Installing needle bearings on a press??

[oley55]

I am contemplating installing caged, full compliment needle roller bearings in the pivot points of an old RCBS A2 press. I am looking at the 1/2" wide B88 bearings for each of the top 1/2" link arm pivot points and a pair of 1" wide BH1016's in the 2" wide bottom 5/8" toggle.

If (a big IF) I decide to make the mods, I am worried that a 5/8" drill press (30 year old Taiwanesium) drilled hole will not firmly hold the bearing cages in place (keepers/snap rings are not an option). The bearings outside cage diameter is: 17.463 mm (0.6875"). The same concern holds true for the lower bearing with an outside diameter of 11/16".

Any machinist folks out there who can advise me on this, or is there an adhesive I could smear in the openings to hold the bearings in place (but is not permanent)? Or should I just take my pieces to a machine shop, or is this just a bad idea all together?

[elmacgyver0]

Why do this?

[SweetMk]

Bearings that "roll" are designed with the intent of some minimum rotational speed.
This movement causes the bearings to pick up, and maintain a coating of lubricant between the steel surfaces.

If you operate the press slow (which is normal) the bearings have time to "squeeze" all the lube out of the contact area,,
this allows metal to metal contact,, the contact will cause the bearing surfaces to gall, and spall,,
A lube impregnated bronze bushing is the perfect answer, it is designed for slow operation,,
Install the largest one possible, width, and diameter.

[SweetMk]

If (a big IF) I decide to make the mods, I am worried that a 5/8" drill press (30 year old Taiwanesium) drilled hole will not firmly hold the bearing cages in place (keepers/snap rings are not an option).

Any drill, high dollar USA, or 30 year old Taiwanesium, will drill a hole that is triangular (shaped like a piece of pizza)
It is just what drills do, most of the time, you do not notice it,,
and, it does not matter if you are just putting a bolt through the hole.

After drilling undersize, you need a reamer to finish the ID to be round.

[Winger Ed.]

If you have to glue something in, JB weld is pretty good.
If heated to around 450F it breaks down to a ash, and can be 'unglued' that way.

[oley55]

Why do this?

At the great risk of this thread immediately going off into the weeds, I'll politely say because my press has some wear which I believe can be resolve by installing bearings.

[oley55]

Bearings that "roll" are designed with the intent of some minimum rotational speed.
This movement causes the bearings to pick up, and maintain a coating of lubricant between the steel surfaces.

If you operate the press slow (which is normal) the bearings have time to "squeeze" all the lube out of the contact area,,
this allows metal to metal contact,, the contact will cause the bearing surfaces to gall, and spall,,
A lube impregnated bronze bushing is the perfect answer, it is designed for slow operation,,
Install the largest one possible, width, and diameter.

I had considered the impregnated bronze bushings, but I have displace steel on the top right pivot arm (possibly from inadequate lube on the pressed-in pin). The harden pin is a little shiny on top and bottom and matches the displace metal on the top and bottom of the link arm's hole. I thought that was telling me the high forces would quickly distort the bronze bushing...??? Especially since the removal of too much steel for a thicker bronze bushing would weaken the link arms. I was of the thought the full compliment of hardened needle bearings against the hardened pin would not be prone to the galling you describe. But I am for sure not arguing against your recommendation, just offering up what I was thinking.

Are there different grades of bronze bushings which can take higher pressures?

I had planned to get a solid top ram made so I can attempt bullet swaging with it. So it will definitely see high stresses.

edit added: It seems the Corbin S press uses needle bearings in the link arms and imprenated bushings for the linier movement of the rams. All links run in bearings, as does the ram (two inch-long oil-impregnated bronze bearings support and guide the ram inside its hydraulic cylinder sleeve housing). Although hard to see in the attached, those are needle bearings. However that doesn't mean they will work for my application.

[nhyrum]

Bearings like that will require (from my little bit of digging) a press fit, which means your hole needs to be within a few thousandths, with a max diameter of .010 over the bearing diameter (according to the one chart I saw). I don't think you'll be able to get that together with hardware store bits. If it were me, I'd buy a cheap reamer that's long enough to do both holes/sides in one shot, because, good luck doing one at a time from the top of each and getting them lined up.

This is just stuff I dug up on the interwebs, and my one year of engineering/machining classes I took in college almost 10 years ago. So by no means am I anywhere near close to having a decent amount of subject expertise

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[oley55]

Bearings like that will require (from my little bit of digging) a press fit, which means your hole needs to be within a few thousandths, with a max diameter of .010 over the bearing diameter (according to the one chart I saw). I don't think you'll be able to get that together with hardware store bits. If it were me, I'd buy a cheap reamer that's long enough to do both holes/sides in one shot, because, good luck doing one at a time from the top of each and getting them lined up.

This is just stuff I dug up on the interwebs, and my one year of engineering/machining classes I took in college almost 10 years ago. So by no means am I anywhere near close to having a decent amount of subject expertise

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concur on processing both holes at the same time, and based on what SweetMK says about the pie shaped drill bit hole, a reamer seems to be the only option. Altering a late 1950's early 60's press is not to be taken lightly, and I surely don't want to end up trashing an old workhorse tool/press. IF I do press ahead, a machine shop seems more and more likely for me.

[SweetMk]

Before you install the bearing, simply envision how a few needles will be under pressure, with almost no surface area touching.

It is kinda like putting your thumb on the pointy side of a thumb tack, then turn it over and push on the flat side of the thumb tack.
It all has to do with area,

The bushing has thousands of times the surface area of contact, so the bushing can be thousands of times weaker.
The bushing wins.

That is basically in all reloading press pivots, cast iron against a steel pin,, the perfect balance of force versus surface area.

Bearings win, when the rotation is fast.

[nhyrum]

I just see the bottom of the races getting chewed up. There's a lot of pressure with little movement. Needle bearings I see being better then ball in my mind. I can see bushings being better as a bearing won't have really any lubricant, but I'd worry about bushings cracking. I'm on the fence between those two.

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[country gent]

I see several issues. Needle rollers on a soft shaft under med to heavy loads will compress the shaft where the needles bear you may want to consider an hardened inner race on the shaft. Drilling and reaming the bore should make an acceptable fit. In most shops a slightly loose fit can be cured with blue or green loctite. Another consideration is the addition of grease zerks to lube the bearings. The rollers might be a improvement but comparing cost to gain I believe that simple bronze bushings will be as good at the slow speed operation. A drill Press can do a lot of work and with a reamer or boring bar can make very accurate round holes. but set up time and the operations take more set up and skill than a mill does.

[oley55]

I just see the bottom of the races getting chewed up. There's a lot of pressure with little movement. Needle bearings I see being better then ball in my mind. I can see bushings being better as a bearing won't have really any lubricant, but I'd worry about bushings cracking. I'm on the fence between those two.

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In my response to SweetMK, just edited in info from Corbin about their swaging presses and they do use needle bearings for the pivot points and their presses far exceed the pressures my press is capable of.

[country gent]

Yes but they may also use case hardened shafts with a surface of 55 rc

[oley55]

Before you install the bearing, simply envision how a few needles will be under pressure, with almost no surface area touching.

It is kinda like putting your thumb on the pointy side of a thumb tack, then turn it over and push on the flat side of the thumb tack.
It all has to do with area,

The bushing has thousands of times the surface area of contact, so the bushing can be thousands of times weaker.
The bushing wins.

That is basically in all reloading press pivots, cast iron against a steel pin,, the perfect balance of force versus surface area.

Bearings win, when the rotation is fast.

I really appreciate your taking the time to help me with this. A point of clarification my A2 (2A) press is cast steel vs cast iron, not that it matters. This link to Corbin and their entry 'S' swaging press and it shows them using needle bearing in the same location I am considering. They do however use impregnated bronze bushings for the linier movement of the ram.
http://www.corbins.com/csp-1.htm

So, for the time being I'll continue to pursue the needle bearings option and finger out the drilling/reaming options.

Again my thanks.

[oley55]

Yes but they may also use case hardened shafts with a surface of 55 rc

Granted, I do not know how hard my shafts are, but they are hard enough to not distort or mar when I drove the two pressed-in shafts in and out with a drift. I'll take a center punch to one end to see how hard it seems. These early (pre-Rockchucker) RCBS A2 (2A) presses where actually made for bullet swaging and were available with solid top half rams for that purpose. My current top ram with cut-out for the primer will buckle/collapse under swaging pressures.

[ulav8r]

Cast iron bushings would be a good solution.

[elmacgyver0]

At the great risk of this thread immediately going off into the weeds, I'll politely say because my press has some wear which I believe can be resolve by installing bearings.

I was just curious, I had never seen a press wear out with proper maintenance.
Of course I don't do that much reloading or know anyone that does.
Anything will eventually wear out if used enough.
If nothing else the needle bearings might reduce the force required to operate the press.

[oley55]

I was just curious, I had never seen a press wear out with proper maintenance.
Of course I don't do that much reloading or know anyone that does.
Anything will eventually wear out if used enough.
If nothing else the needle bearings might reduce the force required to operate the press.

I have no idea who/how this 60 year old press was maintained, but the point of wear is around the top right pressed-in shaft. Getting lube in there requires laying the press on its side or upside down and flooding it with oil/lube. It's my guess it got a squirt of oil while in the bolted down position and rarely got lube into where it was needed.

Now knowing this pivot point needs close attention, I would anticipate any future issues will be component failure vs wear related. Although I can not really feel or identify any binding, under pressure the worn link hole has to be inducing some torque to the press parts and alignment. If I am going to use it for swaging, it needs to be squared away. Otherwise it's just fine for general reloading purposes.

[oley55]

Shafts are probably not case hardened, but they are hard enough to blunt two center punches, a vintage MPC-USA punch and a Craftsman USA made punch. I was able to make a punch mark but it's a tie between tools and shaft material. For whatever that's worth.

A cursory look at the impregnated bushing and the needle bearings, it seems my reamed hole size should accommodate either option...?? If that proves true, I will likely go with the impregnated bronze bushings first. If they don't hold up, then I can try the needle bearings.

[bangerjim]

You will want to drill then REAM for a tolerance fit. I seriously doubt will probably not find a standard A-Z/fractional drill of the right size. and then there is the truth to drilling "triangular" holes! That is why you always STEP DRILL. If you step drill (6-8 sizes) to just under the size you need for the bearing and then ream to tolerance-required size for your bearings, that will get you there.

This IS normally a machine shop function (milling machine) and not something normally attempted by a sloppy quill 30 year old foreign-made drill press.

Best of luck to you in your quest.

banger

[Petrol & Powder]

I agree with the prior posts that recommend against needle bearings.
If, (and it's a big if) you really feel a need to correct the wear issue, larger pins or bushings are the answer.

I don't think a drill is going to result in a perfectly round hole and a finish reamer is going to be called for.

With the proper reamer, you may even be able to get away with reaming the holes slightly larger and then fabricating new pins. You still would have the problem of making the pins out of steel of the proper hardness but I think it would be possible.

[Kenstone]

Bushings would be a better choice.
Needle bearings require a hardened shaft or inner race.
You have neither,
jmo
:grin:

[elmacgyver0]

I have no idea who/how this 60 year old press was maintained, but the point of wear is around the top right pressed-in shaft. Getting lube in there requires laying the press on its side or upside down and flooding it with oil/lube. It's my guess it got a squirt of oil while in the bolted down position and rarely got lube into where it was needed.

Now knowing this pivot point needs close attention, I would anticipate any future issues will be component failure vs wear related. Although I can not really feel or identify any binding, under pressure the worn link hole has to be inducing some torque to the press parts and alignment. If I am going to use it for swaging, it needs to be squared away. Otherwise it's just fine for general reloading purposes.

60 years? I would say it did pretty well.
If you can get the bearings to fit tightly it will probably be good for another 60 years.
Bronze bearings should also work.
Good Luck with your project, it is always gratifying to restore old equipment to working order.

[oley55]

When considering reamers, should I be looking for straight or spiral cut flutes?

My top 1/2" (5/8") holes are in 1/2" thick steal and the bottom 5/8" (3/4") hole is through 2" thick steel.

[jetinteriorguy]

I would call RCBS and see what they say, they have a pretty good warranty and excellent service. If they have replacement parts they’ll most likely send them to you at no cost. If no parts support then who knows what they’ll do, but I wouldn’t be surprised they’ll do something about it.

[SODAPOPMG]

Being a machinist 20+years here is my advice
Forgot about bearings or bushings
This is not a do it yourself job unless you have a milling machine, without one all you are going to do is destroy the press
What you want to have done is ream the holes just enough to make them
Round again this might require the use of a boring bar first
Then you make a new pin to fit the holes
This will fix the press
Bearings need to spin or they will just wear out at the contact area
The Corbin press has much more rotation at the linkages than a reloading press

[Pressman]

First question is why? Are you going to load 10,000 rounds a year for the next ?? years. No, there's no primers available.
Does the tiny amount of wear affect the operation of the press, can you feel any binding as you move the handle?
Take it apart and coat the shaft with white lithium grease and use. Does it feel better?
How much is the work going to cost? Machine shops have a shop rate of $100.00 an hour and that goes up. You can easily spend a $300.00 mountain of cash fixing a flea sized problem.

There is only one regular reloading press with roller bearings in the linkage and that's the Herter's Model O Super, and it has one bearing in the lower link where it connects to the pivot block.

Just my thoughts on the worthiness of the project.

[nhyrum]

Being a machinist
What you want to have done is ream the holes just enough to make them
Round again this might require the use of a boring bar first
Then you make a new pin to fit the holes
This will fix the press


You know (to the OP) there's a guy on YouTube named Adam booth, that goes by the handle abom79, that does a lot of work like this, and he does some mighty fine machining. I could definitely see him making you nice, new, beautiful holes and new hardened pins. Not sure how much he charges though

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[oley55]

Thanks to all for input and suggestion. For certain I need to do a lot more thinking and investigation. My reading of bearing manufacturer information on needle roller bearings confirms what has already been stated, hardened shafts or inside races ARE required.

As I stated in the beginning, "IF (a big if)" remains true.

[country gent]

a set of oil lite bushings might be the best of both worlds here. open up the holes and machine the bushings to fit then soak in med to heavy oil for a couple days install and relube surfaces. The bushings will soak up and hold a lot of oil
We would bore and turn a bunch up for a machine and stack in a 5 gallon bucket then cover with 80 weight oil by a couple inches. a wire over the edge of the bucket to touch the oil ( just an indicator) a couple days later there would be 1-1 1/2" gap between wire and oil. They sucked up a lot of oil.

[1hole]

Ball or roller bearings don't gall unless they have already been destroyed and run dry. After all, the balls/rollers are made to roll between the inner and outer race, they don't slide.

I'd not use an interference fit of more than 1 or 2 thou on those swinging links. More squeeze would do little to hold the races in place and it would greatly increase the risk of splitting the links. In fact, if it were mine I would make the holes a slip fit and anchor the bearing in place with a "Crazy Glue"; it's strong enough for that task and is softened for easy removal with the heat of an LP gas torch.

That said, I believe you're over thinking the problem. IF it were mine I'd likely leave it as is and see if I really could "wear it out". OR, IF I really wanted to tinker with it, I'd mike the present hole and pin diameters to see what thickness of auto parts house brass (or copper) shim stock would fill the gap. A proper size ribbon of brass wrapped around 90-95% of the link pin's surface would be an easy and inexpensive shop made "bushing" to make and install - or replace. (And, yeah, I have successfully done that, but not on a reloading press.)

Finally, a drill bit's tendency to chatter and cut triangular holes is usually too little to see in deep holes. Bit chatter can be largely controlled by maintaining sufficient contact pressure to keep the bit's cutting edges firmly seated in deep holes. And cone (stepped) bits work GREAT on really thin stock because they won't grab and screw themselves in like twist bits do but we can't bore deep holes with them.

All of this is IMHO of course, YMMV.

[SweetMk]

I would call RCBS and see what they say, they have a pretty good warranty and excellent service.

If they have replacement parts they’ll most likely send them to you at no cost.

Just for grins, yesterday, I looked up the RCBS warranty program,,

They make it VERY clear, that an RCBS item will ONLY be considered for warranty if:
You are the original owner
and
The item is mailed back to them pre paid postage
and
The original dated invoice showing certain info,,, BLA, BLA, BLA ,,, is included
and other demands.

Who has an invoice from over 18 months ago,?
Who has an invoice that is over one year old (to about ten years ago) that has not completely faded?

I kinda lost interest in RCBS many years ago, when a Hornady die caused my RCBS Partner press to bend!!
RCBS refused to discuss it, and said it was the fault of the Hornady die (the expander ball was a couple thousandths oversize)
Well, Hornady offered me a brand new Hornady press, and a new set of dies if I sent THEM the RCBS press..

The Hornady guy went on to say, keep the old dies, and try them in the Hornady press,
if the Hornady press is damaged, they would send me ANOTHER press, for free, also.

I have a new Hornady Classic press,, now.
The old dies could not damage the Hornady press.

I talked to that guy at Hornady, at a future date,,
He said he had a LOT of fun at the next shot show,, with that bent press,, :-P
Maybe, that is why RCBS no longer makes that cast aluminum press??

(the die was a 243 Winchester)

I buy RCBS, but, it has to be a GREAT deal, otherwise, I buy "red",,,

[bangerjim]

Ball or roller bearings don't gall unless they have already been destroyed and run dry. After all, the balls/rollers are made to roll between the inner and outer race, they don't slide.

I'd not use an interference fit of more than 1 or 2 thou on those swinging links. More squeeze would do little to hold the races in place and it would greatly increase the risk of splitting the links. In fact, if it were mine I would make the holes a slip fit and anchor the bearing in place with a "Crazy Glue"; it's strong enough for that task and is softened for easy removal with the heat of an LP gas torch.

That said, I believe you're over thinking the problem. IF it were mine I'd likely leave it as is and see if I really could "wear it out". OR, IF I really wanted to tinker with it, I'd mike the present hole and pin diameters to see what thickness of auto parts house brass (or copper) shim stock would fill the gap. A proper size ribbon of brass wrapped around 90-95% of the link pin's surface would be an easy and inexpensive shop made "bushing" to make and install - or replace. (And, yeah, I have successfully done that, but not on a reloading press.)

Finally, a drill bit's tendency to chatter and cut triangular holes is usually too little to see in deep holes. Bit chatter can be largely controlled by maintaining sufficient contact pressure to keep the bit's cutting edges firmly seated in deep holes. And cone (stepped) bits work GREAT on really thin stock because they won't grab and screw themselves in like twist bits do but we can't bore deep holes with them.

All of this is IMHO of course, YMMV.

When I mentioned "step drilling" above, I certainly did not mean those cheap multi-step drill-things like HF sells for cutting holes in sheet metal and thin electrical boxes! I mean drilling (a standard industrial machine shop technique) with a small drill to start and increasing to larger drills in steps of sizes until you are just under the hole size you need.
Then finish with either a reamer (adjustable or fixed) or a boring head in a milling machine. This is absolutely NOTHING that can be done successfully in a cheap wobbly-quill drill press.

And you CAN drill deep holes doing it that way! I do it all the time with extreme accuracy and PERFECTLY round holes all the way thru thick materials!

banger :guntootsmiley:

[oley55]

Thanks Banger, but I swallowed my (Old Pop knows more than all of his boys) pride and talked to my youngest son. He still has access to a military machine shop and he is going to drill, ream and press in the bushings for me. So much for me learning it on my own, I guess....

For those interested, the attached pics show the displaced metal at the top right pivot pin and the (more than I recalled) shine on the lower toggle pin. Interesting that where metal was displaced there is little to no pin shine and where the pin shows shine/wear there is no sign of metal displacement.

At any rate I am proceeding with the impregnated bronze bushings in the top of the link arms and in the bottom toggle.

[bangerjim]

oley55 - - glad you found someone with access and skills in a machine shop! Should be a piece of cake with the right accurate tooling.

I would use bronze bearings if I were doing it too!

banger :drinks:

[EDG]

That little flap of displaced metal you are so concerned about is nothing but a burr from the original manufacturing of the press.

It appears that RCBS drilled and reamed the link and the reamer left that thin burr when it exited the hole.
I have seen that on millions of holes. You should deburr it with your deburr tool and forget it. It is nothing.

RCBS should have deburred that edge of that hole and you would never have seen that. You are worried about nothing at all.

[Three44s]

That looks like a thin brass or bronze bushing to me and its displaced and worn some.

Three44s

[john.k]

The only reason for roller bearings would be a user with severe arthritis,who couldnt exert pressure with a wrist ...or somesuch......In fact a very servicable bearing for slow movement is hard steel on hard steel....with just a smear of oil ,such bearings last a very long time.......Pressed cup needle rollers are also OK ,but IMHO ,reduction in applied force is not an issue with a normally abled reloader.......one issue with needles is the need for a very stable base,holding correct alignment to avoid edge loading the races/rollers.....Not in a loose link press linkage.

[1hole]

When I mentioned "step drilling" above, I certainly did not mean those cheap multi-step drill-things like HF sells for cutting holes in sheet metal and thin electrical boxes!

Banger, when I said cone type step drills are limited to thin stock that was what I meant. And, if you think Harbor Freight is the only source of step drill bits (or anything else made in China) then you haven't noticed what's being sold in Lowes' and H'Depot's tool racks lately.