Scott flame licker build

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madjackghengis:
By the by, John, what exactly is the magneto being built for, if you don't mind my asking? I have a special place in my heart for such things, and am a bit of an expert on their use on full sized engines. I also wanted to say that casting of the hopper is an absolute beauty, and I kind of hope the flames cause the paint to fall away, so it can be fully cleaned up and be a show piece in and of it's self. It is much larger than I thought from the drawings and looks great. To Nick, I used a two in travel dial indicator mounted on a magnetic base as my last resort before buying a DRO. It worked better than clamping two digital calipers on the x and y axis'.
By the way John, that was a very smooth move in the way you got all your horizontal bores in line, and done exactly right, that jig plate worked great. The fact that it remains a good piece of "jig plate" or a spare piece of metal when you're done only makes it practically free, as a jig. Your pictures make this a great build log too. :beer: cheers, mad jack

Bogstandard:
Jack,

The magneto will be used on a R&B engine that I bought the castings for last year and Rob is actually making his own.

http://madmodder.net/index.php?topic=3137.msg34848#msg34848

It will end up something like this, mine will have 2x9" flywheels instead of the one 12"

I'm glad you liked the way the jig plate worked. The R&B will have the same done to it once the base is flattened level.

John

Bogstandard:
Mainly a load of piccies tonight, and only a bit of machining.

These concern the next part to be machined up, the water hopper.

Even though it looked OK from a distance, when I got up close and personal with this casting, I was a little disappointed, as will be seen. I spent nearly an hour, trying to make a descision how I was going to machine it back to how I wanted it. At least one specific face had to be machined perfectly square to the foot, and then bored for the cylinder.

As you can see by the fettling marks, this side has an outwards bulge, and when handled, is more pronounced than shown on this photo.

As can be seen from this shot viewed from the side, the shape is more like a leaning parallelogram rather than an oblong.

When viewed from the top, you can also see that it tapers from one side to the other.
Luckily, although in parts, the casting is under nominal size, there is enough meat on it to get it all square.

I decided the best place to start was the already fettled base, which was reasonably flat, so it was gripped in the vice with the base set level to the table.
I just needed to make sure the cutting forces were kept as low as possible.

With a bit of extra support from the backstop, I used my flycutter, cutting in one direction only (towards the backstop) and with only a 0.005" cut, the base was cleaned up after a couple of passes.

This shot shows just how much inwards lean at the top there is on the sides. The next cut has to be getting the side face that requires boring square to the base.

The casting was set up again in the vice with the base sticking out.
By using a 3 2 1 block and a nut and bolt just slightly smaller than the holes in the block, I jacked the base end up so that the base was perfectly square to the table. Hopefully it will remain in that square position while the face is machined. The block and jacking screw were left in position to help support the part.

I tried to skim this unfettled face with my flycutter, but the skin was a little hard and didn't really want to cut. You can see by the machining marks just how far out this face is.

So I resorted to one of my favourites, a 16mm razor sharp cutter. This went thru it like it was butter.

This slightly fuzzy shot shows just how bent the face was, and this isn't down to full cleanup depth yet.

After going down to just over 60 thou, I had the face cleaned up, and yes, it was perfectly square to the base.
Now I have these two faces, everything else will be an easy job. Even though the angles are slightly out to each other on the two angled faces, as of yet, I have decided they won't be machined, and left as cast.

To me, it is looking better already.

I hope to finish this part tomorrow, then this build has to stop while I get a couple of private jobs done.

Bogs

Stilldrillin:
That's looking good John! :thumbup:

I regularly used to mill fabricated drill rig sections. The welder's ideas of straight and square, were nothing like mine! :bang: :bang:

Machining straight and square. Leaving an unmachined witness area as necessary, sometimes almost amounted to alchemy....... :med:

David D

NickG:
John, the hopper does look way better than when you started with it. I remember now why I got frustrated with the sweet pea castings. The material was ok but the shape of the bits weren't as good as they should have been. E.g., for the pony wheels the flange that was cast in was useless - there was so much material there it all had to come off, which infact meant doing it with castings was pointless - it would have been cheaper and easier just to use round steel.

The cylinders to me look the same - I could just make them from a square block of cast iron, the only advantage is there is a core down the bore (that won't be anywhere near in the right place though so would have to do Stew's trick) and a radius on the outer so less material to remove, but these are outweighed by the fact that there are no datums and it'll be difficult to hold.

Obviously that hopper is hollow and has a bit of shape to it so it'd have been a huge job to make from solid or fabricate. I think you've done it in the best way possible. :thumbup:

Nick

ps that gas engine is a beast, must be capable of real work.

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