movement by means of rack

[Federico4380]

Good morning.

I am following a mould with a screw-driven movement through dense wheels and rack and having passed a bit since the last time I saw one, I wanted to ask for a safety on my calculations performed with the following data:

thread step: 2.33 mm
dp of the thread: 57.34 mm
the movement with the thread must draw of 14 at least then I hold a 7 turn of the thread

by means of the use of 3 serrated wheels z1: 30; z2:70 and z3:32 (the latter performed directly on the threaded movement shaft) with module 2.5.
practically my doubt is about the race that has to do the rack, where from my calculations it comes out about 660 mm running.
is it correct?

 

[TETRASTORE]

Good morning to you.
So, if I understood correctly:
7 spins on z3 solid with threaded shaft,
3.2 laps on intermediate z2,
7.48 laps on z1 commanded by rack.
Whereas 235.5 mm the development of the primitive circumference of z1 is a linear shift of 235.5x7.48=1762 mm therefore, unless errors or omissions, your calculation does not return to me.
can you post a pattern of cinematism and how did you get to 660 mm of racing?

 

[Federico4380]

Good morning.
the composition is like in the image, it comes out 660 mm because I work with the differential, but maybe I am mistaken some calculation.

 

[TETRASTORE]

Now it's clear, I didn't realize that the z1 was supportive of the z2.
considering the 7 laps needed at the two z3s (32) we have that the z2 (70) and the coupling z3 rotate to 3.2 laps (with ratio 70/32=2.19).
considering the development of the primitive circumference of z1 (235.5 mm) you have a rack stroke of 235.5x3.2=753.6 mm

660 mm because I work with differential

What differential?

 

[Federico4380]

Okay perfect, thank you.
as "differential" I used a wrong term I mean the solidarity between z1 and z2 which is half more or less and I considered 6 laps coming so to a race of about 660 mm