How do I guestimate MPH at PTO speed rather than engine rated speed?

[Lowcountry Rebel]

how did they put out fertilizer on old tractors without a speedo?

 

[dnw64]

how did they put out fertilizer on old tractors without a speedo?

In the old days they didn't use tractors. They didn't have them. They just put the livestock out there.

However, with modern measuring and calculation tools, we have the ability to put just the amount that's helpful/needed - no waste and no shortages.

 

[MossRoad]

how did they put out fertilizer on old tractors without a speedo?

They asked their dad how to do it...

 

[joeu235]

You guess conservatively and then drive between the previous tracks until the extra is gone.

 

[MossRoad]

On my lawn I find the general setting for the spreader listed on the bag of fertilizer, then cut that in half. I'll apply it north-south then again east-west. I'm usually within a couple yards of spot on that way and don't have any noticeable missed spots. Many, many years ago I also ditched the drop-spreader and went with rotary after a nice couple stripes of missed or over fertilized spots. :laughing:

 

[Wood_Butcher_Dav]

Today modern row cop tractors use ground speed radar sensors. DICKEY-john | Radar II

Dave

 

[Farmer495]

Speed chart on the fender shown speed range in each gear and a mark indicates PTO RPM.

 

[TheMan419]

Time over distance. The math works regardless of the machine. When I got my sprayer I put to poles on the ground 100 ft apart. Then varied rpms until I found the rpm that got the speed I needed. Took all of 5 minutes. I was impressed this year when I got the manual out for sprayer.... I actually wrote the info down in the manual!

 

[DJ54]

how did they put out fertilizer on old tractors without a speedo?

For row crops, little was put on bulk, like today. Planters had fertilizer boxes to apply a starter fertilizer. With the chain driven gearing, it applied so much fertilizer per foot in the row, with adjustments on the flow rate. It would drop that amount of fertilizer per foot, no matter what the speed was. It was considered a starter fertilizer, so not that much of a great amount. There was either a decal label inside the hopper lid, with the amount you wish to apply, and usually that amount was determined by row width. Or, there was a table in the manual that came with the planter. When the crop, like corn grew to around 18", side dresser units were used, that placed fertilizer along side the row, to boost productivity. Again, with everything gear driven, everything was pre-calculated by the engineers, so you set the amount you want to put down on that unit, and drove.

Other wise, like we did back in the early 60's, we measured the OD of the rear tractor tire, made a mark on the tire, and drove for 30 seconds counting the revolutions, calculating the distance traveled, then applied the math like above.

As for determining the pto speed, most farmers I know had a hand held tachometer used to set cylinder speeds on combines. Allis-Chalmers made a nice little unit, and I still have one we used years ago. When you found the engine speed to to make 540 pto speed, you either marked the notch, like on our Farmall's, or marked a place on the dash, the throttle lined up with. Crude, but, effective.

 

[pmsmechanic]

This is not an original idea. Someone on TBN used this to add a pto speed indicator to his pto on the tractor.

Buy a cheap bicycle speedometer and calibrate it to the wheel size on your tractor. I did this because I wanted to be able to return to the same speed after turning around on the end of a garden while rototilling a large garden. I also do other work where being able to return to the same speed is convenient.

The first bicycle speedometer I bought was a wireless one. The signal wouldn't transmit through my fender so I bought a wired one.