The important bits

One thing on the electric scooter is vitally more important than all others. What could that be?  The badge, of course!

V badge in black and white

Those that know me will see why I chose a ‘V’.  Everyone else, lets just say its along the lines of ‘Volt’ 🙂

V badge

The badge will be constructed of perspex with aluminium bonded to the surface.  LEDs embedded in the perspex under the alu will give a nice, subtle glow. White at the front, red at teh rear.  Not sure on the size yet, but probably around 150mm across.

The boring bits

Not every minute of a project can be packed with excitement. Sometimes, you just have to get on with it.

The biggest excitement on the project by far last week was ‘test driving’ the scooter to work. As I am still a little dubious about the legal requirements, I took a circuitous route down a path along the local river.  Unfortunately, the section I chose to take was not sealed, and I ended up losing my nuts.  Erm.  I mean, some of the nuts came off the bolts holding the fairing to the frame.  This wasn’t a biggie – there are quite a lot of bolts holding the scooter together.  The final construction will use nyloc nuts.  Some observations:

  • The ride quality is great (except on gravel).
  • Torque was fantastic, even hitting maximum speed uphill.
  • Maximum speed was around 32 km/h. Not complaining, really.
  • The brakes are not that good. Yes, this one is a complaint.
  • The handlebars, already at maximum extension, are a little low.
  • There is not quite enough area for feet. It needs pegs.
  • There is no stand. A problem once I got to work! (No beer crates to lean on – will work on that).

After the fun day test-driving, I took the scooter completely apart again.  The plan is that next time it goes back together will be the final time (with nyloc nuts).  Once again I spent some time repairing peeling laminations that the rigours of the drive bought to light.

Localised clamping to fix peeling laminations

I managed to construct a fairly good glue applicator needle from a 10ml plastic syringe with the nozzle cut off and a ball-pump needle screwed in to the hole!  This fits easily into small gaps and allows me to spread the glue well before clamping.  I use a plastic off-cut from a takeaway container as a spatula to spread the glue in the crack.

Home-made glue applicator needle

Detail of the glue applicator needle

K-Mart supplied a cheap, generic, extendible kick stand.  On testing it, it was miles too long, so I threw away the extension and put the hacksaw to use making it shorter.  My plan is now to buy another one, cut it the same and put it on the other side.  They are the right length to stand the bike vertically (rather than leaning).  I may also look at some sort of steering lock so that the front wheel doesn’t move while parked.

The new kick stand

I plan to stain the bike, but also want a racing stripe.  My theory was that masking tape wouldn’t work as the stain would simply bleed under it, causing a wavy/uneven line.  I was pleasantly surprised by the result – virtually no bleed!  I had to sand the surface to an almost polished finish and use a good quality painters tape, but it worked.  Here you can see a couple of test colours, both masked along a line.  Rimu on the left, Kauri on the right.  I think I will use Rimu for the main colour, and something darker than Kauri – maybe Ebony – for the racing stripe.  I used Wattle Colourwood pigmented stain.  Once the scooter is stained, I plan to get it clear-coated (like an automobile).

Testing stain colours and masking

Testing the bits

The first step before getting the scooter on the road, and trusting the integrity of my epidermis to the integrity of this contraption, was to put it all together.

The first step was to drill the bolt holes to allow the body to be mounted to the frame.  I placed the body on the frame, clamped the frame, then flipped the body up to get at the frame.

Drilling the mounting holes

Once the holes were drilled (which sounds easier than it actually was), I flipped the body back around, placed it on the frame and bolted it down.  The bolt holes are counter sunk on top and the M6 stainless bolts sit flush with the fairing.

Attaching the body

The next step was attaching all the hardware up.  I drilled a hole (25mm) through the body directly under the battery box.  A second hole allows the cables to run up into the box – these two holes are offset so that water cannot splash directly up.  All cables are cable-tied along the frame to the hole under the body.  There are connections from the motor (power, control), the throttle (throttle, battery indicator, cut-off switch) and the brakes (cut-off).

I then fastened the battery box down with glue and screws, and I was ready to test!

First test drive (YouTube)!

Update: After attaching a GPS, I have measured top speed at around 32 to 33 km/h.

TV has a home

Wife informs me that this project took 3 years and 10 months to complete.  I told her that the last Olympics didn’t seem like it was that long ago, and the TV cabinet was quicker.  She wasn’t impressed.

Here it is. The TV has a new home.  When the cabinet was started, the little man modelling it wasn’t even in the picture!  It features drawers (upper left and right) to hold CDs and DVDs.  Beneath those the doors fold out and down on cabinet style hinges – these to hold the Wii etc.  Tinted glass doors open to reveal an adjustable height shelf.

Many drama’s unfolded and were solved (or cludged) during this build, including:

  • The drawer faces on the left are pine, whereas the rest is Macrocarpa.  They needed to be stained darker to match.
  • One of the internal walls had cut-outs made on the wrong edge before I realised it was turned 90 degrees. The botch-up is at the back 🙂
  • The glass doors were too wide and overlapped in the middle. A local glass company cut them down 2mm each.
  • I cursed and swore at my ‘cheap, useless’ tools for not cutting straight edges when in fact the cabinet was almost 10mm off-square!  Fixing the top in-place rectified that.

But I get to tick another off the list!  What to start next….

Son modelling the new TV cabinet

Upholstering the bits

If this thing is going to be used for the daily commute, I better make sure it is comfortable to sit on. And looks cool.

As with many parts of this project, this will be another ‘first’ – leather upholstery.  Surprisingly, ‘the internet’ does not seem to have a very large wealth of information on this topic.  Maybe I should have got one of those paper things from the local book hiring place.  I decided to wing it.

The first step was to cut some foam (left over from a friend, Mike’s, completely kick-ass poker table build) to the required shape, and glue it to the seat base.  I had a simple, retro design in mind with a two-colour racing stripe – which luckily was not that complicated.

The foam cut and glued to the seat base

Pulling out the leather supplies from previous projects, I found some suitable pieces in the right colours.  I pulled out the sewing machine and read the manual again.  No, really.  After sewing  a couple of test pieces to get the thread tensions right, I got right on it and sewed up the leather.  The seams were folded over and glued back on the underside to keep them flat (not shown).

Leather sewn and ready for upholstering

Borrowing said-friend’s electric staple gun, I upholstered the seat by stretching the leather over the foam and stapling it into the base. The corners were difficult due to the thickness of several layers of leather where the pleats are folded.  I’m still not happy with them and may add some stitching by hand at a later date.

Here is the finished seat in-place. Yeehaw!

Finished leather seat in place

Shaping the bits

I completed the fairing over the weekend and test-fit it to the scooter. It is really starting to take shape!

The last lamination was glued up, and after allowing it to cure was removed from the form.  Spring-back was surprisingly minimal, as can be seen below with the battery box in place. Pushing the fairing lightly by hand brings it in to alignment.

Fairing removed from the form

As mentioned in a previous post, laminations are peeling in places where the glue has dried too much and lost its bonding ability before the work was properly clamped.  This is due to using a glue with a short open time (10 minutes).  This will be repaired as much as possible before final assembly by forcing glue into the gaps (some back-bending may be required) and some localised clamping.

Laminations peeling in areas

Next I cut out the shape to fit the tubes that make up the existing scooter frame.  This was done by laying the fairing on its side on top of the scooter and marking where the tubes intersect the fairing.  Big radii were cut with a hole saw and connected using a jigsaw.  Lots of filing and sanding finished the job.

Creating the cut-outs for the frame

Test-fitting the fairing over the frame shows that the cut-outs are in the right place.  Now we can finally see the (approximate) final shape!

Test-fitting the fairing

Strengthening the bits

Will the scooter be strong enough to stand on?  Hmm. Perhaps not!

The donor scooter (see second photo) has an existing frame that is perhaps 100mm wide.  The foot board that has been built is about 300mm wide.  The weight of an average human adult would probably fracture the foot board nicely over the frame. Perhaps I should have thought of this sooner?

The answer – fabricate a light frame from aluminium to strengthen the foot board.  Ulrich Aluminium supplied some sturdy and inexpensive box section.  I cut two cross members with 45 degree cuts using a regular drop saw with a waxed blade – slowly! – and two longitudinal members to fit over the top of these.  The total aluminium used represents less than $10.

As can be seen in the photo, one of the cross members had to have a section cut away with a hole saw (using CRC as a lubricant on the drill press) to fit around an existing tube on the scooter.  The two longitudinal members had three sides of the box section removed with a hacksaw, file and some elbow grease. Holes were drilled to match existing mounting holes in the scooter frame (for the old plastic foot board).

Fabricated aluminium parts

The frame will be mounted in place (in the position shown in the photo) through existing holes in the scooter frame, and the foot board/fairing mounted to this.  I had to cut away a section of sheet steel that was welded to the rear of the foot board area at an upwards angle.  The first time I have used an angle grinder – the sheer amount of sparks gave me a bit of a fright, but no problems there!

Donor kick scooter showing frame in place

You can see the hub motor in the rear wheel. The whole unit is cast as one piece.  It is also on the right way around now 🙂

Boxing the bits

The design of my scooter is fairly minimalist.  It would be great if it didn’t need a battery and controller, but unfortunately it does.  And even more unfortunately they are huge and weigh a tonne.

I decided to house everything in a single box that serves double purpose as the seat.  The battery (about the same size and weight as a car battery) and the battery management system (BMS) live at the bottom, and the controller (with all the cable connections) lives upstairs in a separate compartment.  I’m still waiting on some electrical plugs and bits and pieces to be delivered, but in the meantime have constructed the box.

The box width and depth snugly fit the battery, standing on its end, surrounded by packing foam.  The height is designed for a comfortable seat position, which luckily leaves a nice compartment above the battery for the controller.  The box is constructed of 9mm ply, with 20×20 pine for structural elements, glued together. The front and rear faces of the box are bolted on with M6 bolts that bolt into these whatchamacallits that screw into the timber and have a thread to accept the bolts.  This allows the box to be easily opened for repair if required.  I mean, when required.

Battery box showing charging plug

Battery box open showing controller above battery

Gluing the bits

I’m not one to learn from people’s past mistakes – I like to make them myself.  A lot of them it seems.

The next step, after three hours of mindless drilling, was to cut a zillion spacers out of waste MDF, all exactly the same size.  I cut them around 75mm square (from 18mm MDF).  These were glued edge-wise all around the inner circumference of a former, and another former glued on top.  Lining the formers up accurately was done by gluing the spacer against one of the pencil lines (mentioned in the last post) on one former, and then lining the next former up with the same pencil line.

Once all formers were glued together using the spacers I had my finished form, exactly 300mm wide, ready for lamination to begin.  Mental note: It weighs a ton.

After talking to not enough people, I chose an expensive PVA-style glue called ‘Titebond III’ that is apparently the ducks nuts.  It really is – it can stick anything together, and really fast – unfortunately, when you are laminating you need a lot of working time to get things right, and this glue does not give you that.  Mental note: Next time choose a glue with an open time of 30 minutes at least. Titebond III has an open time of 10 minutes, but I swear that the glue became unworkable after 5.

The first lamination consisted of a 4mm birch 4-ply sheet for the outer layer (also called aircraft ply, or thin birch ply), and a 6mm sheet of bendy ply (also 4-ply).  Glue was spread over the birch ply (Mental note: Use lots more glue next time, and maybe don’t use a roller because it seems to eat the glue) and the birch ply was laid over the bendy ply.  Using Father as a helper, we clamped both sheets in the centre (luckily we had marked the centre of the sheets and the centre of the former) and proceeded to clamp outward one way, and then the other way.  This took close to 30 minutes with 2 people. Mental note: Clamping laminations is not as easy as I thought it would be!

One of the problems encountered early on is that it is very difficult to ensure that the two sheets are tightly mated.  Especially in tight corners, the laminations come apart and a tiny gap forms.  Because part of the work has already been clamped ahead, it is almost impossible to fix this before the glue goes off.  I fixed the worst bits later by unclamping the work and squeezing glue down the gaps (bending the ply against the curve to open up the gap), pushing it down with a scrap of plastic cut off an ice cream container, and clamping it back up.

Once all clamps were on, we had the brainwave to strap a strop right around the whole thing and tighten it up.  Genius!  For the following laminations I used strops as the main clamping device, with a few clamps mostly just for positioning.  This is only possible because my form is almost entirely convex.  I would say both methods take about the same amount of time, but using the strops is easier for one person to handle.

Here is a photo showing the first laminations clamped in place and gluing well. Note the strop that we added later to help with the laminations coming apart. Also note the beer crates – great for round the shed.

First lamination, all clamped up

Once the work was unclamped, it sprung back about 100mm at each end, but is flexible enough to move back in to place with very little effort.  This was much less spring-back than I was expecting from only the first two laminations.

First lamination, unclamped

Another layer of bendy-ply to go, followed by the final layer of birch ply!

Preparing the bits

The first real challenge (hopefully the only one) to building my electric scooter is fabricating the fairing.  For the uninitiated, the fairing is the part of the scooter that protects you (a little) from wind, rain and crud that flicks up off the wheels.

I have decided to form the fairing as a single piece of curved timber by laminating together several sheets of ply, of different types, around a former.  The first part of  this is to decide the fairing shape, and then to cut a pattern from 6mm MDF (Medium Density Fibreboard Custom Wood).  I did this by laying the scooter on top of the MDF and tracing the frame.  The fairing shape was then drawn freehand on the MDF (pencil and a lot of eraser) until the final design was reached.  In the following photo you will see a string laid out along the pencil line.  This is to check that the circumference of the fairing is not longer than the sheet of ply (2400mm).

Checking the circumference with string

The pattern was then cut out with a jigsaw and the edges cleaned up with sandpaper, taking care to ensure the curves are smooth and flowing.  The following photo shows the finished pattern placed back on the donor scooter for a final size check.  I’ve traced around the image in white to show where the fairing will go.

Checking the pattern for size

The pattern was then transferred on to a sheet of 18mm MDF by tracing around it with a pencil.  Four of these formers were cut from a single sheet of MDF (1200mm x 2400mm) also with the jigsaw.  Eventually the formers will be evenly spaced (using timber spacers) to provide a total width of around 300mm, which will be the width of the fairing.

The cut formers were stacked on top of each other, lined up as accurately as possible, and clamped together temporarily while they were fastened with 6 long screws.  The screws ensure that the formers are tightly held together while the edges are finished.  Which is of course the next step – using a Palm sander to shape all four formers as one.  Because the fairing will be shaped around all four formers, it is important that they are as identical to each other as possible.

Unfinished formers just before removing clamps

Formers nicely finished with sander

Once the formers are finished with the sander, I marked right across the width of all of them in several places with a set square.  This will help line them up later when assembling the final form with spacers between each sheet.

Markings for alignment

The next part of the process is to drill the holes for clamping.  The flexible plywood will be laminated and bent around the form and will need clamps to hold it in place.  The holes in the the two outer layers of MDF will give the clamps something to purchase.  I am using a holesaw attached to my drill press to drill the clamping holes.  These are around 50mm in diameter.

Drilling the clamp holes