Can anyone identify this Model G part?

Just what he says. A spacer to make the tractor an inch longer. Gives an inch more foot room and room from seat to steering wheel and for a hair longer cultivator. There was a thread on this forum about building long spacers for the G for longer cultivators last spring. I've not found it today. They were looking at welded up spacers 4 to 8 inches long. Two plates and a tube welded together.

Gerald J.

To clear something like a center bolt at that junction in the G structure. There were several pictures of longer spacers in the previous thread that I didn't find by searching. That search was slowed by a thunderstorm taking down my power.

Gerald J.

Gerald J. wrote: To clear something like a center bolt at that junction in the G structure. There were several pictures of longer spacers in the previous thread that I didn't find by searching. That search was slowed by a thunderstorm taking down my power. Gerald J.

The back piece on the big tube up from the drive end is a casting, so it could easily be curved and the front piece is fairly thin steel plate that could curve to the curve of the back piece and some pictures of those I referenced tend to make it look curved, though that could be just the outline curving.

Cast vs machining is a constant decision in making a part. It depends a lot on the equipment available and the time period. Often a casting takes more machining than cutting such a curved piece from flat plate and pushing the possible spherical shape into it with a big press. Today a plasma cutter driven by computer or in recent decades a cutting torch with a pattern cutting attachment to follow a pattern with a magnetic drive shaft could cut steel plate without much manual labor or when set right by much need for sl*g cleanup.

I'd think a cast piece would not be accurate enough to keep the front wheels in the same tracks as the rear wheels at that sensitive point in the G tractor frame, so machining it would need, where the plate was more uniform in thickness.

One thing I've noticed about AC tractors is that there is some tendency to use steel stampings in places where other makers used castings and forgings. As if AC engineers could save money bashing stock sheet with a press compared to working sold rods into forgings with ball ends. Like hand throttles and throttle segments on WD.

So if the extension plate was factory, stamping (and for plate that size punching four of the holes is quick) seems logical. In the smaller shop it all depends on the equipment available. I know a couple shops with torch and plasma cutters and my little Clausing mill with a suitable jig can do the holes. I did 8 bigger plates to change the rear tires and rims on my green tractor a few years ago for spraying. Just posted that picture on the thread about narrow pulling tires a while ago.

Gerald J.

Given that no one on this site seems to recognize this piece, I'm guessing it is not an AC  factory product.  While I may have overlooked it, I don't see it in any of my G parts books.  If it is shop made, it's another example of the skill and creativeness of the North American farmer. 

When drilling a large hole with a standard 118 degree point drill bit the worst time is when the bit breaks through where it digs in and grabs the work piece. If the work piece isn't truly anchored to the table, the piece spins at the drilling speed. So if there's enough clearance without going all the way through its plenty good reason to NOT make the hole all the way through. No broken drill, press, or operator. So that's what? A 5/8 or 3/4 bolt so the bolt head would be about a half inch high and drilling deeper than 1/2 inch just wastes time and electricity turning steel to air space that isn't needed. The stock was reported as being 7/8" thick. Plenty room to stop.

The taper of the drill point will produce an appearance of not flat as it should. The taper of the drill bit point though helps hold the drill centered on the pilot hole which a flat tipped drill will not unless its a special with a built in pilot. And a worn drill often has round corners at the edges of the hole.

You grumble about how a 118 degree drill point wanders try grinding a drill flat with cutting edges and then drilling. Even in wood it will leap all over moving a drill diameter per revolution. I've tried that once. Only drilling with a milling machine is rigid enough to make it work, like a plunge cutting end mill. A drill press isn't stiff enough. A hand held drill motor is hazardous with the flat tipped drill.

Gerald J.