Calibrating the Seed Drill

John Deere Type B Seed Drill

My John Deere Type B Seed Drill needs to be calibrated so that it dispenses the seeds at a predetermined rate – usually pounds per acre. This drill emits seeds based on volume/size rather than weight.

I learned how to calibrate a seed drill from this video.

Setting the drill on stands so the wheels can spin freely and turn the drill to emit seeds.

The first step is to get the drill off the ground so you can spin the wheels freely. It’s a delicate operation as there aren’t many safe places to lift the drill.

I use a shop lift with a chain around the short axle.

The drill is quite heavy and there aren’t many places to lift or jack without damaging the axle or gears.

I use a jackstand to hold the drill up while I’m working on it. Note the very narrow space for the jack stand to rest without damaging the axle and gears.
A good grease job every time helps insure that my drill be continue to be useful in the future. I invested quite a bit of time in rebuilding it so I want to make sure it lasts and works well for a long time.

Greasing equipment is a nasty job but definitely worth it. This drill sits outside (too big to fit in the barn) so taking a little extra care is worth it.

The drill is fully elevated and ready for calibration.

The purpose of elevating the drill is to allow you to spin the wheels freely and emit seed. It also requires that you lower the discs to the lowest position so the seed can flow freely through the seed tubes.

I collect the seeds in an empty water bottle but since we’re going to be dealing with very small measures, a tare on the bottle is necessary.
Water bottles are mounted on stands (bricks or blocks) to mate closely with the seed tubes and accurately collect all of the emitted seeds.
Closer detail of bottle setup for seed collection.
This lever controls the feed rate for one half of the seed drill. There is another lever on the other end of the drill.
The drill wheel is marked with tape to accurately count wheel revolutions.
A small amount of millet seed in the hopper for calibration measurement.
Seed collection while the wheels are turned.
Weighing collected seeds.

Here are my calculations:

Wheel diameter = 86″ or 7.1666′

Row spacing = 7″ or 0.58333′

Tare weight of bottle = 21g

I desire 55#/acre for each of foxtail millet and hegari.

Hegari is first to calibrate since it will plant last.

48g of seeds (plus 21g of tare) needed in each bottle based on calculations from video above.

Loosen and set seed flow lever to 8 based on very faded instructions on the inside of the seed hopper lid for wheat at 60#/acre as a reasonable starting point.

Turn wheel 20 times and weigh seeds.

The 4 bottles resulted in 51g, 54g, 61g, 67g – so too little and need to open seed flow lever a little bit. Also, the right side feeds more than the left side.

Add 2 notches on the left side and leave the right side alone and will be good enough for millet.

Restart calibration with Foxtail Millet.

The 4 bottles resulted in 52g, 55g, 50g, 45g – again too little and need to open seed flow lever more. Sides appear to be balanced though.

Adjust left side to 8 and right side to 10 and retry.

The 4 bottles resulted in 72g, 62g, 55g, 60g – on average too little but good enough to go with.

Adjustments in the lever increase or decrease the seed feed rate.
Seed drill calibrated and ready to plant!


I measured my acreage at 1.8 acres and used 100# each of foxtail millet and hegari seeds. I planted each separately at the rate of approx 55#/acre so I should have almost exactly run out of seed at the end of my planting for each seed.

But, the hegari ran out early at 80% planted (20% short) and the millet ran long at 80% over.

As I was cleaning up I noticed that I had not cleaned out the hopper and seed feed mechanism well enough. I use compressed air and was blowing out the seed hopper and all kinds of crap came up from the seed feed gears that I did not notice early in the process.

I need to do a better job of cleaning and prep to get a more accurate planting next time.

Rebuilding a John Deere B Seed Drill for Bobwhite Quail Habitat Improvement

One of my biggest challenges raising bobwhite quail is managing and improving the habitat. The ranch is located in the Central Texas Hill Country and is typical Edwards Plateau grasses, shrubs, and trees.

“Cedar” or Western Juniper trees are the most prominent invasive plant followed closely by King Ranch Bluestem.

Both of these species act to reduce the habitat suitable for bobwhite quail and my main efforts in habitat improvement are removal (and replacement with native species) of both.

“Clearing Cedar” is done using a hydraulic shear mounted on a 55 HP Mahindra tractor with a brush fork mounted on the front bucket. This allows me to cut and stack cedar trees quite easily. In fact, I can cut much much faster than I can stack. We don’t currently burn the cedar trees due to the wildfire danger.

“Killing KR Bluestem” is an ongoing, somewhat never-ending, project.

KR Bluestem is a bunch grass variety but is just too thick for bobwhite quail to navigate through. My efforts are to reduce/remove the KR Bluestem are limited to shredding, discing and replanting cover crops to kill the KRB and give the native plants a chance to sprout and grow before taken over by the KR Bluestem.

I use a 6′ Mohawk shredder and an antique drag disc to cut the KRB and then expose the roots to sunshine to kill them.  I’m only moderately successful with this approach but don’t want to use fire or chemicals. I have more time than insurance or money.

I plant cover crops to shield the bare ground after discing and to provide some forage/seeds for the bobwhite quail. Doing this work also thins the ground cover dramatically which increases the area where the bobwhite quail can survive and thrive.

I shred and disc approximately 2 acres and without a seed drill, replanting presents two problems – too much seed density & too hard on my arms.

So, in 2015 I found an antique seed drill that looked “pretty good” that I could repair/refinish and then use to plant my ground cover and forage seeds.

I’m not a mechanic, either naturally or by training. So, the fact that I successfully took this drill apart, fixed/replaced parts and then reassembled it without any parts left over was cause for a large celebration!

Here’s how I did it and what I learned.

I found this John Deere “B” model seed drill on an online used-tractor website. It appeared to be in decent condition and was located just north of Dallas. She fit and I brought her home!

I really didn’t know what I was getting into but she looked pretty clean and functional right from the start. I felt fortunate. The mechanics, gears and levers, all appeared to work properly so there would be no need for deep or complex repairs.

The adjustable seed gates/flaps were in conditions ranging from “like new” to “totally rusted out”.

The first thing I needed was a parts and maintenance manual to understand what I had and what I needed to do.

I disconnected the funnels from the seed gates for cleaning and better access. The seed tubes were old, metal-wrapped tubes and were also replaced.

Yeah, I don’t need the suicide bench so I just removed the rusty bench brackets.

I washed and scrubbed the seed bin and I’m grateful it was in good condition. If it wasn’t the seeds wouldn’t flow smoothly into the gates and out the tubes.

The gears that drive the seed feeders are located inside each wheel. Fortunately, they were in good condition as well!

Gibbs is the best! If it’s stuck, Gibbs will get it!

Add a power washer and you can actually see the Zirk!

Again, I was very fortunate. The tension springs and guide bars for the seed “inserters” were all in good condition. There were 2 small homemade repairs that were still working just fine.

The feed rate adjustment handle and mechanism was and remains a bit stiff. It is so deeply embedded in the gears and seed gates that it wasn’t worth it to remove/repair just so that it slides a bit easier. Those are estimates stamped on there and I still had to calibrate it.

Testing the seed flaps and feeders. This is one of the best ones and worked just fine!

So, with everything in generally good condition, my focus will be on fixing the seed gates. This one has rusted out completed.

Prototype seed gate from cheap, thin aluminum. It only has to work good enough and stop the leakage from rusted original gates so an “appliance” that fits over the rusted gate should work, right?

My fancy 3 Dim drawing so I can get them made from heavier metal and bent accurately. is where I went to get them built.

And, here they are!

Since each gate was rusted differently, they didn’t all fit the same. So, I custom fitted and drilled each one specific to a unique seed gate.

The acreage measure is driven off the drive bar that drives the seed gears and was dirty and rusty.  Easy to remove though, with a couple cotter pins.

A little Gibbs, a wire brush and some elbow grease and she’s as good as new!

Having the part manual and exploded diagram really helped me understand how things worked and order the correct replacement parts.

Testing the new seed tubes flowing into the planting foot and discs.

The discs were shot – completely worn out and probably the originals. I suspect that North Texas Red Dirt is tough on equipment.

Once again, the parts manual and diagrams really helped a lot.

Good Lord! Parts have arrived!

Somebody mistreated the hitch attachment point and it needs replacing.

And each disc needs the cleaner replaced. There are both right handed and left handed versions. I know because I ordered wrong the first time!

I originally suspected that finding replacment drag chains would be hard.  It wasn’t. They get lost easily though….

New disc Vs Old disc – lots of wear!

The mounting point for the disc.

I could have sworn that I got the wrong size disc. I had a tough time getting it to fit but it finally did.

As a point of reference, this is the disc I currently use. I call her The Beast!

Almost reassembled with new parts.

Final testing in the yard before heading to the fields.

Clean those Zirks because she’s gonna need clean grease!

Calibrating the seed feed rate. This worked like a charm!

Loaded up like the Clampetts going to Beverly Hills!

Unloading at the ranch.

Dad giving her the first pull while I watch her behind!

My buddy Jeff, giving the seed feed a detailed inspection.

I use the seed drill twice yearly for fall cover crop and spring seed crop. She works like a charm and is 10x better than hand scattering seeds.

In hindsight, I was very lucky that she was in good condition and the only repairs I needed could be done with my limited metal repair skills. I hope my story help you and your seed drill restores as nicely as mine.

Rainwater Collection for Bobwhite Quail & Surrogator

Bobwhite quail don’t usually need supplemental water. In fact, they satisfy most of their water needs from dew and metabolic water. That said, many desert quail do benefit from rainwater collection systems in the wild.

But, bobwhite quail in a surrogator do need water.  And, in the hot TX summer, they drink a lot! Most recently, 120 bobwhite quail drank 75 gallons of water of a 6 week period in July – September 2018.

Since the water tank on the Surrogator only holds 15 gallons, you will need to regularly refill that tank. And, since the Surrogator is best located in a pasture under a tree, the likelihood that you’ve got a hose bib or spigot is almost zero.

A simple rainwater collection system and a small water pump seem to be an ideal solution to carrying water long distances.

I repurposed an old wildlife waterer that had a small 4′ x 4′ collection roof and a 250-gallon tank. I’ve built and used smaller configurations but find that this size almost guarantees I’ll have enough water for the entire summer.

We had a few dry years and expanding the collection surface proved to be very easy.

And then we went and added another just because we could.

In the offseason, I attach a float controlled waterer from Tractor Supply and return the rainwater collector to its original purpose – watering the wildlife!