Cage Gears

   / Cage Gears #1  
O

OldMcDonald

Platinum Member
Joined
May 1, 2005
Messages
988
Location
Mainland, Orkney Islands.
Tractor
None
I am considering a modification to a home made seed drill that currently has the seed plates mounted vertically on a drive shaft and they are cut into small seed boxes, supplied by a larger hopper above, to pick up seed. I sow a wide range of seeds from vetch through to large fava beans and the current system is not satisfactory for all sizes.

I want to change the drive from rotational forward through a gearing to horizontal - exactly the same as a pair of bevel gears would. The seed plates (to be made in diffetrent sizes) would sit horizontally in the bottom of the seed box and drop the seeds through a hole in the base of the box and into the feeder tubes for the sowing tines. There is very little force needed to turn the shaft and I wondered whether I could use cage gears I make myself. Any comments greatly appreciated.
 
   / Cage Gears #2  
Cage gears would be fun to try.

P1020266_preview_featured.jpg

How about using a couple of the small bevel gears from inside an automotive differential?

Bruce
 
   / Cage Gears #3  
1 to 1 ?, how bout some of those 90 degree drill motor adapters ?
 
   / Cage Gears
  • Thread Starter
#4  
I am in inland Portugal. That probably means absolutely nothing to members of TBN, but, the bits and pieces you blokes in the US take for granted are simply not available. In other parts of the world where I have farmed - England, Australia, Scotland for example, I would simply go out and buy the bevel gears I need. I cannot do that. The cost of importing is prohibitive. I make my own or go without.

The photo from bcp is sort of what I had in mind. I believe that the tolerance on fitting the two gears together is a lot more than with bevels and I see no reason why I cannot make such a set-up in metal, but I know there is so much knowledge on this site that I decided to seek some comment.
 
   / Cage Gears #5  
That is so messed up, is there anything I could take apart and send as 'parts' ?
 
   / Cage Gears
  • Thread Starter
#6  
Willl, Extremely kind of you, but it will be no great hardship to make some sets of cage gears. The present drill is mainly for corn and only has two rows, so two sets of gears are all that is needed to try out the idea. There is heavy import duty on anything coming in, and the stories I have heard suggest the amount is not relevant to the value of the imported goods. There is great satisfaction in completing something different that is cheap, effective, even if not as good as mainstream manufactured equipment, and readily repairable.

If the system works (and I see no reason why not) then it could be applied to anything where the force is low and a change of direction is required. I had in mind using half-inch rods for the "spokes". I can turn the delivery on the present set up with one finger when it is raised on the tpl. The drive from spider wheels to the present seed plates is via bicycle cogs and chain. It is set for 1:1 but could be changed with different bicycle sprockets. There is no slip on the spider wheel drivers and forward speed does not alter the number of seeds delivered - only the seed plates do that and I was intending making interchangeable plates along the lines of the Earthway garden seeder to suit the different seed sizes. The spider wheels are one metre diameter so pi times the 1m gives me the ground coverage per sowing tine. I then use the spacing between seeds needed to work out how many to drop per revolution. I have had limited success with altering the seed level in the small seed boxes, and the size of the opening through which the seeds flow to the delivery tubes- round seeds are easier to work with than flat ones like fava beans. I just thought I could improve on my present system.
 
   / Cage Gears #7  
I have seen variable speed friction drives that are similar to the Cage gears, but they use a small rubber tire on a steel plate, one may have to put some thing like expanded metal on the plate for better grip, by adjusting the tire in close to the center or put near the edge one has variable speed, and if you use a small air tire one can adjusts the pressure of the mating surfaces by air pressure,

image from, Ten Variable-Speed Friction Drives | Mechanical Prasad

an intresting use, http://blog.hemmings.com/index.php/2013/03/14/smooth-going-with-friction-drive/
it was used as a car transmission

some lawn mowers and snow blowers us this type of drive for the transmission,
 

Attachments

  • Image 003.png
    Image 003.png
    17.7 KB · Views: 374
   / Cage Gears
  • Thread Starter
#8  
BHD, Thanks for the links. A very interesting possibility, but I would prefer not to have to go through the experimental stage of calculating the amount of slippage. I can imagine this slippage becoming worse over a few acres of use - needing a re-calibration. Additionally I would not be looking for changes of speed, but instead simply change the seed delivery plate inside the seed box.
 
You must log in or register to reply here.
 

Footer Links 1

Top