Question about how to use LOCTITE

[Ninda Kurniadi]

Hi,

I want to ask about applying loctite. If I want to joint housing spherical bearing (made from alumunium 7075) with steel AISI 4130. Loctite what type should I use ?

Thanks,
Ninda Kurniadi
(Garuda UNY Racing Team)526

[Jonny Rochester]

I use a loctite called "bearing retainer" or similar, and I'm not too fussy about it. Google shows this could be 603 or 641 or 620 or a few other options. It's just used to remove movement between the spherical bearing and it's housing. The bearing is still held in place with a circlip. If the housing is machined correctly you won't need much of it, and that's why I need alot of it.

[Ninda Kurniadi]

I use a loctite called "bearing retainer" or similar, and I'm not too fussy about it. Google shows this could be 603 or 641 or 620 or a few other options. It's just used to remove movement between the spherical bearing and it's housing. The bearing is still held in place with a circlip. If the housing is machined correctly you won't need much of it, and that's why I need alot of it.

Thanks Jonny

Yes, the housing is machined. Ok I will try it, I use Loctite 609.

Thanks

[Adam Farabaugh]

It looks like you might be trying to join aluminum (bearing housing) to steel (a-arm tube) with Loctite bearing retainer???? Do not do this! It's not a structural bonding agent!

Maybe I'm the one that's misunderstanding, but I think Jonny might have thought you were talking about fixing the spherical bearing into the housing, not the housing into the a-arm tube!

[Jonny Rochester]

Yes, I was mistaken sorry. I don't know anything about bonding metals. If it was me I would only use similar metals and weld it. I have never relied on adhesives for mechanical parts, and you shouldn't need to with metals. I would have thought adhesives are only required for carbon tubes. For metals, a press-fit will be better than glue.

[Z]

Ninda,

I, too, was thinking along the same lines as Jonny's first post. But I have now had a closer look at your jpg-attachment. Aaaackkk!!!!! (https://www.youtube.com/watch?v=RG0ochx16Dg)

Even if you make your wishbones all-welded-all-steel, the above You-Tube clip will still apply to your bolt-on steer-arm. And to your steering-geometry/upright-design. And to the brake-disc, which is the wrong way around...

Z

[Ninda Kurniadi]

Ninda,

I, too, was thinking along the same lines as Jonny's first post. But I have now had a closer look at your jpg-attachment. Aaaackkk!!!!! (https://www.youtube.com/watch?v=RG0ochx16Dg)

Even if you make your wishbones all-welded-all-steel, the above You-Tube clip will still apply to your bolt-on steer-arm. And to your steering-geometry/upright-design. And to the brake-disc, which is the wrong way around...

Z

If I want to joint alumunium 7075 with steel tube AISI 4130. Besides welded, can use any way ?

Many Thanks,
Ninda

[Ninda Kurniadi]

If I want to joint alumunium 7075 with steel tube AISI 4130. Besides welded, can use any way ?

Many Thanks,
Ninda

[,4lex S.]

Ninda,

You could probably use an epoxy bonded joint, but most teams make the bearing retainers out of steel and weld them to the tubes. I would put a lot more trust in a weld with respect to epoxy. Without proper and consistent surface preparation you could find yourself in a lot of trouble.

If you do end up doing adhesive you should strongly consider testing a number of representative samples to failure to make sure they can handle the loads you expect.

[Ninda Kurniadi]

If using alumunium and steel pipe, how to joint them ?

[DougMilliken]

Search: pipe tubing
on this site. There is a difference in English.

[ChristianChalliner]

Hmmm, Why would you want to do this? is the question I find myself asking!

I should say, we did this last year (not bonding the two together!) but with aluminium bearing housings and steel arms, there's a reasonably simple way to do it but I'm not going to divulge the answer until the above question is answered, purely because I don't want to sway you with my opinions on this design.

[jd74914]

Exactly my question.

There really isn't any advantage to aluminum here since it and steel have similar specific stiffness, and welding is much simpler and more robust (from a process standpoint) than bonding.

[OspreysGoSWOOP]

Hi,

If I want to joint housing spherical bearing (made from alumunium 7075) with steel AISI 4130. Loctite what type should I use ?


You need to make a steel bearing cup and weld it to your A-arm tubes. Your spherical bearing will then be 'staked' into the bearing cup. I suggest going with Aurora (since they provide a 50% discount to FSAE). They provide drawings required for your bearing cup

http://www.aurorabearing.com/product-catalogs.html

[Z]

Ninda,

http://www.fsae.com/forums/attachment.php?attachmentid=526&d=1427032716

Your CAD shows that you have MUCH BIGGER PROBLEMS than just trying to find the right glue.

The above posts from experienced FSAEers are all giving you a simple message. -> Time to call a Team meeting and discuss MAJOR CHANGES.

I would suggest a great deal of simplification. Start by searching the "prior art" of FSAE suspension design (ie. look at the many pictures available on the "Competitions" section of this website). Look closely at the details of the simplest-to-fabricate all-welded-all-steel examples.

(Hints: You have too many "clevises" that will flex because of bad bolt-detailing, and possibly even break. (Edit: Note what looks like a SINGLE bolt holding the upper clevis to upright!) The wishbones' outer-BJs (namely the "Steer-Axis") should be close to the centre-plane of the wheel, so probably much further outboard in your image. The inner and outer-wheel-bearings should straddle the SA, not be entirely outboard of it. The upright's bottom-BJ (the most highly loaded!) would be better mounted direct to the upright, not via a clevis. Etc., etc..)

If you stick (haha :)) to your plan of glued wishbones, then it is likely you will FAIL Brake-Test. Much more fun burning through a set of tyres in Enduro.

Z

[MCoach]

Exactly my question.

There really isn't any advantage to aluminum here since it and steel have similar specific stiffness, and welding is much simpler and more robust (from a process standpoint) than bonding.

This may be true in axial loading. However, this does not extend well to other design considerations. If one considers a beam in bending (such as a control arm taking non-axial forces) and therefore subject to Euler buckling, then this can be a consideration towards minimization of weight of your component. This enters an advnaced realm of material selection and consideration of "shape factors".

Consider page 27 of this lecture presentation for an example of how this works out:

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&ved=0CDIQFjAD&url=http%3A%2F%2Fwww.materials.ox.ac.uk%2Fuploads% 2Ffile%2Fdesign%2Fdesign_notes3.ppt&ei=OMAQVcDxFoOPyASEz4KIBg&usg=AFQjCNG5bUkuGdC7PaGNPu9wl3TTibe8zA&bvm=bv.89184060,d.aWw&cad=rja


Welding aluminum would require heat treat and mostly warp your assembly of spindly little tubes. 4130 would also require heat treat but does usually does not warp significantly. What is your reasoning behind trying to connect these two pieces like this in the first place? What are you aiming to achieve from this design?

It seems reasonable-ish...(well, at least less questionable) when done using carbon tubes. However, aluminum has a MUCH lower specific stiffness than carbon fiber, so I'm not sure what you are trying to achieve. Carbon at least cannot we welded together like the given materials. However, if you insist on this, I may recommend something similar to this:
https://tds.us.henkel.com/NA/UT/HNAUTTDS.nsf/web/7F948428635DFC62852573B600685299/$File/HYSOL%20E-40HT-EN.pdf