Member postings for John Reese

Most of the commercial tap guides have a reversible spindle. One end has a female taper, the other a male taper. Thatway it can be used with any tap. There are many on-line sources.

It is too bad the broken tap fragment is loose in the hole. If it were tight I would suggest a 3mm diamond core bit from Banggood The sets of core drills are dirt cheap so it would be worthwhile to keep a couple on hand. The diamonds are plated on so they will not take much abuse.

I recently did a 3/4-4 Acme. I hand ground the tool bit. The bar I used was 1/2". There was insufficient clearance for me to open the half nuts and crank the tool out. I had to leave the half nuts engaged, back the tool out a bit using the crossslide and run the spindle in reverse to get back to my starting point. With the that small a bar and the very coarse pitch it required MANY spring passes to complete the thread.

Be sure you have sufficient clearance on the proper side of the tool. Calculate the helix angle based on the minor diameter of the thread and add a few degrees to that to get the necessary clearance angle for the leading edge of the tool. The trailing edge of the tool need not have any clearance.

It resembles a Kalamazoo indexer. I have one suggestion for an improvement: Mill or grind flats on the sides parallel with the rotation axis. That will allow it to be held in the vise.

I made my clamps from aluminum. The underside is rebated leaving about a 1/4" heel to contact the table. The screw was located as close to the vise as possible.

I have a large amount of cast iron welding rod (R-CI). It is about 3/16" dia. The finish is sand cast and the halve are slightly offset (mold mismatch). I don't see how they could be used for anything but welding. If you need a smooth cast iron rod I suggest you find a larger diameter and set up a hollow mill on the lathe to reduce the diameter.

Is your threading tool with a sharp point? That would require a greater depth of thread than a tool made with a flat equal to pitch/8.

First make a gauge that matches your spindle exactly. Use that gauge to check your internal thread.

The critical dimensions are the length and diameter of the cylindrical pilot and the OD and pitch diameter of the thread. You can tolerate a relief groove at the end of the threads as long as the pilot diameter isn't touched.

Save the gauge to use on future projects.

I found a coupe on flea bay. Here is a link.ebay.com/itm/Milling-Machine-Part-New-Forward-Reverse-Switch

I purchased one The contacts are rather small so I suspect life will be short if switched between fwd and rev as in tapping.

Check out This Old Tony on you tube. He had a video about building one.

Here is the source of my recommendation:

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From Machine Design Magazine: Surface hardness 58C, 16minRa finish.

Rough machine leaving grins stock. Harden. Grind between centers. Touch up keyseats using a carbide end mill.

Alternative: If 60 case rod is available in the right diameter use it and mill the keyseats with carbide.

I have successfully soft soldered Oilite. Being a porous material it could continue to absorb solder as long as I kept feeding it. Needless to say, the the soldered material was no longer oil absorbent.

When I made my tangential holders I used 12* for side clearance and end clearance for a 1/4" bit. After seeing the quality of finish produced by the round bit I will be making a tsngential holder for a round bit.

I had a Pratt & Whitney 14 x 30 that had identical feeds in X and Z.

My other lathes, 13 x 30 Clausing Metosa and Nardini 16 x 40, had X feed equal to half the Z feed. All three machines had a drive rod for the power feeds separate from the lead screw.

My South Bend 10K has a keyway the full length of the leadscrew. That allows the lead screw to act as a drive rod for the feeds. There is an interlock to prevent the half nuts being engaged when the feeds are being used.

I am in the US and the Pratt & Whitney lathe had a Buck and Hickman property tag on it. I am guessing it was shipped to England in the early 1940s. What surprised me is that it made it back to the US.

I have an old Sky Hook. I use it occasionally to put the vise or rotary table on or off the mill. It is inconvenient to set up. I had considered using it on the lathe to handle the 60 lb. chucks. It seemed like too much bother to lift the hoist into position every time I needed to change a chuck. I had a jib crane that mounts to the receiver for the trailer hitch.

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I made a pedestal for it that is anchored to the floor. It handles the chucks quite nicely.

I usually work bare handed. I learned the hard way about gloves and machinery. My left hand is mangled due to wearing gloves when using a table saw.

Oops! I forgot you said square stock. A sleeve that fits the square corner to corner is needed if using a steady rest.

Tap the outboard end until it runs true. Center drill it. Set the center in the end of the bar, then go back anf true up the chuck end.

Option: center the outboard end with a steady rest before center drilling.

Are you sure your chuck is tight against the shoulder of the spindle? (Only if you have a threaded spindle.

My way of assuring the hole is true is to pilot drill, then open the hole with an end mill, then drill it out to the correct size. The end mill is short and rigid so it barely deflects. Its square end will not tend to follow the pilot hole. I think of the end mill as a poor man's jig bore reamer.