Logan lathe (model 1110008-l00h) by powermatic thread cutting

[beegie]

Hi All,
I am new to this forum and have a logan lathe. I am trying to cut 5/8x24 threads on a barrel and I have had a hard time on a scrap barrel trying to do this. I am sure I have the machine set right or CLOSE but I am missing something. When I check the threads with a gauge they don't even come close. Does anyone have a logan that can help?

 

[JohnEvans]

Question 1 you have the QC box set correctly ? 2 you are using the half nuts? 3 compound set with handle at about 5 o'clock? 4 tool on center and square with the work?
2 and 3 seem to be the most common issues not knowing your experience level.

 

[mach2]

And 4- make sure the 48 tooth and 24 tooth gears under the left gear cover are in the correct locations.

 

[TDegenhart]

Once you have the machine set to what you think is correct, take very light cut, just enough to mark the work, and measure the thread spacing. Will save time and material.

Tom

 

[FredC]

If the machine is new to you possibly the half nuts are packed with chips and tracking different every time you engage them?

 

[GGaskill]

Have you ever cut threads with this machine before? On my 2555VH, I find that you can kind of engage the half nuts at the wrong place if you don't time properly with the thread dial.

Also, what precisely is your problem? Wrong pitch? Poorly formed thread profile? Erratic pitch? Something else?

 

[thermite]

Once you have the machine set to what you think is correct, take very light cut, just enough to mark the work, and measure the thread spacing. Will save time and material.

Tom

Before even that, chuck up a length of white PVC plastic pipe, make your "tool" a whiteboard marker or draftman's thin lead mechanical pencil, measure, take notes, then wipe after each pass until it comes good, ANY thread on the box.

No significant waste atall.

Next up, real threads, but in ignorant HRS or CRS to insure the lathe dasn't fail under load.

You'll then know what can be trusted ELSE needs corrected.

NOW yah dare risk a barrel. Light "proof" pass still a good idea.

 

[beegie]

I will send you pictures tomorrow now that the internet is up and I found out you had to look at your post to see the answers. Thank you very much

 

[beegie]

I'll post some pictures tomorrow of my settings. I have plenty of scrap barrels to work on before I cut the customers bull barrel.

 

[beegie]

I've had the machine for a couple of years now and have cleaned it real good. I'll post pictures of my settings and what the setting is cutting in the morning. I haven't had internet for a while now and it is back on again. Thanks for your response too.

 

[beegie]

Thanks, I'll do that and post pictures tomorrow morning for all to see. I haven't had a good internet connection all day. I live way out in the mountains and just do custom work and had no trouble to cut threads for a new barrel or chambering a barrel. This is the first time I've had to cut5/8x24 threads on a barrel because the customer has a bull barrel and I am putting a comp on it.

 

[thermite]

I will send you pictures tomorrow now that the internet is up and I found out you had to look at your post to see the answers. Thank you very much

?? If you login or "park" on your "subscriptions" page AKA folder zero, any thread you have posted in, your own started or other, plus any you do NOT post in, but "subscribe to" out of general interest, (see "thread tools" top of the display) will show-up until intentionally "unsubscribed" (tick the box, scroll down, delete subscription), then auto-renew again if you post again.

Those will auto-arrange by most-recent post date, with the typeface going bold/black any time there is an unread entry as it rises to the top.

Click the tiny blue arrow - change zoom down, down, down if it is has gone missing, as it is coded very badly - well "dead WRONG" actually.. to go to the most-recent post.

PM can be a time-saver easily more than a time-waster if you but make use of its tools.

 

[beegie]

John, I don't have much on threading but chambering I do. This is how I have everything set up.

John, I didn't know where to post so I posted on general too and a lot of people have answered questions for me and I put some photos on there too.

I am very new to a forum this is my first time on one so I thought I would good emails stating I had answers but I have to look at it and see if I do. I broke a bolt the other day and I am trying to make one for the Idler gears till mine can be made from a machine shop that I have to drive over 100 miles round trip from the shop. Thanks for answering J.R.

 

[GGaskill]

Not quite sure what the magic marker lines on the chuck are for. Your caption says "marke where to start" which leads me to believe you are using that as a reference point. In your picture #3 of the carriage and apron, going by my 2555VH, the right most lever is the half nut lever, the upper central (UC) lever controls which axis is driven and the bottom central lever is the clutch that engages/disengages the power feed. The UC lever should be in the middle hole for threading. I think there is a mechanical lockout that prevents engaging the half nut lever if the UC lever is not in the central position.

The carriage has a threading dial at its extreme right side. The gear on the bottom of it should engage the lead screw and be driven by it when the spindle is rotating as long as both tumbler levers are engaged in the quick change gear box.

There is too much glare on the pix of the quick change box but I will assume you have selected the proper combination for 24 TPI.

Unfortunately my 2555VH is about 400 miles away right now and I cannot go out to it and verify all this stuff I am telling you from memory. I can type you through the threading procedure if that is what you need but without access to my machine, and the fact that you have a different machine which may work differently although it looks the same to me, there will be some risk of error.

 

[GGaskill]

So I checked my machine and there is, in fact, an interlock that prevents engaging the half nuts when the feed selection (UC) lever is not in the middle position.