Router Turned Grinder - Question(s)

[4GSR]

This Lodge & Shipley lathe started out with over .030" wear in the first 3 to 4 foot of the ways. These ways are harden and ground. Today, with the rebuild complete, I only get .0015" in taper IN 12", WITHOUT using a tailstock. The test piece I used was 3-1/4" diameter x 18" long piece of ductile iron. Now, is that good? It is darn good!!!
Yeah, the method I used is non-traditional, but used in special situations where grinding/planning equipment is not available or just cannot be used. In my case, this beast is in my two car garage! I have no 5 ton over head crane to service this lathe nor can I use a engine hoist to work on it. Yeah, I know, we do some of the darndest things in our garage workshops, and my is no exception!

I come from a heavy background of machine tool rebuilding, repairing, that I've done over the years in my past. My dad did it for a living, too back when he was alive. I've been rebuilding basically manual lathes and mills since I was about 14 years old. Still have a couple years to go before I can retire! Been running a lathe since I was 10 year old. Been around all types of NC, CNC machine tools most of my life, too. I will tell others, I cannot program or run a CNC machine tool today! I have brothers that do that! I can tell you a lot about certain ones I've dealt with over the years.

My primary job is right now is designing/engineering of down hole completion and service equipment for the oilfield industry. The word "Fracking", well I'm behind some of that equipment used for this process. I've been in this profession since 1982, not by choice but for survival back in 1982 and been in it since then. The machine tool rebuilding took a backseat up until about 15 years ago and started playing again.

Back in my earlier years, the man I worked for was a family friend of my dads. He was putting together specialized machines for use in the oilfield drilling tool industry. My job was pretty much a project coordinator on getting these machines built. I took care of getting the machine tool beds re-planed if needed, and remember, some of these beds were over 60 to 100 feet long in nature. Complete machine may weigh upward toward 250K lbs.! I made parts, had parts made, sourced and bought all hardware, power transmission equipment, electrical, you name it for building or retrofitting an existing machine with. I do have some experience running a planer back in my earlier years doing some rebuilding work on some of the machines in my past.

To be continued...

 

[4GSR]

Getting back to the Lodge & Shipley Lathe...

Everyone is asking about how did I establish alignment on the bedways for regrinding? It was simple, I use planes or surfaces that had no wear, BUT were ground at the same time the bed ways was ground at the factory. Those surfaces were the top of the ways and the outside edge or vertical surface on the front of the ways. I carefully honed these surfaces lightly to remove any dings, bruises, so it would not leave any "bumps" in the grinding process. Surprisingly, these surfaces were nearly spotless!
The grinding process did not grind the full way surface in one setup. I wound up with a section of bedway about 12-15" long at the tailstock end that did not get ground in the first setup. I had to flip the sled setup to finish the tail end. I did not get the finish as I wanted on the grinding but is acceptable. I came back after grinding and honed the ground surface with mineral spirits and oilstone and improve the finish slightly.
The lathe is functional and will give someone many years to come, good job of work done on this lathe. I don't encourage anyone to take on such a task as I did here, unless you totally understand what you are doing. Do I know what I'm doing here? Well many who have spoken don't think I do. Would I do this again? Absolutely! But I'm not going to. This is my last major rebuild here. I'm reconditioning a 15" Sheldon lathe now that has a fairly nice bed on it with almost zero wear on it. So I won't be grinding the bed on this one or any other bed in the future!

One more thing to add... Don't use a router like I did. That old Rockwell router I had, had a lot of vibration to it, even though it didn't show up in the grinding process. Actually the fixture was beefy enough to absorb most of the vibration. What I would suggest is using one of the water/air cooled VFD run high speed motors you see advertised on eBay. At the time I started this project, they were not popular as they are now. Last, I did have a diamond dresser set up to keep the grinding wheel running true. I used a compound, cross slide, saddle off of a 9" South Bend lathe in the design of the grinding fixture.