Best Mountain Tractor?

TWINKLE_TOES · Apr 9, 2002

Roy,

I think "Grade" is Rise/Run, which is a sin function. The sin of 40 deg is 0.643. Expressed as a percentage, sin 40deg/sin 90 deg= 64.3%
Al

RoyJackson · Apr 9, 2002

I think "Grade" is Rise/Run, which is a sin function. The sin of 40 deg is 0.643. Expressed as a percentage, sin 40deg/sin 90 deg= 64.3%
Al

The error I made was thinking 90° was a 100% slope. This was clarified by a number of folks who explained 45° is a 100% slope.
I think you're making the same assumption I did initially.

If we follow your math, the percent difference between a 40° slope (at 64.3%) and a 45° slope (which, per other poster (and I agree)) would be 35.7° or over 1/3rd the total.
That doesn't appear to be correct.
You might want to draw this out on paper, Al...

Of course, I've not had my first cuppa coffee yet....brain's still a little fuzzy.

Charlie_Iliff · Apr 9, 2002

Al:
There have been a whole series of posts on this. I think Roy started out comparing the slope to 90 degrees, but we couldn't find any reference to that in a search. Where the run is horizontal distance, not the length of the surface (hypotenuse), rise divided by run is the tangent. So, for 40 degrees it is .839 or 83.9 percent. Concensus on the thread seems to be that grade can exceed 100% if steeper than 45 degrees. If you look back in the thread, you'll see some great suggestions for measuring. All we need is a TBN convention, some skyhooks, and a thermometer to make sure the steel measuring tape is accurate to a fraction of an angstrom. (I almost used the acronym for the smallest measure known to man, but decided it wasn't appropriate for a family board.)

TWINKLE_TOES · Apr 9, 2002

Roy/Charlie,

I stand corrected, but not convinced. Maybe before I get corrected again, I should say.. I sit corrected but not convinced./w3tcompact/icons/smile.gif In the link to "Howstuff works" the guy says you travel up this road 1000 feet and its a 10% grade. He then equates this to the tangent. How did he travel along the horizontal if he was going up this 10% grade? He traveled on the hypotonuse which is the sin. I'm betting that when the dust settles on this one everyone is correct in different diciplines or geographic locations. The real solution is keep the grade less than 5 degrees and the sin and tan are equal to three decimal points./w3tcompact/icons/smile.gif
Al

Charlie_Iliff · Apr 9, 2002

The real solution is keep the grade less than 5 degrees and the sin and tan are equal to three decimal points
Al:
Since most train stuff is in that range, you're probably right. The rise/run terminology I've heard as a definition of tangent in other contexts, however, including as a definition of first derivative in calculus class (that I didn't do very well in a hell of a long time ago, so the memory might be completely erroneous.) A friend of mine reported that he was taught in a surveying course that slopes in percentages were the tangents expressed as percent, but he's not a surveyor, he just took a course some years ago.

TWINKLE_TOES · Apr 9, 2002

Charlie,

I think your right. I have most often seen the grade expressed as the rate of change of the grade line. The change in elevation divided by the distance traveled. i.e. the tangent.
definition of first derivative in calculus class 
Your memory serves you well. If you examine the limit of this relation as the distance traveled approaches zero you have the first derivative. I still sit corrected /w3tcompact/icons/smile.gif
Al

Moon · Apr 10, 2002

Sounds like a mowing monster! Over 7' cut on each pass. Cool, very cool.
The invite is open to you or Charlie anytime. I'd really like to see a PT1845 on my property, and if Charlie brought his is about that only way that will happen!
Good luck on getting your PT soon. I'm getting real anxious for mine .....

Moon · Apr 10, 2002

Yo wasabi;
This thread has spread many directions with lots of good info. I was just wondering if you had decided what might fit the bill best for your situation?
Moon

wasabi · Apr 10, 2002

Moon,

I've not witten the check yet, but am strongly leaning toward the Power-Trac 1430 with some, but not all, of the trimmings, if (and this is a significant if) I can locate the elusive budget strecher.

I've seriously considering a Grande L Kubota, but am heavily swayed by the PT quick connect and lower center of gravity. I'm guessing a trip to PT land will seal the deal. So many projects, so little time....

In the meantime I'm enjoying the research as Charlie suggested.