Do you have a question on rebuilding I could help you with?

[Richard King 2]

Hello everyone,
For those who don't know me, I am a Journeyman Machine Tool Rebuilder and when Hobby Machinist started, I was this forums Moderator. I answered the members questions on all things mechanical repair of machines. As you can read I have been teaching people how to scrape and rebuild machines. I would be happy to help you. Just ask. If you want to see more about me I have a web site handscraping.com

Below are Some gifts I have receive from the Machine Tool Industry of Taiwan where I have taught a total of 3 years there in 20 years of trips. The other is from students in Austria. If you read my testimonials in my website you can see one from Timken bearing and Spinner machine a new machine builder in Germany and Turkey. Plus my Hobby Machinist student on here. Makes me proud when they write about what they learned!

 

[vocatexas]

Hello Mr. King. I was really hoping to take your Texas class in February but my schedule wouldn't allow. Are there any plans for another one next year?

 

[Richard King 2]

Steve Watkins has to decide on that. He is retired now and he and his wife have a big RV. One of the students in the last class lives in Austin and he said he wants to do one next year. If I am healthy and am asked. I would do it.
Rich.

 

[MontanaLon]

How much wear on lathe ways is too much? Keep in mind it will be for hobby use and not making parts for NASA. I've been looking at a lot of used lathes lately and the amount of wear on some has concerned me to the point I have passed on them. Most of them have been 60-70 years old and I expect some wear but at what point is the wear unrecoverable?

And assuming the wear isn't terminal, is there any benefit to flaking without scraping in slowing down the wear? If the purpose of flaking is to allow oil to hold on the surface of the part when the flaking is worn off is there any benefit to refreshing it?

 

[vocatexas]

That would be great if it happens. My county is the geographic center of Texas, so that would make the trip two hours as opposed to six for me. I'll be watching for the announcement!

 

[Richard King 2]

How much wear on lathe ways is too much? Keep in mind it will be for hobby use and not making parts for NASA. I've been looking at a lot of used lathes lately and the amount of wear on some has concerned me to the point I have passed on them. Most of them have been 60-70 years old and I expect some wear but at what point is the wear unrecoverable?

And assuming the wear isn't terminal, is there any benefit to flaking without scraping in slowing down the wear? If the purpose of flaking is to allow oil to hold on the surface of the part when the flaking is worn off is there any benefit to refreshing it?

You can see some real bargains if you wait. There is a simple method to check to see if a lathe is worn out and has a camouflaged fix that many used machine dealers do.. You look at the rack under the ways. if the teeth are the same size from front to back the machine has not been used much. If the rack near the front has sharp teeth, then pass on it. As far as accuracy goes. It depends on if you are going to use the lathe with and with-out the tailstock between centers. Or just do short work and drill with tail stock. I have seen some totally worn out machines turn a bit bigger by the chuck, but the operator files or emery clothes the big end. A quick and dirty way is to take a mag base and indicator with when you inspect the machine and mag it to the saddle front wing and indicator on ways reaching out as far to the front as you can reach. Then crank it toward the tailstock end. remember the wear on the saddle ways doubles as your turning one side. Another trick one can do is twist the bed out of level / alignment so it cuts straight if your only doing shorts. Be sure to run the machine and run it it in all the spindle speeds and feeds on quick change. not running it is like buying a car at a used dealers lot and not starting it and taking it for a test drive. If you are buying it in another city buy a cheap seat on an airplane and go test it. better safe then sorry. One can't trust many when it comes to selling used machines from folks. 1/2 moon flaking helps improve the lubrication. But remember many dealers flake the machines to camouflage worn out machines.

 

[Suzuki4evr]

Good day Mr. King
I have mill/drill machine and I am thinking of making a raiser block to get a bit more travel on my z-axis. I am wondering,can I use aluminium or must it be cast iron? Basically it will be a spacer and the head will not be moving on that part when I need to swing it over. The machine design is in such manner that I can make a spacer and just use longer bolts.








The reason for asking is that aluminium would be easier to come by in the size needed to manufadcture the spacer and easier and cleaner than cast iron,but cast iron would probably be better but harder to come by. I would appreciate your opinion on this.

Thank you
Michael

 

[Bob Korves]

FYI, that style machine in the photos is usually called a "knee mill", not a mill/drill. Using that nomenclature will help to avoid poor communication...

 

[Suzuki4evr]

Hi Bob.
I called it a mill/drill because of what is on the name plate. But sorry if I got the name wrong. Thanks Bob

 

[Bob Korves]

Not Richard, but here is my take on it. Aluminum has a lower modulus of elasticity than cast iron does, which means it flexes easier, and does not dampen vibration as well as cast iron, either. The head will not be as rigid after installing the spacer anyway, due to the longer path between table and head, and using aluminum for the spacer will just make it less rigid yet. How much that might impact your work depends on a lot of unknown things, like how you use the mill.