The Sun Goes on a Diet

I'm waiting for some supplies to arrive before I can continue with the saddle. When you live in New Zealand this can mean a reasonably long wait if the stuff is coming from overseas. When local suppliers tell you that it's coming on the next shipment, that's generally exactly what it means. In the meantime I've spent my time putting the sun on a crash diet. If you recall from almost a year ago (now where did that go?) I'd had the teeth cut into my blanks but then I'd put the gears to one side to concentrate on other stuff. Other stuff has been done so it's time to look at the sun again.

I need to make holes in the sun to make it appear the same as the original, the gear features five spokes, one of which carries Renouf's patent wedge to secure it to the axle. I decided that the best approach would be to accurately drill holes at the corners of the cutouts and then drill extra holes around the perimeter to allow the bulk to be quickly removed.

First make an accurate arbor so that the gear can be easily mounted in a chuck. I work near a railway line and routinely pick these up as they are discarded.

Discarded 1" railway bolt.

They are made from a very high tensile steel and machine reasonably well. Very useful for throwaway stuff like temporary arbors.

The location of only four of the corner holes needs to be carefully marked, the rest can be divided.

Sun spots?

Then make Swiss cheese of the centres...

...and use a junior hacksaw to join up the dots. This removes a lot of material quickly.

The inner and outer arcs can be milled using the side of the cutter. 

I would have preferred to use a rotary table to do this but I didn't for a very good reason. I haven't got one. The Myford dividing head worked OK though as it has a 60:1 worm which means slow feeds are possible. I did try to buy a rotary table about a year ago and everything that was available to me was junk or made from cheese so I didn't.

Then get busy with a file. 

I may have mentioned this before, but I really enjoy hand filing. I'm not sure what that says about me, I'll let you decide <cough> OCD </cough>

At this point the sun gear looks similar to the original but there are still many details to put right.

First file the front of the outer rim to be a curved profile. 

This completes the front side of the gear.

Flip it over and machine a recess into the back of the gear, 

I should probably have done this before I cut the holes.

Then file the inner rim to the same curved profile as the outer,

also blend the transition from the central boss to the spokes.

Next I have to profile the rear side of the spokes to match the original.

I bought a few ball nose slot drills a while ago for exactly this job, after a little testing on some scrap I was able to work out the speed and feed rates to avoid chatter.

Bolt the gear down directly to the mill table and align it with the spoke square to the bed. Then machine the recess in either side of the spoke.  It's not possible to get the profile correct at the rim end of the spoke using the mill but a few minutes with a small carbide burr in the Dremel soon cleaned up the blend.

Notice the complete lack of clearance and visibility.

All that needs to be done now is to polish, harden and plate which I'll do later when I have more parts ready. For the record, the weight has almost been cut in half by the diet, from 1lb 8.25oz (~0.69kg) down to 12.75oz (~0.36kg)

I'm quite surprised by the slender cross section of the spokes in the original gear casting. I'm unsure of the material it is cast from but clearly it is strong enough to handle the torque involved. My spokes are marginally thicker and certainly stronger being made from 4140 chromoly. Consider the size, material & thickness of your average mountain bike granny gear and then consider the torque as you stand on the pedals in first gear and winch yourself up your local mountain. You do have a local mountain don't you? If you don't, we have lots in NZ that you can borrow.

In other news, I've been off the bike for the last two weeks with a very serious case of manflu. I rode into work again this week for the first time in 2 1/2 weeks. A 70km round trip is probably not the best way to get back into regular riding and I suffered like a dog. Getting old is wildly overrated, the only tangible benefit that I can see is I get better at cryptic crosswords.

The nights are drawing in faster now as we approach the steep part of the seasonal sin wave and the early mornings are noticeably colder. I like riding in autumn though, there is less wind and the days are usually warm.

Plating EQC Frames

I have a very good excuse you know.

I mean for not posting an entry for such a long time. The house has been repaired from the earthquake damage and we have been forced to take refuge in a B&B for the last month. B&Bs are OK for a few days at most, after a few weeks they become tiresome and after a month, positively ghastly. We turned the house over to the builders and my lovely wife (resident soft furnishings expert) chose new paint and wallpaper. We got lucky, our builder was excellent, indeed he is worth a mention. David Peach of North Canterbury Renovations did an excellent job, it's just unfortunate that the rest of the house looks a little shabby now. But I digress.

The B&B was at just the wrong distance from the house, it meant evening visits to The Shed were awkward at best and consequently I have made little progress. As promised, I have made a new seat post mount (at the correct angle this time) from a slightly thicker strap of steel. I wasn't happy with the old one but this one is good, much stronger. Also I've plated all of the saddle components which means the saddle is now ready for a leather top.

 If I've counted correctly, there are 48 individual pieces that have all had 

to be hand made in the saddle frame, no wonder it's taken me this long.

I plated the parts over three consecutive nights. I did the rails last and 

needed to borrow a Lego storage box from my son to get the length I needed.

Ready for a good leathering.

I was asked last time if I am going to make one or get one from Longhorn Leather here in Christchurch. This is a good question not easily answered. I can dismiss the Longhorn option immediately, not through bad workmanship, they are very good, but because I find their saddle tops too two dimensional for my arse. I've ridden a few 90km days on one of their tops and it just didn't fit my backside very well. A long time ago a friend of mine offered to make my leather top, so he could contribute to the project. Tim's work is first rate and at the time I happily agreed. Now though, after 20 months of this business, I'm of a mind to make it myself. I've done a lot of leather work in the past and even a few saddles. It also means I won't lose my precious frame in the post, a problem that unfortunately I have recent experience of. Tim is acting as my mentor for this stage, more later.

In other news, I had a disaster whilst we were out of the house. I have a pair of lovely wood rimmed wheels (28 x 1 3/8") or 700A, ETRTO 37-642. These have sat in my lounge for ages waiting for a suitably ancient frame to turn up. When we had to clear out I noticed that the rear tyre was soft so put 30psi in to maintain the shape and moved it into the garage. The next time I saw it, it looked like this:

Oops (and other, stronger words).

I will mend it but probably won't be able to ride it again. The sad thing is, I now have a frame that would suit these very well.

Also this week, two other projects are nearing completion. The fruit of Young Dylan's labour was brought round to my shed this week to get all the threads and bearing surfaces cut or cleaned up. I have one of these you see.

You are welcome to have use of it but it doesn't leave my shed.

I'm more than happy to prep frames for other people at no charge if they bribe me with sweeties, biscuits or beer. He's done a great job and I look forward to his report of the first commute on it. Not bad for a tyro ;-)

Tweed Pete has also brought his newly complete MkII round to my shed for the same purpose, this features 4130 chromoly tubing which Pete has TIGed together himself. Pete has also thrown some old parts on it so he can ride it tirelessly up and down his road with a big grin on his face. I can imagine his neighbours children commenting "Mum, that special man's riding his bike again". I'm not yet allowed to post a picture. It will be making it's debut once fully complete.

Sadly, both Pete and Dylan are unnecessarily tall and consequently I'll be unable to ride either one properly.

The Tension Mounts

As promised, I've been busy making the tensioning hardware for the saddle this week. I am fortunate in that I have a Brooks saddle from this period in my possession so I have been able to make exact fac similes of the components relatively easily. This is convenient because I had a brain fart and neglected to take any measurements of these bits on the original.

 Too much tension, or more likely just shrinkage from 125 years of neglect 

has caused the original leather to part company at the nose piece.

Lots of photos but no measurements. 

Unfortunately, this week I did the exact opposite, I took loads of measurements but no photos. So you'll just have to look at the finished bits and imagine the steps involved. Sorry about that.

 Some fiddly filing fun.

 I have some nice copper rivets ready for these holes.

Now that the saddle frame is finished, I'll probably

 make  a new seat post at the correct angle this time.

The camera has made it appear worse than it is.

I still need to polish and plate all the saddle stuff which will take a little time, then I need to have a little think about what to do next.


In other news, it is with some degree of sadness that I must report the death of the pub argument. I am a member of a pub quiz team, quite a successful team as it happens. But that is incidental, the pub quiz is merely an excuse to go down the pub and talk nonsense and escape from reality for a short period of time. Our particular pub quiz only actually runs during the winter months, however we still attend the pub on 'pub quiz nights' throughout the year. We have a loose collective of professional members and whoever turns up turns up. It is suspected that certain members have not told their respective wives of the winter only thing. As a team we can generally clean up on the 'real' questions on science, geography, literature, proper sports, decent music from our youth etc. However, we are utterly hopeless on the 'fluffy' questions. Who won American 'X' Factor Idol Got Talent last year? Not a clue. I hesitate to suggest that it may be because we enforce a strict 'no girls allowed' rule.

In these off season evenings certain topics come up from time to time that cause discussion, sometimes heated but always cordial and enjoyable. Classic pub arguments. These would often last until the next week when somebody would have looked it up to prove the point and get a free pint. This is now a thing of the past, what happens now is that somebody whips out one of these modern "electric smart phone" devices and the prosecution rests m'lud. Not as much fun...

Front Saddle Mounts

As mentioned last time, I've spent my shedweek making the front mounts.

 I've never seen front mounts like these before. 

They match the catalogue illustrations, so clearly the original saddle and worth copying.

These are tricky little blighters with lots of angles and sticky out bits and holes and stuff. After a little planning (read trigonometry) I calculated that I could just get them out of a piece of 1 1/8" bar stock if I was careful and had a bit of a tailwind. The mounts have angled holes and faces in multiple planes which means that I need to machine the containing shape out accurately before drilling and tapping the relevant holes. Only when this is done can I then smooth out the angles and make them appear more organic. The originals would have been castings with very little clean up.

My new milling machine got an extensive trial this week, I'm still learning the best way to use it with the tooling I have available to me. Also I spent quite a considerable period of time making the thing run a bit more quietly. This is a known issue with the Mk1 Dore Westbury mills. They have an epicyclic gearbox that uses straight cut Myford change gears that are noisy in use.

Initially I machined the angled flats by using a Myford swivelling vertical slide, but after a period of time I realised that I could get the same results with more rigidity if I just used a machine vice and set up the work with a combination square with a protractor head.

A series of photos will illustrate the process as usual.

 Mill flats on either side of the bar stock.

 Mill the angled faces using the swivelling slide.

 And again.

 Before I ditched the swivelling slide due to clearance issues 

and just used a combination square to set the angles.

 Mill another flat on the side.

 Mark out and cut the two halves. 

And now mill faces in the other plane.

Hacksaw off some excess...

... before milling to size.

 All the faces are now done, so I can drill and tap the

 holes at the correct locations and angles.

 Starting to clean up with a file.

Beginning to take shape.

A little more  thinning is still needed before I'm happy.

Next week I'll start on the saddle tensioning components.

In other news, the whanau have left me and gone to visit relies in Australia for the week, Whilst they have gone we have had 30+ degree days and bush fires. Honestly what has 'stralia got that you can't get right here in Canterbury. A few weeks ago I even saw a wallaby at the side of the road as I was cycling home. It was just at the Tram Road and Northern Motorway intersection. I know that they occur down in South Canterbury but I never seen one this far North before. I know for certain that it was a wallaby because I was able to watch it for a long time without it running off. In fact I would have been greatly surprised if it had run off since it was dead. I looked it up and apparently it is a Red Necked or Bennett's Wallaby. It is of course possible that it was killed down South and inadvertently or otherwise carried North. It wasn't there the next day so it was probably just resting or something.

Saddle Rails

The next part of the saddle to get my attention is the rails, the front to back members that bolt to the neck at the front and the cantle plate at the rear. I cross checked measurements of the original facile saddle with a couple of original Brooks of the period and the wire is 9/32" or very close to 7mm, if you prefer. This is quite a substantial gauge to have to bend by hand, even more so when you consider that the rails are made from spring steel which must be bent cold. Spring steel is hard to shape since it is designed to bend back (obviously), it is tough stuff.

A quick trip around the corner to CMI Springs and I was able to get some straight lengths of 9/32" spring steel wire. They don't normally sell small volumes to the public but I chatted the receptionist up and she caught the boss on a good day. This was just before Christmas and they were all looking forward to the holiday. I bought a few spare lengths at the same time.

Most of the bends are very straightforward, the hard one is the eye loop at the rear of the rail which bolts to the cantle plate. I don't like hitting things, I prefer to use measured force so I made a little jig to assist in the process.

First make a loop in the wire as tight as possible by gripping the end very firmly

 in a large vice and bending back on itself so that it forms a coil. 

This was about the limit of my physical strength and I ended up 

on my arse a few times as the wire slipped in the vice. 

When the basic loop has been formed, the vice can be 

used to decrease the size of the loop and also to flatten it. 

Then carefully cut off the end that has been gripped and 

again squish it in the vice to flatten as much as possible. 

I needed to use various spacers to push the coil too far the other way so that when it sprung back it was flat. Cutting spring steel is also a bit of a mission, hacksaw blades will dull very quickly. An abrasive cut off wheel is probably the best option.

The basic loop can now be squished into the jig...

... and bolted up so that it can't move. 

This is then held in the vice and the return bend completed. 

The jig lends a certain amount of uniformity to the shape of the eye.

With the eyes completed, the remaining bends seemed easy in comparison. The only difficulties were ensuring that both sides remained identical mirrors of each other and that the straight, front section of both rails were parallel to each other. This is where the saddle tensioning hardware slides back and forth.

According to the head guy at CMI, all I need to do now is soak in my oven for an hour at 200 degrees Celsigrade to remove the residual stresses from bending. No other heat treatment is needed. I'll have to be a bit careful about when I do this, I don't particularly want my lovely wife to find out.

I have been slightly surprised by the length of the saddle on this bike, from the front tip of the rails to the back of the cantle plate is 16.5". This is much longer than the usual Brooks B70s found on contemporary penny farthings. The reason becomes clear when you consider the rationale behind the bike, the whole idea being to get the rider lower and further back as a safety feature to help prevent headers. Remember that the bike was in direct competition to Starley's new rear driving safety and of course we know which design became dominant. Over the course of the 6 years that the geared facile was in production, the bikes became less upright and the rider was placed further back. It is very fortunate that the original I am copying is so complete, even down to the saddle leather. Had I not had an original saddle to copy I would have made it to the same dimensions as a conventional Brooks B70 International saddle.

The original saddle from the geared facile.

Next week I'll make the front clamps that bolt the rails to the neck, the ones on a facile being particularly complex (of course).

In other news we've been having more weather this week, we had 38 degrees Celsigrade in my garden on Saturday, it was so hot that we all went down to a local swimming hole at the river and messed around for a couple of hours. The braided rivers in our part of the world are excellent for making dams and other contrived hydraulic civil engineering projects. Much fun can be had diverting the river about. Of course after the next big rain, all our efforts will be washed away as the river shifts again.

It has also been too hot to do much machining, but after seeing Tweed Pete's spotless shed a few days ago, I have forced myself to have a tidy up in mine. I've found all sorts of things that I'd forgotten I had, hidden under several feet of swarf. I may have to do it more regularly.