of the same data but only 4 days so you can get a better idea of what happens on a day to day basis)

One is on a shelf to the side of the the cool-box, one is inside the cool-box, another one is on the floor just outside the cool-box and one is outside.

Some obvious things to note is

  • Purple (outside) has a very large variation and has some quite significant drops as you might expect. The probe is subject to direct sun, wind and any other environmental factors.
  • Blue (shelf) is basically right next to the computer recording the data, although the exhaust fan is on the other side and blowing the other way. It currently can get direct sun for a few hours though, and as it is higher I would believe that it is subject to generally higher temperatures as heat rises.
  • Green (floor outside cool-box) is, except for the cool-box, the least affected by direct sun. and being on the floor should generally be the lowest of them all, although there is still some large variations
  • Red (Cool-box) is the smoothest of them all, although it is noticeably but only by a little bit, higher in temperature than some other probes most of the time.

This graph shows how much time is spent in the optimal temperature zone (16-21 degrees c) and how much time is in the extremes. Outside and garage probe 1 are in the red quite a bit as you would expect. Surprisingly, garage probe 2 spends the most time in the optimal temperature, and almost no time in the extremes. This is good as this is about where I plan to have an air intake to cool the box should its internal temperature be higher than the external temperature.

So far the project is a success, but I need to install either an internal cooling system, either by peltiers & light bulbs or possibly using mains water to cool the box. Over winter I may use a relay switched heating pad to maintain an even more constant temperature. Although this assumes it’s going to be too cold in there of course.



Motorcycle chain oiling system

I have often been frustrated with the task of oiling the chain on my motorbike, I want a Scottoiler but I don’t want to pay for it. So I built something that would do the same sort of thing only temporarily. When you want to oil the chain, you fix it on, go for a small ride or spin the wheel a bit, then take it off again.


  • Easy to put on and take off
  • will spread lubricant evenly on the chain
  • cost effective

The basic idea I came up with was to place a rag on the chain with oil flowing onto it at a slow rate, the oil would spread over the rag and onto the chain. This is how I built it.


I had intended to attach it either by using the rear stand thread but I didn’t have any bolts that size, but I found a piece of wood would very happily wedge into the swing-arm very tightly. I took an off cut, drilled a hole through it at 9mm then applied a piece of 10mm threaded rod to it (installed the thread into the wood very happily, the threaded rod was tightly stuck in there.

offcut with threaded rod insertedAn ‘arm’ was needed to reach down to the chain, so another off cut was attached with a couple washers and bolts. This also meant I could adjust the angle to suit when on the bike.

adjustable angle arm bolted to holder

Then I built the oiling base itself, I made two because the first one wasn’t large enough to be drilled again for the second rod. Basically its a small off cut with a 5m hole drilled in it for the hose.

block 1 drilled

Inserting the oil flow tube.

base with tube inserted

The “oiling system” is a folded up rag. I kept the rag and the block the width of the chain to keep the oil where it should be.

first oiling system ready to have the rag attached

I used electrical tape to keep it on. Electrical tape works here because of its ability to stretch. whilst it doesn’t stick to the wood etc. It’s basically working like a rubber-band in this instance.

first oiling block tested on the chain

Its looking good here, but because I cant really attach it to anything I remade it slightly larger, The threaded rod is the second arm between the first and the base, I used threaded rod again so I could adjust the distance.

block two with tube and rod inserted

This is the full mount set. The small block on the right is the wedge for the swing arm, then there is the arm that goes down to the chain. Then the rod that goes inwards to the right distance to place the oiling block where it should be. Bolts for Africa to keep everything in place.

Full mount set - dryInstalled on the bike:

installed on bike from side

chain and base oiler in placeI was a little surprised at how sturdy it is. you would expect with wood, tape, bolts, threaded rod, and something that’s just wedged into the swing-arm to be quite fragile, but its pretty solid.

At the other end of the tube is an adapter I had made earlier for a standard soft drink bottle. I drilled a hole that was 1m too small and  used a small off cut of another tube to make the base. some hot glue to seal and then inserted the smaller tube. I didn’t have any hose clamps handy so used some 20 gauge wire to make my own clamp sort of thing. works well 🙂

sprite zero connector

So now I have my oil input ready. for testing its just sitting in the pillion foot peg.

oil input readyIdeally I will have a small, thin, seal-able tube that has a screw thread on both ends that I can use to put the right amount of oil in, and maybe it has a gauge so I can see how fast its draining etc. but for now; the top of a sprite bottle will do.

ready to roll... and oil

So I put some oil in the “reservoir” and let it flow through. the tube thickness and oil viscosity control the rate at which oil gets onto the chain. and it was flowing through the tube at about 1cm per second, which was perfect. The oil goes through the rag and onto the chain as expected. I am a bit slow here, I was too busy taking pictures and musing to start rotating the wheel which is why that small drop is on the bottom. the idea is you pour the oil in and go for a ride around the street to drain it. Today I just tilted the bike on the stand and manually rolled the wheel, this worked just as well.oil through the chain

Full system off the bike (excluding reservoir)

full system off the bike

Overall, this was a resounding success. It does everything I wanted for very little cost (I had everything already) Its not too fragile, its not too bulky, and it actually works!


Possible improvements

  • I would like a better ‘wedge’ system perhaps some sort of clamp that fits on the underside of the swingarm
  • I should remake it with a better material than wood
  • I need to build a better tube style reservoir

Macro Photography with a budget point-and-click camera

I wanted to purchase a new camera with some good macro options to get better project shots. I also wanted to experiment with a bit of amateur macro photography for a bit of fun. But my budget, as always, was about $0.

Project considerations

  • Low cost
  • Can’t modify existing camera
  • Can be removed or attached easily
  • Works…
  • The first thing I needed was a new lens. I picked up a Macro Zoom Ring +10 Diopter from trademe for $15NZD which was pretty similar to this :

    My budget point-and-click camera obviously couldn’t mount it so I needed to make some things….

    First I needed to make a small extension tube for the lens, and some way of mounting it to the camera. Conveniently, the first thing I laid my hands on, the cap of a bottle of degreaser, just so happened to hold the lens quite snugly. I secured it with black electrical tape, and also wrapped the cap with it several times to block out the light. Then, I cut a hole in the top of the cap, around the size of the existing camera extension tubes so that it could fit snugly on there.

    NB: Cutting through the plastic is much easier with the tape applied. It meants it doesn’t crack when cutting it.

    To mount it to the camera, I built a small perspex base that attached to the bottom of the camera and extended forward so that I could attach the lens and its extension tube to it. When I attached the camera and placed the macro lens onto the mount, it seemed to hold itself in there quite well. (although I may add another bolt to secure it firmly…)

    Now all I need to do is turn the camera on, the lens moves into the hole and I can take macro shots!

    Now for some example shots…