Boring Bar Holder

I recently harvested a nice new Kennametal 1.5" dia. Coolant Through Boring Bar off of eBay for about 10% of it's retail cost. I needed the bar for an upcoming job of turning bushings from 5" 4140 pre hard tubing. I'm not a fan of wimpy boring bars!

First a piece of 3 1/5" 1018 square bar is trimmed to size using the Band Saw. This is a vertical Band Saw with a traveling table so it can be used for cut off operations. It has a 12" capacity.

The block is then Face Milled to both clean it up and square it up. Love those face Mills!

A 5/8" hole is then drilled through the block for the mounting stud that holds it to the compound slide of the Lathe. The hole is then chamfered.

Two 9/16" vertical holes are drilled half way through the block and then tapped 5/8 18 to a depth of 5/8" to accomodate large set screws that will push against bronze wedges to lock the bar in place.

The taper being cut on the bronze wedge at a 30° angle using the mill. Two Wedges will be dropped in the vertical holes with large Set Screws installed after them. When the Set Screws are tightened, they will push the Wedges against the side of the Boring Bar forcing the Boring Bar against the bore in the holder and locking it in position.

The Wedges being parted off. One on each end of the bar.

The block installed on the compound and being squared up to the spindle axis prior to boring.

Using an edge finder to find the edge so I can move in a specific distance for drilling and boring.

Center drilling in preperation for pilot drilling.

A 3/8 pilot drill being pushed through in preparation for boring the hole for the bar.

A 1" drill being pushed through. Note the coolant now entering from the back side.

The rough boring is done on the Lathe after the 1" drill was used.

I moved it to the Jig Borer as I needed to be working on another job, and it runs a lot beter and safer with less supervision than the Lathe does.

The last few thousandths are honed from the bore for final sizing. Not really necessary, but I like the finish and had the machine, so I did!

The Wedges ready to drop in and install the set screws to lock the bar in place.

The finished Tool Holder and Boring Bar with the coolant hose connected to it ready to go to work. That's the piece of tubing standing behind it.

Thanks!!

Glenn

Mounting an 8" Adjustable Chuck on a D1-5 Camlock Spindle

About six years ago I bought an 8" 3 jaw chuck for my 12" bench lathe as I had run into an occasion where the 6" chuck would not hold the part I needed to turn. I found it in an MSC "Inventory Blowout" sales flyer for $119.00 and it was listed as an Import 8" three jaw self centering chuck with two piece jaws so I ordered one. Much to my surprise, it turned out to be an Adjustable or Set True type chuck. I never got around to mounting it on my 12" lathe and forgot I had it. About a year ago I ran accross it sitting on a shelf with the box nearly rotted off of it so I decided I'd mount it on my 14" lathe so I set out to find an adapter plate for it to fit my D1-5 Camlock spindle. I measured the chuck and it was 8.3" in diameter and The only D1-5 plates I could find were exactly 8" which would place the mounting bolt holes right on the edge of the plate. I made lots of phone calls and finally identified the chuck as being made by Phase II so I tracked them down. It turns out that they never madeany adapter plates for it as it was a replacement chuck for a Super Spacer. My only option then was to buy a 10" adapter late and machine it down. I ordered a cheap Import plate for around $75.00 and set it on the shelf with the chuck and never got around to mounting it as I have a couple of 6 jw Set-Tru chucks that I use. I now have a little project that would benefit from using soft jaws so I figured I'd mount it up and use it to save wear on my good chucks.

Hope this info is of use to someone!



















Here's the 8" 3 jaw and 10" adapter plate. The adapter plate looks more like a brake rotor and I have no idea wht those six 10mm tapped holes are for> The box had been opened when I got it so possibly someone else put them in there for some silly reason and then returned it!




















The next step is to remove the existing chuck from the spindle. I always place a block of wood under a chuck befor I loosen it, so if (when) it falls off it won't ding up the bed ways or my fingers.

This is what a D1-5 Cam Lock Spindle looks like with tha chuck removed.

Now the new 10" Adapter Plate is installed using a wood block as described above. Amazingly enough, the runout was only .0003". I removed it and installed it a few timesand every time it was .0003-.0005" so it seems to seat fairly well against the spindle.

Next the centering boss for the chuck needed to be turned down a couple of inches for the chuck to fit over it. .250” depth of cut @315 rpm on a 6.5” diameter=HOT CHIPS!!

Then it needed to be shortened up about ¼”. Those goofy holes are in the way, but it will still work just fine other than the interrupted cut.

Now it gets faced off. Not a bad finish for cast iron!

The large OD it turned down to match the diameter of the chuck. A little chamfering, and we’re good to go. Too bad those six tapped holes were there, but it will still work just fine.

Next the plate was removed from the spindle and set up on the Super Spacer for drilling and tapping the mounting holes for the chuck. I centered the spindle over the Super Spacer using a test indicator and a piece of ground rod in the chuck since this is not going to the Space Station. The holes were drilled and chamfered. This is the side of the adapter plate that fits onto the spindle. These pins plug into the spindle nose and secure the adapter plate/chuck to the spindle.

And then tapped for the 10mm X 1mm bolts.

Ready to bolt the chuck to it. This is the side that plugs into the lathe spindle.

Here is the Adapter Plate bolted to the Chuck and ready to plug into the lathe spindle.

The Chuck bolted onto the Adapter Plate and the assembly is plugged into the spindle ready to be indicated in.

I got the silly thing to adjust down to a little under .0002” total run out and it held for three consecutive loosening and tightening of the jaws.

That’s it!

It’s ready to use.

Thanks for looking!

Glenn

Extended Tool Post

I needed to do a job that required a small face grooving tool with a very long reach due to the size and shape of the part, a housing. The housing to be re-grooved was within 1/8” of contacting the bed ways on my 14” swing lathe and the carriage contacted the end of housing way before I could reach it with a tool. Turning the compound parallel with the z axis and using it’s full travel still left the tool well short of the groove, so……I decided to make an extended Tool Holder to use in place of my Tool Post.
I grabbed a 6” long piece of 2.5” square 1018 steel bar and squared it up in the mill using a 3” face mill and skimmed .005” off of the sides.

Probably not the correct way, but the ends were then skimmed using an angle plate and a machinist’s square for setup.

Next, I drilled it to accept the 5/8” mounting stud on the compound slide that normally holds the QCTP in place.

Then chamferred it.

Since the QCTP is taller, I needed to make a spacer to go on the stud so I didn’t run out of thread for the nut that will hold it in place. 2 1/4" steel round bar was used.

I cut a little relief on the underside of the spacer so it would distribute the load a little nicer when the nut was tightened.

Next, I attached it to the Compound and indicated it parallel to the Z travel so it would be easy to setup in the future.

I then located the edge with an edge finder, moved in .400” and drilled a 15/32” hole to accept the required grooving tool.

Then the bore was finished using a .500” Jig Reamer which leaves a very accurate nearly mirror finish bore.

Next it’s back to the mill for drilling and taping for set screws to lock the tool in place.

I then ground up a face grooving tool from an old boring bar and assembled the whole deal. The bore size is perfect as when you push the tool in the air pressure behind it pops it back out and when you get it to stay in, the suction draws it back in when you try to pull it out!

The housing is in the chuck and indicated in and we’re ready to groove! (Actually enlarge an existing groove) You can see how the new tool holder just reaches around the housing and places the grooving tool right where it needs to be with PLENTY of rigidity. I originally thought about tapering the new tool holder and rounding the edges so it didn’t look like a block of steel, but the way it is, if I cross drill the hole for the mounting stud I can rotate it and have four more surfaces to attach various cutters to it if needed in the future.

You can see above, by looking in the right lower corner of the image, just how close the carriage is to the housing even when using the extension.

Thanks for looking!!

Glenn