- Motor type and quantity
- Current limit
Motor
- Motor torque at limit and stall
- Free speed
- Calc
Long shaft vs split shafts
Guide 7
Ties to the scrimmage maintainability issue. A long 1/2 in hex shaft driven from one end twists, the far side lags, and alignment is painful. Compare three layouts: driven at the end, driven at the center, and split segments with couplers.
Driving at the center roughly halves the path. Splitting eases service but adds backlash. The calculator shows that split, including the extra drop from sharing torque.
Every inch of shaft adds twist
Same ½ in hex, same load, three layouts. Dashed line = unloaded; amber line = twisted (exaggerated).
appliedcalculatedwatchfailure point
Twist grows with length (θ = T·L / G·J), so driving at the center roughly halves it.
Every inch of shaft adds twist; drive point and splits change it
- Inputs
- Joint
- Calc
- Check
- Drive at the end or the center
- Reduction to the shaft
Drive point
- Torque into the shaft
- Torque per side
- Calc
- Length per side
- Steel or aluminum, solid or bored
1/2 in hex span
- Twist per side
- Torsional stiffness
- Calc
- Bearing count and spacing
- Max unsupported span
Bearings
- Longest unsupported span
- Flag if over the limit
- Check
- Load torque per side
- Output radius
Left and right outputs
- Left-right mismatch
- Mismatch at the output
- Check
- Segments and coupler type
- Coupler backlash
Split-shaft option
- Twist plus backlash per side
- Mismatch vs a single shaft
- Calc
What it teaches
Maintainability is a design input. Every layout trades stiffness, backlash, and service time.
Session hook
Clamp one end of a long hex shaft, hang a known weight on a lever at the other, and measure twist against the prediction.