Swing Power

[kdsekh]

:usa I purchased a John Deere 690c excavator. My question is how much power should the side -to -side (swing) motion have? Should it be able to knock over a yard of soil with the sideways swing motion if on level ground. I don't think my machine could! The machine is very very strong in all other aspects. It just seems like it should be stronger in the swing motion. For example It's almost as if I was standing next to the bucket on level ground pushing on it and someone else was in the cab trying to swing against me I would win:beatsme However if I had a full bucket of gravel ten feet in the air I can swing it uphill while on a slight grade.
Please let me know if this seems normal. If not where should I begin checking for the cause?:confused:

[Dirtguru]

Not sure how to answer? Gravel is usually much lighter than dirt. Try swinging uphill with a full bucket of wet dirt. If your machine swings fine with the bucket in the air your swing motor is probably fine. In my experience symptoms of problems with swing mechanisms start out like a kind of stuttering of the motion, extremly slow swing sometimes accompanied by a sqealing sound from the hydraulic pump. Also late reaction when you move the control. Swing mechanism is nowhere near as strong as the dig mechanism especially on older machines. The newer ones are somewhat stronger but this equates to much faster swing rates rather than more powerful swing in my opinion.

When your trying to grade by swinging try knocking the top off first. Always keep the bucket slightly off the ground. Learn to look a little ways ahead of where you are swinging and react to changes on the groung by curling the bucket and raising the boom slightly as you swing. A yard of wet soil can weigh as much as 3000 lbs. Most machines would have trouble with this. When you swing you are turning half or more the weight of the machine, if you touch the ground add to that the resistance caused by the bucket touching the ground. This is very hard on your machine.

When you sit in your 45000 lb piece of iron it's easy to feel that it is invincible and capable of anything and in a way it is as long as you stay within the capabilities of the machine. Every machine has limits based on what it was engineered to do. As you spend more time on your machine you will find out what those limits are and be able to do everything you want to do, it just takes time.

This may sound stupid but this is what I tell new operators. "Light touch and be the machine". Think about it, if you were an excavator you would probably have no proplem gouging the ground with your fingers without too much pain. Try backhanding a pile of dirt as hard as you can and it's gonna sting, may even dislocate your shoulder. If you gently brush the pile a couple of times it shouldn't hurt at all. An excavator is exactly like a human arm. See where I'm coming from?

I hope I havn't offended you as there may very well be something wrong with your machine but from reading your previous posts my gut reaction was to suggest spending more time with your excavator to get used to it's idiosyncrosies. Might not hurt to get another operator on the machine for a second opinion and go from there.

A Chapman

[esobofh]

:usa I purchased a John Deere 690c excavator. My question is how much power should the side -to -side (swing) motion have? Should it be able to knock over a yard of soil with the sideways swing motion if on level ground. I don't think my machine could! The machine is very very strong in all other aspects. It just seems like it should be stronger in the swing motion. For example It's almost as if I was standing next to the bucket on level ground pushing on it and someone else was in the cab trying to swing against me I would win:beatsme However if I had a full bucket of gravel ten feet in the air I can swing it uphill while on a slight grade.
Please let me know if this seems normal. If not where should I begin checking for the cause?:confused:

Resurrecting this thread, because the discussion interested me. It seems to me that the swing operation is pretty well limited to skewing the machine, with full weight in the bucket - that it's not intended for working at load and with force. i.e. if you wanted to level something you'd do that with the normal bucket/stick/boom movements toward or away from you - and not with the swinging motion of the machine.

is that correct?

[ditchdiggerjcf]

just about everybody uses the heel of the bucket to knock down small amounts of material during back filling, dress up, etc.... They will not move near as much material this way, as the swing function is noticeably weaker than other functions.

[gasfield315c]

you could also try moving the bucket in closer to the macine to sweep with, it wont sweep as much extended out all the way

[Chris5500]

Slew should have plenty of power, one of the more important functions on an excavator, not only used to rotate the superstructure but also commonly used to slew the undercarrdige. Generally the slew relief is set higher than the MRV. I take it you haven't checked your slew and main relief pressure? Get some specs to compare with too. While your there, may aswell check the relief pressures of other functions too and tune up as required.

[John C.]

Swing pressure is never higher than main relief pressure in any excavator I've ever worked on. It is generally at least 500 PSI less than main pressure.

Excavators are generally made to start swinging a loaded bucket from dead stop to full rotation speed in an engineer determined amount of time. Swing power is generally determined by the reduction in the swing gear box and the sizes of the swing pinion and ring gear. Make the swing too powerful and the speed is reduced loosing production. Make the swing too fast and you loose start up power and use more fuel because of the increased load on the engine. The upper range of excavators use two sets of swing machinery to get the house turning. In either case the swing torque is limited to reduce the amount of side loading on the house and carbody.

With the advent of shovel logging where the machines pick up logs and throw them forward, instead of using skidders and towers, swing power has become the new battle ground. Most of the shovel manufacturers are installing two sets of swing motors and reduction gears to increase torque like the big mining shovels. The extra gear do seem to increase the life of the swing machinery boxes over the single box machines.