Finally wrote-up my "How to Design Parts" section...

"Metal Man Joe" wrote in news:1148755104.484188.237730 @j55g2000cwa.googlegroups.com:

Nice and informative. I did notice a spelling error though. Look for quited -->should be quoted

Joe,

Good stuff, I've been drilling this into engineers heads for over 25 years. I work primarily as an engineer now, but my roots are in the shop. It still amazes me how many engineers, with decades of experience, still don't understand these basic things.

I work for an engineering consultancy now. We have a fairly extensive machine shop with several CNC's. I'm in a position to really hammer (in a friendly, but firm manner) the other guys when they do stupid stuff. Ironically, the guy with the most experience, is the worst offender. Everything he does has die cast or molded type features. He's retiring next year, and it's time.

There are some cases where allot of these rules "have" to be broken simply because of the physics involved it thier function. Wave guides for aircraft avionics and satellites comes to mind. And yes, companies are charged a very heavy premium for the risks, and the time.

There're also some cases that are just plane stupid as well. I did some contract programming, a while back, for a tier1 Boeing supplier. On several of the parts, they had holes that required a 90 degree attachment. Imagine a part with several pockets with holes on the internal vertical walls. They were nothing but clamp attachment points for cable routing. I saw the whole wing assembly. They would have actually worked better if they'd been on the floor of the pocket.

Mark

Thanks Anthony, I fixed it.

Joe

You might want to add this, or add a link to it, in the new .wiki being set up at

Joe,

Nice job.

Joe -

Thank you! This is exactly what I've been telling several of my customers for almost 20 years. And you're right - sometimes I get prints that are so bad that I don't bother to quote them. And I'm amazed at how many prints I get that are ambiguous, unclear, poorly dimensioned, *missing* dimensions, or - and this stuns me - with dimensions that don't add up or figure correctly.

Thank you, thank you, thank you, thank you thank you, thank you, thank you, thank you, thank you thank you, thank you, thank you, thank you thank you, thank you, thank you, thank you, thank you thank you, thank you, thank you, thank you thank you, thank you, thank you, thank you, thank you thank you, thank you, thank you, thank you thank you, thank you, thank you, thank you, thank you thank you, thank you, thank you, thank you thank you, thank you, thank you, thank you, thank you thank you, thank you, thank you, thank you thank you, thank you, thank you, thank you, thank you thank you, thank you, thank you, thank you thank you, thank you, thank you, thank you, thank you thank you, thank you, thank you, thank you thank you, thank you, thank you, thank you, thank you thank you, thank you, thank you, thank you thank you, thank you, thank you, thank you, thank you thank you.

I'm going to be pointing several engineers to this very shortly

Tom

Joe:

You've addressed many points that we have to deal with on a day to day basis. Sometimes engineers (and/or the parts), are amenable to change, sometimes not. Excellent job.

Very good, now if you can get them to read & understand it life would be better. I get some where the tap drill called out would make 120% thread. Think about adding something about tapped hole percentages. And if a form tap is ok.

Thanks for the reply and encouragement Mark, I really appreciate it!

Joe O.

Thanks Bryan, I'll look into doing that.

Joe

Thank you, I really appreciate the encouragement.

Joe

Wow! Tom, thank *you* so much for the encouragement. It's posts like yours that make all the work worthwhile. I *really* appreciate it.

Best Regards,

Joe

Thanks Bob, I really appreciate it.

Joe

Thanks Why. I just added a new section at the end of the prints section about this. I *hate* it when people use those CAD hole wizards that spec the tap drill as if they are doing the machinist a favor. 99.9% of the time, they designer should let the machinist decide on the tap drill and the exact technique of tapping (cut, roll, thread mill, etc.). I really appreciate the comments.

Joe

"Metal Man Joe" wrote in news:1148755104.484188.237730 @j55g2000cwa.googlegroups.com:

Joe, Content related, you might want to include a few of the points from a post of mine a while back.

Specifically, points: 4, 6, 8c (I forgot the c in the post, the last line of 8 is to what I refer), 12b, 14, 15 and 17.

Joe, Very good job. Like others I've tried to drum this into my customers heads for years now.

I'm going to bookmark and pass along your design tips to my customers.

One thing you forgot is the section on paying on time, and how this will get you lots of favors from the shop owner! :)

Best, Steve

Good point Steve! I meant to add that to the Do's and Don'ts section. Thanks for the comments.

Joe

Gee, if we can get them to draw the prints right you want to go for the GOLD & have them pay on time also ;)

Anthony:

That is a *great* post! I'd like to add a link to it in the Resources section. Is this OK with you? And will the link

be around for awhile? If not, I could put it in HTML and host it for you. Either way, how would you like to credit yourself?

Thanks again,

Joe