What's new
What's new

Proper control cable for oil immersion and flex

rklopp

Diamond
Joined
Feb 27, 2001
Location
Redwood City, CA USA
I need to replace a control cable that runs immersed in oil. My Euro-style mill has a spindle lock for undoing the drawbars. There is an interlock switch inside the gearbox to prevent starting the mill with the spindle lock engaged. A cable runs from the switch down to the bottom of the oil sump, and them back up and out through a gland in the side of the gearbox. The cable fatigued off because, being a Euro-style mill, the headstock moves to achieve the Y-axis motion, and the interlock switch moves along with it.

I went up to my elbows in the gear sump and pulled out the broken cable. It seems brittle from age, so I am reluctant to just cut it back and make a new end even though I have enough slack.

Given that I want to replace the cable, what is the right high-flex control cable suitable for continuous oil immersion? The old cable is 16/2 with about a .22" (5.6 mm) OD. McMaster has this. I'd be looking at the 300-V version, probably pairing up the conductors in the 20/4 size. Would this cable it survive submersion? What cable is used inside auto engines?

I need the interlock because I occasionally forget to unlock the spindle, and the drive train has enough torque to overcome the lock and possibly break things when in low gear. (Fortunately, the belt slips if the lock is left engaged when in high gear.)
 
I need to replace a control cable that runs immersed in oil. My Euro-style mill has a spindle lock for undoing the drawbars. There is an interlock switch inside the gearbox to prevent starting the mill with the spindle lock engaged. A cable runs from the switch down to the bottom of the oil sump, and them back up and out through a gland in the side of the gearbox. The cable fatigued off because, being a Euro-style mill, the headstock moves to achieve the Y-axis motion, and the interlock switch moves along with it.

I went up to my elbows in the gear sump and pulled out the broken cable. It seems brittle from age, so I am reluctant to just cut it back and make a new end even though I have enough slack.

Given that I want to replace the cable, what is the right high-flex control cable suitable for continuous oil immersion? The old cable is 16/2 with about a .22" (5.6 mm) OD. McMaster has this. I'd be looking at the 300-V version, probably pairing up the conductors in the 20/4 size. Would this cable it survive submersion? What cable is used inside auto engines?

I need the interlock because I occasionally forget to unlock the spindle, and the drive train has enough torque to overcome the lock and possibly break things when in low gear. (Fortunately, the belt slips if the lock is left engaged when in high gear.)

I'd actually look for a "better way" to sense locked/not and not NEED that switch or cable. Mechanical rod to external switch, mechanical push-pull cable that oil is a friend to, not an enemy, then an external flag or switch. Disable the OEM lock and add my own, etc.

Even being assured as to the effects of oil immersion - long term - isn't easy:

The Importance of Oil Resistant Cables | Lapp Tannehill News & Articles | News & Articles| Wire, Cable, Tubing, Connectors | Lapp Tannehill

Tests are short-term. But the damage - such as your embrittlenent - is long-term.

Oil Immersion Cable Testing | Eland Cables

No idea what had been used, nor what MMC is carrying.

This may be what the European makers would use "today":

OLFLEX(R) Oil Resistant Power & Control Flex Cable

Could easily last as long as the OEM.

Make two, keep a spare, and that seems to guarantee it wont fail. Until you misplace the spare, of course!

:)

As said, I'd re-engineer it so "oil" was friend, not foe - and no longer have the problem to deal with at all.

As to wire "INSIDE" auto engines? Or transmissions? Where hot oil or coolant lives with vibration, metal nano-paricles, carbon soot, acids, and harsh additives?

None.. unless the design Engineer had his head "INSIDE" his ass. Deeply. Very!

Miles of "underhood" and even "ON" block wire to sensors. But the sensor has a probe to the inside so the wire need NOT "go there".

Challenging enough life already, those wires have.
 
Colt45 sent me a PM pointing me to Igus. They seem to list exactly what I need. Thanks Colt! Thermite's links were helpful. I don't see a practical way to re-engineer the system, plus I want to keep it as original if I can.

LOOKS GOOD! I've bookmarked that source in case I need sumthin' tougher than average meself in future.

"PM, doing what PM does best"

:)

Curious they spec just "TPE" AND say no Halogens (Teflon is a Halogenated plastic - Fluorine).

"TPE" is VERY general term covering a HUGE "class" with an astonishing array of players, which see:

Thermoplastic elastomer - Wikipedia

If I had to guess? Since I DO "have to guess"? I'd suspect Olefins.

Then again.. when I Sawzalled all the conduit out of my first 10EE to do Solid State Drive? Near-as-dammit all of the vintage 1942 pale blue jacketing on the wire was still like new even in the conduits where leaks and spillage had them partly full of oils.
 
Five years ago or more I looked into this for underhood car wiring because Ford got it wrong, maybe part of the Volvo merger since Volvo had problems earlier. The best I could find then was teflon insulated. Not teflon coated but pure teflon insulation. The wire can not be tinned, it must be silver plated at the factory so it costs more.
Bil lD
 








 
Back
Top