I would have done this totally different and began in a vertical mill, finding center and squaring up off the threaded post with a DTI. Drill, ream or bore an undersized thru hole at the proper offset and then go to the lathe and indicate the bore in X/Y. Bore to finished OD and commence with threading. No worries.

One nice thing about machining that bronze is the nice little chips that result, making it easy to evacuate the chips through the drill flutes. 😊

You got me, Keith. It always messed with my mind that by accident, I'd hit the rapid traverse lever on the lathe. Just as I thought that you sped up the video and I jumped...lol. bugger!

I know nothing about Leblonde lathes, but wouldn’t you want to ensure that the threaded hole is bored to intersect the mounting boss at right angles? Or am I overthinking this?

Transferring the part number is a nice touch.

I read the title and immediately thought "yuck"! You did a great job on that.

You are the man Keith! Thanks for sharing your knowledge and your years of experience. I am 78 years young and would NEVER, EVER lean on your on your ability, judgement and expertise. Keep em' coming. YEA!!!!!

A bit tricky building a nut to fit a lathe that probably has a lot of wear in the carriage and working off a nut with worn out threads. The vertical alignment can be adjusted by adding shims or removing some material, but the side to side alignment is not adjustable and if the hole is off center or not straight through the casting it will bind. The hole should be centered on the the vertical pin, not just halfway between 2 sides of a rough casting. To be sure the hole goes through straight, flats should be machined on the three sides to be equal with the centerline of the mounting pin.

Great work!

We're all feeling better seeing that part number being stamped in.

Thank you for sharing.👍

Great informational video as always Keith

How are you sure the lead screw hole is at a dead right angle to the threaded shank?

excellent work keith

Very nice work!

Great video thanks for sharing

Thank you Keith!

Most excellent.

Thank you Keith 🥰🥇

Thanks Keith for the video. Another great job.

Thank you!

Interesting video, thank you

Thanks Keith for the video. Another great job

Thanks for another interesting video Keith. -Curt

Once again another great video... Thanks Keith !!!

Nice job

Great work ! I love the threading job.

Good job

Good morning Keith. Thanks for all the work making the videos. Have a great weekend.

Very nice. You are an accomplished fellow indeed. 👊🤜🤛

I commented on part 1 and I'm glad to see you stamped the part number on. Not that you didn't film it before my comment!

Doesn't the axis of the lead screw threads have to be coplanar with the axis of the vertical boss? I really don't see where the setup accomplishes that.

You had me at hypotonus. And at 18:46 JK thanks Keith. love your work.

Nice job Keith

Maybe just me, but I would have found the center of the hole in the existing nut, referenced from the machined flat, and used that to layout the center of the hole for the new nut, again referenced from the machined flat. The new casting is admittedly oversized and using a sloppy half-the-width measurement as a basis for laying out the hole center referenced from the radius of a rough, oversized casting just doesn't give confidence that this nut wouldn't end up binding. Maybe just me and maybe my reasoning is flawed. EDIT: Two followup comments. One, my comment was meant for those who don't know any better so that they think about their layouts and setups. Two, my comment was in the context of the external threading and machining having been completed already, which was the improper sequence in the first place in my opinion. That said, none of us are without fault and (again) my initial comment was meant to be constructive for new guys who don't know any better. 👍🏻

While you have cut many threads of many sizes on your channel ( I even remember a left hand acme lead screw that ABOM did for you at the museum) I don't recall an internal 5 pitch acme cut in reverse feeding in. A lot of left handed threads are cut outwards from the chuck. Thanks for sharing this rarely video taped procedure. Interesting there wasn't an oil port for that nut/thread. I also liked your craftsmanship in stamping the part numbers onto the nut. Since you were returning the original, you might have left that out, but worn-out loose parts often get lost in a shop. I'm still awaiting machining of precious metals in your shop! Thanks for your videos.

Happy Friday Keith! 😊

Excellent work....Thanks Keith.... Shoe🇺🇸

Thank you for the video Keith. Looks like you are taking more backlash out of this than you had hoped for.

Great video as always,👍👍👍😎😎😎

I love Tap Magic

Why didn't you align the bore of the ACME thread with the threaded post on the bottom of the nut?

We had to replace the block nut and the cross-slide on my lablond as well. except we purchased a left hand brass long nut and milled down the outside. The cross-slide wears more in the middle since that is were it is used more. We also purchased a left hand acme shaft that matched the nut size and milled it down for bearing mounts and handle. We used our old parts as reference. The outer ends of the shaft hardly wear. That is why you might have more back lash in the middle when you checked the block. Nice video as usual.

A coaxial indicator would made for an easy setup. Even if it doesnt need to be perfect, just my ocd talking. Love your vids Keith, been watch for a long time....

Nice job Keith. Came out great.

Well that was dumb thinking of me that Keith would forget stamping the partnumber. Last but not least. 😅

I don’t think I have not had to take a little more.Much better than taking too much

Tight

Thanks Keih, as a newbie, one question: when holding the rough casting in the four jaw, how do you ensure axial alignment - or did you just guess it would be within tolerance?

It is nice that you can do a job for somebody local. TM Long time viewer

Hi Keith, you made a lot of effort to make reference surfaces, But then didn't use them...Unless i missed it ?

Very Nice . Kieth my question is do you make a video on the 1st part of the machining of the nut with the external threads ?

Nice job. Not an easy operation.

Keith, I just hope you don't end up like Steve Watkins, after cutting the LH internal thread (I think his was square thread, pre-Acme), he then found that the lead screw from the shaper was a two start thread.

I am thinking you may still not have a good fit when installed. The center of the Acme thread hole should be the same as the shoulder of the machined stub in one axis, and the other axis should be measured off the flat around the stub. The outer dimensions do not matter at all.

Everybody tried to find out how he will maintain symmetry, squares and align with the fixing nut's symmetry. And he marked it like it was a piece of sqare iron for a shelf 😂, aligned the raw casting with the jaw with protector 😅. Funniest guy, it must be a joke.

As an apprentice, I was required to Lap Nuts with a dedicated Lap mandrel ID then run the Screw thru the nut. "Zero fit".

I can only concur with others, personally I would have placed the centre of the leadscrew hole to match the centre point you put in the thread you machined, on the East/West plane and taken centre on the North/South plane from the flat machined surface

Wouldn't you want to add the Ackme thread measured from the locating shoulder on the part to its mounting position at assembly

Keith, I was wondering, if you already established the center of the nut when you machined the threads for the nut. Why not transfer that center to the face of the hole you were drilling? When I drew parts as a draftsman many years ago, we drew off a datum point. Since you machined the off sticker ( please excuse my lack of terminology) first, the datum would be the center and face of the face. Dimensions for x. Y and z would be measured from the centerline and face of the screw. By establishing multiple centers off different surfaces you compound errors. Bob

That's Amazing 👍👍👍

that's how it's done 😊👍

What's the range of that internal micrometer, you are using on the bore?

Ring finger is looking good....

Many comments about the thread hole alignment. I was going to ask, as well, why not reference from the machined threaded stud? I'd be concerned about the load it would put on that long leadscrew if not perfect. Thanks for sharing, Keith.

I hope it's a single leed, use a dead center to indicate to center punch

Nice job EXCEPT Acme threads are 29 deg.

Surely ACME is 29deg, trapezoidal (metric) is 30deg, so if you feed the compound in at 15deg the thread will not have the correct form.

did the threads get shortened for the nut that holds it on?

Oil hole?

Keith. What kind of leblond lathe was the cross slide nut for? I have a leblond Regal 13 inch I'm restoring.

I was wondering Keith; do you ever use fixtures for stamping the numbers/letters into the parts so the characters are spaced properly? I always make and use stamping fixtures when stamping or pressing numbers into metal and wood.

20:58 At this time stamp looks like the threads are full of swarf, was this due to roughness on the finish or actual brass chips?

😛😛😛😛😛😛❤❤❤❤👍👍👍👍👍👍

You should put your name on there with the serial number, my friend. I can see someone trying to puzzle out, a hundred years from now, why LeBlonde made one part that was clearly better quality than all their others, and why the number stamps don't match all their others.

What is half of 1 1/2 ?

Yeah...I don't think this nut will work out well for the local guy.

I notice you never use air to blow off chips. It's a very good practice, especially before performing any precise measurements. Any reason why?

29 degrees for acme thread. If your insert is 30 degrees you are cutting metric trapezoidal thread, not an exact match for the acme spindle. Good enough for the purpose.

If this thing works even halfway right it will be yet one more proof of the old adage that it is better to be lucky than it is to be good. I couldn't believe what I was seeing here. He has a presumably good and true reference point to start from yet he ignores it and approximates from a rough casting! A pipefitter or a rough carpenter might be able to get away with this sort of stuff, but a machinist, not so much. As it is, the hole is not aligned in either axis and it is not even truly round as you could hear the intermittent cut as he was threading. What a mess.

Funny. I asked you for help on exactly the same part, and was told the tap to do it was too expensive. Now internal threading is feasible but wasn’t a couple years ago. I got my Leblond running anyway- but it would have been nice to have this instead of having to use the cast iron part Leblond sells now.

Normally i don't critique someone but Keit come on.. "right on the money"- when we clearly saw it was going further.. and why did you drill it out to 9 thou under? LIKE WHAT you need a minimum of 20 thou if not more to get it actually cleaned up. Now you got a hole which is wider in one direction then the other.....(you could hear it clearly when he was making the scratch pass when threading). Disappointed to say the least

Did you say, "half of inch and a half is inch and three quarter."?

"Where I'm at"!? As such? As so, yes, as such yes, like such, definitely is that English, ending a sentence with a preposition? clearly so! it's not 'Where we're at", it's "I do not follow idiots, who can't speak the English language.

Half of inch and half is inch and three quarter? 😅

I don't understand why he calls it a half nut, it looks like a nut to me. Ron W4BIN

this all sucks, no way that this nut will work properly, tolerance wil need to be 0,001 and now 1/16 at the best

There is no way that ACME thread is perpendicular to the existing machining on that part. But hey, this is the "Eyeball it" machining channel. 🤡

Stop wearing that shirt.