Repairing a Heat Selection Knob on a Fan Heater

Well this was frustrating! The range selection knob on my fan heater was turning without doing anything. I decided to try and open the case to see what was wrong, but of course the manufacturer had used security fixings, relatively uncommon triangular ones too!

I have lots of shapes and sizes of Torx bits and screwdrivers, but they would be useless in this situation. Luckily I managed to undo two of four screws from the upper side of the heater using a large jeweler's screwdriver. This allowed me to pull the case apart just enough to remove the knob.

Part of the shaft of the knob had snapped off in the switch. Gluing, even with superglue wouldn't be a permanent fix because the resistance of the switch was such that a large torque was needed to change range.
First I removed the broken-off piece of shaft from the switch using a woodscrew. The piece was hollow as was the other piece of shaft remaining on the knob. I decided to attach the two pieces together using a rivet pin.

I hoard lots of scrap, and rivet pins are part of my collection, along with self tapping screws, springs, nuts, washers and all sorts of other miscellaneous items! Some of these pins were exactly the right diameter.

I dripped some super glue into the hollow interior of both sections and also on the broken surface, then joined the two pieces together. Some heat from another fan heater accelerated curing of the glue.

After trimming the pin, I replaced the switch, cost of repair? Zero!

How Do I Mix Fuel for My String Trimmer, Hedge Trimmer or Chainsaw?

These garden power tools generally have a two stroke engine (also known as a two cycle or 2T engine), and to make them lighter, they don't carry motor oil on board as in the case of a lawn mower or road vehicle. Instead oil is added and mixed with the petrol (gas) before use.
In general petrol/oil ratio for 2-stroke engines is 40:1 or 50:1 which is 2.5% or 2% oil. 50:1 is equivalent to 20ml in 1 litre or just over 2 1/2 US fluid ounces per US gallon. 40:1 is equivalent to 25ml in 1 litre or 3.2 US fluid ounces per US gallon. 
After adding oil, swirl the contents around to ensure it's thoroughly mixed.Consult the manual of the machine for details of the recommended ratio.

How to Stop Nails Splitting Timber

Flat or round nails can split timber, especially if they're used near the edge because the sloped tip acts as a wedge. An old tip is to shear the tips off wire nails to stop them doing this. The nail then shears and cuts through fibres rather than acting as a wedge, pushing them apart and splitting the timber.

Homemade Tools - Snow Rake

I put this together from scrap 2 x 1 and 3/8" (10mm) plywood. I used some pieces of waste wire from electric cable (string would be just as good) as ties to stop the board pulling off the end of the 2 x 1.

New Science Q&A Article for Children

Just published a new science guide for children.

"Top 100 Interesting Science Questions for Kids" covers space, nature, technology, engineering, elementary math, chemistry, physics and biology.

AA to C and D Battery Converters

These are useful little gadgets if you don't have any C or D cells to hand. AA cells are readily available in cheap packs from pound/dollar/euro shops and are probably also optimised to have a higher energy density.

Snow Shovels by Briggs & Stratton

Think I'd prefer shovelling by hand to warm up, but these snow shovels by Briggs & Stratton could be useful!

Lidl Tools from the Centre Aisle - Air Wedges

Picked up this set of air wedges in Lidl . They're like a mini version of what firemen use. Handy for lifting and positioning stuff and pushing things apart.

Valves for Shutting Off Water in the Home

Just a reminder folks to identify where all your gate valves are for shutting off water in an emergency. Tie a label around them or write the function on the wall behind with a thick marker. Valves can and do seize, so it's good to exercise them at least once a year. You don't want to be running around like a headless chicken when there's a water leak.

Cutting Down the Overgrown Sycamore

My shepherd's hook for pulling down the overgrown sycamore in the back garden. The plan was to cut low and reach high with the 20 foot hook to get leverage, without having to climb up to tie ropes.

The hook was made from a 6m length of 12mm rebar, with a loop at one end for hooking around limbs and a smaller loop at the other end for attaching a rope. Unlike a rope, the hook was rigid and could be extended high up into the crown, without having to do any climbing.

One 8" bough down, about 8 more to go. This one managed to land on a sheet of steel that sliced into it.

I decided to make a rope saw for cutting through some of the limbs that were nearly vertical. It would have been dangerous to cut these with a chainsaw while I was up the tree. Using a rope saw was slow and hard work but really safe because limbs could be cut remotely and pulled down using a long rope and my sheperd's hook. The saw was made from an old chain saw chain. I cut one of the links with an angle grinder and opened it out, then attached the ropes to rings passed through link holes in the ends of the chain.

Finally finished cutting!

Lots of logs to cut up.

I chipped all the branches. They can be used as fuel on a stove or as a mulch in the garden for suppressing weeds.

By winter last year after a warm summer, the tree had put on 6 feet of new growth. Looks as if I'll have to do more lopping this year!