Question about how to use LOCTITE

[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/attachmen...6&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=...,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