Spherical bearings mounting

[mangel83]

What's the difference between mounting a spherical bearing with it's hole axis vertical and horizontal? I've never seen a FSAE racecar horizontal hole axis mounting, but some guys here in our team say they've seen that.

Any good book regarding this?

[mangel83]

What's the difference between mounting a spherical bearing with it's hole axis vertical and horizontal? I've never seen a FSAE racecar horizontal hole axis mounting, but some guys here in our team say they've seen that.

Any good book regarding this?

[UTA racer rikki]

mangel,

I have seen it done with rod ends extensively, but rarely with a spherical bearing. My first question is why?

My second comment, mere speculation, that the bearing would be more likely to act as a bearing with the hole in a vertical orientation than a steel sleeve around a bolt in a horizontal orientation. I would think the friction in a spherical bearing would prevent it from rotating freely around the axis of the hole in a horizontal position.

Not only that, it seems to me that a bearing cup design would get a little complicated for fitting a-arms when dealing with a horizontal orientation.

Having said all of this, I think a horizontal orientation isn't the optimum.

[Jeff The Pyro]

Its pretty simple actually.

a spherical type bearing (regardless of whether its pressed into a rod end or just a round bearing race) is not a sound design to take loads in thrust, a thrust force being one pushing along the axis of the bolt that goes through the bearing hole. If you just look at the bearing, you can basically see how if you were to put a force on a spherical bearing in thrust there wouldnt be much material stopping the bearing from popping out. the other type of load is any force perpendicular to a thrust force, and in this direction, there is a "ring" of material directly constraining the ball from moving. This is the way that spherical bearings are designed to be loaded. The reason you see some bearings mounted vertical and some horizontal is because the bearing should be oriented according to what type of loading it is going to see.

As an example, our car uses pullrod actuated bellcranks in the front, so the most vertical forces are going to be seen on the top outboard bearings, thus we oriented our upper outboard bearings vertically (with the bolt hole axis pointing longitudinally with the car). On the bottom, however, there almost no vertical force, and the most significant force is from the braking force, so the sphericals are mounted horizontally (with the bolt hole axis pointing vertically).

Despite this, you will ALWAYS see cars where the spherical bearings are used incorrectly. If you doubt the bearing's weakness in thrust, just ask our machinist billy, who managed to pop the ball right out of the race while simply pressing the bearing into the a-arm.

[Denny Trimble]

You should smack your machinist upside the head for pushing on the ball, not the race, when installing spherical bearings.

Spherical bearings have ratings for axial load, usually 10% of the rated radial load. Check your catalogs.

We run spherical bearings with a vertical axis orientation at our lower ball joints (pushrod), because the lateral and longitudinal forces are greater than the vertical forces. For a given vertical load, there is 1.5 times that available in-plane at the contact patch, multiplied by the "levarage" factor of having a balljoint about 4" above the ground.

You can successfully run spherical joints in a number of orientations, as long as you do the analysis and testing. But to just say "vertical axis is incorrect" with no numbers behind it, doesn't pull much weight with me.

[Buckingham]

First, I agree with Denny, especially about the smacking the machinist in the head part. Most bearing catalogs have sections regarding proper installation procedures.

Second, you must also consider the motion range of the spherical. A typical high-misalignment spherical can handle about 23 degrees of motion. In a horizontal orientation, this could limit your steering range.

[CMURacing - Prometheus]

we were getting a junk (welded, bead blasted, and painted) spherical bearing out of an a-arm to put a new one in, and we ran the ball right out of the race. the race makes a nice ring for those car-oriented chicks we all go nuts over.

[Daves]

Speaking of the ball and the race, how do they get the ball in there in the first place? How do they get the ball in rod ends, too?

[Ben Beacock]

The spherical mounts I make have a large step on one side that just clears the ball and tapers out with a snap ring groove on the other side. They are oriented so that the step is loaded in bump and should help prevent the ball popping through. The only one loaded in bump is the front lower and I haven't seen any problems (same design as last year). They are Aurora 5/16" PWB-5T

[SD]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Ben Beacock:
The spherical mounts I make have a large step on one side that just clears the ball and tapers out with a snap ring groove on the other side. They are oriented so that the step is loaded in bump and should help prevent the ball popping through. The only one loaded in bump is the front lower and I haven't seen any problems (same design as last year). They are Aurora 5/16" PWB-5T </div></BLOCKQUOTE>

Hi Ben,

Were your bearing housings welded to the a-arms? Did you machine them to spec before or after welding?

Thanks for any more information,
Spencer

[Jeff The Pyro]

oh he got smacked allright...

hehe

at any rate, we used stepped cups with snap rings last year, but they were bulky, which made the entire upright/a-arm assembly a lot heavier because the tabs had to be even wider as well as having enough clearance for turning/wheeltravel, etc. etc.

this year we scrapped that whole design and just press fitted them in with green loc-tite... if i remember correctly the shear strenght of the loc-tite (4000psi) over the surface area it was applied to was higher than the thrust rating of the sphericals... with the press fit adding even more. it sounded a little scary at first, but the ball popping out of the race is proof that the press fit alone is stronger than the bearing race.

[Cement Legs]

I'm trying to source out better prices on bearings. Specifically spherical bearings. Where have you guys been buying them from?

[UCBrothers]

We also had some issues with spherical bearing duing competition. We mounted our spherical bearings (rod ends) with the pin axis vertical and were docked at design for having rod ends in bending. I'm not the suspension guy, but its spherical!? Anyway, one of the things that kept us out of design finals.

Matt Brothers
http://www.eng.uc.edu/studorg/sae/fsae/fsae.html
University of Cincinnati

[Denny Trimble]

When the judges say "rod ends in bending", they mean the threaded shank is in bending. If you use "rodends" or "heims" on the outer ball joints (steering axis), they will be in bending under brake torque and pushrod / pullrod force.

If you use "spherical bearings" or "monoballs" held directly in the control arms, there is no threaded shank to put in bending.

[Cement Legs]

Is that still as big an issue if no thread are exposed after installation?

[Denny Trimble]

Well, you could weld a female rod end (no external threads) into your control arm. But even threading a male rodend all the way in, with the required jam-nut, will leave threads in bending. They are natural stress concentrations.

And if you insist on still doing it, don't make the mistake we made through '03 and weld only the outer circumference of the threaded insert into the tube. Make sure you do "rosette" welds inboard, to prevent a failure similar to ours at 150 hours on our '03 car:
http://students.washington.edu/dennyt/fsae/a-arm_failure/

[kozak]

Well what would the judges say if you had rod ends that were known to be strong enough to handle any axial load yes they are still in bending but they can handle the load these specific bearings have a axial load of 15% the max radial load. So for the .4375/.5-20 rod end that would be 3517.8 lbs axial load right.

http://www.hrpworld.com/client_images/ecommerce/client_...oducts/pdf_482_2.pdf (http://www.hrpworld.com/client_images/ecommerce/client_39/products/pdf_482_2.pdf)

http://www.hrpworld.com/client_images/ecommerce/client_...oducts/pdf_482_1.pdf (http://www.hrpworld.com/client_images/ecommerce/client_39/products/pdf_482_1.pdf)

[Ben Beacock]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by kozak:
Well what would the judges say ... </div></BLOCKQUOTE>

They would say that you could do the same thing with a ligher spherical bearing installation. From what I've seen/heard this year, the judges now don't want rod ends on your a-arms at all.

[Dan B]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by kozak:
Well what would the judges say if you had rod ends that were known to be strong enough to handle any axial load yes they are still in bending but they can handle the load these specific bearings have a axial load of 15% the max radial load. So for the .4375/.5-20 rod end that would be 3517.8 lbs axial load right.
</div></BLOCKQUOTE>

You could always do that...it will just weigh 3X (at least) what a spherical bearing of the proper size would weigh.

[Denny Trimble]

Kozak,
I think you misunderstand a little. The axial and radial load ratings are based on the strength of the spherical ball joint itself. You have to calculate the strength of the threaded shank, which is the part of the rodend installation that sees bending loads if you use it outboard on a-arms.

Yes, rodends are easy to install and fabricate parts around, but they are much heavier (we saved 3 pounds this year moving away from them) and less safe than spherical bearings pressed into welded structure.

I guess I shouldn't be preaching about how you should design your car, but please at least calculate the stress on your rodend shanks (with a stress concentration factor for the threads, and preload from the jam nut, and brake torque reaction, and pushrod/pullrod reaction, and cornering loads).

[kozak]

ok i think you guys have steared me away from rod ends to pressed bearings, how come the Rutgers team did so well and they are using rod ends all around the car on both sides of the
a-arms. and maybe i should specify if i haven't already we are a first year team and are currently building a car for next year.

[Lyn Labahn UW-Madison]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by kozak:
how come the Rutgers team did so well and they are using rod ends all around the car on both sides of the
a-arms. </div></BLOCKQUOTE>

Maybe they got away with it, but ask the team that had their wheel fly off and smack some poor lady in the face what they thing of rod ends. You admit that you know nearly nothing about design, yet you are asking the people trying to help (Who have 5-6 years of formula sae experience) to quadruple justify their answers. Quit wasting everyones time. Better yet, go ahead and be lazy and make a-arms with rod ends and come here bitching when they break. Apparently verbal advice isn't enough.

[Cement Legs]

peace http://fsae.com/groupee_common/emoticons/icon_cool.gif

[kozak]

Ok first of all dude, relax. Second of all i never said that i dont know anything about design. third if you think helping other people out and asking questions is a waste of time then don't respond. if your just going to bitch and moan then don;t say anything go read a book or something. The reason i am asking this is because i still see a lot of teams using rod ends in "bending" situations or some teams using a mix of rod ends and pressed bearings.

[Lyn Labahn UW-Madison]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by kozak:
Ok first of all dude, relax. Second of all i never said that i dont know anything about design. third if you think helping other people out and asking questions is a waste of time then don't respond. if your just going to bitch and moan then don;t say anything go read a book or something. The reason i am asking this is because i still see a lot of teams using rod ends in "bending" situations or some teams using a mix of rod ends and pressed bearings. </div></BLOCKQUOTE>

OK maybe that was a bit grumpy of me, but I am personally a bit tired of people just expecting to have their hand held while they make mundane decisions, or defending a point which is almost universally accepted to be bad design (i.e. rod ends in bending) against people who have experience. I didn't mean you were stupid by saying you don't know anything about design, but you are a first year team. Maybe instead of being a bastard I should have posed this question:

What have you read, what calculations have you done, what have you experienced that would indicate that it is a good idea to use rod ends on control arms?

Seeing it done on another car is a pretty shaky system of verifying good design, unless that car was in design finals or something.

[kozak]

I know that it is not a good practice to just copy other peoples designs with out knowing what they do or how they work, but if you reverse the roles you guys are telling me that "it is bad just trust us", i do realize that puting anything in bending is not good and all the people i've talked to have proven what they said. i'm just asking this stuff so i don't make these mistakes the first time out, and i do have legitimate questions about this stuff. i don't know i want to do rod ends because i know they are easy and will be easy for a first year team to do but i also know pressed bearings would be a better way to go. decisions, decisions.

[adrial]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by kozak:
Well what would the judges say if you had rod ends that were known to be strong enough to handle any axial load yes they are still in bending but they can handle the load these specific bearings have a axial load of 15% the max radial load. </div></BLOCKQUOTE>

They would say. OK, thats nice but sphericals are a better design. The judges this year were specifically told not to let anyone into design semi's that had rod ends in bending.

You can make rod ends in bending work just fine; we've done it for years. It's easier than sphericals. Sphericals are the better solution though.

[kozak]

so what about using sphericals on the wheel side and rod ends on the frame side.

[Jeff The Pyro]

rod ends inboard and sphericals outboard is the way to go as far as i'm concerned. inboard rod ends are almost entirely in tension/compression so there's not as much of a problem with them snapping off/bending. its also pretty convenient because you can change castor with the rod ends.

the other way is sphericals inboard with bolt on brackets and shims, but i personally dont think its worth the effort on a steel frame car, because its so much easier to just weld the tabs strait to the frame. i guess the shim plate method would work well (cant really see how else you could do it) for a carbon fiber chassis because the brackets help distribute the load over the surface of the monocoque.

[CMURacing - Prometheus]

i found a picture last night of rod ends in bending on an 80s ligier f1 car. perhaps its not as bad as the design judges make it out to be.

granted, that rod end was probably titanium, so its only okay if penn state wants to start making them.

[kozak]

i don't think that rod ends in a slight amount of bending isn't as bad as every one makes it seem. I even have a older book that shows you a good way to mount rod ends in a-arms. I think that the falures are related to rod ends in excessive bending or under sized rod ends. the judges should specify a bending safety factor for rod ends on a-arms.

[rjwoods77]

This is not in a mean tone so dont get mad at me. The judges hate it. There are a couple simple methods of having sphericals in non adjustable holders that are adjustable by other means. The point is the judges dont like it, its not the smartest of ideas, so just dont do it. There is no excuse for them unless they are a pushrod/pullrod or steering tie rod(even not necessary sometimes). If anyone has the opinion that it cant be done without bad comprimises.... blah blah blah, then you just havent looked at it hard enough. Take a gander at what the upper level teams are doing and you will ge the drift. This isnt directed at anyone in particular.

[kozak]

wow you were really trying to cover your a$$ weren't ya.

[jack]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by CMURacing - Prometheus:
i found a picture last night of rod ends in bending on an 80s ligier f1 car. perhaps its not as bad as the design judges make it out to be. </div></BLOCKQUOTE>

just about every vintage racecar i have seen has rod ends in bending. most don't have seat-belts either...

[kozak]

Hey theres no proof that seatbelts actually "save" your life.

[Jeff The Pyro]

hah... yeah... because if you dont have seatbelts you'll get thrown free of the wreckage right? i always got a good laugh out of that one.

hehe... and im kinda hoping the design judges didnt NEED to be told not to let people into the semis who had rod ends in bending...

[markocosic]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by kozak:
Hey theres no proof that seatbelts actually "save" your life. </div></BLOCKQUOTE>

Definitely!

People have told me that they would have died if they'd been wearing their seatbelt - because of the way the cabin got crushed. They lived because they were thrown from the wreckage.

I've never met anybody who said they died because they weren't wearing their seatbelt and were thrown from the wreckage.

That /must/ mean nobody has died from not wearing their seatbelt, yeah? http://fsae.com/groupee_common/emoticons/icon_rolleyes.gif http://fsae.com/groupee_common/emoticons/icon_rolleyes.gif http://fsae.com/groupee_common/emoticons/icon_rolleyes.gif

Airbags *are* questionable (front-facing ones - side-impact curtains are useful) - IMO those are a gimmick to try compensate for the terminally stupid who don't wear their seatbelt, shoddy seatbelt/seat/pretensioer design, a deformable cabin and poor crumple zones. I can appreciate the argument for allowing you to fly forward in the cabin and slow down inside the car helping to reduce the deceleration, but the conditions in which the airbag helps are too specific - whereas a good cabin, decent restraints and good crumple zone save your bacon in a multitude of situations.

[Travis R]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by jack:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by CMURacing - Prometheus:
i found a picture last night of rod ends in bending on an 80s ligier f1 car. perhaps its not as bad as the design judges make it out to be. </div></BLOCKQUOTE>

just about every vintage racecar i have seen has rod ends in bending. most don't have seat-belts either... </div></BLOCKQUOTE>
Yeah, um, try the Cadillac LMP car as well. They had it in the GM machine shop one year ('01 IIRC) for the tour/dinner. I'm pretty sure it had seat belts though. http://fsae.com/groupee_common/emoticons/icon_wink.gif

[kozak]

that reminds me on sat i went to a porsche car concourse and a dealer was there showing off their carrera gt (which sounded, looked, and just plain was, awesome), the guy opened the back lid to let us look inside and guess what i saw rod ends...but they weren;t in bending. the carrera gt aparently has an inboard suspension, and they had a push rod with rod ends on either side to transmit suspension travel to the shock. but this post is the first thing i thought of when i saw that.

[BStoney]

First, I'd like to correct what one of my team members incorrectly interpretted...

We run spherical bearings at the outer ball joints and rod ends at the inboard locations. In order to get around and not worry about the misalignment limits of the AM-4 rod ends that we use, we made a design compromise and positioned the inboard rodends with the bolt going horizontal. I realize why someone may feel that the rod ends are put in bending at this point...

However, we made a design compromise that may have bitten us in the end. Future plans show us moving towards sphericals at all locations. Although, the rod end bearing surface would see all loads in this position unless deflection of the a-arm exceeds the misalignment of the rod end. If this were the case, the A-arm would have deformed beyond elastic limits, causing failure not from bending, but failure of the link(s). So I am not sure how it was claimed that the rod ends were in bending, if it is assumed, which we do, that there are no transaxial loads seen on the shanks, only tensile and compressive forces.

I think this got jumbled up in a mix of thoughts, but hopefully this clears up what Matt had said before.

Any other comments are welcome.

[kozak]

hey ben how did you guys end up doing in the race.

[BStoney]

Finished 48/111, thought we had a top 15 car, easy, but had cooling issues during endurance due to Murphy's law. Such is life. Didn't fair well in accel however. Contact me off the boards for more details...

[Infinity]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by BStoney:
First, I'd like to correct what one of my team members incorrectly interpretted...

We run spherical bearings at the outer ball joints and rod ends at the inboard locations. In order to get around and not worry about the misalignment limits of the AM-4 rod ends that we use, we made a design compromise and positioned the inboard rodends with the bolt going horizontal. I realize why someone may feel that the rod ends are put in bending at this point...

However, we made a design compromise that may have bitten us in the end. Future plans show us moving towards sphericals at all locations. Although, the rod end bearing surface would see all loads in this position unless deflection of the a-arm exceeds the misalignment of the rod end. If this were the case, the A-arm would have deformed beyond elastic limits, causing failure not from bending, but failure of the link(s). So I am not sure how it was claimed that the rod ends were in bending, if it is assumed, which we do, that there are no transaxial loads seen on the shanks, only tensile and compressive forces.

I think this got jumbled up in a mix of thoughts, but hopefully this clears up what Matt had said before.

Any other comments are welcome. </div></BLOCKQUOTE>

About the rod end with bolt going horizontal...... i have seen very lesser number of cars with that configuration. Cant figure out why doesnt most of the universities go for the design... I guess most of the movement is required as vertical motion of the wheel so it would be better off with rod end in vertical plane than rod end in horizontal plane.
P.S. Correct me if i am wrong..

[J. Vinella]

You need to think about stiffness and deflection in braking. Which way would be stiffer?

Also even rod ends mounted with the bolt vertical give you enough travel. Given the lengths of Formula SAE a-arms you can get at least 2 inches of movement in bump and droop.

[rjwoods77]

Infinity,

The wheel has vertical movement but that vertical movement is transferred to the spindle of the upright which then applies a front view torque on the uprights ball joints in reference to the spindle. Do a free body diagram of the forces and you will see it. So in reality while the ball joint exhibit vertical motions, the forces coming into them are roughly perpendicular to that motion. A rod end/spherical joint(ball joint) strength lies in radial loading and not axial loading. Look at Aurora rod ends catalog and in the engineering section is quoted the relative weakness of the joint in axial forces. So that being said is seams as if mounting the ball joints with the bolts parallel to the ground would be okay but then you are mounting the joint in its weakest state for braking forces. Looking at a side view torque free body diagram you will see the joints are being loaded axially. Aurora says that 2 piece rod ends have 15% of ultimate strength axially and 10% for a 3 piece. They also go as far to say you should design the joints for a 4:1 safty factor. So 10 or 15% of a 4:1 safety factor on FSAE sized joint means that you could be asking for real trouble. I know it is dead easy to mount these with the bolt parallel to ground but it isn't recommended for a reason. I hope this helps and more importantly I hope my explanation is accurate.

http://www.aurorabearing.com/technical-resources/terms-...nitions/default.html (http://www.aurorabearing.com/technical-resources/terms-and-definitions/default.html)

[rjwoods77]

Infinity,

Just to add I was looking at our front axle brake torque at 1g deceleration and it was 28,300 in-lbs. Divide by two for the two front wheel2 and that is 14,150 in-lbs per tire. Our ball joints are spread 8" apart equidistant from the spindle which means that would induce 885lbs of load into the rod end/spherical joint. I would say most teams use a COM-6 spherical as a ball joint which has a Ultimate Radial Static load capacity or 8400lbs. 15 percent of that value is 1260 but then Aurora says you should have a 3:1 or 4:1 safty factor which puts it well below that braking force.

[Mike Cook]

Rob, it seems as if you are talking about an outboard spherical bearing but it sounds as if the other guy was talking about inboard rod end positioning. Correct me if I'm wrong, Infinity? Anyways, having the bolts parallel to the ground on the inboard side isn't really a big deal. Actually it is probably a better setup because if you angle the brackets so that they are in plane with the a arm member, there will be little to no misalignment in the rod end. In a tension compression member, rod end misalignment will lead to axial forces on the rod end (what rob mentioned) and the rod ends are pretty weak when it comes to that. So you do want to try to minimize the misalignment. The nice thing about running the bolts in the vertical direction is that every mount on the car doesn't need to be specific to the a-arm (i.e. in plane with the a-arm member). This makes manufacturing easier I think. Also a lot of teams are using square tubes in which they cut out one side of it and have the a-arm mount inside of it and therefore is only really possible to have the bolt aimed in the vertical direction.

Almost all other race cars have inboard rod ends with bolts parallel to the ground.

[murpia]

Regarding outboard sphericals, most racecars have them mounted 'vertically' (bolt parallel to ground), at least on the lower upright pivot for cars with pushrods. Cornering and vertical (downforce) loads are therefore taken radially in the spherical, with braking axially.

The drawback is less potential steering lock, so I suspect that for FSAE with no downforce and tight corners you are in fact better off with 'flat' outboard sphericals.

Regards, Ian

[Infinity]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Mike Cook:
Rob, it seems as if you are talking about an outboard spherical bearing but it sounds as if the other guy was talking about inboard rod end positioning. Correct me if I'm wrong, Infinity? Anyways, having the bolts parallel to the ground on the inboard side isn't really a big deal. </div></BLOCKQUOTE>
Ya Mike it actually is the Inboard mounting point. Also we have a way to minimize the misalignment to almost zero so i guess that would be no problem.....
Rob, Towards the outboard side we have planned to use a Spherical bearing inside a ring onto which the suspension pipes will be welded??? .... is that an feasible design?? I fear Welding there would weaken the bearing. What bearing make should we use for better strength???

[murpia]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Infinity:
Towards the outboard side we have planned to use a Spherical bearing inside a ring onto which the suspension pipes will be welded??? .... is that an feasible design?? I fear Welding there would weaken the bearing. </div></BLOCKQUOTE>
Take a look here (http://fsae.com/eve/forums/a/tpc/f/125607348/m/41810201411)...
And to state the obvious, don't fit your bearing until AFTER you've done the welding...
Regards, Ian

[Mike Cook]

Infinity, what I do is make the sleeves undersized and weld them up. Then I use a reamer about .0003-.0005 under to ream the hole after welding. Its the best way to do it.

[Drew Price]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Mike Cook:
Infinity, what I do is make the sleeves undersized and weld them up. Then I use a reamer about .0003-.0005 under to ream the hole after welding. Its the best way to do it. </div></BLOCKQUOTE>

...Only if you are not locating the bearing on a shoulder on one side, ie circlips on both sides, so that you can pass the reamer all the way through the housing.

Best,
Drew

[Mike Cook]

No, we have a shoulder on one side and a snap ring on the other. The you need to insure that the radius on the tool is smaller than the radii on the bearing. Works fine.