when an inch isn't

Hi,  trying to get the travel to actually measure correctly. 

I have entered:
200 motor steps
1.9 microstep
pulley 1:1
max velocity
max accel 30

Right now an inch measures 1.016"

What is my next step?

Cheers!
 

Technically an inch is actually defined as 25.4mm, this came about in the 1930 or so as different regions had different definitions. The development of slip gauges or "Joe Blocks" had a bit to do with this.
I still can't understand why some regions of the world will attempt to use anything to avoid using the metric system......Yes it's as big as 3 football fields and as deep as 4 school buses.

en.wikipedia.org/wiki/Inch

Tho it makes no reference to slip gauges.

Leadscrew ptich is required or the numbers mean nothing (or if belt drive belt pitch)

Look at geometry and lost motion.

Remember that the distance between London and Paris is the same whether you represent it in kilometers or miles. The only difference is the way you slice it.

A quick way to get a rough idea of the problem

Jog your machine to one side

Using a tape measure from your spindle/head/whatever put a block a known distance near the end of your travel.

Tell the machine to go that location.

If it way overshoots or undershoots you have a "steps per inch" problem. Change your steps accordingly. 1.016*24in = 24.38in ...... This would be very noticable with the above method.

If it's almost spot on. E.g. 24.016 Then it's probably a backlash or squaring issue. Could also be a gearing issue if your are using a rack and pinion with that low of a step count.

The trouble comes when one assumes km instead of miles or the other way round, ask NASA about that one.
From what I’ve heard congress in the US actually officially adopted the metric system in the mid 70’s, could of been ‘76 which would make sense as to why it was ignored.
To me consistent units of tens makes more sense than 12 inches to a foot, 3 feet to a yard, 22 yards to a chain, this where my knowledge of it stops apart from 1.6km to a mile.
At least a smidge, just a bit and poofteenth (this maybe just a term to my local), “about that much” & “you can drive a truck through it” are easily understood no matter your base unit. There’s a few others but not entirely in line with “the code of conduct”

I only measure in bannanas

smc.collins wrote:

I only measure in bannanas

That is most wise