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Cazeneuve HB 575 Lubrication pressure question

mjk

Titanium
Joined
Oct 20, 2005
Location
Wilmington DE USA
When I picked this lathe up a few years ago the oil pressure gauge had a cracked bezel.
It was hard to read, the needle would get stuck on the glass.
I replaced it about a year ago with a 0-30 psig which was within the range of the normal pressure.
Mounting and adapting was a pain but it looks good and works.
But it was pegged most of the time and after reading more of the manual cleaning of the sump screen is recommended.
The high pressure issue is apparently common with this lathe.

Had first tried changing the oil, didn't make a difference.

So now I've went into the sump and I've removed the sump screen and have cleaned it
Replacing the return lines as they were hard as a rock.
I'm also upon reassembly going to add a metering valve in the pressure line.
This has been a fix used by previous owners/posters to solve the high pressure.
Possibly the only problem with having the high pressure is the front/spindle seal.(I don't want to have to replace that)

So attached is a pic of the sump pickup(left) and an unfound located "Nozzle"(right)

The sump is easy to find, and upon reassembly I'll make a few modifications to make it maintenance friendly.
But is the detail in the right side of the pic recognizable to any HB575 owners, or is it only part of part of the 500 or 725?
 

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Started looking thru the manual again for the word "nozzle" as search function of pdf didn't return anything
But the "big picture" of lube points showed it clear as day.
The "nozzle" is located in the headstock

Not at the shop right now, but will look first thing am

All I had to do is post and I found the answer......
 
Was able to remove the "nozzle" following the instructions from the manual.
No obstruction/dirt that would cause the pressure increase.
The "nozzle" contains a small orifice (0.060") that leads directly to the spindle bearings

Hope to have the sump modified and flow restriction valve installed within a week.

Modifications to the sump will allow easier "filter" cleaning without having to remove return lines and entire top cover of sump.
 
Update to above.
Pic of screen shows what previous owner installed for a "filter"
Wasn't real happy about finding it this way.
Oil in sump was discolored but no signs of burning or nasty's

idler shaft was only spot that I found an obstruction. (finger pointing to end of shaft)
hint of this was lack of oil coming from end of shaft prior to disassembly/not knowing how change gears were lubed.Prev owner screen.jpgidler shaft.jpg
 
Oil sump cover (20" x 8")that has to be removed to clean filter
Not a lot of room when trying to prevent dirt from falling into sump and keeping the drive belts from getting any oil on them.
pic taken after modification to allow only filter mount (6" x 6") to be removed
This allowed removal without disconnecting the (2) 1/2" return drains
 

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New filter "basket" with a fine mesh screen

As mounted to cover/pickup
 

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After the new screen/filter was added, cleaning of the idler shaft and a recharge of oil, pressure was still high.
My original intent was to add a flow control valve to drop the pressure to the lathe after the pump as it is fed to the system.
When I did the first run with the new oil I had a few drops from the chuck/seal area and the drive pullet shaft seal.
Both of these were happening before the recharge of the oil.
I attributed this/hoped it to be a function of high oil pressure "blowing" past the seals.
I couldn't find a bypass valve of normal design in the oil system schematics or cross sections
The sump pickup contains a set of balls that appear to act as check valves during pressure/suction cycles of the oil pump lines.
These are the 2 braided lines going to the sump. The 6 mm copper line is the pressure line feeding the lathe.

I decided to use the flow control valve tee'd as a bypass immediately after leaving the sump with 1/4" nylon.
I dumped the bypass excess back into the sump.Flow valve can be easily adjusted to compensate for temp and also locked in position.
Gauge pic shows the result, oil pressure within the limits.
Getting sufficient oil coverage on the change gears as oil exits front and back of idler gear/shaft
No drips from the pulley shaft seal or chuck seal
 

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...
The sump pickup contains a set of balls that appear to act as check valves during pressure/suction cycles of the oil pump lines.
...
Hi,

I understand that the checkvalve with the balls is for the chuck-direction. One valve for forward the other for reverse.
Does the gauge still shows pressure with the chuck in reverse ?
BTW: I haven`t seen a kPa Gauge in ages ....

Drops at the spindle seal I have when machine/sorroundings are cold let`s say below 50F.
Now at 35F I have more drops. After a cig length in neutral and low speed it`s over. The manual says the same

Rainer
 
Rainer

Gauge shows pressure in both spindle directions, with no value difference.

That now makes sense that the 2 lines from the pump to the sump switch from suction to pressure depending on drive motor rotation. As they wear/break in over time they allow more flow?

Yes I noticed the mention in the manual, but have also seen comments from owners about the drip...never stopping
The manual also notes about only needing a low pressure to achieve proper lubrication.
I'm hoping my logic regarding keeping the pressure in the "green" will prevent a drip that doesn't stop.

The dual value gauge was a std catalog item from McMaster Carr. Not that I needed to have the kpa values, but it was appropriate considering the reference label above the gauge from Caz

Mike
 








 
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