Checking for twist on Lathe and setting up round column mill

T Bredehoft said:
I can't knock Warner and his tools, but you will sometime need to know how to grind tools, Warner may not make inserts for your needs. Just don't become dependent upon commercial tools. Get some 1/4" square HSS tools and grind a couple of cutters. You'll benefit from the experience.
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Thanks T,

I just posted to Chewy that I was a grease monkey for a long time, and making my own would be great, and I would agree 100% with you getting and making my own cutters, thanks again
 
The Headstock to Tailstock will get you stared in the right direction. Twist or if the Tailstock is out of alignment side ways will get you cutting tapers and un-straight (?) pieces. That will take time and experimentation to correct. Lots of videos on how to do this. By the way, this not a one time and you are done, at least not to start.
I understand what you are asking about the mill. It doesn't matter. You can watch You Tube and see on real Bridgeports where they swing the head out back and forth and on angles to reach features. The head MUST NOT MOVE from where you have it. After that the mill table will cut perfectly straight in X or Y axis. Try this. Move your head about 5 degrees from straight and do some cutting. Everything should be OK. If you think you might be a degree or so from perfect, it doesn't matter.

I have AXA tool holder and just made an adaptor to hold HSS 1/4" It doesn't make much snse to me to grind an .028 wide cutter from 1/2" when 1/4" will do fine. The cutter is for E clips, .010 deep.
 
By the way, I was a grease monkey on heavy duty stuff for years. I learned my machining in small shops making my rush part myself when they were busy. They did the initial setup and figuring out and explaining. I did the job and paid them for the privlage of doing it. Bottom line was the customer paid and was happy and I learned a lot.

Try that these days!!!
 
A plumb bob is nowhere near as accurate as a precision level. My precision level has a sensitivity if .0005"/10"per division. A Starrett 199 level has a sensitivity of .0005"/12"per division. This is equivalent to about .0015" of movement for a 36" plumb bob. I doubt that anyone can visually defect a movement of .002". Even the Starrett 98 series levels have a sensitivity of .005"/12"per division which would be equivalent to a movement of .015" for a 36" plumb bob.

As to a reference surface for your level, I would just remove the compound and use the top of the cross slide.

There is no pressing need to level a mill. The tramming procedure would ensure that the spindle axis is perpendicular to whatever surface you are referencing. Usually, it is assumed that the surface of the table is parallel with the x and y axes and that surface is used. The parallel condition of the table to the ways can be checked by sweeping the surface with an indicator.
 
Chewy said:
The Headstock to Tailstock will get you stared in the right direction. Twist or if the Tailstock is out of alignment side ways will get you cutting tapers and un-straight (?) pieces. That will take time and experimentation to correct. Lots of videos on how to do this. By the way, this not a one time and you are done, at least not to start.
I understand what you are asking about the mill. It doesn't matter. You can watch You Tube and see on real Bridgeports where they swing the head out back and forth and on angles to reach features. The head MUST NOT MOVE from where you have it. After that the mill table will cut perfectly straight in X or Y axis. Try this. Move your head about 5 degrees from straight and do some cutting. Everything should be OK. If you think you might be a degree or so from perfect, it doesn't matter.

I have AXA tool holder and just made an adaptor to hold HSS 1/4" It doesn't make much snse to me to grind an .028 wide cutter from 1/2" when 1/4" will do fine. The cutter is for E clips, .010 deep.
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Thank you very much. appreciate all the advice. I will probably start working on all this during the week. I’ll keep you informed of how things are going and possibly any further advice. thanks again
 
DJS, 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
 
to 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.
 
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

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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.
 
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.
 
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