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Old 01-31-2017, 11:39 PM   #21
deverett
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Looking at my pictures, I've realised I didn't mention the crankcase door windows. They were milled flat and the window cut. There was very little metal left in some places.

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The cover plates had previously been squared up and holes made for the securing screws (not shown on the drawings).

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Both sides were done in the same way. Thinking about it afterwards, I wondered why the crankcase had windows machined when the doors were to be epoxied in place.

On now to the exhaust stub platform. When this was milled, the area was well undersize for the exhaust stub, so an application of JB Weld will be necessary.

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The water inlet was drilled and tapped at the same setting. Afterwards, the casting was turned over and the water outlet was drilled and tapped.

The casting for the exhaust stub was rough-looking and remembering how poor the surface finish ended up on the crank brackets, I decided to ignore it and make the stub from a handy piece of cast iron (that would have been used originally, so that's a good enough reason for me to change it!)

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The drawing shows an 8mm hole through the stub and a 10mm hole through the cylinder body. Looking at the shape of the casting, I think there may have been a mistake in the stub drawing. Anyway, I made an extension of the stub with an 8mm hole all the way through that fitted in the 10mm hole and if I am careful, I should be able to get it to a reasonably close fit against the cylinder liner. The extension was made overlong for trimming later.

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Old 02-01-2017, 01:39 AM   #22
Brian Rupnow
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Dave--You are doing a marvelous job, and I am following with great interest.---Brian


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Old 02-08-2017, 11:59 AM   #23
deverett
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The engine side of the coupling seems to have been secured by a couple of set screws into dimples in the crankshaft. One picture I have shows what a mess this became after many years (ab)use.

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My coupling started out as a piece of 1-1/8" round bar and I initially used a trepanning tool to make the recess but it didn't have enough clearance for the depth required and so a small boring bar finished the job off.

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I will not be driving anything with the engine so the coupling will be in one piece with a groove to simulate the bolted joint. Four set screws were made from 3mm square bar and the coupling bolts are 10 BA.

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Old 02-15-2017, 09:44 PM   #24
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On now to the flywheel. The brass casting was very tight and try as I might, I could not get it set up to give me the full dimensions shown in the drawing.

I faced the first side then drilled the hole for the crankshaft 9.8mm, used a small boring bar to straighten the hole and then ream for final sizing. I got a nasty shock when I went to use the reamer and found it went straight through! When I used the boring bar, I didn't take into account the cut on the backstroke while withdrawing the tool. Nothing for it but to enlarge the hole and fit a new piece in place and start again. The new piece was press fitted in place with the addition of the Loctite.

Before drilling, I machined the eccentric which is used to drive the water pump and in full size, the ignition system. This was done to ensure there was still some wall thickness of original metal round the new insert. When done, the flywheel was reversed in the chuck and drilled out to 9.7mm. Using the boring bar cutting a few thou at a time, I enlarged the hole checking when the 9.9mm drill would just start to enter. Now it was time for the reamer and after trying, the crankshaft was now a nice light push fit.

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The flywheel is held in place with a 1/16" taper key. I have a Dore slotting attachment that mounts on the cross slide. The smallest insert bar I have has a 1/16" cutter, but when I tried it the tool would not enter the hole. Reluctantly I had to remove the flywheel and make up a new slotting tool. The Dore type would be very difficult to make in a smaller diameter bar, but fortunately Michael Cox came to my rescue. He had designed a unique keyway slotter to put keys in a modified pulley wheel he was working on. That would do just nicely, thank you Mike. http://mikesworkshop.weebly.com/smal...ting-tool.html
However, I didn't use his method of hammering the cutter through the hole! The clamp is to hold the heel of the cutter in place and also act as a length guide.

As an aside, for those who have not seen his site there are some quite good ideas that can be adapted for other machines.

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Full size, the flywheel is fitted with a retractable starting handle. This is not shown on the drawings, but is easy enough to make. Using my centre finder, I lightly scribed a line that went through the keyway and this was carried over to the flange. The hole for the starting handle was drilled on this line at the half-way point on the flange. The handle itself was a piece of steel bar threaded at each end. On the inner end, a collar was attached and Loctited. The outboard side has a threaded brass button for the knob. A suitable light spring from the 'spring store' is the retracting mechanism.

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The position of the holes should be rotated from that shown on the drawing and they were repositioned as far as I could without hitting the counterbalance weight. There are also an extra 2 small holes that should be drilled.

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The pencil arrow was to remind me which way to offset the holes!

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Old 02-15-2017, 09:54 PM   #25
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Nice work Dave.--And--You're not the first person to suffer from "Reamer Surprise".
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Old 02-15-2017, 10:01 PM   #26
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Quote:
Originally Posted by Brian Rupnow View Post
Nice work Dave.--And--You're not the first person to suffer from "Reamer Surprise".
That was down to lack of concentration, Brian!

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Old 03-03-2017, 01:52 PM   #27
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I followed the drawings for the construction of the cooling water pump, but as usual I 'improved' the shape somewhat.

The pump cylinder was the first part. Just a simple turning exercise. The full size one had a gland on the top, mine is a dummy. The cross bar was from a piece of thick wall brass tube, with the outside reduced a bit and bored out a tad. These two parts were silver soldered together and the cylinder bore was drilled all the way through and then reamed.

The pump piston was turned to a tight fit then lapped to the cylinder. The drawings wanted a 5mm O ring as a seal on the bottom of the piston, but I don't have any so what I have done is to put 3 grooves in the piston to act as a labyrinth water trap. If it doesn't work, I can enlarge one of the grooves and use some Teflon string as a seal.

The bottom of the cylinder was sealed with a silver soldered plug.

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The pump uses two balls in the horizontal bore as a check valve. Three inserts within the horizontal part trapping the balls form the guts of the pump check valves, the side extensions accept the cooling water hoses.

On any water pump that uses balls for check valves that I have seen always have notches filed on the upstream side, or some other way of allowing the water to pass. On my drawing these are not shown or even mentioned. Any potential builder not aware of this would find that their cooling pump would not work!

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The sphere part of the check valves were made with a form tool. The valves being brass I just used a piece of 3/16" x 3/8" steel. A hole was drilled in one end and the end machined away to a bit less than half diameter. A clearance cut on each side and the horns were rounded over. The tool was then case hardened.

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The check valves were machined as a pair. Slow speed and no chatter gave a good finish. The swarf came off in nice curls as the ball was formed.

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After the spheres were turned, the filing rest was set up and a hex was filed on either side of them.

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A pilot hole had already been drilled through the pair and this was enlarged so that they would fit on the pump. They were then parted off as two pieces and then the hex ends were brought to length. A recess was milled in the spheres to take the screwed cap, which would be Loctited in place. The screw head was filed square and stuck in place.

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Pump finished

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Old 03-11-2017, 12:01 AM   #28
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The cooling water pump and ignition are driven from an eccentric on the back of the flywheel.

The plans show a piece of bent wire soldered to a brass ring for the eccentric strap that would have been a casting in full size. I made the strap in 4 parts silver soldered together. The strap will not be adjustable - the bolts are dummies. The ring started as a slice of brass bar and after rounding the circumference was sliced in half with a 1/8" slitting saw.

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The bolting flanges are a piece of 1/8" brass bar trimmed to the right size. In order to keep these three bits lined up during soldering, I drilled 2 holes in each part for dowels.

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Once these bits were silver soldered, the rod anchor was filed up and a notch milled in the top of the disc.

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The disc and rod anchor were silver soldered in a second operation. The rod will be trimmed later.

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The top fitting on the eccentric rod - the connector to the pump rod - was drilled clearance for the connector bolt. It was then shaped while still attached to the parent stock

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After being parted from the parent, the part was filed to shape and drilled/tapped for the eccentric rod.
Final assembly looks like this:

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Last edited by deverett; 03-11-2017 at 12:07 AM.
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Old 03-11-2017, 01:06 AM   #29
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Very nice, very finicky work Dave. I didn't build that part on my home-grown clone of that engine, because I already had a gear pump made to handle the water circulation. I do appreciate the amount of work that goes into a simple assembly like that.---Brian


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