Bushing Restoration...Is External Knurling OK?

[JAndrew]

Hello,

I'm rebuilding/restoring an Atlas 10Hx36 lathe. I have a brass bushing that spun in the for the reverse lead screw bevel gear. I was able to remove it in one piece undamaged. What I was wondering is if it is okay to fix it by knurling the exterior before re-pressing it into the housing?

I'd replace it but you can't source just the bushing and the whole housing is pricey. I'd rather not have to source brass to machine a new bushing either.

If I knurl the outside will it last and stay put? The bushing interior is fine and I am replacing the short segment shaft that fits inside it so the fit is very good. I cleaned all oil from the bushing outer surface and the housing inner surface (which is made of ZAMAK). I also considered coating it with JB-Weld or Loc-Tite before pressing it back in...?

Thanks all! I have very few posts here on HMEM but have been "lurking" for quite a while. You gentlemen are brilliant and very helpful! Being a younger guy with little experience I have learned a ton just by reading these posts.

-J.Andrew

 

[Wizard69]

This is a question that will likely generate varied opinions. Doing maintenance work I've knurled shafts before, to support ball bearing inner races or loose pulleys. It has never been something that I like to do.

Hello,

I'm rebuilding/restoring an Atlas 10Hx36 lathe. I have a brass bushing that spun in the for the reverse lead screw bevel gear. I was able to remove it in one piece undamaged. What I was wondering is if it is okay to fix it by knurling the exterior before re-pressing it into the housing?

Honestly I'd say no. You would be far better off to fit up a properly sized bushing.

One question though, is this a plain brass bushing or an oilite style bushing?

I'd replace it but you can't source just the bushing and the whole housing is pricey. I'd rather not have to source brass to machine a new bushing either

Have you tried bearing supply houses? Many bushings are standard off the shelf solutions.

If I knurl the outside will it last and stay put?

There are a lot of ifs and bits here. It might or it might not, that isn't exactly helpful but the answer depends upon many factors.

The bushing interior is fine and I am replacing the short segment shaft that fits inside it so the fit is very good. I cleaned all oil from the bushing outer surface and the housing inner surface (which is made of ZAMAK). I also considered coating it with JB-Weld or Loc-Tite before pressing it back in...?

If it is plain brass and the installation done properly, the right Loctite will hold better than knurling. If it is oilite most people will tell you it is a bad idea to use Loctite on it. I've used Loctite for the maintenance of machinery for years now, so have a good feel for when it will work well. You need to make sure the conditions are with in spec for the Loctite you are going to use. In this case you would want some sort of bearing retaining compound. Finally you need to consider lubrication as no lube will cause more grief than just about anything.

As to JB Weld I've never used it for this sort of situation so can't offer fact based advice. However my gut feeling is that this won't work as well as Loctite mainly because pushing the bearing in will scrap much of the JB Weld off. Obviously it depends upon the gap but let's face it, if the gap is too much for Loctite you really should be making a new bushing.

Thanks all! I have very few posts here on HMEM but have been "lurking" for quite a while. You gentlemen are brilliant and very helpful! Being a younger guy with little experience I have learned a ton just by reading these posts.

-J.Andrew

Hey I'm a 50+ old goat that learns something new almost every day here. My interest in motors is relatively new, even though I've worked with machinery for years.

 

[JAndrew]

Wizard69,

Thanks for the reply.

It looks like you have 2 questions for me...

First... Is it Oil-lite or plain brass? I would have to answer, "I don't know." The bushing still fits pretty tightly such that I would have to press it in but it did have an existing oiling hole drilled that no longer lined up with the housing oil port due to it spinning about 90 degrees (that I could see anyway). Is there an easy way to tell if it's Oil-lite or is that something I would have to know from technical documents?

Second...Have I tried any bearing supply houses? No sir I have not. Can you recommend any good online sources?

I only considered knurling it or loctiting because it is such a tight fit already. If I loosened up the clearance between the interior shaft and the bushing and re-drilled the oil hole it seems like it would be good enough but I'm no expert.

Thanks again,
-J.Andrew

 

[bazmak]

Try Knurling you dont have anything to lose
Must uce a straight knurl though not diamond pattern

 

[Brian Rupnow]

Try Knurling you dont have anything to lose
Must uce a straight knurl though not diamond pattern

And why not the diamond pattern? I have used the diamond pattern for similar situations with no problems. Perhaps I will learn something I didn't know----

 

[Tin Falcon]

.

Have I tried any bearing supply houses? No sir I have not. Can you recommend any good online sources?

I often deal with McMaster Carr Huge selection fantastic service I often get items delivered over night via UPS ground service. They also have will call service. Call in an order or order on line and pick up at the warehouse.
I even stopped in one day unplanned I called in an order from there desk waited for the order to be picked and was still in and out in about 1/2 hour to 45 minutes. I would recommend calling ahead as it usually takes an hour to process an order.
I deal with the NJ / Philladelphia area location but the LA/Santafe springs warehouse should work well for you.



http://www.mcmaster.com/#bronze-sleeve-bearings/=oitfc3

Not a terrible place to buy metal either especially if you happen to be in the area and can save the shipping cost.

a 3/4" od bushing 1" long for a 1/2 shaft should run you less than $4. Like I said lots of choices.

If it is a good fit a and not worn couple drops of sleeve grade lock tight may be all you need.

Tin

 

[Wizard69]

Wizard69,

Thanks for the reply.

It looks like you have 2 questions for me...

First... Is it Oil-lite or plain brass? I would have to answer, "I don't know." The bushing still fits pretty tightly such that I would have to press it in but it did have an existing oiling hole drilled that no longer lined up with the housing oil port due to it spinning about 90 degrees (that I could see anyway). Is there an easy way to tell if it's Oil-lite or is that something I would have to know from technical documents?

When new oilfield bushings have a look that suggest porosity. With used bushings it may be hard to tell at first look. Generally I would expect an oilite bushing unless there is a specific reason not to. From what you describe this isn't a demanding application.

Second...Have I tried any bearing supply houses? No sir I have not. Can you recommend any good online sources?

I'd look in your local yellow pages for bearing or power transmission houses. One big name is Kaman, a city of any size will have more than one supplier. Someone already mentioned McMaster-Carr for online, MSC also has a limited selection.

More targeted sources:
American Sleeve bearing: http://www.asbbearings.com/?gclid=CNyz64DAzrkCFUxo7Aod4FgAiA
Some useful info from NSK: http://www.nskamericas.com/cps/rde/xbcr/na_en/CNSK_Oilite.pdf
Someplace out of the ordinary: http://www.aircraftspruce.com/menus/ap/bearings.html
Reid Supply: http://www.reidsupply.com/products/...ssion/bearings/sleeve-bearings/?fl=4294947772
Atlas Bronze: http://www.atlasbronze.com/BUSHINGS_BEARINGS_s/1836.htm?gclid=CMiWnJfCzrkCFctr7AodsAwA3A
Bunting: http://www.buntingbearings.com/index.html?gclid=CPTswYLDzrkCFSnxOgod5TAAvQ
isoStatic: http://www.isostatic.com/index.html
national Bronze: http://www.nationalbronze.com/

That is a quick list of bushing related businesses. Many of the manufactures above work through distributors but they are of course helpful in one way or another finding you local distributors. As far as the retailers above, some list prices to give you an idea if you are about to be ripped off or not. The other problem is the low prices which can run afoul of some retailers minimal order values. This is one reason why finding a local supplier is important. Ether that or you combine an order with other goodies to get yourself above the threshold.
[/Quote]
I only considered knurling it or loctiting because it is such a tight fit already.
[/Quote]
If that is so then knurling isn't required. As noted before loctiting oillite bearings is not recommended by many users.

If I loosened up the clearance between the interior shaft and the bushing and re-drilled the oil hole it seems like it would be good enough but I'm no expert.

Thanks again,
-J.Andrew

You don't want too much clearance.

In any event best of luck. Frankly the way you make this sound I'm not sure you even need a new bushing. Id concentrate on a making a replacement shaft precisely to dimensions and add any clearance that may no be needed in the bushing.

 

[JAndrew]

Tin Falcon and Wizard69,

Thank you for the replies. I have ordered from McMaster in the past and you're right...they are FAST! If I order from them by 8 or 9am it will usually arrive same day.

I didn't think that the bushing would be a standard enough size and so readily available but it is. Good to know that it's only $13 and a day away.

Since this isn't that high load or high speed and its easy enough to take apart I am going to do as Bazmak and suggested and just put a light knurl in it and use some loctite.

I had some time today to play with the old bushing and I don't think it's an Oil-lite. I heated it a bit and no oil came out of it. Like Wizard69 said it doesn't look porous either.

Thanks again Wizard69 for the suppliers list! I'm going to file that away for use down the road.

Thanks all for the advice and input. Almost have the Atlas completely cleaned up and most of the assemblies are back together now. I'll post some before and after pictures here in a week or so.

-J.Andrew

 

[bazmak]

From what i learned as an apprentice,straight knurl is superior as it bites and acts like a sline
cross knurlinl tends to scrape off as it is pressed in.Iether method is not ideal if the shaft is hard and the
bush soft.Straight knurling and loktite always seemed to work for maintenance of old machines

 

[Walltoddj]

If you look on eBay I've found a lot of bushings at a reasonable price including the shipping. As far as knurling the bushing oil lite is soft that's why a the smooth od because it compresses when in stalled. You might think of using Loctite Liquid Metal I've used it once and it' s still running. I would have to agree with the others if can use a new bushing.

Todd

 

[Hopper]

You have a a lathe but you can't make a simple brass or bronze bush to do the job??????
I wouldn't faff about with makeshift solutions when I could make a new part to the needed size.