Levers Part 3 (another pivotal moment)

This shedweek I've made the lever pivot mounts, these are the bits at the very front of the levers through which the pivots bolt.

They turned out to be relatively easy to make after I'd worked out how to do it and I was able to knock them out in just a couple of evenings.

First job is to realise that I don't have any bar stock big enough so I do a raid on Kung Fu Pete's metal stash for some 2" bar to cut into salami.

Mark and drill opposite centres. All will become clear...

Machine the outer face, this recess is to accommodate the special locknut.

Then flip around and machine the inner edge, this 

locates against the pivot on the end of the fork extension.

Hacksaw diet.

Mount between those centres and machine the trunnions to be a tight fit inside the front ends of the levers.

I only need one of the trunnions, the other only serves as a temporary way to...

... hold the work whilst I bore the trunnion to make it easier to braze...

...and feather the edge to reduce a stress riser.

Then chop off the spare trunnion.

Mount directly onto the mill bed to create the round shape. I machined some very accurate spacers so that I could bolt up securely and yet still turn the work easily. I searched high and low for a piece of tubing of the right size to act as a handle to rotate the pivot. I then realised I had exactly the right size sitting on the workbench next to me. Duh.

These little needles of swarf are deadly sharp and have got everywhere. 

I'm still picking them out of my hands.

Done.

Next week I'll make the pedals, these will be the last actual parts to make. I have a folder of photos of the original bike on my computer, whenever I finish a part and have no further use for the photos of it I move them to a different folder. I started with 264 photos and I only have 9 left, all of the pedals. I'm ignoring the rear mudguard for now.

In other news, I knocked the bike over this week. I had the front wheel slightly overlapping the workshop door and when I pushed the door shut it gently pushed the bike off balance. I was mildly annoyed and may possibly have taught the children three doors down some exciting new grown up words. It fell on the right hand side and fortunately didn't do too much damage, there is some scuffing to the hand grip and the lever pivot. But the con rod suffered the most, getting badly bent. It turns out that the brazed joints aren't strong enough after all. I'm going to chop out the centre section and ask Kung Fu Pete to weld in a new bit. I should have done this from the start I guess. The left hand side is OK at present so I'll leave it for now. We learn by our mistakes.

Levers part 2 - Beefy Bottom Mounts

Hoorah, I got the welded levers back from Pete.

As usual, he has done a brilliant job TIGing them together for me. I have some reservations about strength and the nature of welded 4130 so I'm going to get them normalised before I go too much further. If they break in use I'll have a re think about how to make them again.

This week I'm going to make these bits.

They are the bottom mounts for the con rods and are really quite beefy.

Starting with some scrap 3/4" mild steel plate, mark out and bore a counter sink at the correct depth.

Then using a series of drilled holes remove most of the excess metal from the mounts. 

Drill bits are cheap compared to milling cutters...

Then bolt directly to the bed and mill the final thicknesses of the mounts. 

The top part is just a tad thicker than the lever at 0.675" and the bottom part that the conrod bolts to is 0.375".

Next flip the mounts over and again bolt down square to the bed. Mill the sides to the correct width.

Then using these new milled surfaces as the reference, mount in the machine vice and mill the top of the mounts.

Next mill the slots for the lower con rod bolts. 

Recall that these bolts had flats machined on them. These flats locate into these slots.

Next mount at 45 degrees and mill away most of the excess of the upper thicker section...

...tidy up with files.

Then mark out the outer shape of the mounts and get busy with the hacksaw and files.

The last operation is to machine a curved slot into the upper thicker section so that the levers are wrapped by the mount, this needs to be a nice fit so that the brazed joint will be strong. Careful measuring of my Myford and the lever radius means that I can just turn these by mounting on the faceplate. It really is pushing the lathe to it's limits though. Simply bolting the mounts to the faceplate won't be rigid enough, the interrupted cut will soon knock the mounts out of alignment and make me a bit grumpier. In one of those rare moments of serendipity, I discovered that the slots in the faceplate are the same width as the slots in the mounts, This means that I can make some spacers that will rigidly locate the mounts onto the faceplate. By drilling a hole through, I can very securely bolt the mounts at the correct radial distance so that the bottom of the cut is the inner radius of the levers.

Very securely held in place, the correct radius can be adjusted by sliding in or out...

...and then bolting up.

With such a large diameter of cut, I needed to slow the lathe right down to successfully machine the groove. The interrupted cut meant that the feed in had to be very gentle.

I was also cutting almost blind, in that it was very hard to see where the tool was contacting at any time. 

I found that placing some white paper beneath the tool and viewing directly downwards with one 

eye shut wearing magnifying glasses and standing on one leg helped a lot.

Once I got close to final size and depth, I used the same trick that I used when filing the neck to fit into the backbone. The levers were coated with engineer's blue and slid around the groove, the marked high spots were then machined off and the process repeated.

Great Success.

I'll start on the lever pivots next week.


In other news, the strange fruit that was discovered in my garden has correctly been identified as an Akebi fruit. Thanks for that Christian. I found the vine that it grew on (we have a big garden) and discovered a few more, they don't grew on top but underneath a top layer of leaves which is why I've never seen them before. The plant, known as a chocolate vine, is classified as a noxious weed here in NZ. In the interests of scientific discovery I immediately ate one of the fruits, seeds and all. It wasn't too unpleasant, a little like melon, but had a bitter after taste. Later that evening I became slightly disorientated and nauseous. The following morning I had a mild headache and slept in a little later than usual, I seemed to be sensitive to light and loud noise. It must have been the space fruit, it couldn't possibly have anything to do with the beer I'd drunk to get rid of the bitter taste.

Nailed It - Con Rods Part 1

After weeks of painting, plating and making things look pretty I've finally got back on the machine tools making swarf and thoroughly enjoying myself.

Isn't it pretty? Even my lovely wife think so. 

I caught her showing it off to some friends the other day.

The gear guard in place for the first time.

It took me several evenings to get it back together, I didn't rush it and only got the one deep gouge in the paint where I had to spring the forks to install the front wheel.

I seem to be rapidly running out of bits to make which is both good and bad. Good because the bike is nearly done and bad because the hardest bits are still to come. I'm going to make the connecting rods next. Everybody knows what a con rod is, it connects a piston to the crank shaft. Well so do these con rods if you think of your feet on the end of the levers as pistons and the crank as erm... the crank. Even though the ICE wasn't yet in wide use, it had been around for years and the term would have been familiar enough to the makers of the geared facile, Ellis & Co, to use it in their catalogs. But I digress.

This page is from the 1884 Ellis & Co. catalog from my own collection. 

Email me, using the link at the right, if you'd like a complete scanned copy.

Ellis and Co. have used at least two styles of con rods on the geared faciles. Early ones such as the Percy Nix machine in the Coventry museum has tubular arms, later ones are solid and much more slender in section. I'm going to be making the later style.

The Percy Nix machine from 1888 (second year of production) has the earlier, tubular style of con rods.

The later style are solid and much more slender.

You can see from the photo above that three of the ends are identical (apart from oiler placement) which means I can make all three at the same time. If I had access to a big lathe, I'd simply make each con rod from a single piece of stock and bore each end at a time. The centres on the con rods are 8.5" and I would need a fairly hefty lathe to swing that, even in the gap. I don't have access to such a machine so I'll do it in sections on my trusty little Myford and then join them up. The right hand con rod will be made in three sections, both the ends and a centre section. The left hand con rod will be made in two parts since the top end doesn't need to be turned. I'm having a dilemma about how to successfully join the sections. I could ask Pete the Welding Ninja to TIG them up for me or I could silver solder them with a lap joint. The difficulty comes from the need to harden the bearing surfaces. I'm going to have to think about this. As usual, here's a stack of photos.

Calculate the minimum size of bar stock required and mill a flat on each side.

Then saw it into the three pieces and mark out the shape of the end.

I'm going to bore the holes and bearing surfaces in a four jaw so I need to remove as much material as possible from the stub to prevent vibration when running off centre at speed.

Mill the sides so that the stub is at the correct width. 

Roughly file the fillet from the stub to the body and mill the corners off 
so that the shape can be held securely in the four jaw.

Repeat with the front and back. 

I've left enough material to produce a nice fillet between the end and the shaft.

I've needed to make a parallel spacer out of some scrap tube

 to ensure that the work sits square in the four jaw 

Centre on the marked punch and drill and bore the central hole 

Also clean up the outer face. I can't profile the outer edge at this time as I need

 the flat surface to align square against the parallel spacer when it's turned around.

Rough out the shape of the bearing surface at a 45 degree angle...

...and use the profile tool to machine the bearing. Then polish the surface.

Then flip over, re-centre on the bore and repeat.

Next mount on a mandrel...

...and machine the edge profiles.

Then mount on the mill and clean off all the 'corners'. I would like to use a rotary table 

for this but I haven't got one so I use my dividing head instead.

Finally give them a little tickle with a file. I'll wait until I have the centre section made 

before I profile the stub that attaches to it. As I said I need to have a think about it first.

In other news, I did a most stupid thing this weekend. When Pete (hired muscle) came and Kung Fu'd up the old deck, we just threw the wood into a heap behind the facile factory. I'd been meaning to do something about it ever since but my lovely wife forced my hand this weekend and made me do it. The old deck boards had many rusty old nails sticking out at all sorts of dangerous angles. I laid the boards down and knocked the nails flat with a hammer before sawing the timber up for our wood burner this winter. The timber is untreated hardwood so useful as fuel. I thought I'd got all the nails done and went inside briefly to answer the phone. Afterwards I ran down the back door steps and put my full body weight on the one remaining nail that I'd missed. It pierced the sole of my shoe and then carried on through my foot and came out the top. Of course the nail was a special deck nail with annular grooves that made it hard to get out. I had to put my other foot on the board and yank my crucified foot off the nail. Being male, I naturally didn't go to the doctor until it had got properly infected and had gone an interesting colour. I thought I'd had a tetanus when I had my spectacular crash two years ago but apparently not, my last recorded one being in 1993. Probably best that I don't put a photo of my foot up I think. It does mean that I'm having to soft pedal with my right foot and standing on the pedals is out of the question.

An annular grooved nail, yesterday.

Lacking Wisdom and Getting Cranky

My lovely wife celebrated a very significant birthday this week and she is no more grumpy than usual. But that's not what I mean anyway. This shedweek I have started work on the right hand crank arm, this is a far simpler affair than the planet gear carrier but I'm not going to mention that in case I screw something up again. What with arranging the lavish parties and the parking for the convoy of trucks carrying her presents, I haven't had a great deal of free time (as usual). My brother has prompted to me update the blog though, so I'll have to take some time out from my hugely busy social life and post an entry.

The original right hand crank arm.

As before, I'm going to start with round billet and machine off one face

And then flip it over and machine the other.

Next I can saw off the thinned section and remount parallel to the ways. 

Using the same techniques as last time I can space the centre holes and 

also thin down the end of the crank to near final size.

Bolt down using the new hole and thin the centre section.

Remount on the faceplate and machine the back of the boss. 

Of course I forgot to take photos of the faceplate set up so you'll have to take my word for it.

Now mill the angled face at the back of the crank.

Then using this new angled surface as a reference, I can start to mill the relief into the front of the crank. 

This cut is at full depth so I can now get in with the ball nose cutter...

...to make the correct shape of the relief.

Mark out the shape of the crank...

...and chop it out with the hacksaw.

Finish off with hand files.

Finally mill the slot for the locking tab.

I now need to finish off a lot of little jobs on the geared assembly. The cranks need to be attached to the axle with taper pins, the locking tab needs to be made, the hole for the oiler needs to be drilled and tapped in the left hand arm and finally the patent information still needs to be stamped into the crank. All little jobs but I'll start on those next week.


In other news, my lovely wife's sister has just gone back to England after coming over for the birthday celebrations. We all had a fantastic time together and she has very warm memories of the visit. She's also pretty much back to normal after her operation a few weeks ago which is a huge relief for us.

Last Thursday I had my bottom two wisdom teeth taken out, they've been border line for the last 20 years and they finally got bad enough to need some action. I now look like a grumpy hamster but less cute. I have an interesting drug cocktail to take, some of which I'm not supposed to operate machinery with. Ho hum...

In more other news, my brother has sent me a link to a video he made of this years Benson run. The Benson run is one of my all time favourite antique bikes rides and I couldn't make it this year. If you are ever in Benson, Oxfordshire, UK on the first Sunday of July and you happen to have a pre 1928 bicycle about your person, I strongly recommend you try it.