thanks, Ron, sorry I didn't get back to you sooner but have been very busy and waiting on different tooling and had to return some stuff. I just throw my first chips on the lathe yesterday and have still a lot of fine-tuning, will keep all you folks in the loopDJS, late but another tooling option. Invest in, or make on your mill, tangential tool holders. Then the tooling is easy to grind and generally only takes lapping not re-grinding, when dull. A piece of HHS lasts a long time because you don't have to Red grind for rake angles. I purchased Warner HHS inserts and tooling for threading. After some frustrating lessons on the correct tool orientation, am pretty pleased with it.
Ron
Thank you. I finally figured it out and got a Starret 98-4-4'' and its seems to be within a 1/4 bubble or less with shimming the tail end withto check the lathe bed for twist i used 2 four feet long straight edged aluminum extrusions . one on each of the lathe bed they will angle up . then a carpenter level across the ends of the straight edges . when the bed is level as indicated turn the level end for end and recheck. the reading projected 4 feet from the lathe bed and leveled should be dead on.
thanks Mickri. I have watched Joe-Pi, and the lazy machinist quite a bit and understand that twist and level are totally different. the level is not that important as long as it is in the same plain. but I did get most of the twist out when I got the Starret 98-4-4''. I currently have 1/4 bubble or less of twist indicated on the level.Everybody talks about making the bed level. The bed does not have to be level. What you are trying to get rid of is twist. Twist is different from level. The bed can be slanted front to back or end to end. The slant just has to be the same at each end of the bed. I think that Joe Pi has a video on this.
To tram your RF 31 make marks on the table centered on the quill that duplicates the column bolt pattern. Take a reading with your DI at each mark. Set the DI to zero at the biggest reading. Then measure each mark again. You will now know how much you need to shim each bolt to tram your mill/drill.
There are all kinds of contraptions that people spend hours making to bring the head of a round column mill/drill back into alignment if you have to move the head to change tooling. You can achieve the same result with DI. This is my set up
View attachment 371077
Put the magnetic base on the table so that the rod touches the quill. Set the DI to zero. Move the head to change the tooling. Now bring the head back till the quill touches the rod and the DI reads zero.
With careful planning you shouldn't have to move the head to change tooling. I call this the longest tool method. I got this from a video by the Lazy Machinist. Figure out the tooling you will need for a project. Then set the height of the head so that you can change tooling without moving the head. Where I think that people get into problems with changing tooling is that they want to switch between different types of tool holders. Typically switching between a drill chuck to hold drills and collets to hold end mills. Drill chucks take up a lot more space than collets. I only use ER32 collets on my mill/drill. Since switching to only using collets and using the longest tool method I have not had to move the head to change tooling.
Forget about using inserts. Your lathe was designed to be used with HSS tool bits. Read MIkey's thread on grinding tool bits. Use a belt sander to grind the tools bits. Way easier than fooling around with a bench grinder. Unlike inserts which have to be replaced often HSS tool bits last forever.
I run a round column Jet mill drill and never worry about setting the head exactly 90 to the table. It does not matter. Once it is locked the table is what moves and it will move correctly along X and Y. The only time round is an issue, as others have mentioned is when you change the height. I try to never have to adjust during a set up. When I do, you just have to get your edge finder out again and reset to your start point and go again. If you really feel the need to set it to 90 I would put a dial in the spindle. Center a vise in front of it and pivot the head. It is a radius so you will be able to see the highest/longest point on the dial when you are at the peak of the radius you are pivoting. If making a jig to hold it square, this is how I would initially set it. Otherwise truly no need. How that helps.
sorry didn't read this post yet, now I understand. THANKS!!!Tramming a round column isn't about making the head 90 to the table. It doesn't matter if the head is 90 to the table. It is about making the table and the head in parallel planes. When a mill is trammed no matter how you move the table or the head you will mill a flat surface because the plane of the table is parallel to the plane of the head. If the plane of the head and the plane of the table are not parallel than you won't be able to mill a flat surface. The end mill will cut an angle because it isn't square to the table. You will get ridges.
Thanks, I read these posts a little late.I run a round column Jet mill drill and never worry about setting the head exactly 90 to the table. It does not matter. Once it is locked the table is what moves and it will move correctly along X and Y. The only time round is an issue, as others have mentioned is when you change the height. I try to never have to adjust during a set up. When I do, you just have to get your edge finder out again and reset to your start point and go again. If you really feel the need to set it to 90 I would put a dial in the spindle. Center a vise in front of it and pivot the head. It is a radius so you will be able to see the highest/longest point on the dial when you are at the peak of the radius you are pivoting. If making a jig to hold it square, this is how I would initially set it. Otherwise truly no need. How that helps.
Thanks MM, but have more questions now. Obviously, I have to loosen, in my case the tailstock bolt. which then I have twist, but when all is said and done after shimming .042 and retightening the tailstock bolt. I had it set with about 1/4 bubble of .005 level from headstock to tailstock.This is a little late but another way of checking you are not introducing twist into the bed when you bolt it down is with the hold down bolts slacked off, grip a long bar in the chuck and put a dial indicator gauge on the tailstock end. Then tighten the holding down bolts. If you find any movement on the gauge then you might have to shim accordingly until there is no movement
Thanks very much for taking the time to explain that to me. I’ll YouTube and watch how they do the two collar test.Checking centre to centre will give you a rough idea, but a more accurate way is to machine two collars on a shaft about 10 inches apart. Once you are happy there is no twist in your bed try the following. You need a shaft at least 1 inch thick and machine it down so that the collars stand proud. Then take a finishing cut on both collars without changing your tool setting. Put the micrometer on both collars and compare diameters - if they differ then your tailstock is out, so set it until they are exactly the same. There may be folk with more experience than me who can suggest other methods, but it's what works for me. Hope it helps
