Machining steel round outside diameter on vertical mill

[JimFromAZ]

The way I have done this operation on the past for similar parts is very simple.

On your rotary table use 2ea. 1,2,3 blocks set far enough apart to allow you to make the hole with clearance, set your work piece on top of the blocks and use the t-slots in the table with t-nuts and strap clamps to hold it down. Center up your work piece, clamp it down and drill a .500" hole in the center then change over to a small end mill 1/4" would be my preference and make laps inside the .500 hole checking at each lap the size of the hole until your have it the size you need.

Once you have your hole use a bushing to space it off the top of your table, you'll have to play with what you have; but I would use a 1,2,3 block with strap clamps to hold it down centered on your rotary table with a spacer or bushing and the work piece on the top with a bolt through into one of the threaded holes in the 1,2,3 block. once you have the piece centered up use the same end mill and clean up the OD.

That is how I performed this type operation before I had a larger selection of tooling to choose from.

Just as a thought; another way you could work the OD would be to remover the guard on your grinder place the piece on the arbor and tighten it up, turn it on and dress the OD with a file and flat stone...

Both ideas sound good to me, VW. Any thoughts on which rotary table you prefer? I see a few on Amazon for $200 to $300, mostly 6" tables. Thinking about an 8" rotary table, though. My mill bed is 7" deep x 28" wide. Thanks! Jim.

 

[JimFromAZ]

If the hole is 1/2" or below. Hold the ring on a bolt with a nut then hold the bolt thread in a pistol drill chuck then spin the ring over a linishing belt to clean up & add some chamfers. If the hole is above 1/2" then make a tube to suit the hole & the thread size.

Hey Parlo, this is one of my backup plans! Good idea! Jim.

 

[verbotenwhisky]

Both ideas sound good to me, VW. Any thoughts on which rotary table you prefer? I see a few on Amazon for $200 to $300, mostly 6" tables. Thinking about an 8" rotary table, though. My mill bed is 7" deep x 28" wide. Thanks! Jim.

I have a 10" vertex which is made in Taiwan which I like very much, I looked at a number of rotary tables before I bought it.

Although I have not messed with their rotary table, I have many Accusize tools which I like and they give good accurate service thus if I were looking I would consider their 8" rotary table. Additionally Best Equipment and Mophorn seem to have reasonable ratings and are likely the same table with different badges. The 8" Vertex will set you back 6 or 7 hundred, the Accusize 8" comes in around 4 or 5 hundred and the Best Equipment unit looks to be 2 to 3 hundred. If it were me I would buy an 8" for your machine size, it is easier to setup the hold downs on the larger table.

If you do not have a lathe or the money nor desire to buy a lathe currently, a rotary table for your mill is a very good investment. you likely already know this, but for the sake of saying it, I would invest the time to read the 3 & 4 star reviews for the less expensive models because those reviews will usually allow you a window into the price point.

 

[Larry$]

Any thoughts on which rotary table you prefer? I see a few on Amazon for $200 to $300, mostly 6" tables. Thinking about an 8" rotary table, though.

I have an 8" RT. It's the largest size I'd want to handle. I got one with 3 T slots to match the 8" chuck with through mounting. More T slots would be better for clamp mounting. By the time I clamp work an 8" table doesn't have a lot of room for the workpiece. I cast an aluminum 11" round, T slots in 8 places and bolt that onto the RT. Within limits you can do that to other sizes also. I made a MT arbor for the center of the table and use that to center the 3 jaw chuck by just closing the chuck jaws & bolting it down. I've also made center pins for the MT hole in the RT much like Blondihack's scheme. But I my toolmakers vice is also a quick & "dirty" way of holding a strap you want to do a radius around a hole on the end of a strap. Minimal setup time to make any radius.

Once set up I keep the center location on the DRO INC scale and use the ABS scale to offset for the required radius.
I bought the dividing plates at the time I got the RT but have rarely used them. I've only used the RT in the vertical position a few times. It can substitute for an Indexing head for some things. I have the footstock for it and again haven't used it very often.

 

[verbotenwhisky]

I have an 8" RT. It's the largest size I'd want to handle. I got one with 3 T slots to match the 8" chuck with through mounting. More T slots would be better for clamp mounting. By the time I clamp work an 8" table doesn't have a lot of room for the workpiece. I cast an aluminum 11" round, T slots in 8 places and bolt that onto the RT. Within limits you can do that to other sizes also. I made a MT arbor for the center of the table and use that to center the 3 jaw chuck by just closing the chuck jaws & bolting it down. I've also made center pins for the MT hole in the RT much like Blondihack's scheme. But I my toolmakers vice is also a quick & "dirty" way of holding a strap you want to do a radius around a hole on the end of a strap. Minimal setup time to make any radius.

Once set up I keep the center location on the DRO INC scale and use the ABS scale to offset for the required radius.
I bought the dividing plates at the time I got the RT but have rarely used them. I've only used the RT in the vertical position a few times. It can substitute for an Indexing head for some things. I have the footstock for it and again haven't used it very often.

Sounds like a nice setup. I know what you mean about all you can handle, the 10" I have is 110 pounds, I will get a "round to it" eventually and build a small cart with a small crane similar to a sky hook to deal with all my heavy stuff.

If you like your table please recommend the brand to JimFromAZ, he is looking for one, it'll give him additional information.

 

[Larry$]

If you like your table please recommend the brand to JimFromAZ

I have the Vertex 8" rotary table. No issues. I see there are reviews of the Vevor RTs on YT. Looked good and considerably cheaper. I don't know if Vevor sells the indexing plates for it or if the Vertex plates would fit. A bit of advice about using one of these: Don't try to use these as something to hog material off while cranking the table around. By the very nature of these tables there isn't a huge area of worm to worm gear contact. Take relatively light cuts and all is well. The worm shaft is eccentrically mounted I swings in & out of engagement with a ring on the input shaft. Be sure to lock the worm shaft in the fully engaged position before rotate cutting.
The scale has a vernier which allows very fine positioning. 360°, 60 minutes, 10± seconds of arch.

 

[verbotenwhisky]

I have the Vertex 8" rotary table. No issues. I see there are reviews of the Vevor RTs on YT. Looked good and considerably cheaper. I don't know if Vevor sells the indexing plates for it or if the Vertex plates would fit. A bit of advice about using one of these: Don't try to use these as something to hog material off while cranking the table around. By the very nature of these tables there isn't a huge area of worm to worm gear contact. Take relatively light cuts and all is well. The worm shaft is eccentrically mounted I swings in & out of engagement with a ring on the input shaft. Be sure to lock the worm shaft in the fully engaged position before rotate cutting.
The scale has a vernier which allows very fine positioning. 360°, 60 minutes, 10± seconds of arch.

Excellent points, I agree 100%

 

[Jimsehr]

Hi All,
I'm making giant steel washers for my bench grinder (one step in trying to eliminate vibration, and, yes, I'll dress the grinding wheels). These disks are 2.5" in diameter and I'm milling them to 0.250" thick on a manual PM-728VT. The next step is to mill a 0.625" center hole which should fit perfectly on the bench grinder axle.

Finally, I want to mill the outside diameter concentric with the center hole. The final diameter isn't critical but I imagine I probably need to remove 5 or 10 thou. I don't have a lathe, just the vertical mill. How do I mill the circumference? On a rotary table? If so, and assuming I now have that 0.625" center hole, is there a recommended way to mount this disk to the rotary table? Any suggestions other than a rotary table?

Thanks Everyone! Jim
View attachment 471817

If you can hold 5/8 stud in your mill‘s collet pinching washer with two nuts. You could put your washer on stud then fix a turning tool to table then turn od of washer by raising and lowering the table.

 

[verbotenwhisky]

If you can hold 5/8 stud in your mill‘s collet pinching washer with two nuts. You could put your washer on stud then fix a turning tool to table then turn od of washer by raising and lowering the table.

Or the quill....

Sharing something I said to another member...

If you have a bolt very close to the hole size with a counter sunk head then you could use that and tighten up against the back with a flat washer and nut (I would use a nylon lock nut) and the counter sunk head will center it then you can chuck that up in your mill or drill press and use a file.

Another trick I have used with my drill press (It was set up as a small mill) was to use the counter sunk bolt trick and fasten a small lathe tool into a drill press vise and turn it down that way, as long as you do not get aggressive this works and you can get these small lathe tools at Harbor Freight. Once you fasten the tool into the vise and your part into the chuck use your table to adjust the cut and your spindle to feed the part across the tool, take very light cuts and be careful.

 

[JimFromAZ]

I have a 10" vertex which is made in Taiwan which I like very much, I looked at a number of rotary tables before I bought it.

Although I have not messed with their rotary table, I have many Accusize tools which I like and they give good accurate service thus if I were looking I would consider their 8" rotary table. Additionally Best Equipment and Mophorn seem to have reasonable ratings and are likely the same table with different badges. The 8" Vertex will set you back 6 or 7 hundred, the Accusize 8" comes in around 4 or 5 hundred and the Best Equipment unit looks to be 2 to 3 hundred. If it were me I would buy an 8" for your machine size, it is easier to setup the hold downs on the larger table.

If you do not have a lathe or the money nor desire to buy a lathe currently, a rotary table for your mill is a very good investment. you likely already know this, but for the sake of saying it, I would invest the time to read the 3 & 4 star reviews for the less expensive models because those reviews will usually allow you a window into the price point.

Hi VW, thank you for all the great information and help with rotary table selection. Very helpful!