Planting gear question

[Kirk-NJ]

I was looking thru the 172 manual and under the richmond corn hopper section and there is a table of planting distances (page 9). It has the sprocket on countershaft and sprocket on feed shaft But it doesn't state which final drive sprocket was used, a 10 tooth or a 13 tooth. Was the 10 tooth the standard and the 13 tooth an option? Would the 13 tooth increase the drop distance rate? If so by how much?

Thanks Kirk

[PVF1799]

Good Morning. Since the 1960's we've always used the 10 tooth gear. While we always had the books that showed the planting tables, I recall Dad always jacking up the drive wheel, tying a piece of twine around the wheel, rotating the wheel and verifying the amount of seed that came out in 3-5 rotations.

The 13 tooth gear being bigger would slow down the planter rotation, thusly decreasing how often the plate passes the drop point. So in summary, I think you're wanting to use the 10 tooth gear. The question does remain - what is the 13 tooth gear used for?

Ken

[Brandon Webb]

I had heard they made a 13 tooth but had never saw one. The manual should say what it does I haven't read it in awhile. I'd say stick with the 10 because that's how the charts were figured. Those charts are amazing to realize they figured all that back in the day without computers. I like the part at the bottom where they calculate adjustments by percentage for the optional tire sizes. They were some smart guys back then.

[bob in CT]

The 13 tooth planter sprocket was standard on the later 173A/174A planters.

[bob in CT]

[quote="Brandon Webb" They were some smart guys back then.[/quote]

At GE in the 60's they needed to calculate if it was possible to get to the Moon and back. All the calculations were done on one-arm mechanical calculators with paper tape. Fifty women worked in a room for a month to come up with the result. When the engineers reviewed the results, they found a small mistake in one of the initial formulas and they had to do it all over again. This is a true story told to me by a late friend that was responsible for the fuel cell program that powered the Gemini missions.