Noticed yesterday that the old J&S 540 surface grinder, which doesn't get used much, was acting strange. When the cross table traverse feed is in use, it slows down the x axis power feed? I checked, and topped up the oil, so apart from that I am at a loss. Any ideas ? Bob
OK it's a hydraulic pump belt operated iirc. The cross feed is a rachet thingy that obviously takes some oomph to operate and push the table, so it suggests that the hydraulic long feed is marginal or the amount of oomph required is abnormal if it is being slowed down.
So is the belt tight, is the pump worn, is the workshop unusually cold making the oil more gummy, is the cross slide adequately lubricated? Some of the oil from the long feed cylinder goes via drillings to lubricate both the long feed and the cross feed - are the drillings blocked. Are the catch buckets at each side of the base under the table filling with oil that then drains back to the tank as it should, or are they dry? (This is the oil that lubricates the ways)
Over and above everybody else's comments. The 1400 has a Purolator "twist the handle to clean, every few months" filter. If there is a similar one in the
540, is it blocked up with sporge?
Had the 1400 running for 6 hours solid today. The workshop got nice and warm. :-)
it relies on a wire mesh basket for the oil to go into before it enters the sump ...... plus the wells at each end of the table act as settlement reservoirs.
and the vast quantity of oil in the tank .with oil pick-up high ...so that the rest of the crap settles to the bottom of the tank.
the oil pick up has another fine mesh cylindrical filter....this may be worth a check .but requires you to...remove front panel, disconnect hydraulics, pull the whole tank out..........unbolt the rubber mounted motor and hydraulic unit from the tank .and invert it to get at the filter.
if you get that far ...you may as well empty the tank .clean the tank .and put new oil in it. 18 litres / 4 gallons of Mobil vacuoline
1405...this should be changed every twelve months if you use the machine every day
Nothing too unusual at all with that. Hydraulic cylinder speed is a function of flow control, and whilst pressure in the hydraulic system is constant, the speed will vary with the volume of oil delivered to the cylinder in a given time. The cross traverse on a 540 is sub-ported off the longitudinal travel
- it won't work unless this valve is opened first - so in effect it is 'stealing' some of the flow volume from this. When it slows down a touch all you have to do is crack the main table valve open a fraction more and the problem goes away.
However, if you already have this all the way open and your table isn't moving so fast that it tries to launch itself across the workshop, then you have either a major flow delivery or leakage problem. If it's delivery, then the problem may well be in the tank. If this hasn't been cleaned for a while you may well find that half the contents resemble jelly more than oil, and this will neatly block the pickup mesh. If it's leakage, then the problem will probably be in the cross traverse rams inside the main valve block, but without stripping the whole thing you won't know.
Finally, it might be as simple as some air in the system. The system is self bleeding, but it needs to run for a little while first to achieve this. The remedy is to set the table to maximum X traverse at a slowish speed and let this run for a while.
With regard to oil, I use Castrol GC32 which was a little easier for me to source than Mobil Vacuoline.
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