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Frozen drive Fairbanks Drive Shaft


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I am restoring a 100#  Fairbanks-Dupont Power Hammer that went through a fire and then sat out for a year.. I have been able to remove the ram and toggle arms with a minimum of trouble and have them moving freely. The problem is the drive shaft. The brake is released and not touching the drive pulley. I have been spraying regularly with PB Blaster and squirting it into the oiler holes. One problem is the oil holes are on the side of the shafts so I am not sure that oil has migrated all the way around the shaft. I then wrapped a sling around the drive pulley and lifted it with my hoist. The pull is in the direction of rotation and thought it might free the shaft but the machine just lifted up instead. So now my question…

 

I am considering attaching my arc welder leads to the drive pulley and fly wheel which sit on each end of the drive shaft. I am hoping that this will create enough heat to expand the shaft slightly and then release upon cooling. So is this crazy and/or is there another suggestion on how to get the shaft to release and turn.

 

Thanks for your help.

Fairbanks Shaft.JPG

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 I see a steel shaft that is rusty inside of babbit/brass bushings.  We know the the shaft is just supper tight because of the rust expansion versus a steel bolt being siezed in a steel part where they actually become one piece. So short of putting it upside down in 50 gallons of wd-40 or the like I think your on the right track with the forced rotation of the shaft. Just have to figure out how to apply more torque and maybe use 4 weed burners to apply heat to the bushing areas and a couple of air hammers to induce a high frequency vibration in the shaft could possibly break it loose. I dont see a gentle way of getting that huge shaft to turn. 

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I think it is a steel shaft in a steel bushing.  From the outside, t will take a lot of heat to get through the steel casting and into the steel bushing.  Maybe I could use my forge burners instead of a weed burner. That is why I was thinking about the arc welder, so that it could heat and expand from the inside out. Looking for the safest way to heat the cast steel body of the Fairbanks.

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I was suprised too. In my head I was not expecting such an issue because I thought there were bronze bushings and that they looked good after the fire (no sign of heat stress) and did not think rusting would be an issue. Right after the fire, I was able to move the drive shaft. When I finally got to cleaning it up 18 months later, I put a magnet on the bushing and it was magnetic. 

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i was thinking in a more radical method. Would work better if you can remove the pulley or flywheel.

Find a large nut that fits on the end of the shaft and weld it with a stick welder, inside and outside all around. 

Let the heat sink in and then start working it with an impact driver like the one used in the tyre shop, 3/4" drive. 

You may break the weld, not a problem, grind flat and weld again. A chamfer on the outside will help. And additions of penetrating oil ... transmission fluid and acetone? Sounds good, never used it. Best of luck!

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Are the oil holes threaded?  Either way, it might be possible to install a zerk fitting at the hole location and then force penetrating oil in under some pressure---grease fittings also work pretty well with oil, the issue is finding a gun to inject it (safety glasses!).  Some simple oil cans can do this but not under much pressure...at least a little though. 

Alternatively, you can install a tubing riser to the shop roof and get a little constant pressure--or even add a little air pressure to that to get some constant force on the penetrating oil through the oil holes.  Sometimes that can improve penetration over simple capillary action.

Ditch the PB.  The only benefit of that stuff is that it's cheap and available.  Kroil is much better (and less stinky).  Haven't tried the ATF/acetone myself so I'll go with what others have said.  

 

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Kroil is Da Bomb

If you are dealing with a rust issue, what about building a containment around it and doing electrolysis?

I have also seen ultrasonics used to free up rust seized items, but not real practical for this application.

When heating, you only need to expand the outer shell by a few thousands, and weed burners work fine for that.

 

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  • 2 weeks later...

No luck yet, I bought a small auto air hammer and brazed some brass on the end of one of the tools, been tapping on the shaft, oiling and praying. No luck yet. I like the idea of the nut on the shaft with an impact hammer, might try that next. There is a bit of shaft extending out that I can weld to . I am still thinking about getting a 300 amp stick welding and clamping onto each end of the shaft to heat it up .......

 

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