5 replies to this topic

[wdturner]

We are replacing all of the hanger head bushings on two of the Borvig triples that we have this year. In years passed we have replaced bushings on our NDT chairs, when the bushings come to us we have had to reem out the bushings to make the grips fit. Has anyone out there run into the same problem, if so are there any jigs that have been made to reem these bushings square? We have been making it work, but was woundering if there were any "tricks" out there!

[liftmech]

We don't have any Borvigs, but we do run into that issue from time to time on other types of bushings. We've used a tapered centering device that fits on the end of the ream (from the opposite side you would start the ream) and that seems to work well. No jig required that way.

[Kelly]

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Kelly
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[mseneca]

wdturner, on 22 March 2010 - 01:27 PM, said:

We are replacing all of the hanger head bushings on two of the Borvig triples that we have this year. In years passed we have replaced bushings on our NDT chairs, when the bushings come to us we have had to reem out the bushings to make the grips fit. Has anyone out there run into the same problem, if so are there any jigs that have been made to reem these bushings square? We have been making it work, but was woundering if there were any "tricks" out there!

I have also come across the same issue with two Borvigs of are own. I have attempted numerous techniques. My last brainstorm was to machine the outside diameter by .01 of an inch.\
With regards to the inside surface. Id like to keep that surface as smooth as I can. Being it is a bushing! the old techniques that the crew has used is much to course on that inside surface and I believe does nothing in our favor. Im sure the surface that you and I can produce with an inside reem is nowhere near what the factory can give us. after machining the outside I could push the bushing in the head with my hands with some force. it my seem to loose for some but once You install the grip it shouldn't turn inside the chairhead. If you install the bushing in the head dry you will see that the grease WILL stay were it belongs. You might also notice some migration on the bushing while you pump the grease, once you see the bushing begin to move thats it. Remember that the grease in the head is acting like a Hydraulic cylinder. If kept up on greasing schedules you will find that the bushings will not turn in the head and just turn at the grip. It took me a bit of time to narrow this problem down but I definitely works to our advantage. You must be very picky with the way the bushing fits. But it will save you from wearing them out for some time. Remember a tight smooth greased bushing is a happy bushing.

[timberlaker]

for around $800 you can get a lathe to accomplish your goals. We are lucky enough to have a machine to size all our bushings correctly inside and out. The advantage of a lathe is speed, once you have it set up you can almost save enough time and wasted material to pay for it in one lift line worth of bushings.Harbor freight offers one new for around $700 but you could find one used cheaper.

[eastcoasteragain]

we replaced all of our bushings this last summer and the reamer that we used was very hard to create a uniform product. after reading the lathe idea i wish we would have thought of that. save that one for next time.