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metalmagpie
08-03-2011, 04:13 PM
I have this part. It slides up and down a ground rod. It's called an "end weight" on a Globe meat slicer. The bad news is that the bronze bushings are worn so there appears to be about .003" of slop, which is enough to cause the part to bind up. The worse news is that the bushings are pressed into circular pockets such that zero or almost zero of the bushing's ID is available on the inside to push the old bushing out. So I'm looking for a clever idea as to how to remove the bushings, one at each end. The bore is only about 2-1/2" long so I could easily get a punch to bear from the back end except there's nothing to catch if you get my meaning.

I am familiar with the old dodge of somehow injecting grease, getting the grease to push out the bushing(s). But if there's nothing for a punch pin to push against, there's nothing for grease to push against either.

The bore is about 0.437" on the bushings. I'm thinking of trying to tap them 1/2-13 and pull them out with a bolt. Don't see any way other than to keep on tapping right past the bushing (only about 3/16" tall) into the part's bore, though. And there wouldn't be much "meat" for the bolt to grab onto.

I suppose I could braze a plug in there. Then it would be possible to punch it out from the back.

Ideas? Comments?

metalmagpie

Tony
08-03-2011, 04:41 PM
Bore it out?
turn it into chips instead of pulling it as one piece.

though I like tapping. Why are you tapping into the part? Bushing too
short? flat-bottom tap?

I've seen pipe extractors with the cam tip to grip from the inside, problem
is it'll put pressure in the wrong way but maybe if you get it spinning it'll
work its way out?

Stepside
08-03-2011, 04:45 PM
If I understand what you have then tap one bushing and run in a bolt. You now have something to punch against. Tap the second bushing and repeat with the hammer.

SGW
08-03-2011, 04:46 PM
I think I might try tapping the hole and using a bolt as a puller. I'd probably drill the hole out to 29/64 and use the fine thread, 1/2-20, to get more thread engagement. It's still not great, only 3 3/4 threads, but it's lot better than the approx. 2.4 threads you'd get with 1/2-13.

There is also a NEF thread, 1/2-28 (tap drill 15/32), that would give you 5 1/4 threads of engagement in the 3//16" thick bushing, which is looking really good.

At this point I expect you are looking at the need to buy a tap -- I would be. Is the project worth the price of a tap? Up to you....

darryl
08-03-2011, 05:25 PM
Turn a steel shaft for a close fit into the existing bushing, then concave the end of the shaft as much as possible, leaving the edge sharp. Then bandsaw into the end from two rotations, leaving four fingers. Jam something in the cuts to spread the fingers a bit in both directions. Turn it again to get most of the OD on the fingers down to the shaft size.

Insert the shaft from the uncut end and force the finger end into the bushing about halfway or so. Now as you apply force on the shaft, the sharp edges on the fingers will dig in and get a hook on the bushing.

baldysm
08-03-2011, 05:51 PM
I think I would just bore it out.

The objective is not to entirely cut out the bushing, but make it really thin (few thousandths).

I've even purposely been off center a few thou and just sneaked up on it. You'll break through 1 side of the bushing and it's much much easier to pull out. If the bushing is brass/bronze, just center it bore it. Steel is stiffer can offsetting it tends to make it a bit easier to remove the bushing.

If you're careful, you don't touch or damage the hole that the bushing sits in.

metalmagpie
08-03-2011, 08:07 PM
The problem with boring it out is holding the dang thing. See the part:

http://www.oldhobartslicerparts.com/i/Globe%20Berkel/100_4860.JPG

I'm not saying it isn't possible. Just doesn't seem practical.

The quartered concaved shaft driven halfway in is pure genius. Sadly, I have sold my last metal lathe and my neighbor who loved to help me out died, and my other buddy who is willing to help me out usually is extremely busy. So I'm kind of on my own.

metalmagpie

tdmidget
08-03-2011, 08:29 PM
Start a tap in to it and then drive it out from the other end by hitting the tap.

Bruce Griffing
08-03-2011, 08:55 PM
Bore it out on a mill.

metalmagpie
08-03-2011, 09:13 PM
I thought of another trick. Drill a cross-hole right through the part and the bushing. The bushing's OD is 3/4". Take a spring pin that fits the drilled hole and either buy it 5/8" long or cut it off at 5/8". Drive it completely in, so it fits completely inside the bushing. Then put a long pin through the bore so it bears on the spring pin, and tap it out from the back side.

I'm not going to do it, because of the nature of this part - it's a meat slicer, with intimate contact with biological material and I don't want to create another crevice for germs. But I like the idea ..

metalmagpie

Black_Moons
08-03-2011, 09:31 PM
Drill it out with successively bigger drills untill one gets stuck and rips it out because it catchs badly. :P

Boostinjdm
08-03-2011, 11:40 PM
Use a die grinder or dremel to grind through one side of the bushing. Then a sharp punch to bend it in and close that gap. Should now be easy to push out from the other side.

After doing that, I might strongly consider reaming the whole thing and pressing in a full length bushing.

Dan Dubeau
08-04-2011, 12:40 AM
mini hacksaw. Thread the blade through and reattach. Then cut through, or part way through the sidewall.

Surely you have one of those mini hacksaws. You know those cute little things that beg you to buy one from the end of the aisle bins. You can immediately think of a million reasons why you need one, but when you get it home it sits for years in your toolbox unused because anytime you need a hacksaw you need a real one. Then after a couple years of lying dormant in your toolbox you forget it's there because you've never used it. Then one day you're cruising the local hardware store and you come to the end of the aisle.......I think I have 3.

Black_Moons
08-04-2011, 01:01 AM
mini hacksaw. Thread the blade through and reattach. Then cut through, or part way through the sidewall.

Surely you have one of those mini hacksaws. You know those cute little things that beg you to buy one from the end of the aisle bins. You can immediately think of a million reasons why you need one, but when you get it home it sits for years in your toolbox unused because anytime you need a hacksaw you need a real one. Then after a couple years of lying dormant in your toolbox you forget it's there because you've never used it. Then one day you're cruising the local hardware store and you come to the end of the aisle.......I think I have 3.

Hah, I remember a post about a guy saying he got paid very well to snap his bandsaw blade and reweld (Or maybe he just melted the braze and rebrazed it, in retrospect..) it after puting it through a hole in a workpeice to saw some large feature in or another..

lakeside53
08-04-2011, 01:31 AM
Pretty common problem - many blind hole bushings out there. At least you can get to both sides!

Insert slide hammer blind bearing puller, pull out.

Or.. grind a couple of pockets, insert Stihl oil seal puller, lock and pull out.

Drilling or tapping? many times the bushing will spin, so just use the tap to grip and then push out.

lakeside53
08-04-2011, 02:18 AM
duplicate post

Patch
08-04-2011, 04:44 AM
You use "2" woodruff keys and a flat bottomed bolt.

A.K. Boomer
08-04-2011, 08:09 AM
Start a tap in to it and then drive it out from the other end by hitting the tap.


Now why in the world would you go through the trouble to tap a hole and then not put a bolt in to hit against instead of a HARDENED tap that only has about 40% the threaded surface area? you just got some kind of a thing against taps? or you don't like the threads they create?

its a good idea - if you remove the tap and put in a bolt.

A.K. Boomer
08-04-2011, 08:48 AM
I thought of another trick. Drill a cross-hole right through the part and the bushing. The bushing's OD is 3/4". Take a spring pin that fits the drilled hole and either buy it 5/8" long or cut it off at 5/8". Drive it completely in, so it fits completely inside the bushing. Then put a long pin through the bore so it bears on the spring pin, and tap it out from the back side.

I'm not going to do it, because of the nature of this part - it's a meat slicer, with intimate contact with biological material and I don't want to create another crevice for germs. But I like the idea ..

metalmagpie


You could epoxy after - or install aluminum plugs and file to flush then sand...

not a bad idea, as long as you don't lose one of the plugs and it ends up in someones sandwich...

If your really careful and mark your drill bit and use the proper length pin and punch it in the perfect depth then you only have to drill one hole in the casting to patch ------------- but IF you screw up and push your pin in too far or its too long to start with your totally screwed...

you have plenty of material to work with though - so stop the drill short of going into the other side and use a short pin that will not hang out into the drilled casting.

RussZHC
08-04-2011, 09:03 AM
Make yourself up a "custom" remover.

Drill a couple of small holes at an angle, make yourself a "Y" with the tops of the "Y" at same or very close similar angle, use the base of the "Y" to drive on...if I am understanding correctly, just make certain to go in the direction opposite the bushing was inserted. It may be best to beef up the joint on the "Y". Same idea but it could also work with a single punch alternately driving on opposite holes.


For that matter, more time consuming but "neater" machining solution could be to cut an internal circi clip groove, inserted clip and let that be your edge to pound on...

ilndr
08-05-2011, 10:40 AM
Hi, I have removed lots of bushings, blind and thru-hole, one really easy method is to grind a quick and dirty cape chisel from a 3/8 or smaller piece of round stock. Just grind a 30-40 degree angle on the end until you have a point and slice through one or two sides of the bushing and collapse it. David

Scottike
08-05-2011, 12:43 PM
I've had good luck with this method to remove bushings and bearings from blind holes: Fill the pocket of the bushing or bearing completely full with grease and use a piece of shafting that has a snug fit to drive the bushing out. Nothing fancy, I've even used wood dowling, it just needs to be a running fit on the tight side. The hydraulic pressure created when you hit the end of the shaft with a hammer will force the bushing out. Sometimes it take a few whacks and once things start to move you may have to top off the grease before the bushing come out completely.

jkopel
08-06-2011, 01:41 PM
Cut a piece of .5 shafting the same length as the total length of both bushings plus enough length to push a bushing out. Grind off a little bit off the diameter everywhere except maybe .125 of one end to leave a little ring the full .5 diameter. Remove enough that it is easy slip fit in the bushings. Grind the end with the ring as flat as possible and leave the edge sharp! Cut two crossed slots as suggested and knock the rod into one bushing with the ground end going in first. Bang it in so the slots compress a bit and it is maybe half way in. Pound something into the slots to expand them and then knock it out from the other end.

metalmagpie
08-07-2011, 12:21 AM
I'm the OP. Wound up tapping 1/2-13, winding in a bolt, punching out from the back. Easy.

Lot of great ideas you guys came up with!

Have to say lakeside53 came through bigtime. Turned & reamed new bushings, then chucked up the shaft they turn on (worn unevenly) and polished it here and there, trying the part until it all fit nicely everywhere. Shades of Forest Addy ..

Anyway, this is now the nicest fitting top weight any Globe meat slicer ever had! Go HSMs!

metalmagpie

lakeside53
08-07-2011, 01:15 AM
Well heck... I had to do something while MM was welding up all the cracks in my recently aquired lawnmover deck. Amazing what happens to sheetmetal when the crank has 0.12 INCHES of runout 3 inches from the engine. ... :D