I finally got sick and tired enough of the sloppy feel of the T-nut on my Aloris tool post and decided to make a “corrective” base to bridge the wallowed out compound on my South Bend Lathe. Any of you guys out there with a lathe that came from a High School shop class probably know the situation I was up against. The tool holder locked down alright MOST of the time, but I was never REALLY sure. Here’s a shot of the compound, and the damaged area:

The project was to build a T-slot nut with a tighter fit, and long enough to bridge the damaged area of the compound, so that it supported the nut and allowed for a good solid lock-down. I made it the full width of the tool post.

Machine T-slot Nut For Lathe Chuck

The composite pressing plate is a fixed casting machine accessory for formwork, jig and plate. Wide range of use, machine tools, molds, lathes, CNC and all kinds of metal cutting machine tools clamping, fixed workpiece, its clamping force is large, easy to use, safe and reliable. Features: -Saves time when setting your job on the milling machine -Large clamping force, simple structure and easy. Anchor your work into Smithy table slots with these nuts. Every shop should have a handful within reach. Note: Pricing is for one piece only. Note: the critical dimension is the slot opening at the table surface. 35-105 - 7/16' - Fits on Granite and Midas milling tables, 6' Rotary table. 35-110 - 1/2' - Fits on.

The machine work was pretty straight forward on the Bridgeport, due to a good Kurt vise, and some set-up fixtures. I had planned on whipping up a few extra for sale in the store, and took the time to make a couple of jigs to speed things up. I whipped up about a dozen, and plan on making some for the 9 Inch size lathes shortly.

Anchor your work into Smithy table slots with these nuts. Every shop should have a handful within reach. Note: Pricing is for one piece only. Note: the critical dimension is the slot opening at the table surface. 35-105 - 7/16' - Fits on Granite and Midas milling tables, 6' Rotary table. 35-110 - 1/2' - Fits on.
T-Slot Bolts For quicker setups than a separate T-slot nut and stud, slide these bolts into T-slot tracks on machine tool tables. T-Slot Nut and Setup Stud Kits For mounting items to your machine table, these kits contain the full system of necessary components.

I left the load bearing surface on the lower step of the nut ROUGH to add traction to the grab on the compound. I thought it might look like hack machine work, but it just looks like it means business. I tried a couple of “blueing” methods, with mixed results, and finally just decided on the old blacksmith’s oil quench blackening. I heated the nuts to cherry red, and quenched it in used motor oil. This has the added benifit of hardening the metal and blackening it too. I can’t tell you the Rockwell hardness, but the finish looks pretty darn good for something I’m never gonna see, anyway. It should protect it against corrosion too.
I have to do some research on heating temperature to make sure I’m getting hard enough, without getting it brittle, but I’ve tested them, and they seem perfect to me. I will fine tune the heating on the next batch, as these seem to have areas where the “black” is light in the areas where the rosebud got too close to the nut. Live and learn; I’m not a blacksmith.

The hardened studs are about a half inch long for the Aloris tool post and the Phase II I tried. I plan on trimming mine, but will probably ship the others out long for the final user to trim to fit. The 5/8″ studs are stout, like the hardened flange nuts. Lots better than the old setup I was using. It has a solid feel that you know is locked down every time.

These are in the store section, and will ship in a Priority Mail Small Flat Rate Box @ $4.95 regardless of quantity. This version is for the Aloris BXA size (Phase II 250-200 size), and should fit any offshore clone sold as BXA compatible. The 9 inch (AXA size) is in the work and will be available shortly.

All in all, a good project, and gave me some good experience for a future post on heat treating / blueing metal. More on that at a later date.

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Tooling for my Taig lathe

Part of the Making Stuff collection
by Douglas W. Jones
THE UNIVERSITYOF IOWADepartment of Computer Science

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The stock Taig toolpost is mounted using an Allan-head cap screw through thetoolpost into a square nut that fits the T-slot in the cross slide.This poses two problems.

Each time you need to adjust the screw, you need to fumble for anAllen wrench.
Attaching the toolpost to the lathe involves sliding a square nut intothe T-slot. If you do this while the nut is not attached to the toolpost, itis easy enough, but then you can't see the nut when you are trying to screw inthe hold-down screw. Alternatively, if you leave the nut on the end of thehold-down screw, you need to manipulate the nut, out of sight below thetoolpost, in order to get it to fit the T-slot.

I hunted for a better way, and found these two blog posts:

Irv Bakeland’s Extended Height T-slot Nut
Lew Bishop's Latest includes a toolpost modification.

Machine T-slot Nuts

I found Irv Bakeland's solution first; that inspired what I did. Only laterdid I discover that Lew Bishop had done almost the same thing.

As with Lew Bishop, I modified the hex head bolts used to clamp things to thecross slide. He did some of his work on a mill, where I used hand tools, butthe results are essentially the same:

Chuck each bolt in the lathe collet to face the end ofthe head, making the head thin enough to fit the T-slot.
Hand file opposing flats on the bolt head until the head is narrow enoughto fit in the T-slot.
Hand file flats on the side of the bolt shank so it fits in the T-slot.

Unlike Lew Bishop, who made lever-operated nuts to fit the top of his toolpost,I opted to use a simple wingnut working against a brass washer. This workswell enough that I don't see any reason to make anything more complex.

I've made a number of mounting bolts, in different lengths, and I've drilledseveral pieces of 1/2' aluminum bar stock to fit the bolts. These bolts andbars have served me very well as furniture for mounting various workpieces andtools on the lathe carriage. My first use for this furniture was in drillingthe toolpost to clear the new bolts.

The hole in the toolpost doesn't need to be perfectly centered, so my approachto drilling it out may be overkill, but here's what I did:

Suspend the toolpost between centers over the cross-slide, and clampthe tailstock ram in place. This holds the existing hole in the toolpostexactly on axis, and it holds the toolpost floating about 1/2 inch above thesurface of the cross slide.
Insert auxiliary posts in the cross-slide T-slots, one on each side of thetoolpost you're drilling. I used 1/2' aluminum bars that were drilled on axisand held down by some of my modified 1/4-20 T-slot bolts, but you could just aseasily use a pair of stock Taig toolposts for this, if you've got spares.
Use a C-clamp to loosely pinch the toolpost you're drilling between thetwo support posts. At this point, the supporting furniture is all loose,the only thing that is tight is the tailstock center holding the hole to beenlarged exactly on center. Also, lock the cross-slide. On the Taig, you dothis by tightening the middle cross-slide gib screw with an allen wrench about1/4 turn.
Gradually tighten the mounting bolts for the suport posts and theC-clamp. Give each screw or nut a turn until you feel a little resistance,then give each screw a bit more torque until you feel a bit more resistance,and so on. The idea is to tighten things gradually so that the centering ofth