Is it doable?

[iron1951]

I am a newbie and my machine (new to me) is old and worn. It is an Atlas 618. M6-36A, the screw on carriage assembly (feed screw for lower swivel base) is in need of replacement along with the nut, M6-19A, needs replacement. The lead screw for the carriage is looking worn near the head too along with the half nut too

Starting with feed screw for the lower swivel base assembly, M6-36A, would my lathe be capable of cutting this thread? If yes, my next question is going to be how or could you direct me to some online information about acme thread cutting.

BTW I am not sure if this post belongs here or in the Atlas thread.

Thanks

 

[Sandro]

To answer your question, yes it's probably doable if you have a lot of patience. Acme threads can be trickier to cut compared to regular threads because of chatter, which can be caused from the large surface area of the thread. The lead screw can be turned around so the worn end is at the tailstock end of the lathe, though this may require one or both ends to be modified to fit.

A simpler, though not cheaper, solution may be to replace them with new screws. Factory original parts may be available if you search online, but standard sized Acme threaded rod is available. Reid Supply sells them, but again you would need to do some modifications to the ends of the screws to fit them to your lathe.

Hope this is some help. Let me know if I can help in any way.

Sandro Di Filippo

 

[xalky]

To answer your question, yes it's probably doable if you have a lot of patience. Acme threads can be trickier to cut compared to regular threads because of chatter, which can be caused from the large surface area of the thread. The lead screw can be turned around so the worn end is at the tailstock end of the lathe, though this may require one or both ends to be modified to fit.

A simpler, though not cheaper, solution may be to replace them with new screws. Factory original parts may be available if you search online, but standard sized Acme threaded rod is available. Reid Supply sells them, but again you would need to do some modifications to the ends of the screws to fit them to your lathe.

Hope this is some help. Let me know if I can help in any way.

Sandro Di Filippo

The prices aren't bad for what it is. I'd seriously consider purchasing rather than cutting my own at that price. Reworking the ends is way easier than cutting those acme threads. No matter what you have to do the ends.

 

[Splat]

If you decide to purchase you could try Joe @ Plaza Machinery. He's usually got lathe parts for different brands and though I've not dealt with him he's supposedly a stand-up guy. http://www.plazamachinery.com/

 

[Tom Griffin]

That would definitely not be a beginner's project. As pointed out, Acme threads are difficult to cut and trying to cut one on an Atlas would be even more difficult due to its lack of rigidity. Also, the lead screw is longer than the capacity of the lathe so it would need to be cut in several sections and you would need a follower rest to support the screw as it was being threaded. Your best bet would be to find a used one and Plaza Machinery would be a good source.

Tom

 

[GK1918]

As they say anything is possible, as for Acme threading, if you understand lathe threading, Acme
will be no different except you will need Acme gauge's example I somehow lost mine and got a
real Starrett new in package for $5 ebay. This gauge (fish) is a must have. I think your lathe will do
it just take light cuts, oil, and take your time try it with PVC. Check out MrPete222 on Utube on
acme threading very good presentation with excellent audio and vidio. No camara shakin like others
and noisy backgrouds. Or If you had a freind with a long bed for this lead screw?

 

[iron1951]

Thanks for all the replies, I gave much to think about. It seems that purchasing aprecision grade Acme threaded rod would be the best way to go. But the threads do not go the entire length of the screws ? What to do? Has anyone done this type of repair on the Atlas 618?

 

[Tom Griffin]

Thanks for all the replies, I gave much to think about. It seems that purchasing aprecision grade Acme threaded rod would be the best way to go. But the threads do not go the entire length of the screws ? What to do? Has anyone done this type of repair on the Atlas 618?

Just turn down the end of the threaded rod and press it into a bored hole in a piece of round stock. Make sure it's a press fit and it wouldn't hurt to cross pin it just to be safe.

Tom

 

[iron1951]

Thats what I am going to do. Turn down the end, drill and pin. Seems like McMaster-Carr is the best place to order the rod from. Have to see how they handle orders to Canada.

While I am doing this, I had seen a picture of a lathe with a handle at the end of the feed screw. Good idea or not?

Anthony

 

[Tom Griffin]

While I am doing this, I had seen a picture of a lathe with a handle at the end of the feed screw. Good idea or not?

Anthony

Anthony,

Take it one step further and mount a gear motor on the shaft with a variable speed drive. Then you'll have the same set-up as Hardinge uses for feed on their lathes.

Tom