The Plan
Starting with the original specs let's compare them to more modern machinery:
| H14W | Red King Cobra | Bow2-TDS-12.0 | |
|---|---|---|---|
| No-load line speed | 8-14m/min | 58m/min (race) | 9m/min |
| 22.8m/min (Titan) | |||
| Line Speed at 1000kg load | 8-14m/min | 18.5m/min | 2m/min at rated 12k load |
| 10m/min (Titan) |
It's worth noting that the H14 basically runs the same speed whether unloaded or fully loaded, right up to the point you hit the pressure relief valve limit, as the speed is a pretty direct function of the engine RPM and the hydraulic pump & motor.
While I don't want “race” winch speeds from the H14, I also don't want to be waiting forever while winding the rope back onto the drum.
Doing some rough maths based on the 90mm drum diameter and stated speeds…
- Original speed: 8m/min = ~28rpm drum speed
- To hit 20m/min: ~70rpm drum speed
- To hit 58m/min: ~207rpm drum speed
At a very rough guess if I could hit 100rpm drum speed with no load that seems like more than enough (that would give ~28m/min so re-spooling a full 30m drum in one minute) - given that's 4800rpm motor speed it could be a bit ambitious for a regular hydraulic motor but we'll see where we end up.
Rudimentary calculations
NOTE: I am approaching this section with minimal knowledge of real world hydraulic systems or engineering calculations, this is all very “back of envelope” stuff based on a bit of googling and some very rough rounding up of numbers etc. really just to give me an initial idea of whether the motor & pump specs come out as anywhere near feasible or if I've totally knobbed it up.
Assumptions:
- If we take the 90mm drum diameter and nominal 12mm diameter for the rope, that puts the 1st-layer pull at about a 100m diameter give or take.
- Let's assume 6000kg pull is the target
- I don't really want to pull very fast under full load but I'd like to hit ~100rpm / ~28m/min no-load speed.
