Can you spell "product liability insurance"? I consider that to be an expensive, but necessary evil.
Finite element analysis, fatigue testing, and destructive testing might also be useful. Ken Dave Engvall wrote: > On Jan 15, 2009, at 10:38 AM, Tom wrote: > >> Jon Elson <el...@...> writes: >> >> snip... >> >>> This is for a ** V8 ** bike? Is this a showpiece, or something >>> somebody >>> is going to ride a lot? >>> >>> The milling of parts like this tends to leave sharp inside corners >>> that >>> worsens the problem. You might be able to get a stronger part by >>> using >>> a bull-nose end mill to get rid of the sharp corners. >>> >>> Jon >> Hi Jon, >> Yes my customer is making 10 more of these trikes, there are 6 or 7 >> currently in >> his shop. >> Yes, they get ridden quite a bit, as they handle really well, and >> are very >> comfortable to ride in for days at a time... not to mention super- >> fun fast;-) >> >> I agree re: radiusing the inside corners. I might possibly even get >> rid of the >> lightening pockets altogether, since the sum of weight saved would >> amount to >> only 10 oz or so - this is a heavy trike anyway. (See my response >> to Gene's >> comments) >> >> Tom > > 7075 only buys you something in bulk parts. I have no idea where the > division between bulk and > thin wall comes. > > I'm not so concerned about dynamic stress as I am about fatigue > cracking. > Decent radii on the corners will certainly help. > > One trick is to machine the part out of plexiglas and then heat to > stress relieve. > Then stress the part and view with polarized light; one can see the > stress points and engineer the > design to compensate from that knowledge. > > Boeing used a lot of 4340 and 300M for critical parts. > > Good luck. > > Dave > > >> >> ---------------------------------------------------------------------- >> -------- >> This SF.net email is sponsored by: >> SourcForge Community >> SourceForge wants to tell your story. >> http://p.sf.net/sfu/sf-spreadtheword >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users > > > ------------------------------------------------------------------------------ > This SF.net email is sponsored by: > SourcForge Community > SourceForge wants to tell your story. > http://p.sf.net/sfu/sf-spreadtheword > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- Kenneth Lerman Mark Kenny Products Company, LLC 55 Main Street Newtown, CT 06470 888-ISO-SEVO 203-426-7166 ------------------------------------------------------------------------------ This SF.net email is sponsored by: SourcForge Community SourceForge wants to tell your story. http://p.sf.net/sfu/sf-spreadtheword _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
