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How we bore...

Posted: Sat May 23, 2020 9:07 pm
by Casey Burns
This video shows on a rather massive scale how some of us makers drill the initial pilot bores on flutes. Usually a little beeswax and sometimes blowing compressed air through the end of the gun drills is all that is needed with wood, instead of cutting fluid. Aside from that the process is the same.

See https://www.youtube.com/watch?v=CL-YLN2MeLc

Casey

Re: How we bore...

Posted: Sun May 24, 2020 11:21 am
by Hi4head
Thanks for sharing this Casey! I'm always amazed how equipment like this can stay true in three planes.

Before I retired I used to work with lots of different types of manufacturing industries and loved to see how different things were made.

Chris

Re: How we bore...

Posted: Sun May 24, 2020 1:06 pm
by PB+J
That's remarkable. I'm a pretty good teacher, but one of the things I fail to convey--though I try--is the sheer grandeur of large scale industrial processes and industrial processes in general. The forces required, the degree of precision, the wealth of knowledge and experience drawn on, the vital utility of the work. I used to teach a book that described the work of a pattern maker, who has to be able to make of model of a part, exactly small enough to account for enlargement in casting, crafted and smooth and polished so that casting medium would not stick and the mold would break cleanly, while still retaining full functionality of the part under stress. I would highlight the passage and read it in class to try to convey how admirable and astonishing this was, and the students would mostly have that look in their eyes that "why is this guy so excited about this?"

I force them to watch some of this series about the functions of WWII analog fire control computers, which could track a moving target from a moving battleship with considerable accuracy; all the calculations done with slide rules, all the machining of the immensely complicated device, roughly the size of a side by side washer and drier set, done by hand.

https://vimeo.com/340223785

A few of them, you can see their jaws drop.

Re: How we bore...

Posted: Sun May 24, 2020 1:19 pm
by Hi4head
Two great videos. The second got me thinking back to engineering school (many years ago) and guys trying to figure things out with the old right hand rule.

Re: How we bore...

Posted: Sun May 24, 2020 4:18 pm
by an seanduine
Next up should be a video of truing up railroad wheels. . . :D

Bob

Re: How we bore...

Posted: Mon May 25, 2020 9:50 am
by Geoffrey Ellis
I've had the good fortune to work with a brilliant machinist who just happens to live in my area. He is one of those rare birds who may be a dwindling species. Started training as a machinist on board an aircraft carrier in the mid-60's, then worked at Hughes aircraft while getting his degrees in physics, engineering, etc.. Been in business for himself for many years and has truly jaw-dropping skills. Not just as a machinist, but as a problem-solver. I'm continually amazed by his ability to find a solution for any sort of hare-brained problem I bring to him.

One of the cool things about working with him is that he is really great about teaching as he goes. So I don't just bring him a job and go away while he deals with it. I get to work with him on the job and learn how he does things. It's been a game-changer for me. But the point of all of this is to say that one of the big things I've learned from him (and which he has made a point of driving home) is how much goes into setting up a job, prior to actually executing it.

Watching that giant piece of steel being drilled out is a perfect example. So many things must be put into place to do it accurately, especially since it is bored from both ends! Anyone who has used gundrills on something like wood can tell you that if you are drilling any distance, one thing you don't want to have to do is flip the work around and drill from the other end! Drill bits can "wander" off course, and you risk having your bores meet off-center.

Drilling a huge piece of steel with a really large and rigid boring tool (and doing it slowly) you are not going to have that same problem that faces a flute maker drilling a length of wood, but nonetheless the set up for that job must have been extensive to ensure the necessary accuracy. They had to true up the outside sections of the steel, especially the parts that are going to be held by the lathe chuck and the center steady. And of course they would have to make sure that all the parts of the lathe (tailstock especially) was nicely calibrated (I've had to do this a couple of times with the tailstock on my metal lathe--they are adjustable and can drift out of "true" over time).

I find it amazing (like PB+J's students probably did) that in an age before computer modeling and CNC manufacturing that machinists and engineers were able to execute such staggering feats of precision. That's why I like working with my friend, because his career straddled both the analog and the digital age. He says a lot of young wannabe machinists these days feel that they are qualified if they only know how to use the modeling software!

Re: How we bore...

Posted: Mon May 25, 2020 11:16 am
by Conical bore
Geoffrey Ellis wrote:I find it amazing (like PB+J's students probably did) that in an age before computer modeling and CNC manufacturing that machinists and engineers were able to execute such staggering feats of precision.
At the risk of crossing with the telescope thread here, one of the most amazing books I've read is "The Perfect Machine: Building the Palomar Telescope" by Ronald Florence. Most astronomy nerds will naturally be interested in the decades-long drama of the primary mirror. But the story of how the horseshoe equatorial mount was designed and built to ridiculously high precision in a pre-computer age, is just as fascinating.

Re: How we bore...

Posted: Mon May 25, 2020 7:08 pm
by Loren
79 years ago we could produce 1 B-24 Bomber every 55 minutes, now we can’t even produce enough incredibly simple little N-95 masks for healthcare workers, let alone the general population.

I find it difficult to watch this video about B-24 production and not come to the conclusion that we’ve gotten worse, rather than better, at so many things since the end of WWII. https://m.youtube.com/watch?v=p2zukteYbGQ

Re: How we bore...

Posted: Tue May 26, 2020 4:10 am
by PB+J
Loren wrote:79 years ago we could produce 1 B-24 Bomber every 55 minutes, now we can’t even produce enough incredibly simple little N-95 masks for healthcare workers, let alone the general population.

I find it difficult to watch this video about B-24 production and not come to the conclusion that we’ve gotten worse, rather than better, at so many things since the end of WWII. https://m.youtube.com/watch?v=p2zukteYbGQ

It's worth pointing out that the US did not start producing like that all at once--it took years to ramp up production to that level. This is a great piece by two eminent military historians: https://warontherocks.com/2020/04/warti ... -pandemic/

it's just worth noting that the amazing production levels the US accomplished didn't happen overnight. Interesting side note: Francis O'Neill's collaborator Selena O'Neill, no relation, worked in the Pullman rail car factory which had been converted to war production


It's not clear to me why we aren't seeing masks and I'd hesitate to speculate because it would violate forum rules. We certainly had effective leadership in the 1940s