Frontend on!

After lining everthing up I found that the headstock was too far forward.  It was fine but I want this to look compact, almost cartoonish and keep it small for the little lady.  With that in mind we redid the headstock, moving it back about 2.5 inches.  When I say "we" I refer to the odd time I work on this at my Dads.  When working with "The Fast Fossil" you tend to stand around while he starts a flurry of activity, producing a part before you have thought about what to do...

Here you can see the shorter frame and to be honest it looks much better.  It is also in a thicker section of wood so will be stronger as well, always a plus.  You can also see the attached swingarm with basic shaping to it.  I was going to have it with small radius on the front edge but I am now thinking of rounding it down to avoid little heels hitting it when scooting around.  I need to make the "twin shock" uprights for the swingarm as thats what the TZ flattracker had and it will not be strong enough as it is.

Here is the fork/triple clamp in place.  Currently it just has two bolds going into the headstock but I will be making a single bar going through the whole lot.

It is starting to take shape and looks like a bike.

I had to scallop the bottom triple clamp as it was hitting the downtube when the steering was moved left/right.  In retrospect I should have finished and painted the forks and clamps before gluing them up (only the top clamp is glued) but it wont be too difficult to finish them off.

The Frontend

The build has been lagging a bit of late, too many things to do!

Time to make the frontend though (yaay) and get it into a rolling chassis at the very least.  Looking at existing designs for wooden balance bikes they tend to use a sheet of ply, typically 24mm thick or so.  I think they look ok but for this i think it would spoil it a bit so am after something a little more realistic.

A trip to a hardware store and I found this.

£3.99 for the broom with a handle thick enough (from the looks of it).  I had to try a few of them though as they seemed to be randomly bendy or stiff.  This was the stiffest handle of the (identical) brooms.

I aim to use this as the fork legs.  I made up some "triple clamps" out of plywood.

They are the right shape but need finishing off etc.

The assembled frontend looks pretty neat even though they need a bit of tlc with the sander and some paint.

They feel stiff enough, I was a bit concerned about the bottoms but once bolted up they will be great!

Next up, how to attach them.  After a bit of deliberation we went with an alluminium tube with a plate welded down the center.  The plan is to channel out the frame and slot this in, glued and bolted to create a strong headstock that looks neat.

The metal headstock is shown here.  Tig welded, its strong and neat.

 The frame with a slot cut out to accept the plate section of the headstock.  To make it slightly neater still a hole was drilled and then the frame cut through the hole just forward of the hole center.  Doing this allowed a semi-sunken tube location rather than have it stuck on the end of a flat cut.

Here is the tube in place.  Even in its unfinished state it looks neat.  The surrounding wood will be sanded so it smoothly surrounds the tube.

Next up will be the engine, I have made the rough blank for the cases and barrel shape already.  

(Not so) Swinging Arm

I realized after cutting the frame blanks that I forgot to modify the templates to account for a change in how I am attaching the rear swingarm+uprights.  Originally I was going to have straight wooden beams acting as the swingarm but, as ever, when mocking it up in cardboard the spread at the rear was huge to account for it going from 2.5" to 4" (at the axle) in just 6" of length.  These were to be clamped onto the frame using bolts. I changed the design to make curved swingarm sides that are glued (and pinned) to the frame at an oversized mounting point.

When I cut the frame I forgot to add this oversized section, I had already transfered the template to the wood and with one thing or another made the "first cut" after coming back to it days after making changes to the design!  I was about to make another but decided to try and retrofit some disks onto it.  If it doesn't work I can always cut my losses and do it again.

 So I cut out enough disks to pad the mounting point to the required 2.5" and glued them onto the frame with a 6mm threaded bar through the whole lot with nuts+washers at the ends.  It looks like it will be more than strong enough which is good.  Once the swingarms are done I will drill the 6mm hole and clamp them to the frame with the bar+nuts before shaping it.  Once shaped I will be glueing it all up, clamping it on the rod and hiding the nuts (somehow).

So, onto the curved swingarm...  As previously mentioned bending the 4mm ply I have is a bit sketchy, it is prone to cracking with fairly minimal bending so I steamed it first.  Works well enough.  I made a jig out of some wood, made sure everything was square and glued+clamped.

 

In these pics you can see some leftover circles I used on the frame.  I will put pics of that up when I remember...

 Out of the jig the arms retained the curves with no perceptable springback which was good.

Next up I will be shaping these blanks and making the uprights that will serve as the twin shock setup the TZ750 FlatTracker used.