This IsAs Far From CNC Machining As You Can Get......

jackie schmidt

jackie schmidt

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This Is As Far From CNC Machining As You Can Get......

But we make a lot of money doing it.

This is what I am doing this week. In Port Neches Texas align boring the large hinge assembly abutments on a Dump Scow Barge. The holes finish 13.75 inches in diameter, and will have Thorplas Bushings installed. The pin that goes in the hinge will be Stanless Steel overlayed, 13 inches diameter.


http://benchrest.com/attachment.php?attachmentid=18929&stc=1&d=1485881755

http://benchrest.com/attachment.php?attachmentid=18930&stc=1&d=1485881828

http://benchrest.com/attachment.php?attachmentid=18931&stc=1&d=1485881936
 

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jackie schmidt said:
I sent this to my daughter and had it put on YouTube.

https://youtu.be/aAINgE2y6K8
Click to expand...

That setup puts Rube Goldberg to shame..but, hey, it works.

I also watched your 10EE neck turning video. I had just finished reading an old PS article by TJ Jackson where he wrote that the only way you could shoot in the ones was to bore the case necks. Question, can I borrow this portable machine to bore some case necks?


.
 
Jackie I laid awake last nite after looking at your prop shaft fitment....

"HOW does he keep the prop perpendicular to the shaft?"

HOW does he KNOW??"

"HOW does he get that spaghetti noodle shaft flat to take measurements from?"

"HOW does he take the side waggles out? Align the supports? Adjust the hts?"

"Does he spin it in "vee blocks" of some sort??"

"Just how much jigging/setup/index equipment do these guys keep around?? MAKE jigs for every assembly??"

"HOW in the #$%^ do you drive that taper on/off?"

"Does he have to set the key every time?"

HOW MUCH is Dykem by the 55 gallon drum??"

And ON and ON and ON!

You have a fascinating trade my friend....
 
JerrySharrett said:
That setup puts Rube Goldberg to shame..but, hey, it works.

I also watched your 10EE neck turning video. I had just finished reading an old PS article by TJ Jackson where he wrote that the only way you could shoot in the ones was to bore the case necks. Question, can I borrow this portable machine to bore some case necks?


.
Click to expand...

You noticed that 10EE has a turret on it???????
 
JerrySharrett said:
That setup puts Rube Goldberg to shame..but, hey, it works.

I also watched your 10EE neck turning video. I had just finished reading an old PS article by TJ Jackson where he wrote that the only way you could shoot in the ones was to bore the case necks. Question, can I borrow this portable machine to bore some case necks?


.
Click to expand...

Jerry, there is a method to all of that madness. Take a look at the size of the cut. If I have to, I can take over 1/4 inch to the side cuts in a 13 inch bore. That is 1/2 inch per cut out of the ID.

The tool bit is a piece of 3/4 Rex 95 with a positive take cutting edge. The feed while rough cutting is .010 per Revolution. I change two gears in the feed head that knocks it down to .004 per Revolution for the finish cuts.

As crude as all of this looks, it is our biggest money maker as far as billing rate goes. This type of work is always "cost plus", so if the bar is turning, it's making money.

On this job, I also bored the the abutments that mount the huge Hydraulic Cylinders that open and close the two halves of the Barge. Here is a picture of the smaller bar set up down in Hydraulic cylinder compartment.

http://benchrest.com/attachment.php?attachmentid=18938&stc=1&d=1485925293
 

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Brings back a lot of memories. Back in the sixties, we had to line bore the center pivot bore on the 12yd electric shovel, 14" dia I think. Had to build it up first with weld to take care of the wear. Sometimes it was even in the winter when the temp was below zero and the shovel was in the mine pit. Then we had to press in magnesium bronze bushings.
 
Jackie, you do some very interesting work. My hat is off to you.
It's nice of you to share this with us. I look forward to your posts.

Later,

Gene Beggs
 
Butch Lambert said:
Interesting comments from the Practical Machinest forum.

http://www.practicalmachinist.com/vb/general/prop-shaft-machining-tugs-330540/#post2910911
Click to expand...

Butch, I glanced over there. It seems that one of the posters doesn't realize that we are cutting a keyseat in a tapered fit.

They are well meaning, but they must know that we have cut keyseats in this manner about 10,000 times:D

As for the roller rest under the shaft, I would let him think about that for a while before he relizes why you can't do that.

If you could, post that YouTube video of the Portable Boring Bar over on that Site.
 
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Hey Jackie. What kind of tolerance can you hold on stuff like that? I am a river boat pilot so I spend some time in their shops when I can. Seems most places are happy around .010. Stephen
 
Here is the finished bore end of the first hinge. I moved to the other end this morning.

http://benchrest.com/attachment.php?attachmentid=18960&stc=1&d=1485980840

http://benchrest.com/attachment.php?attachmentid=18961&stc=1&d=1485981252

The bushings that go in here are made of Thorplas, a high impact non-metallic material that is self lubricating.

http://thordonbearings.com/system/d...rPlas_Blue_Industrial_brochure.pdf?1381422411


The bushings will be installed by shrinking them in frozen CO2, (dry ice), and slipping them in..
 

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I worked in a

chem lab at a specialty W and Mo products manufacturer owned by Philips Elmet...45 years ago. The machine shop did a bit of outside work and they had a fitting into which a round piece had to be fit and held by fiction. They would bring us the insert piece and we would shrink it in CH3OH chilled by lots of dry ice. We could, as I remember, get the alcohol down to about minus 40 C. It worked very well.
 
glp said:
chem lab at a specialty W and Mo products manufacturer owned by Philips Elmet...45 years ago. The machine shop did a bit of outside work and they had a fitting into which a round piece had to be fit and held by fiction. They would bring us the insert piece and we would shrink it in CH3OH chilled by lots of dry ice. We could, as I remember, get the alcohol down to about minus 40 C. It worked very well.
Click to expand...

We prefer to use liquid nitrogen, you can completely submerged the piece for an even shrink.

However, it is not recommended to use liguid nitrogen with Thorplas. The word is it will possibly shatter if cooled that quickly.

We have shrunk large Bronze Bushings in Methanol and dry ice for installation. It's the next thing to liquid nitrogen as far as getting something really cold. But having a deep washtub full of flammable liguid in the shop can give you a pause.
 
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sdean said:
Hey Jackie. What kind of tolerance can you hold on stuff like that? I am a river boat pilot so I spend some time in their shops when I can. Seems most places are happy around .010. Stephen
Click to expand...

A Set Up such as this will bore dead straight, within .001 in that length. The out of roundness can be from .001 to .003, which for this type of work is tatally acceptable.

The bushings shrink in, the pin will have approx .025 clearance inside the bushings.
 
Big boring job

Jackie..... pretty kool pics..... esp. the operation where your boring on location.....
how do you measure hole size with that bar thru there..........????
that job is a good candidate for a G&L boring bar.....
bil
 
bill larson said:
Jackie..... pretty kool pics..... esp. the operation where your boring on location.....
how do you measure hole size with that bar thru there..........????
that job is a good candidate for a G&L boring bar.....
bil
Click to expand...

These holes do not have to be a specific size, as in "thousandths of an inch". The print says "13 3/4 inches, stepped progressively out on each side from the center abutment".

I will take the sizes and custom machine the bushings to fit each hold.

I finish the center abutment to 13 3/4, and then step each of the three abutments on each side of it around .030 larger.

If I do have to bore to a size, I use spring calipers. Using plain old Spring Calipers, I can size a hole within .001 inch if I have too. It's all in knowing how to use them.

Is a Giddings &a Lewis bar a traveling head bar like this? I suppose you could call ours a R.C. S. &. S, since we made just about everything you see there.
 
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