[AT] Tractor safety

[Jim Becker]

That is the equivalent of what I just commented on regarding dual front wheels.  With the roll-a-matic, the pivot point really is in the center (effectively about the same as a single front wheel).

Jim Becker

From: Indiana Robinson 
Sent: Monday, September 02, 2019 1:06 PM
To: Antique Tractor Email Discussion Group 
Subject: Re: [AT] Tractor safety

I still have a John Deere A and while I was still farming my last primary tillage tractor was a Deere 4020. Both were narrow front with Roll-a-matic. I often wondered if the Roll-a-matic would have an effect on side stability even if extremely minor. If, say the tractor was leaning down hill to the right  the down hill tire would be able to lift and at the same time the up hill tire would be pushing down placing a slight lift to the up hill side. Minor I know but when nearing the actual tip point you can about push one over with one hand. The NF on that 4020 was about 2' wide.
All of my other NF's (AC-C, WC, Farmall's, Case, MM etc.) are all rigid as you would expect.


.


On Mon, Sep 2, 2019 at 12:21 PM James Peck <jamesgpeck at hotmail.com> wrote:

  My childhood friend turned over a NF JD A in his early teens while plowing on flat ground. The issue was turning too fast. It went on its side but did not roll over.

  [szabelski at wildblue.net] Under identical conditions, and with the same rear wheel spacing and weight distribution, identical WFE and NFE tractors will have different roll over characteristics. The reason is that in order for a tractor to roll over there has to be a rotational moment applied. The rotational moment occurs as one of the rear wheels comes off of the ground. 

  Now consider a man standing on two legs and somebody pushes him from the side at his shoulder. At the time of the push a rotational moment is being applied to his shoulder, trying to tip him over. One of his feet may come off of the ground, but he should be able to stay standing.

  Now consider the same man standing on one leg and the same push is applied to his shoulder. He’s going to have a harder time staying upright.

  If you could find some people who would be willing to test their tractors on a tilt bed, and who had the necessary parts to change their WFE to a NFE (I know that older Farmalls can be switched between WFE and NFE with some simple bolting work) you could get all the data you need to put this issue to bed.

  You could attach strain gauges to the safety chains/cables of the test bed and determine the amount of rotational moment it takes to cause a specific tractor to roll. It would be nice to get a variety of tractor types and sizes to see how tractor manufacturer/size affects the the rolling over concern.
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-- 

-- 

Francis Robinson
aka "farmer"
Central Indiana USA
robinson46176 at gmail.com











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