Lapping lathe ways?

[HMF]

This is a good thread, let's just keep it factual, rather than personal. If you guys disagree, that's cool, but let's leave out the ethnic stuff. I just want to make sure that there aren't any hard feelings.

 

[samthedog]

I did read your comment and I'm guessing if you've been doing this for forty years you are not a hobbyist. Taking anecdotal data and creating emphatic reasoning can be confusing to the beginner. How does a manuafacturer's way oil recommendation wear out the ways? I know this is a long way from oil soaked 500 grit under the saddle which no manufacturer would recommend. What tasks a person may perform on a lathe plays a part in all this. e.g. How often a person uses a file and how they use it, or how often does a person use emery cloth to take off the last .0005'. One important fact is how often you wipe down the ways, and another is how often do you apply the hydraulic fluid.

The apprentice says to me; Hey, cut me some slack, I'm just a beginner. I say; Okay, I can go with that, but tell me why you ignore my specific instructions? So I'm asking the question based on what the beginner needs to know. They already think my way isn't in a textbook and it's just something I've been doing for years, but that's because they never read the book. -Russ

Any oil is better than no oil at all and if I am machining cast iron, I use hydraulic oil instead of way oil as way oil is very tacky and does not flow away from the way wipers as well as hydraulic oil. I don't know if this results in grit under the wipers but I do notice thinner oil washing the dust away from the wipers.

This video here is very interesting:

I used mineral engine oil for years and did not notice any major wear. I figured the oil was cheap so I used lots of it. The more expensive the oil, the more stingy we tend to be with application.

Paul.

 

[Rustrp]

Do you have a suggestion for a better METRIC lathe?
I have had trouble finding a comparable lathe which is metric.

I understand you asking this as a better metric lathe when referring to Asian imports. There are quality metric imports from Europe.

 

[burdickjp]

I understand you asking this as a better metric lathe when referring to Asian imports. There are quality metric imports from Europe.

There are. I've yet to find one which is priced accessibly to a college student. That's where I was when I bought my mini lathe, and that was the point I was trying to make.
If a mini lathe owner had access to the tools necessary to grind or scrape the ways then they wouldn't necessarily be in the market for a mini lathe, would they?
I tore mine apart, cleaned it, adjusted what I could, and it was still behaving inconsistently. I lapped it and it behaved much better.

I don't think anyone is portraying the need to do this as being a GOOD thing, or that this is a GOOD fix. It's a corner condition and should be treated as such.

 

[burdickjp]

i have a LMS 3536 lathe I'd like to "tune up" a bit. I've seen You Tubes where some 500 grit in oil was brushed onto the ways, and the saddle slid back and forth to smooth/polish them.

Just wondering if this process would take off enough metal to screw up alignment. Maybe make one side higher than the other...or whatever...

Wouldn't think so, but just checking.

I'm not sure how different the 3536 is compared to the 7x mini lathes I'm familiar with. Can you take a picture of the cross slide saddle straps, the gibs, and the dovetails?
The saddle straps on my 7x were not at all straight, square, flat, or smooth. The gibs were similarly rough.
Put some effort into those and see how it behaves. Put as much effort into those as you can before taking anything abrasive to your bed.

 

[harrzack]

The 3536 is an 8.5" x 16" lathe - a bit more substantial (but still kinda a 'kit lathe') I did a lot of that tuning when I got it and may do more.
Here is a link to a post I made about machining a rib from the saddle - will give you a rough idea of the size.

http://bit.ly/2p1793V

Also check out my website (http://www.avrdev.net) as I show a number of views of the lathe.

 

[Rustrp]

There are. I've yet to find one which is priced accessibly to a college student.

Understood, and price is relative to just about everything. If it just happens to be that someone fell into a good deal on a quality lathe you say good for them, otherwise quality and price are relative. The same applies to the big lathes or any piece of metal working equipment.

 

[burdickjp]

The 3536 is an 8.5" x 16" lathe - a bit more substantial (but still kinda a 'kit lathe') I did a lot of that tuning when I got it and may do more.
Here is a link to a post I made about machining a rib from the saddle - will give you a rough idea of the size.

http://bit.ly/2p1793V

Also check out my website (http://www.avrdev.net) as I show a number of views of the lathe.

It looks like the saddle gibs design is the same as the 7x lathes.
Are you noticing thr saddle being tighter in some parts of the bed than others?

 

[Rustrp]

I used mineral engine oil for years and did not notice any major wear. I figured the oil was cheap so I used lots of it. The more expensive the oil, the more stingy we tend to be with application.

The only thing about this conversation that I'm having a hard time coming to grips with is this "I do not recommend way oils for small lathes, they can and will cause more wear than if using good old grade of hydraulic oil." and all it takes to clear it up is explain why.

I have a fair amount of knowledge on or in lubricants (no it's not my career field) but if you present hydraulic fluid/liquid as the lubrication medium do you mean the standard old pink we use in a Boeing B-52 and John Deere (older models) or the clear stuff that will burn your skin that we put in the T-43 (Boeing 737)? Water can be used as a hydraulic liquid too but I'm thinking that's not what is intended.

At the center and core of this discussion is how a person cares for the piece of machinery they are using. If you wipe the ways, use good practices for keeping them clean, follow the do's and don'ts, then the possibility of claiming one form of lubricant over another is minimalized. If a person doesn't have emphirical data to support their claim then it's no more important than someone with no knowledge on the topic. We go to great lengths in discussing the how to's of arriving at .0005" yet disregard lubricant engineering because we're too stingy/cheap to purchase a quality product. If you take an ounce of cast iron chips and dust and mix them in a quart of hydraulic fluid, then do the same with a quart of way oil, which lubricant suspends the chips the longest?

 

[samthedog]

At the center and core of this discussion is how a person cares for the piece of machinery they are using. If you wipe the ways, use good practices for keeping them clean, follow the do's and don'ts, then the possibility of claiming one form of lubricant over another is minimalized. If a person doesn't have emphirical data to support their claim then it's no more important than someone with no knowledge on the topic. We go to great lengths in discussing the how to's of arriving at .0005" yet disregard lubricant engineering because we're too stingy/cheap to purchase a quality product. If you take an ounce of cast iron chips and dust and mix them in a quart of hydraulic fluid, then do the same with a quart of way oil, which lubricant suspends the chips the longest?

Sorry, I should have specified hydraulic oil - not MEG as used in subsea oil and gas hydraulic systems. I have no dog in this fight as I use both way oil and hydraulic oil. I also have done a great deal of reserach on oils as I have had to make conversion charts for my machines from the 60's and early 70's to replace obsolete oils. My only point is that I find the bead that builds up in front of my rubber way wipers from hydraulic oil tends to displace the chips and dust as it's less tacky. This is anecdotal and at the end of the day, if the way wipers are doing their job this probably does not even matter.

No doubt the technology in lubrication is advancing each year but given the amount most of us use our machines we probably couldn't wear out our machines with the cheapest dollar store oils.

Paul.