The site does look good - is it just me though but on the "The Craft" page all the images are the same? - the descriptions sound like they should be showing different parts of the process but they're all the same side profile of the front of a bike?
It's not the years, honey. It's the mileage.
Yes, it is unfinished.
I need to re-edit the text, sort the pics and get the merchandise section organised.
The first two just need time, the last needs the labels for the products to be finalised and I'm still testing the chain treatment and wax combination.
Mark Kelly
Mark Kelly
Almost every cock-up I've made on a frame has involved the chainstay alignment somehow, so I've changed the build process in an attempt to make this less likely.
Part one of this process was making a small aluminium machinist's clamp from two short aluminium bars and two M6 studs. I could have used wingnuts to tighten this but I had fun making the brass lollipops:
Chainstay Clamp
The stud placement was calculated so when the clamp is positioned where it is it ensures the chainstays are parallel and at the selected tyre clearance, for this clamp it is 32mm (+10mm, so 42mm gap).
Part two involves building the bike in a different order: like everybody else I defaulted to building the front triangle then adding the rear but this isn't working for my processes. I am now building out from the bottom bracket, so chainstays first, then down tube and head tube get added to form the spine of the bike, then the superstructure.
Chainstay Bonding.
Loving the 3M dual plunger (DP) system: it's been virtually unobtainable here as the local distributor has never heard of the idea of customer service, they will only sell a full box most of which would be out of use by date before I got to use it.
The clamp also makes it very simple to put the bondline under pressure as per the 3M datasheet whilst keeping everything where it should be: a simple plate behind the clamp and a carpenter's F clamp onto the BB shell is all that is needed. This is the part that was very difficult previously: with the other tubes in place the clamping tended to pull the chainstays out of alignment.
The piece of green plastic is a go / no go gauge for the gap from the chainstay to the edge of the BB.
Mark Kelly
So the idea of building from the spine out is working as planned.
Spine
The spine built up in perfect alignment, helped by a new method of cutting mitres which I will explain when I've done a few more.
Octomitre
The absurdly complex eight faceted mitre for the bottom of the seat tube.
Octomitre_placed
fits.
Mark Kelly
Simple but effective method of making cut templates for the tube laterals using overlain strips of masking tape:
Templates
These laterals are in lightly fiddlebacked myrtle beech and it occurred to me that the leaf is bookmatched so I could make matching pairs for each tube:
Bookmatch
Retrospectively obvious, though it wouldn't have made much difference with laterals of rose gum or similar as it's too straght grained.
Note that the strips are cut to avoid using a couple of knots and shakes which might create weak spots. Similarly I cannot use deeply fiddlebacked leaf, if the figure is too deep I can't get the leaf to lay flat without removing too much material. These leaves came up nicely sanded to 0.05mm depth (yes, I measure it every time):
Bookmatch_Sanded.
And they look pretty good in situ:
Laterals.
Mark Kelly
Fiddle Back
The maple used in traditional violin making has a repetitive banding pattern due to compressive distortion of the wood fibres during tree growth. The association is now so strong that the figure is called fiddle back or fiddleback, even when it occurs on other woods.
Example above by a certain Signor Stradivari who worked in Cremona a while back and made violins that people seem to really like.
Mark Kelly
Lyrebird Anvil
I made myself an anvil from apiece of old railway line; works a treat.
Headbadge_start
Much better result more easily obtained.
Headbadge_K2S
Silver treated with K2S then the highlights polished back to bare silver.
I had a request to try to do the headbadge in gold so I bought some Aura 22k gold paste, $170 for one gram which should do 3-5 headbadges.
Headbadge_Aura22k
Here is the paste coated on the bare silver and allowed to dry. I decided to do the body and display feathers in gold and leave the fine feathers silver.
Headbadge_Heat
The paste needs to be heat treated to bond to the silver, a jeweller's oven is recommended. I don't have one of those but I do have a lab with a bunsen burner. One hour at a soft red heat should be enough.
Headbadge_Fail
Or not as the case may be.
Headbadges will be silver for the forseeable future.
Mark Kelly
The bunsen burner is in the winery lab. The apparatus behind it performs Rankine's aspiration method for measuring SO2 in wine: aspiration of unheated wine gives you the free SO2 content, heating it whilst aspirating gives the bound, hence the bunsen burner.
The stuff up turns out to be because I used sterling silver for the headbadges; it gives a better reaction with K2S but for the same reason it won't bind to gold. I will buy some more "4 9s" silver (99.99% purity) and try again.
Mark Kelly
Sterling has 7.5% copper which makes it much stronger than four nines but more reactive.
I decided to try to exploit this by inducing oxidation (oxygen and sulphur being in the same chemical family, group 6A in the standard periodic table).
headbadge_2
It actually looks quite good in the flesh, the bird is quite gold and the background subtly opalescent.
Even good photographers struggle with highly reflective objects and I am anything but a good photographer.
Mark Kelly
Looks fiddlebacked. Is it fiddlebacked? I know boats!
Bookmarks