Posted 9/2/2020 18:40 (#8472549) Subject: Update on 'old seed drill'.
North East Wimmera district of Victoria.
A little while back I posted a photo of an old seed drill, a 14 row "Sun" designed to be horse drawn.
Interesting posts followed on things like seed distribution cups, with a coarse side and a fine side, with a flip over plate for selection.
Last post on that series was from littlejoe who said "They got kinda a variable speed transmission to change rates--- a flat open gear that has texture like galena ore. You open a nut and pick size of circle you want gear to run around,"
The drill on our farm when I was a kid had that 'flat open gear', from small [low rate] in near the drive shaft, to big [high rate] about 8 inches out, to vary the seed rate. The distribution 'cups' on ours also had coarse and fine sides.
I'll include a photo I took this morning of the rate change cogs on the "Sun" drill from the other post. [I think a bit may be missing - but you'll get the idea]. The large cog on the left of the flat strap is driven by a smaller cog - mostly hidden - on the axle, driven by the wheel. The rate change cogs are to the right of that flat strap, and could drive onto either the large or small side of the double cog , which would be reversible.
The rate change was achieved by using different sized 'intermediary' cogs between the drive cog on the axle, and the shaft that drove the distribution cups on each row.
By the time I was home from school and working, the Massey Harris drill we had, with a screw instead of a lever for depth setting, and the 'pull rope' that winched the whole tine assembly up if you were getting bogged, as talked about on the old seed drill postings.