All those holes can't be good for it?

When drilling holes in a frame or front axle how much is too much. How can any one tell if the part is still structurally sound? May be this will clear up an argument im having right now.

 

do a search for "drilled axle" or something similar..there've been multiple threads on this topic..the general thought is that if it's just the WEBBING that's being drilled,you're not REALLY tapping into something that's structural
creepy

 

Consider this.......when drummers smash their cymbals hard enough to crack them, ( much softer alloy than steel ) they drill a hole in the crack to stop it's spreading.

 

You are probably right...for your own peace of mind. Don't do it. No need to be a lemming and follow the crowd.

Just don't try to convince us that like it that we are wrong. Fair enough?

 

well, consider this. A front axle is basicallt and I beam, right? Drilling in the center of an I beam doesn't really reduce it's structural rigidity that much at all, as the "i" shape is where it really gets it's strength. (Look at warehouses that use drilled I beams on the ceiling.... MUCH more weight and force there on those ones.)

As for the frame, same difference. Square or rectangular tubing gets its strength from the rounded corners of the tube on 4 ends. If you drill out the flats across two paralell sides, you aren't reducing the continuity of those "edges" or "corners", which is what gives it the strength you need.

 

Recently there was a company that did some scientific destructive testing of their own beam axles, both drilled versions and un-drilled versions, and found that the drilled versions were actually stronger.

 

They hole is to stop the cracking, but that isn't a strength issue. It runs the stress fracture at an end point. Drilling the holes before a crack formed would not neccesarily prevent the crack in the first place as the stresses would have expolited that natural stress riser.

Geez, I still miss Mr Moon. Frickin' maniac!!!

 

If you are really serious and want to put a number on this then your answer is as close as you nearest Machinery's Handbook. First look at the STRENGTH OF MATERIALS section - find the equation that describes the Moment of Inertia and Section Modulus. Solve for each using the appropriate cross section - one being a simple "I" Beam - and the other representing the portion of the "I" beam with the hole in it (that might look like a couple of mirrored "T" sections or just a couple of horizontal rectangles depending on how big your holes are. Next you can solve for the Stresses and Deflections in your 2 beams and make an honest comparison.
Will your answer be YES or NO - well not really but you WILL be able to see a direct correlation between the part's stiffness and stress level after those holes are in there.

Machinery's handbook really is a pretty darned good bible for this stuff. And while they don't spoon feed you all the answers if you sit down and read it - it WILL take you through all the steps. Your other option is to find a computer geek and model the two versions and compare the FEA's.

Good Luck