Metric Transposing Gears

The errors with alternate gear sets are small. For instance, the 37/47 set will give an error of .0032"/ft; the 44/56 set will give an error of .0327"/ft; and, the 63/80 set will give an error of .0002"/ft. If any set was to be problematic it would be the 44/56, however, you should not notice anything over the length of any normal nut, or any nut, even a long one, running on any length of shaft that you thread using these alternate gear sets.

For what it is worth.

This was posted earlier:
"Perfect ratio is 1.27:1 Take the other ratios and divide to get decimals 47/37= 1.27027027...
Error = 1.270707/1.27*100= 100.0213%"

If that is Correct, im still wondering what Math equation is used to obtain "the 37/47 set will give an error of .0032"/ft" ?

In the past, i believe i had read that the error for this (37/47)gearset was .0026"/ft.

In no way am i arguing the fact that the % of error is minimal for any of the gearsets, i only want to know exactly how it is calculated.....ie, how the % error equates to 0.000"/ft
 
This was posted earlier:
"Perfect ratio is 1.27:1 Take the other ratios and divide to get decimals 47/37= 1.27027027...
Error = 1.270707/1.27*100= 100.0213%"

If that is Correct, im still wondering what Math equation is used to obtain "the 37/47 set will give an error of .0032"/ft" ?

In the past, i believe i had read that the error for this (37/47)gearset was .0026"/ft.

In no way am i arguing the fact that the % of error is minimal for any of the gearsets, i only want to know exactly how it is calculated.....ie, how the % error equates to 0.000"/ft
 
Last week, I cut the 37 and 47 gears in a 0,400" nylon plate for my SB 9" changing gears using a milling attachment and a protractor to index each toot. The gears are not perfect but they wook perfectly. And today, I just read all this interesting forum.

The way to calcculate the error is : (1,27027 - 1,27) / 1,27 = 0,00027 or 0,027 %.

This error applies to any measure coming from the gear combo so, in one foot or 12 inches the error is 0,00027 x 12 = 0,00324 inches.

If any is interested with the way I cut my gears just ask, I will post some photos and explanations.

Good wook to all, Andre
 
Sounds like you got the ideal gear set. For any others out there reading this- I built the gear/bushing described in this link:

http://ixian.ca/gallery/metric/metric.htm

It works great and was pretty easy to make. Probably all you need unless you are threading something really long.

Rick

Evan took his site down to reduce his "Internet Visibility" and quit lots of forum sites so the Government couldn't follow him but the linked page (and most of the rest of his site) is still available here -

https://web.archive.org/web/20150812072032/http://ixian.ca/gallery/metric/metric.htm
 
Back
Top