Building a Solid Carriage Stop for my Lathe!

[widgitmaster]

Well, the one thing missing on my New lathe is a solid carriage stop, so I designed one in CAD!
First I had to reverse engineer the dimensions from the lathe so the clamping mechanism would work, and the position of the adjustable stop screws would not interfere with any other part of the lathe!

I decided on a five position indexing turret, which uses 5/16-24 UNF threaded screws!

When the CAD work was finished, I called Speedy Metals and ordered a 4"x4"x4" cube of solid grade-40 Cast Iron, along with a 2" dia x 3" long piece of 1018 steel, and a 3-foot piece of 5/16-24 threaded rod from McMaster Carr!

The Cast Iron cube cost me $30.63

[widgitmaster]

The first task was to square up the cube in the mill, using my 3" shell mill cutter.
The block was oversize 4.375"x4.375"x4.375", which is normal for cast Iron material.

After cutting 1/8" off one surface, I placed the cube in the mill vise so the newly machined surface was flat on the floor of the vise. Then I set up a couple parallels and a pair of L.S. Starrett Hold-Downs, to force the block downward onto the vise floor. Now when I machine the top surface, it will be perfectly parallel to the opposing surface!

Next I flipped the block 90° so the machined surfaces were between the vise jaws, this ensures the next cut will be perfectly perpendicular to the parallel surfaces!

Next I flipped the block 90° again, and carefully seated the parallel surfaces between the vise jaws, and took a finish cut on the 4th side to make it parallel & perpendicular to the rest!

This is the tricky part, as I need to get the next two surfaces milled square to the rest! To do this, I flipped the block again, and took a light cut across the top.
Then I turned it upside down, and rotated it 90°! The reason for this is on the last cut, only two surfaces were squared, as they were held between the vise jaws, so by rotating the part 90°, I have used the vise to correct the out of square condition of the block. Be sure you seat the block in the vise by wiggling it as you close it!


Now, by taking a cut on the top of the block, it will produce a nice parallel, perpendicular & square surface! Lastly, I flipped the block one more time, putting the perfect end down, and finished machining the last surface!

[widgitmaster]

For the next operation, I sprayed blue layout die on the block, and scribed accurate lines with my surface plate & height gage. Then I put the block back in the vise and picked my zero corners using an edge finder, and proceeded to bore the large diameter hole!

Well, that took too long to do in the mill, and I didn't have a long and ridged boring bar! So I decided to put the block in my lathe's 4-jaw chuck protected by little pieces of aluminum, and dialed in the bore center, and the face of the block. This ensures the bore is parallel & perpendicular to the block surfaces.

Now that it's all dialed in, I found a nice boring bar, and ground up a piece of carbide to make heavy cuts in cast iron! I ran the lathe at 150-RPM, as the block was so offset it would damage my spindle bearings at high speeds! The carriage feed rate was .0016"/Revolution.

Using a flood to control the dust, I proceeded to bore the 1.8125 Dia. hole 4" deep! By doing it in the lathe, my mill was free for me to work on other projects!

To be continued . . . . . .

[widgitmaster]

After studying the layout and CAD drawings, I decided it would be wasteful to just mill off all the material and turn it into useless chips!

So I added a few more lines so that I can use my bandsaw to cut out a couple large chunks of cast iron! With a nice 10-TPI bi-metal blade, cast iron is really easy to cut, but I will need a dust mask to protect my lungs!

When finished, I'll have a chunk of cast iron 1.6x1.5x4" and 1.1x.9x4", I'll use it on something neet!

I have ordered a 1" dia. Ball Endmill with a 3/4" shank, to mill all the fillet radius's on the inside corners, and a .500 radius corner rounding endmill for the outside corners.

[balsaman]

Nice job.

E

[widgitmaster]

Next I milled the .500R corner radius and all the steps for the clamping mechanism on the bottom of the block.

Then I positioned the block in my vise at 45°, and proceeded to mill the notch that sits on top of the Lathe's ways!

My 1st cut was to establish the .200" dimension from the edge near the large radius, then I set my DRO to zero in that axis. Now I moved the Z-Axis to increase the depth, until my calculated dimension over a .750" dia. pin was achieved!

Lastly, I band sawed more material off the block, and will wait for the .500R ball nose end mill to arrive so I can finish more surfaces!.

[widgitmaster]

Well, the UPS truck showed up with a package containing my 1" Dia Ball End mill! So now I can finish milling all the fillet radius's on the block!

The Ball endmill cost me $51.31 from Enco!

The CAD can supply many of the critical coordinates, and along with a little patience, all the radius's blended perfectly!

Next operation will require a rotary table!

[widgitmaster]

After dialing in the bore to the center of the rotary table, I dialed the bore to the center of the spindle!

Then I grabbed the same large endmill I have been using on the part, and made a counterbore and spotfaced the bore with the end of the endmill!

Then I switched endmills and started to work on the outer radius of the bore.

This took a little time, as there was a lot of material to remove, and I had to run the RPM low so the long endmill didn't squeal and annoy my neighbors!

When finished, I removed the part, deburred it slightly, and turned it over to dial in the opposite side!

This side was easier, as all I needed to do was mill the counterbore and spotface the bore!

Tomorrow I'll drill and counterbore the two holes for the clamping bolts!
Then I'll mill up a small strip of steel to be used as the clamp!

Then I'll have to turn the steel indexer, and knurl one end !

[Jason Marsha]

As usual great work! Keep those pics coming

Jason

[widgitmaster]

Originally Posted by Jason Marsha As usual great work! Keep those pics coming Jason

Thanks!

[widgitmaster]

Today I turned the index spindle and put a course knurl for easy turning by hand! Then I cut off the end I needed, and faced it to length, and chamfered the knurls.

Next, I need to drill and tap 5 equally spaced holes for 5/16-24 UNF

I have order a long reduced shank spiral point tap just for the task!

When I knurled the part, I made it extra long, so that I could make the collar to keep the index spindle in place. I will make that next!

Eric

[jcdillin]

That is just amazing how you can turn a block of cast iron into something like that. I can only hope to be able to learn how to be able to do beautiful work like that some day.

Thanks for sharing