Re: Scaling up Kossel Mini

@hercek:

I found no contradictions in the Gates chart.
Post the units, and show your work to avoid confusion.

Using a 6 mm wide GT2 belt with a 28.57 newton-force (6.42 pound-force),
there is 0.00023 mm (0.000009 inch) of belt stretch.
For all practical purposes, this is equivalent to zero stretch.

For All Practical Purposes (FAPP)
FAPP is a pragmatic approach towards the problem of incompleteness of every scientific theory and the usage of asymptotical approximations.
[en.wikipedia.org]

Quote
hercek
A typicall stepper dynamical force change (usable torque about 0.2 N/m and pulley with 14 mm diameter) can be about 2 * 0.2 / (0.014/2) = 57N.

0.20 N-m holding torque.
14 mm diameter pulley.

1 meter = 1000 mm
1 millimeter = 0.001 meter

14 mm dia / 2 = 7 mm radius
7 mm / 1000 mm/m = .007 meter
7 mm radius * 0.001 meter = .007 meter

0.2 N/m / .007 m = 28.57 N
28.57 newton = 6.423 pound-force

Young's modulus has units of pressure.
Young's modulus = Tensile modulus or elastic modulus.
[en.wikipedia.org]

Pounds per square inch
[en.wikipedia.org]

Quote
hercek
18000/25.4*6*0.82 ≅ 3486.6 lb (or about 15509 N)

1 inch² = 0.00064516 meter²
1 pound-force = 4.4482 newton

Tensile Modulus = 18000 pound-force/inch²
18000 pound-force = 80068 newton
Tensile Modulus = 80068 newton/0.00064516 meter²
[www.translatorscafe.com]

Belt Elongation = (Belt Span Length x Tensile Load) / Tensile Modulus
Belt Elongation = (1.0 meter * 28.57 N) / 80068 N/0.00064516 meter²
Belt Elongation = (1.0 meter * 28.57 N) / 124105648 N/meter²
Belt Elongation = 0.00000023 meter = 0.00023 mm = 0.000009 inch