fixture for truing the bore of a hyd cylinder rod eye

[Frank S]

The construction company installing the fiber cable for our area phone lines noticed that I have several machines while they were upgrading my landline service. yesterday their maintenance guy stopped by to ask me if I could or would do a repair for them.
retirement being what it is why have all of these machines if I'm not making or repairing something with them.
So I drove out and had a look at the problem.
A Hydraulic cylinder with a spherical rod end that he said keeps shattering the bearing cup.
Sure it does it was the wrong application for the size bearing and there was no need for a spherical bearing to be there in the first place.
The superintendent said they have replaced the bearing a dozen times in the past 3 months and he wanted a solid bushing or sleeve type bearing installed in place of what was there.
They pulled the cylinder off and brought it to me last night so here is what I had to do

First off I noticed that what the man wanted wouldn't solve his problem for the long term. What he wanted was to simply machine a thick bushing a little wider than the rod end and press it in then weld it in place. Which would have been fine except when the bushing would eventually wear out it would have to be cut out and another one made.
I decided to take this 1 step further by making the bushing then making a sleeve bearing to the size of an off the shelf standard sleeve bearing.
But the rod eye bore was severally damaged so first that had to be taken care of

Now how to hold this thing in place so I can bore it out

I know I will make a fixture and clamp it to the compound and cross slide First I cut a 8" long 3 x 3 x3/8" angle from scrap

next I cut another piece of the angle then clamped it down to cut off a strip to fit in the holding slot of the compound.

Next I cleaned up the face of the rod eye

Here you see the fixture with the cylinder rod clamped to it and the boring bar to clean up the rod eye
Note the missing paint near the end of the rod where it joins the eye. To make sure the bore was perpendicular to the rod I checked the alignment of the rod to be parallel tot eh lathe chuck by using a known straight cylindrical bar positioned against the cylinder rod then measured the distance to the lathe chuck face with dial indicator the magnetic base on the chuck I rotated the chuck until the needle struck the bar at the horizontal my chuck is 12 " in diameter so I was checking the bar that distance apart I figured it was close enough once I found zero in 2 places.

Another view Has anyone ever used tool holders as clamps

The fixture


the bore cleaned up

[Frank S]

TO complete the repair I made the bushing and sleeve bearing out of some old stock I had left over from other projects. Like the top roller of my plate roller

I left the bushing about 0.010" oversized on the OD with a 1/2" wide flange 0.100" larger OD to give a positive locating stop.
Then after heating the rod eye hot enough to allow the bushing to slip in I welded it in place



Now I heated the sleeve bearing to red hot then water quenched it. I told the guy that the bearing will not last near as long as store bought one but this will get them by until the bearing I ordered come in

No picture but after quenching the file test was fair but nothing to write home about. I knew it wouldn't be because I figured the steel didn't have much carbon in it to harden anyway.
While the rod eye and bushing was still quite hot I installed the bearing still had to drive it in with a sledge hammer so everything is good

[DIYSwede]

Thanks, Frank!
Smart, fast and operative solution with what you've got around!
Keep up the good work, and good luck with the final bearing mount and its longevity!

Cheers
Johan

[Frank S]

Thanks, Frank!
Smart, fast and operative solution with what you've got around!
Keep up the good work, and good luck with the final bearing mount and its longevity!

Cheers
Johan

here is a bad picture of where the application is on the machine. And the primary reason why the spherical bearing on a rod end is not the best choice.
It is the articulation cylinder for a vibrating plow that installs poly piping in the ground.
note the 4 inch distance between the top and the bottom plates. The spherical bearing is only 2" leaving a void of 2 inches.
A tremendous amount of vibration is transmitted throughout the machine. those ball ends have a thin outer shell which is hard as the bearing the constant vibrations cause the ball to hammer against the bottom plate and the gap above allows the movement to be more violent. this ultimately is going to cause them to shatter.
Now had the manufacture made the rod eye thick enough to allow retaining clips like a snap ring on both sides of the spherical bearing housing and filled the gap above and below the bearing then the design would have stood a much better chance of lasting for quite a long time. An extreme duty spherical bearing with a thicker outer shell would also help.
Now there is one issue with the solution the superintendent and I came up with. Now that there is such a long ridged through hole in the bearing if there is any angularity in the vertical plane between the cylinder rod end and the mounting plates very high stresses on the pin are going to be introduced the cylinder rod is 3" in diameter and the travel is less than 9" so if the manufacture was lax in making everything square and perpendicular assembling the cylinder back on the machine is going to be difficult. As other pivoting points allowing for the articulation of the machine begin to wear higher stresses are going to be introduced on the 2" diameter pin. But millions of machines with articulating assemblies similar to this one have been made for decades without using spherical bearings in those areas quite successfully more especially when violent vibrations are in play. So I guess our idea is at the mercy of how well the rest of the machine was constructed at this point.

[Altair]

Thanks Frank S! We've added your Hydraulic Cylinder Machining Fixture to our Lathe Accessories category,
as well as to your builder page: Frank S's Homemade Tools. Your receipt:

Hydraulic Cylinder Machining Fixture by Frank S

tags: fixture

[Toolmaker51]

the bore cleaned up

This is real machining. . .for scale, note size compared to head of the combination square.
Frank S is line boring again. Some would hesitate hanging that much weight off-kilter to the carriage and ways. Au contraire, it's balanced on the offside, in a choker slung from a chain fall, probably on a rail and trolley gantry crane. Effectively centers load on the carriage.
Take that Mr. Gravity!

[Frank S]

This is real machining. . .for scale, note size compared to head of the combination square.
Frank S is line boring again. Some would hesitate hanging that much weight off-kilter to the carriage and ways. Au contraire, it's balanced on the offside, in a choker slung from a chain fall, probably on a rail and trolley gantry crane. Effectively centers load on the carriage.
Take that Mr. Gravity!

Just as you said the weight is held by the chain hoist hanging from my
jib crane
Jib crane for my machine shop van
Where ever I need one of these I'll build and install one
Just another jib crane
And if those can't do the job there is always this
"A" frame gantry
The carriage and more importantly the compound only had to hold the cylinder true to the bore line And carried no weight at all.
The cylinder was really not all that huge but it was all that 3 men could do to load it in the back of the guys pickup to bring it to me.
When he showed up he asked if I had a fork lift. Of course I do but why would I want to use it on that little thing I asked, just back up and I'll in load it. I grabbed a nylon loop sling and swung the jib over the cylinder the most I had to strain was to use a thumb and fore finger to pull on the chain.
I need one of those he said.
I'll build you one and mount it in the back of your pickup I said.
I wish, he said. It's a company truck and they wont spend the money.
Yeah but they can pay a law suit for a back injury can't they?

[Toolmaker51]

We do the same thing at work; suspending oversize [in this case ludicrously oversized] side plates for a machine; it makes ball mill spheres. It's about 2.5 x 30 x 40. The gantry holds heavy end while milling a pair of 1" keyways 10" long. They get re-cut 1.06, 1.125 and 1.25 as they wear out. An import mill, it's done many of them
and seems to hold up.

[Frank S]

We do the same thing at work; suspending oversize [in this case ludicrously oversized] side plates for a machine; it makes ball mill spheres. It's about 2.5 x 30 x 40. The gantry holds heavy end while milling a pair of 1" keyways 10" long. They get re-cut 1.06, 1.125 and 1.25 as they wear out. An import mill, it's done many of them
and seems to hold up.

Yep as long as any required movement X or Y is not hindered by the supporting device there is no reason why the mill should receive any undue wear or stresses.
virtually no different than having to support a heavy or oversized component in a band saw or a drill press. The key is in planning how best to accomplish the task with equipment on hand.
I thought about doing a set up on my mill to do the bore but my homemade boring head is not as stable as I would like for it to be for making bores above 3" in diameter as was required for the rod eye in the cylinder.

[Toolmaker51]

Agreed, getting jobs out is what keeps shops afloat.
But The key is in planning how best to accomplish the task with equipment on hand causes issues. Too much reliance for 'we always did it this way'. A commercial entity should look for improvements, even being incremental, to have some kind of competitive edge. Old ways don't offer pay increases to employees, causing turnover and delivery interruptions. It restricts daily output regardless. Worst is probably when rush jobs come in; vice ability completing them in regular hours yet charge the OT premium for rapid service.

Need proof?
Right here in HMT.net. I'm positive the majority aren't operated for profit, yet look to improve on how they do work.