Calibrating PTO spreaders.

[bleeting]

I've read how to do this by doing test runs, using the width and distance spread vs weight spent. I don't really like the idea of wasting a bunch of fertilizer doing this, and 100 times so on expense seed.

You can fairly quickly, and with little waste, find the effective spreading width with your material. Distance spread is simply a factor of time. So using that why couldn't one just pull the spinning disc off and just let fertilizer drop into a bucket to be weighed.

Example;
50' spreading width
10mph (14.67 feet per second)
=733.5 sqft/s = 1 acre coverage every 59.38 seconds, round up to 1 minute.

Now if you know you need to spread 500# fertilizer per acre, can you not just pull the disc and see which setting drops 500# in a minute (or 250 in 30 seconds, or 50# in 6 seconds). There should be no difference in amount through the gates while actually spreading with the disc or dropping straight down. It's not like the spinning disc causes a backup or slows the rate or anything.

Practical tests are always going to trump, but this should output very close to a practical test, maybe even more accurate since it removes a factor of operator error.

Am I crazy?

 

[jimmysisson]

What's the difference betw that and a test run? Sounds like the surest way to get an accurate rate.
Jim

 

[bleeting]

What's the difference betw that and a test run? Sounds like the surest way to get an accurate rate.
Jim

Ever looked at the cost of bahai seed? The difference is wasting hundreds of dollars. Or for fertilizer probably more like 50 or so and not burning out a huge area.

 

[RPW]

Understand your plight. Have done the same for a number of years. Switched over to a grain drill a couple of years ago and never looked back. Now I use the cone spreader only occasionally. Much easier and way less waste. My seed runs around $500 for a 50# bag.

 

[bleeting]

Understand your plight. Have done the same for a number of years. Switched over to a grain drill a couple of years ago and never looked back. Now I use the cone spreader only occasionally. Much easier and way less waste. My seed runs around $500 for a 50# bag.

What do you use, I've been looking at slit seeder/over seeders no till drills etc and they all seem to be 10k+, can't justify that expense for how much I would actually use.

 

[deranged]

What do you use, I've been looking at slit seeder/over seeders no till drills etc and they all seem to be 10k+, can't justify that expense for how much I would actually use.

My local feed/seed store will rent a notill drill for a half day for about 250. Might see if yours does that or ask the local farm extension office of they know where to rent one

 

[leonz]

I've read how to do this by doing test runs, using the width and distance spread vs weight spent. I don't really like the idea of wasting a bunch of fertilizer doing this, and 100 times so on expense seed.

You can fairly quickly, and with little waste, find the effective spreading width with your material. Distance spread is simply a factor of time. So using that why couldn't one just pull the spinning disc off and just let fertilizer drop into a bucket to be weighed.

Example;
50' spreading width
10mph (14.67 feet per second)
=733.5 sqft/s = 1 acre coverage every 59.38 seconds, round up to 1 minute.

Now if you know you need to spread 500# fertilizer per acre, can you not just pull the disc and see which setting drops 500# in a minute (or 250 in 30 seconds, or 50# in 6 seconds). There should be no difference in amount through the gates while actually spreading with the disc or dropping straight down. It's not like the spinning disc causes a backup or slows the rate or anything.

Practical tests are always going to trump, but this should output very close to a practical test, maybe even more accurate since it removes a factor of operator error.

Am I crazy?

===================================================================================


The bucket test is the best way to to this as you will know exactly
how much you are spilling through the volume regulating passage
of the spreader in a set time period AT ANY TRAVEL SPEED.

The volume regulating passage is going to dump the material
through it no matter to the travel speed.

So much of this is going to depend on the quality of the material spread
as fertilizer that is dusty with no prills (pellets) is going to drop like a stone
and burn everything.

 

[vtsnowedin]

You must have nice fields if you can spread at 10 mph. I've calibrated salt and sand spreaders using a stop watch and scale but that might not apply to a cone type spreader. Dose engine rpm/ pto speed need to be constant?
I think I'd put one bag in the spreader set on it's next to smallest setting and measure how far that went using the gear and pto speed I wanted then adjust up from there one bag at a time until I got it where I wanted for that material.

 

[Fallon]

You must have nice fields if you can spread at 10 mph. I've calibrated salt and sand spreaders using a stop watch and scale but that might not apply to a cone type spreader. Dose engine rpm/ pto speed need to be constant?
I think I'd put one bag in the spreader set on it's next to smallest setting and measure how far that went using the gear and pto speed I wanted then adjust up from there one bag at a time until I got it where I wanted for that material.

PTO speed determines how fast the disk spins & how far it flings stuff. Stuff just falls out of the hole above the disk, so the disk doesn't affect how much falls. Unless its not spinning at all & stuff backs up to the hole.

 

[vtsnowedin]

PTO speed determines how fast the disk spins & how far it flings stuff. Stuff just falls out of the hole above the disk, so the disk doesn't affect how much falls. Unless its not spinning at all & stuff backs up to the hole.

OK so the pto speed determines the width and the gear selection determines the length and the hole setting determines the lbs/minute? You could vary any one of them to change your application rate and you should change just one at a time to find the right combination. So to simplify the process I'd set the engine to 2400 pto speed for 540 pto rpms then pick a gear that was comfortable on the ground in question and then just adjust the hole opening until I found the right hole size to give me the desired rate.