A reversing-groove traverse shaft can move a guide back and forth while the shaft rotates continuously. The groove lead and shaft speed set the ideal axial guide speed between reversals.
Traverse Bar Interactive Calculator
Vary shaft speed, axial lead per revolution, ideal guide stroke and an entered cable diameter. Outputs are kinematic timing and nominal spacing arithmetic, not a winding-quality prediction.
Equation Used
- Constant shaft speed and constant axial lead magnitude between crossovers.
- The guide follows the groove without slip, backlash or lost motion.
- Reversal is instantaneous at the entered stroke endpoints.
- Cable diameter is used only for the signed lead-minus-diameter comparison.
- Drum rotation, winding diameter growth, tension, fleet angle, packing, material behavior and capacity are not modeled.
Reversing Groove and Guide Pawl
A continuous groove changes handedness at the ends of a traverse shaft. A follower or pawl engaged with that groove moves axially in one direction, crosses over at the end and returns while shaft rotation continues in the same direction.
U.S. Patent 6,830,209 describes a level-wind shaft with a continuous helical groove extending in one direction and then the opposite direction, together with an engaged guide pawl.
What This Calculator Represents
The tool converts entered shaft rpm and axial lead per revolution into ideal axial guide speed. Entered stroke then determines ideal one-way time and complete out-and-back cycle rate.
The cable-diameter input is used only to subtract diameter from lead. The result is not a winding defect, acceptance tolerance or process recommendation.
Ideal Traverse Kinematics
one-way time = S/guide speed
full cycles per minute = NL/(2S)
nominal spacing difference = L-d
N is shaft rpm, L is axial lead per revolution, S is ideal guide stroke and d is entered cable diameter. Positive spacing difference means lead exceeds diameter; negative means diameter exceeds lead.
Worked Kinematic Example
At 300 rpm and 5 mm/rev lead, ideal guide speed is 25.0 mm/s. A 100 mm stroke takes 4.0 seconds one way and produces 7.5 full out-and-back cycles per minute. With entered cable diameter 5 mm, the nominal spacing difference is zero.
Model Boundary
- Calculated: constant-lead axial speed, ideal stroke timing, cycle rate and a signed dimension difference.
- Not calculated: actual groove geometry at crossovers, pawl contact stress, acceleration, backlash, wear, drum speed, winding ratio, layer buildup, fleet angle, tension, packing, gaps, overlap, crushing, cable suitability or safe machine speed.
Frequently Asked Questions
Does one shaft revolution always move the guide one lead?
That is the defining ideal assumption used between reversals.
Why is cycle rate divided by twice the stroke?
One complete cycle travels one stroke outward and one stroke back.
Is lead minus cable diameter a pitch error?
No. It is only a nominal signed spacing difference.
Does zero spacing difference guarantee level winding?
No.
Are reversal acceleration and pawl loads included?
No.
Can this calculator select a winding process?
No.
References
Building or designing a mechanism like this?
Explore the precision-engineered motion control hardware used by mechanical engineers, makers, and product designers.
