how to find 5TA pin weight w/no CAT scale

[Chris R]

I do not have easy access to truck scale. I did found a sketch from 2016ish that showed how to measure hitch weight with a bathroom scale and that it could be adapted to determine 5TA pin weight, but it's short on details.
Short of buying a Sherline scale, is there any way to do this? Google does not help much.

thanks

[Brian B-P]

Even with a Sherline scale, you need to handle the height - a long stick between a scale on the ground and the king pin wouldn't be good. Since you must have a truck if you have a 5.0, I suggest placing the scale (whatever arrangement you choose) in the back of the bed of the pickup, on blocks or whatever is structurally sound and available, to support it at a suitable height. Unfortunately, the truck will move down as the weight is applied to it, which is dicey for the scale setup; I might put jackstands under the truck frame to prevent that.

I stuck a pressure gauge on the port of a small hydraulic body repair kit cylinder to make a hydraulic scale functionally like a Sherline (although you need to calculate piston area to determine the calibration). A Sherline is more convenient, and has a better base (wider), if you can readily get one and are willing to pay for it.

The accuracy of the lever method (shown from the earlier discussion) depends on knowing the ratio of the lengths accurately, so it would be wise to put something with an edge or other line contact on the horizontal beam so the load is at that line; the illustration uses pipes for this, but I would use a piece of angle iron, vee point up, for stability and ease of measuring positions.

And of course if using the lever method a 2x4 stick of lumber would be entirely inadequate for the pin weight of a 5.0TA... I wouldn't even try that with the tongue weight of a 17'. I wouldn't even stand on the middle of 2X4 laying flat across supports three or four feet apart - why would anyone support a trailer tongue that way, if it's too heavy for a bathroom scale?

[Chris R]

Originally Posted by Brian B-P

Even with a Sherline scale, you need to handle the height - a long stick between a scale on the ground and the king pin wouldn't be good. Since you must have a truck if you have a 5.0, I suggest placing the scale (whatever arrangement you choose) in the back of the bed of the pickup, on blocks or whatever is structurally sound and available, to support it at a suitable height. Unfortunately, the truck will move down as the weight is applied to it, which is dicey for the scale setup; I might put jackstands under the truck frame to prevent that.

I stuck a pressure gauge on the port of a small hydraulic body repair kit cylinder to make a hydraulic scale functionally like a Sherline (although you need to calculate piston area to determine the calibration). A Sherline is more convenient, and has a better base (wider), if you can readily get one and are willing to pay for it.

The accuracy of the lever method (shown from the earlier discussion) depends on knowing the ratio of the lengths accurately, so it would be wise to put something with an edge or other line contact on the horizontal beam so the load is at that line; the illustration uses pipes for this, but I would use a piece of angle iron, vee point up, for stability and ease of measuring positions.

And of course if using the lever method a 2x4 stick of lumber would be entirely inadequate for the pin weight of a 5.0TA... I wouldn't even try that with the tongue weight of a 17'. I wouldn't even stand on the middle of 2X4 laying flat across supports three or four feet apart - why would anyone support a trailer tongue that way, if it's too heavy for a bathroom scale?

thanks Brian. I can't manoeuvre the truck under the pin, so I will construct a platform to take the weight after I get a scale.

[Brian B-P]

Originally Posted by Chris R

I can't manoeuvre the truck under the pin, so I will construct a platform to take the weight after I get a scale.

I'm guessing that's due to the current location of the trailer, since obviously the truck which tows the trailer will fit under the trailer. Heavy-duty sawhorses, perhaps?

[Chris R]

Originally Posted by Brian B-P

I'm guessing that's due to the current location of the trailer, since obviously the truck which tows the trailer will fit under the trailer. Heavy-duty sawhorses, perhaps?

Now that the price of lumber has dropped to sort of reasonable levels, I can do the saw horses, they always come in useful for other projects. My trailer is parked off an alley that requires a custom motorized dolly to park it.

[GregWCIL]

Originally Posted by Chris R

I do not have easy access to truck scale. I did found a sketch from 2016ish that showed how to measure hitch weight with a bathroom scale and that it could be adapted to determine 5TA pin weight, but it's short on details.
Short of buying a Sherline scale, is there any way to do this? Google does not help much.

thanks

What is your truck? Is it really critical that you know right away? I would just plan a trip that would take you by a scale. In addition to being inaccurate the scale won’t tell you what other items including people that will affect your truck axle weights.
I’m lucky since my truck scale on the farm is only a quarter mile away. And grain elevators nearby have outside scale read outs that can be used for free after hours.
Think bulk commodities. Do they weigh lumber, gravel or other items nearby? Most places are happy to let you use their scales. At least here they are.