Learning to operate Manual Lathe for Basic Ring Machining 1

[MechEngineer2012]

Hello Engineers:

I am interested in acquiring the skill of operating a manual lathe and performing basic ring machining. This entails working with raw stock material, including additional material on the inner diameter (ID), outer diameter (OD), and length and machining it according to provided drawings, adhering to tolerances of +/- 0.001 inches on ID, OD and length.

The learning process would involve machining the ID, OD and length to match the specifications outlined in the drawing & cutting chamfers on the edges.

Considering your expertise, I would like to inquire whether it is feasible to cover this learning process within a single day. Will I be able to machine the ring next day If I am completely focused during training.

I can hire a machinist for a day & have him teach me. I understand the safety aspects and will definitely adhere to safety rules. The manual lathe is available. I am an Engineer who is looking to be more hand on. Thank you!

 

[ctopher]

Any machining skills will help you in your career. Good to know you're willing to learn safety. I have seen some horrible stuff in shops.
You may learn the basics in a day, but will take much longer to learn little details and other tricks using it.

Chris, CSWP
SolidWorks
ctophers home

 

[CWB1]

Many folks have learned the basics of machine work via YouTube and the operator's manual for their machine. Not sure if your "ring" is a wedding ring or a bushing/bearing, but I wouldnt count on making accurate parts by day 2. You can certainly learn the basics of operating a manual lathe in an hour or two but the specific part's complexity may require using some specialty tooling or techniques. Measuring accurately to 0.001" is similar, it may be a very straightforward task or very complex depending on the part and dimension being measured.

 

[EdStainless]

Is there a technical/trade school near you?
They may be willing to give you a short introduction course on lathe basics.
Or you might be able to hire one of their instructors to come to your site and give you basic training.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[tygerdawg]

I teach a course in Manufacturing Processes to Engineering students.
My philosophy is "We are not in the business of training Technicians, but educating future Engineers." If a student wishes to become a Journeyman Machinist, I suggest they go to a different school.

They get three lectures to learn the terminology & math of turning processes.
One lab is used to explore how to run a lathe and make a very forgiving plastic part. I don't grade on dimensional accuracy on what is most likely these student's very first time to touch a lathe. That would be stupid: it takes many hours of practice to become proficient at precision lathe operations.

Here's the end result of a very fun & entertaining lab experience: every one of those bores is supposed to be 0.7 inches in diameter.
It makes for a fun afternoon and the students learn a lot.

My lesson for the day to these future Engineers:

"If you have the time, equipment, inclination, and talent to be your own machinist, then go for it. Otherwise focus your efforts on being an Engineer and pay a qualified machinist to do it for you."

TygerDawg
Blue Technik LLC
Manufacturing Engineering Consulting

http://www.bluetechnik.com

 

[GregLocock]

I think you are better of going to a local tech college. 1 thou is certainly possible for a home machinist, although you'll struggle to measure the bore to that accuracy.






Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[mfgenggear]

MechEng
The answer is no.
It takes years of hands on practice.
One mistake can cost you a finger, or a hand or worst. Safety and the proper education on safety and proper operation. Now if your serious take a proper course in machining. Then have an experienced machinest that has lots of years experience mentor you.

Do not try to operate a lathe with self taught
Instructions. Like some one said bad incidence can happened.

 

[GregLocock]

"It takes years of hands on practice."
Um, no it doesn't. After 3 months of EP1 Workshop Skills we were building functional intricate assemblies of gears and screws and so on, using lathes, milling machines, boring machines, shapers, and grinding machines to make the parts. Admittedly in my case I'd already built a steam engine at home from castings, but not many of my workmates would have had access to a lathe at home. I'm not saying that we were qualified machinists by the end of that, but we knew more or less what we were doing, even if some of it was a bit monkey see monkey do.
.


Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[mfgenggear]

Greg
All it takes is one second to loose a finger.
Al I can say for you is good for you.
It depends on the complexity of parts.
Turning a 12 inch part VS a 1 inch part or a 3 ft long part. Takes different skills. I have seen operators lose all their hands. Even machinist with years of experience. 50 years of working in shops. That's right fifty years of working in shops. Do not tell a rookie newbie with one day of experience he can do it. Manual lathes are dangerous. With improper training. Sorry Greg I am calling you out.

 

[Artisi]

Having serve an apprenticeship as a fitter and turner probably before many members here were even born, I can say with a fair amount of certainty that to even understand the basic basics will take a lot more than a day, as for becoming proficient to actually machine something to a +- 0.001" tolerance forget it, that takes a lot of time and dedication and many disasters along the way.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[Sparweb]

I would encourage you to go ahead with your idea, to hire a machinist for a day to teach you these basics, and then to practice, practice, practice. I think it's a good idea and my only caution is to set realistic expectations. The machinist you work with should also share the same expectations - but it will only be worth your time if that machinist is well-prepared to teach you. If you just hire "a guy who knows how to use a lathe" then to two of you will waste a lot of time while he figures out what to show you.

The better suggestion made by EdStainless is to find a trade school that gives night classes and do that. I did that myself before buying my own lathe, and I know a LOT MORE about how to use it after about ~20 hours of formal training and countless hours of just using it. I make no pretense that I'm anything but a novice, though.

 

[enginesrus]

The plus minus .001. Remember both the machine and the machinist need to be capable to do that. And remember when you dial .001 on a cross slide on the average home owner type lathe it usually means that is .002 coming off the diameter. So you will either need a good dial indicator or digital readouts on the lathe, for a trainee to be productive it will be a necessity to have that DRO.
You will not want some old worn out world war 2 surplus machine to hold that tolerance, unless it has be rebuilt. You will need a fairly low hour newer machine.
If your going to machine aluminum, it should be fairly easy, the harder the material the more difficult.
How long will the parts be? The longer they are the more difficult holding the ID will be, and same with the OD. If they are large diameters like say in inches of 2.7 OD and 2.0 ID and say 2.0 long it should be fairly easy to do. You will need coolant, to help maintain the temperature.

 

[mfgenggear]

depending diameter can be very difficult to keep and maintain roundness, the type of material, and the heat treat required. in addition maintaining size. rings should be machine in a free state. 3 jaw chucks are not conducive to maintaining roundness. typically pie jaws produce better results. i would recommend a cnc lathe. typically can produce better results with less effort.

 

[kjoiner]

Hello,

What type of ring are you wanting to machine? Is this a ring for an industrial application or is this jewelry?

What type of material do you want to use? Every material has different machining characteristics.

What type of lathe do you have access to? Is this a smaller bench top lathe or a large machine? What is the condition of the lathe?

I would agree with others about the learning curve and safety. Depending on the lathe, there are a lot of controls although for beginning, operating the handwheels is the best place to start. Learning about the carriage and cross slide power feeds would come a little later.

Safety is the most important factor. Lathes don't necessarily look dangerous because the workpiece is turning rather than a cutter. They are not that loud either. As others have mentioned, however, a loose piece of clothing, hair or other items that become entangled in the machine can be tragic. I'm not trying to scare you but want you to be aware of this so you don't rush into a project without keeping safety in the front of all decisions.

Kyle

 

[MechEngineer2012]

Thanks to all for replying to this post.

Ring will be used as impeller wear ring.
Material 410 SST not heat treated.
ID 4.5", OD 5.0" Length 0.75".
Manual lathe.

 

[mfgenggear]

Ok look at turning from bar. If using a 3 jaw chuck. Have 1.5 inch excess. Chuck on the excess then face , drill bore and turn . Then part off.
Have mag base drop indicators. On both cross slides. Check the amount of back lash and wear.
Rings are one the most difficult to obtain roundness and size. Compensate for wear and back lash on the lath. In addition use soft Jaws and learn to true up by facing and boring. Don't recommend harden 3 Jaws. Good luck

 

[CWB1]

Sounds like a good first project, not terribly difficult but will teach you a few things about workholding and setting up different operations. Your part is reasonably stiff but one challenge will be maintaining both roundness/cylindricity and flatness across the ring as clamping and cutting forces will want to cause distortion. Another challenge is simply that stainless tends to work harden so you'll need to maintain a reasonably aggressive depth of cut and feed rate. Shallow cuts and/or slow feeds often cause the tool to rub the surface more than cut, causing work hardening.