How Much Cable Needed for #25 on D7

Hey OilSlick,

Good question.... Too many times I find people wanting to put a lot of extra cable on the drum. Not needed and it causes problems. The bowl will need to drop a bit more to cut, but when down all the way, I usually give them about 4-6 wraps on drum. maybe half way on drum on first layer. Cable in scraper doesn't usually break. The most wear is in the cable unit itself. While rolling cable up into unit, if when starting to eject, if the operator let the cable loose, it can start it pattern off in wrong spot. As it wraps wrong, a lot of wear is created. It causes the weak spots in the rope. It might not break at the next go around, but it won't be long. Cable must be wound on the drum correctly. When a cable breaks going to the scraper, the spare cable is in the back. It is moved towards the cable unit. So the thought of extra cable on the drum in case some breaks is all wrong. Just put enough on to go half way on first layer and you'll be perfect. As a cable gets more wraps on drum and is larger in diameter it looses pull power anyhow, so why go there. When people put 40-50 feet of extra cable on drum and it gets loose, the cable starts laying crossed up. That's what causes the most wear. Sorry so long winded on this one, but it's my pet peeve. My wrenches some times want to help me out by putting extra rope on. Nope, it's not right.... Too much cable on drum is just BAD for it!!!!

Hi, 'Slippery'.
'Pops' is right. (For once. LOL.) Too much cable on the CCU drum is bad news. For the bowl rope, if you have 6 falls of rope on your sheaves and your bowl is on level ground, you will need around 6 extra feet - roughly 3 wraps - on the drum to be able to cut 1 foot deep - plus 1 1/2 to 2 wraps extra to reduce the load on the cable wedge or clamp. NOT a whole lot of rope, is it. If you have 8 falls of rope on the bowl lift, add about 8 feet on the drum. (IF you wanna cut deeper than 1 foot, you will need extra rope on the drum - - - - AND a D9 behind the scraper.)

For the apron and ejector, about 2 1/2 to 3 turns around the drum is usually plenty 'cos you are always pulling rope ON to the drum when operating these functions.

To increase longevity of ropes, try to keep slack out of them at all times, NEVER keep either line 2-blocked for any longer than ABSOLUTELY necessary, especially on rough ground or when turning and always be aware of when a line IS 2-blocked and let some slack out. There is pretty much NO excuse for travelling with the bowl all the way up anyway 'cos it increases the risk of a roll-over, especially with those older 'Le-TURN-over' scrapers.

Is there gonna be a 'warranty' claim on your Chinese rope at Santa Margarita? A kew-ree-yuss mind would like to know. LOL.

Just my 0.02.