Plans - lathe tool post

It would seem that after grinding the tool a couple of times, the cutting height would be dropping down below center. Peter, That looks great, and I'll certainly try it, once I'm a bit more confident. Thanks for that link. Ah, that feature did not show in those pictures - but each tool has about ten or fifiteen thousanths of shim under them. The toolpost is deliberately done so a quarter inch tool is somewhat low, so shim is inserted under the tool. I like to make my turning tools with zero back rake, so when sharpened by grinding only on the front the height basically does not change at all.

A tool setup like this can be mated to a rocker type toolpost, because it can be removed, and re-installed, and the tools are all set right to the correct height. Slack the clamping bolt and turn to get whatever tool you want cutting from the set of four.

Obviously not designed for really heavy cuts but for a small machine, handy. Join Date Mar Location Calif. If you keep it simple, this general design is very practical and as only two critical dimensions need to be met, post OD and block ID, they are very easy to make. I put the height adjustment at the front for additional support and if you use HSS be sure to throw in 10 degrees or so of back rake into the tool blocks.

Because I have tons of it, I machined the post from B and the blocks from 1x1. I have been told that if you use a 1. To insure interchangeability, maybe someone with an Omni Post would be kind enough to measure and verify the exact dimensions. As a general source of scroungable materials, I like the B7 fasteners that are now commonly used in commercial construction, its and the stuff I have runs about R C This also allows you to use these holders on the side position with round tools, [ I often use mine for slotting screw heads with a slitting saw in the chuck ].

Set the holder in the milling machine and mill out the slots to the shaded dimensions in Fig. Mill all the holders at these settings. Change the cutter for the dovetail cutter and mill the slots out to 2. Test with the block or gauge for an easy fit. Remove from the miller, mark out and drill and tap the five top holes.

The hole for the height screw only requires tapping with a taper tap to allow the screw to wedge in the hole. The clamp screws can be anything to hand but if you have to purchase anything then allen screws make a satisfactory job of it. Figure 6 — Boring Toolholder These are made in exactly the same way and at the same time as the normal toolholders.

The difference comes when putting the hole in for the boring tool. Assemble the complete toolholder and fit it onto the lathe. Square the block up by holding it up to the face plate or a parallel bar in the chuck and tighten up. Fit the boring toolholder on in mid height position and lock.

Wind the crosslide in to the center line and grip a center drill in the three jaw chuck, center and drill through. To stop the block attempting to twist push the toolholder with the tail stock. If two different diameters are required turn the block over, line up with the drill in situ and redrill to the larger size.

Figure 6 — Parting Toolholder This is a special holder and needs to be made only if you use parting tool blades as opposed to square tools ground up to shape. These blades can be obtained in various sizes so make sure you have a stock before starting and amend the tool dimensions on the holder drawing if necessary. There is nothing more infuriating than to make a toolholder and then find out the blades or tips are obsolete! Face to length and mill slots and dovetail as previous holders.

The strips need to be at the bottom of the bottom face and the top of the top face as in Fig. This operation is for people without a swivel head miller or tilting vice, however if you have one it is still quicker than moving and then reclocking square. Mill the slot to depth and width so that the blade nearly slides in.

Change the cutter for an old or broken slot drill. Grind one flute back for clearance and grind the other to 15 degrees to suit to bottom edge on the blade and back off for clearance. This sounds very crude but for a one-off job, it is also very effective. Mill the bottom edge of the slot out until the tool is a nice slide fit. Reduce to final size after brazing the post to the baseplate. Also ensure that you centre-drill the top end of the post — this is essential for the finishing operation.

I brazed my assembly with the post up as in the photo below. Liberally position shaped lengths of brazing rod around the perimeter of the post and apply heat. What a mess! Note the centre-drilled hole on the top of the post. If you have access to a mill you may choose as I did to fly cut the bottom surface.

Otherwise, tidy the bottom of the assembly by rubbing with sandpaper set on a surface plate or sheet of glass. Mount the assembly into the workholding faceplate using Position A blue holes. Use a wobbler bar and the centre-drilled hole in the top of the toolpost to centre the work. Turn the post to final size and also turn out the boss around the post. The final thickness of the main part of the baseplate should be 8mm see plans.

I would also suggest aiming for as smooth a finish on the post as you can manage. This will make for a closer fit with the tool holder and also make it easier to adjust the height. The exact diameter of the post is not important as we will be making holders to fit. I mounted the blanks in my 4-jaw chuck and bored a hole close to the measured final dimension of the post. I then test fitted the bore of the tool holder on the post after each pass.

When I got to a tight sliding fit I stopped boring, and finished the inside of the bore with sandpaper. I used a 12mm end mill to mill the large slot in the toolholders. You may choose to make a lever or other fancy arrangement to clamp to the toolholder to the post — I chose a simple M8 capscrew as the allen key for this is the same as those on the tailstock, and is therefore always close to hand. The only real decision to make with the tool holders is which side to mount the clamping screw.

I made one of each, and find that each one is better suited to some operations. For example, if the clamp bolt is mounted on the left as per the pic below , the capscrew head can get in the way when boring. November While I do love my little lathe, the design could do with improvement in a couple of areas… in particular the topslide compound slide which often fouls the tailstock, does not help with rigidity even when locked , and adjusting it is a pain due to the four mounting screws and limited rotation.

Lastly, a QCPT would not help with one of the key design requirements: rigidity. Construction method — workholding faceplate There are many possible approaches to this, however I chose this slightly long-winded way because I felt it would produce the most accurate and tidy result.