Author Topic: Leadscrew  (Read 1612 times)

Offline steamer

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Re: Leadscrew
« Reply #30 on: March 27, 2019, 09:25:54 PM »
OK   a few in process shots.....I also made a new nut, a "P" shaped affair....not much photo evidence on that, but I was in "bull in the woods" mode ...12 hour day yesterday

Anyway...a few more shots that seem pretty self explanatory.

To cut the thread, I left the cross slide locked and just moved the compound to add feed.   That allowed the follower rest to stay in position.    I also left the half nuts closed, and just used the VFD to crawl into position.   I had thread reliefs on each end, so that simplified everything.

If I had to do this again, I'd make a cross slide mounted follower that had HSS lathe blanks to bear against the part.  The bronze just wore too fast.   I ended up dressing the surfaces on the mill 3 times to make that screw....and as it wore, the screw would push away..  It was tedious.

Always take a scratch cut...and Always check it with a thread gage.....ALWAYS!

Dave



"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline steamer

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Re: Leadscrew
« Reply #31 on: March 27, 2019, 09:30:00 PM »
And Another thing

The tool is a "thinbit" threading insert, that fits in my new grooving tool.   It cuts the nicest finish!....I had polished chips coming off 0-1 tool steel, which can be tough to get good finish on unless the tool is really good..    Now I'm old school and never really used insert tooling in my shop....If I needed a threading tool, I usually grabbed a blank HSS bit and got cracking grinding one and checked it on a "Fish Scale"  ,,,,but not anymore!

Thanks for turning me on to those Steve Huck!

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline steamer

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Re: Leadscrew
« Reply #32 on: March 28, 2019, 01:58:11 PM »
I checked the assembly    total backlash installed    0.003"....a good deal better than 0.019"!
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline Maryak

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Re: Leadscrew
« Reply #33 on: March 28, 2019, 07:52:33 PM »
 :cheers:
Если вы у Тетушки были яйца, она была бы Дядюшкой

Offline steamer

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Re: Leadscrew
« Reply #34 on: March 31, 2019, 03:10:46 PM »
A vid of the threading operation ...about 1/2 way into it.

https://www.facebook.com/mcandrew.piper/videos/2268228856787841/?t=2

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline Dave Otto

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Re: Leadscrew
« Reply #35 on: March 31, 2019, 04:55:05 PM »
Looks good Dave!

Dave

Offline steamer

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Re: Leadscrew
« Reply #36 on: March 31, 2019, 04:57:46 PM »
Looks good Dave!

Dave

A hardened steel follower rest that mounts on the cross slide is on the list of accessories I'm going to build...
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!