Tesla Model 3 Towing Dinghy

I wanted to get an idea of energy usage involved in towing Custard – a 14′ Wanderer sailing dinghy – so I could work out our range when towing the dinghy.

A Better Route Planner provides an easy way to work out how to get somewhere with charging stops along the way. You can also tweak your car’s energy usage. Their base figure is nominal usage at 65mph.

Custard’s trailer has higher drag that I would expect – in my Mazda 6 it looks like petrol consumption goes up by 25%. This doesn’t appear great for something that is fairly aerodynamic (boat shaped) and not particularly heavy (I guess around 340kg). When I used to tow a Jaguar 21 – 1100kg plus trailer – it seemed to double petrol consumption so for something much smaller 25% seems high.

Anyway, first guess was that the energy consumption in the Tesla would go up by 25 – 33%. The nominal energy consumption per mile is around 255Wh/mile at 65mph according to A Better Route Planner. This seems close to what we get on a normal local journey. So this would mean consumption of around 320 – 340 Wh/mile.

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Mounting trailer tyres with hand tools

The best way to mount 8″ trailer tyres is to take them to a tyre fitter. This method is how I did it and I’m noting it for future reference. However a lot of swearing is involved.

First look at the wheels and tyres. The ones I did years ago went on fairly easily. These laughed at me – no way were they going on.

Rim is far too big to go into the hole
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Kids longbows

My eldest daughter asked me if we could make a bow and arrow for her. She’d done some designs and wanted to make them.

We watched some videos on YouTube on how to make bows and had a go. The first attempt broke.

Broken bow. Wood wasn’t great and was too thick when I test pulled the bow.

So we tried a different approach. I’d cut down an Ash sapling in the garden a few months ago – we’ve got Ash trees at the bottom of the garden so we get saplings growing everywhere. The top of this was about the right stiffness for a bow. So we cut off a suitable length and started work.

Trimming the side branches with an axe – watch those feet!

There are some key design points to making a bow. Any wood that is weak enough to bend is likely to break, so the idea is to trim the wood in such a way that it is still strong, bendy but doesn’t break.

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Mazda 6 Sill Trim

My car had a minor altercation with a post in a car-park which resulted in the sill trim falling off.

I know my car is well worn but this is a bit too scruffy

There was also a minor dent in each door plus paint damage.

It didn’t seem worthwhile getting a full bodyshop repair done – the repair would cost more than the car is worth and there are a few other scratches in the paint anyway. But the plastic bit needed to go back on – otherwise the car just looks horrible.

First step was figure just how to refix it. The trim is held on with plastic clips and these were (mostly) still in the car body panels. Some had been left in the car-park so more were going to be needed. On first glance it looks impossible to put it back on as the clips need to slide into the plastic sill in different directions, but eventually I figured out that if you take the clips out of the car and put them into the sill it becomes easy – the side is tapped into position first, then the bottom clips swing up into the bottom of the metal sill.

Next I had to have a good think about whether it would be safe. The plastic sill is large and heavy – if it fell off at high speed it would be dangerous. I therefore decided to replace all the clips regardless of whether they needed replacement or not.

I phoned Mazda parts and discovered that the clips were £5 – £6 each. Ouch. Ordered them anyway, but they delivered the wrong ones. This gave me a chance to get the part numbers and find them on the Internet where they were around £3 for a packet of 10. If you need the information the part numbers for my car (2010 Mazda 6) are:

Side clips: G18K-51-SJ3

Bottom clips: BP4L51SJ3

I bought them from VehicleClips – good service and the clips look very good indeed.

Getting the old clips out is an art. I found a pair of children’s scissors that were flat enough to fit between the clip and the metal panel; I could then squeeze the clip enough to get it out without damaging anything.

Getting a side clip out
The clip once removed showing the bit I was trying to squeeze

Once all the clips were out I could fit the new clips to the plastic sill and bang it into place. This is quick and easy once you’ve got it set up.

To make the metal bits look better I washed down with car shampoo followed by car wax. This filled in the surface scratches making the damage much less visible. Overall you can still see some scuffs, with minor dents visible if you look for them, but it is now OK and a coat of winter grime will hide it all.

Bafang BPM front hub motor cable replacement part 2

As mentioned previously I used the existing cable – just shortening it a bit. The remaining length is ok and I didn’t need to get a cable through the axle from scratch.

I carefully drew a diagram of the colours of the wires and reconnected the new ends to the correct colour. The soldered joints were covered in heat shrink and self-almalgamating tape.

I didn’t use any glue, putty or sealant. I reused the existing wire ties and added another around the omega clip.

Recut wire soldered in

Note that the wire exits the axle inside the motor on the same side as the aperture on the end of the axle. This means that if the aperture on the end faces downwards, and any water gets into the axle, it will drain into the motor. Whereas if the aperture on the end faces upwards then water cannot get out of the axle into the motor.

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Bafang BPM front hub motor cable replacement

As mentioned in a previous post I damaged the cable for a Bafang BPM front hub motor. I found various instructions on the web for strip-down instructions – notably this strip-down on Endless Sphere.

My motor isn’t exactly the same as any of the stripdowns I’ve seen – mine is a front hub 250W motor without sensors. I’ve put some details here if only for me when I need to do this job again!

The cover plate comes off easily enough and the motor unit can then be pulled out of the hub. Note any washers between the outer hub and the motor unit!

Two shim washers on the non-wire side of the hub

The clutch and planetary gears can be pulled off. The sun gear can then be unscrewed from the motor and the circlip underneath it removed.

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Mazda 6 Mk2 Rear Seatbelt Issue

I’ve got a 2010 Mazda 6 with about 100,000 miles on the clock. It’s a great car – lovely to drive and very reliable. However it did something interesting to me the other day.

I folded the rear seats down to get a bike in the boot. When I tried to put the seats back up one side wouldn’t move – the seat belt had locked itself. I suspect the inertia reel units have something to stop them locking in the down position and this has stopped working due to age.

The seat is designed to be worked on when it is in the upright position – locked down everything gets much harder! I wanted to take the car to the garage for them to have a look but all the Mazda garages are closed due to COVID-19.

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Rebuilding steel-framed bike

One option to get fitter, reduce car costs and reduce carbon emissions is to:

  1. Drive myself and the kids to school in the car;
  2. Get bike out of the car boot and cycle home;
  3. Cycle back in at pick up time, dismantle bike and put it back in the boot of the car;
  4. Get kids and drive back in the car.

I discovered that a bike my dad bought me for school will fit in the boot of the car with its wheels off. It is a nice bike – great fun to ride. However the freewheel was free in both directions and the paint was coming off, leading to rust.

First stage was to strip off the old paint. I was going to get the frame shot-blasted and powder coated. However I couldn’t find anyone locally to do this – most calls went unreturned – and I didn’t want to put the frame in the post due to the risk of damage. For this bike I don’t really care what it looks like – the paint needs to stop rust and if it looks rough it is less likely to get stolen.

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Arkana tulip table repair

We’ve got an Arkana tulip table. Nice thing – very second hand and a bit battered but practical and nice to look at.

However there isn’t much structure in it – the skin is the only thing holding it together and that is just plastic – no fibreglass reinforcement. This obviously works – the table has lasted around 50 years – but in the summer the base cracked. When this happens it isn’t obvious – there is a loud noise but the table remains mostly stable and it was a while before we found the crack.

Hmmm
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