It’s Been A While Since I Worked Something “Between Centers”.

[jackieschmidt]

We are currently involved in a refit of an old 3000 HP Harbor Tug that is going to be sent to Trinidad after the rebuild.

We are rebuilding the Prop Shafts, (9 inch, 30 feet long), and the steering, The Reduction Gear people are rebuilding the gears. When the Shipyard removed the intermediate “spool shafts” from the gear output flange, sombody got carried away with a sledge hammer.

The Gear people sent them over to us to see if we could make sure the flanges were still true with each other.

This is not as easy as it would appear. I figured the best way would be do them “between Centers”. Only there were no canters in either end.

So, I chucked each one up, trued the flanges OD, and established a true center in each end. I then checked up a slug and cut a 60 degree center. This allowed me to place one end on that center and use a live center in the other while driving it off the chuck with a dog.

It worked great.

Amazingly, none of the young men in my shop had ever seen this set-up. They learned something.

Anyway, I like fixing damaged parts. her are some pictures.

 

[Judd]

I always love when you share your work stuff with us, thanks Jackie!

 

[nwmnbowhunter]

You do amazing things. More pictures!

 

[Gun Smith]

Way cool Jackie, always love your write ups of your work. Thanks!

 

[LVLAaron]

I really enjoy this kind of stuff. When I retire I see myself having a job shop to tackle stuff like this.

 

[AlNyhus]

Jackie, is the slug a press fit? -Al

 

[jackieschmidt]

Jackie, is the slug a press fit? -Al

No, Al, it is a 60degree center that I machined that fits in a center drilled hole in the spool. I should have taken a picture of that.

There is a center in each end. You put it between the centers, face one flang, the simply turn the piece around, put back between ethers, and face the other flange.

 

[Silo1616]

No, Al, it is a 60degree center that I machined that fits in a center drilled hole in the spool. I should have taken a picture of that.

There is a center in each end. You put it between the centers, face one flang, the simply turn the piece around, put back between ethers, and face the other flange.

Looks like a couple of the hammer blows were on the edge of the flange face - not good. I like the drive dog.

 

[Walt Krafft]

Does that boat have some EMD's that don't meet the current enviro regs?

 

[Dusty Stevens]

Will they put it on one of those drydock ships to take over there? We have a pirate around here somewhere that could drive it over and not even spill his drink

 

[jpx2rk]

Must have been a good sized fella using the sledgehammer. Does he have previous work experience for the airlines????

 

[tobnpr]

The Gear people sent them over to us to see if we could make sure the flanges were still true with each other.

Cool stuff. Quite a process, re-shafting; getting the engines, shafts/struts perfectly aligned. I mirrored the mechanics when I had it done on the 40'er I used to own, if ya think dialing in a barrel is time consuming...

Did you face them off because you found significant runout?

 

[jackieschmidt]

Cool stuff. Quite a process, re-shafting; getting the engines, shafts/struts perfectly aligned. I mirrored the mechanics when I had it done on the 40'er I used to own, if ya think dialing in a barrel is time consuming...

Did you face them off because you found significant runout?

The Gear Rep wanted them refaced after seeing what the shipyard did.

This is pretty common. Keep in mind, a standard shipyard hands tool kit consist of a cutting torch, a pair of channel locks, and a sledge hammer.

“Heat it and beat it, it will give up sooner or later”.

 

[jackieschmidt]

Does that boat have some EMD's that don't meet the current enviro regs?

Not real sure. I think it had a set of KT-50 Cummins. The new engines are Tier 4 35-16 Cats.

 

[Judd]

The Gear Rep wanted them refaced after seeing what the shipyard did.

This is pretty common. Keep in mind, a standard shipyard hands tool kit consist of a cutting torch, a pair of channel locks, and a sledge hammer.

“Heat it and beat it, it will give up sooner or later”.

I have some friends that live by that philosophy

 

[X Count]

It's more efficient to skip to plan E

 

[matthias]

So this may sound a bit out there. Have you thought about creating a youtube channel? There are several machinist channel s that have very large followings and I would assume make extra money. May also be too much effort.

I enjoy your posts and find them really interesting.

 

[Dusty Stevens]

So this may sound a bit out there. Have you thought about creating a youtube channel? There are several machinist channel s that have very large followings and I would assume make extra money. May also be too much effort.

I enjoy your posts and find them really interesting.

He may not want alot of their proprietary tooling and setups out there for copy. When i worked for GE i had a mechanic get fired for posting a shaft alignment video comparing dial indicators and lasers on a turbine inside a cruise ship. The cruise company told ge they couldnt post videos of their equipment and he was not welcome on their property anymore

 

[matthias]

Dusty, That makes alot of sense.

Just saying I would watch videos of 30'shafts being turned. Hell I would buy a ticket to watch from the rafters for the afternoon.

 

[Dusty Stevens]

Dusty, That makes alot of sense.

Just saying I would watch videos of 30'shafts being turned. Hell I would buy a ticket to watch from the rafters for the afternoon.

I heard that! Houston is a nice town this time of the year- no snow tires required. I bet jackie will give you a good tour