Flex drive shaft lubrication??

[tripster]

Just picked up an electric boat. Look like a huge Dewalt motor on a flex shaft. Looks like the outer tube of the flex shaft is plastic/nylon. What do you lube the shafts with? Do you lube them? How can they withstand the RPM?

Mike..

[George Pfeifer]

Mike;
It MUST be lubed, usually any marine grade grease, such as lubriplate, synthetics seems to be better than petro based. Should be available from any boat store. Some guys like to mix a few drops of Mobil 1 synthetic oil with about a thimble full of grease before applying.
The "Plastic" tube, is Teflon, at least it better be. Teflon doesn't melt.
Tips:
Cable can be cleaned and polished with WD-40 and 600 grit wet dry sandpaper. Clean well with WD-40 after polishing, then grease liberally.
If doing serious racing, the cable should be regreased after every run. If sport running, it should be regreased every few runs, or if it starts to make noise.
A properley greased cable should last a long time. Improper greasing or really high RPMs 50,000 plus will cause failure.
There should be a 1/16th to 1/8th gap at the propeller end, (distance between strut housing and drive dog) as the cable will shrink under load.
Hope that helps;
George

[tripster]

Sure does. I hope it is teflon. Boat came with a 10 cell 2400scr pack so I am sure the rpm's will be pretty hi.

Mike..

[George Pfeifer]

I doubt that you will see higher than 20,000 RPM. Motor sounds like it might be a 700BB. If it is you should be able to go up to 14 cells in series. A 700 BB comes in 8.4 volt, 9.6 volt and 12 volt. The most popular one for boats is the 8.4 and you can run double that thru it without a proplem. Much beyond that and you risk letting the smoke out.
The 8.4 on 12 cells, with an R/C Hydros controller by Andy Kunz is becoming the standard accross a lot of the classes. It is a cost effective racing combination.
George

[Seattle Jim]

Tripster, Don't mean to appear nosey, but what kind of boat is it? Just curious! Thanks .......... Jim.

[So.Cal. Craig]

George is right, use it well. It is not only a lubricant but it also keeps the water from climbing up the stuffing tube. I would get about 1 or 2 spoon fulls of water in the hull until I used more and now not a drop gets by.

My wife is a Nurse and she gave me a syringe to try with the grease. I use Cable Grease from Prather Products, (green blueish flex cable lub.) and I draw up 1/2 a syringe (no needle) and then hold it tight to the tube and inject it in, slide cable in, prop on, wipe excess at other end, and vuola! I can see in inside the nylon tubing going up. Kinda hard to draw up into the syringe because its thick but goes in nice and clean, no mess. Clean it out at end of day, don't need water or the gunk to sit for long. Check it out, works for me.

[tripster]

My wife is a nurse also. Great idea. George it is a Hustler mono hull.