Flex shaft 'stuck'

[Iron Mike]

Have 70+ hours on the machine and thought I'd do service prior to doing three carves I have planned. The shaft was starting to run somewhat warmer of late . . . . not HOT by any means but starting to get there.

Cleaned, lubed the rails, guides, etc. took the flex shaft out but the 'core' would not come out of the sheath. I removed the sheath at the motor and still couldn't get the flex core out of the motor. Removed the motor and was able to pull the core out hand but it was pretty tough doing so. Seemed to be quite 'dry' and a little rusty. Used the correct lube and reinstalled everything.

About 30 minutes into a carve I felt the shaft and it was VERY HOT! Stopped the project and pulled out the core and lubed again - re-installed and continued with the carve . . . . however it continued to get very hot after 10-12 minutes. I let it cool then ran it until it was hot again and let it cool down. Finally got the project done in 10-15 minute carve periods. Can't understand why after lubing it would then start to overheat so much . . . MUCH hotter than prior to the maintenance.

Anyone have an answer for me? Should I try to clean out the sheath?

[bergerud]

One of the main reasons for heat is compression of the core. Make sure the slot in the motor is cleaned out and that the core is free to float.

[Iron Mike]

bergerud,

I did clean the motor core slot out with WD40 and a Q-tip. Was quite rusty - added lube and re-installed. The core goes into the motor quite smoothly. The 'spring' looked to be in fine shape by the way.

[bergerud]

Do both ends of the core slide freely in the square slots? There are no stray wire strands? The ends are not twisted?

Maybe you should clean out the sheath. Some rust might have made it up the sheath and be distorting the spring. (Al has reported before that a kink in the spring caused him a melt down.)

That is all I can think of unless it is something else like a bearing going in the spindle.

[Iron Mike]

Do both ends of the core slide freely in the square slots? There are no stray wire strands? The ends are not twisted?

Maybe you should clean out the sheath. Some rust might have made it up the sheath and be distorting the spring. (Al has reported before that a kink in the spring caused him a melt down.)

That is all I can think of unless it is something else like a bearing going in the spindle.

Both ends are easy to get into and out of the slots . . . didn't see or feel any broken strands. I'll remove again tomorrow and inspect closer for kinks and twisted ends.

Does the spindle bearing come out easily? I saw it was secured with a C-clip. How about lube/grease for the bearing?

Thanks for the help.

[bergerud]

The spindle bearings are not that easy to deal with. The top of the spindle can be quite tight in the top bearing. I would not consider taking it apart unless you really know it is the problem.

[fwharris]

I would suspect something inside the flex core or possible bad spring. Remove the flex core and the shaft/spring from the core and with a rag on one end blow some high pressure air through it.

[Iron Mike]

I would suspect something inside the flex core or possible bad spring. Remove the flex core and the shaft/spring from the core and with a rag on one end blow some high pressure air through it.

I'm thinking I'll run a waxed lacing cord through it and pull a small cloth patch through - like cleaning my pistols.

[fwharris]

I'm thinking I'll run a waxed lacing cord through it and pull a small cloth patch through - like cleaning my pistols.

That should work.

[Iron Mike]

Well . . . I found nothing but lube in the sheath - the swab didn't feel like it got snagged or anything so I think that part is okay. The spring inspection showed nothing suspect at all either.

When I took the flex cable off the core was again stuck in the motor . . . . I removed the sheath from the motor and was able to pull the core out from the motor without removal - wasn't as tightly stuck as the first time but was hung up pretty good.

The end of the core that was in the motor had an ever so slight bend just above the squared end . . . very, very slight. Upon re-installation I switched the core ends with the good end towards the motor; we'll see if that makes a difference on my next carve this evening or tomorrow.

Thanks again for the suggestions, you guys are a great sounding board and help.