Hello, my company is constantly exploring alternate bearing materials (largely as a means of boosting catalogue options- there isn’t a specific performance goal in mind). One such material family is leaded bronzes like SAE 660.
I have been opposed to adding leaded products to our catalogue-...
Interestingly, this ball joint incorporates a sintered bearing (and zerk)- a significant departure from the sealed polymer bearings that are in use today. Maybe the fact that it's facing upwards will mitigate grease starvation, but otherwise I'd be concerned about potential adhesion between...
An update for all- EdStainless was correct, the temper step is at a low temp to maintain surface hardness. Subsequently, any baking/curing process that is above this temp is causing further hardness drop.
@mfgenggear- for reference, we were focused on maintaining case hardness. You are correct...
Anecdotally I believe these failures occur more frequently at low speed because:
More weight on the front wheels
Generally more turning/ball joint rotation
I've never looked into it but it makes sense to me intuitively.
The Accord suspension is certainly flawed from a design standpoint- not...
It is not- most (modern) double wishbone suspension designs will have the LBJ in compression.
The only two applications I am aware of are the Tundra and some generations of the Honda Accord.
I’m certainly not opposed to other coatings, but it seems like Geomet requires a curing step that would likely have the same effect.
I’m thinking my immediate actions are ensuring the h/t process is correct, and explore alternative coatings in parallel.
Hi Ed, there is a temper step in the current ht process (above 200C).
Are you implying that a secondary heating process, below the temper temperature, should not affect hardness?
Hello, our company currently specs a 4140 component, induction hardened to 55+ HRC. However, we then apply a corrosion resistant (ZnNi) coating which involves a baking step at 200°C to mitigate hydrogen embrittlement. In doing so, there is a mild annealling effect which decreases the surface...
Hello all,
BS970-1955 lists all mechanical properties for a given steel grade, considering heat treatment processes. For example, it lists UTS and Yield if for a steel if the steel is annealed, normalized, QT, etc.
Is there a standard, textbook, database etc that lists these properties for SAE...
Hello all, I'm looking for a standard and can't confirm that it exists.
ISO 3290 describes the acceptable tolerances of ball bearings themselves (the actual rolling elements). Is there a comparable standard for tapered rolling elements?
I suppose this question first hinges on another:
In general, are a car’s brakes strong enough to lock the wheel?
Given that locking the tire (skidding) is detrimental in terms of stopping distance, and given that a brake system can effectively lock the wheels, is there a benefit to increasing...
"Axial" and "thrust" are synonymous- are one of these actually radial loads (perpendicular to the shaft)?
Are you using a single bearing, or a pair in tandem?
Hello, I'm having trouble reconciling the induced axial loading in a TRB as a result of an applied radial loading. "Essentials of Bearing Concepts" provides a formula using the various contact angles, however bearing manufacturers (SKF, NSK, Timken) all use an equation where Fa=0.5/Y*Fr (the 0.5...
Hello all, thanks for the replies
Regarding my sketch, it was done as though I would not be allowed to install a ledger (hence the long spans).
@LuK13, it turns out I have pockets in my wall. You mention that using these would not be code-compliant, why is that? It would solve all my problems...
Reconvening on this- I put together a sketch of the existing supports, as well as a basic idea of the joists and beams (disregard the validity of this design for now, it is just a basic mockup).
I'm mostly confused as many houses in my (old) neighbourhood have decks of this design, and they are...
Hello,
I'm looking to install a deck to my old brick house- it is not a veneer wall.
Looking at the IRC and DCA6, I can't find any info about attaching a ledger to a true brick wall, just that it is prohibited to attach to a brick veneer.
Am I out of luck here- will I have to make the deck...
Admittedly I don't know if shear will be an issue- would you be able to recommend what topics I should research to learn more on the subject? Similarly, where did you get the 1500 psi value for compressive stress?
Again, I agree with the engineer's assessment- I'm looking for the calculations to determine HOW the assessment (beyond code and intuition).
There is nothing preventing me from replacing this joist, would just like to do the math myself.
Thanks for the reply- I apologize for the lack of clarity and information in my original post.
Firstly, you are correct that this notched would be in compression, not tension- shows how long it's been since I've thought about beam deflection. Regarding the rest of your questions:
The joists...
Hello, I have a floor joist with an enormous notch on it- much larger that acceptable.
Naturally the corrective course of action is to replace it, however I'm curious to determine if bridging this notch is a viable solution. Based on the notch location, the bridge would need to replace the...
