Usually the holes would intersect, and one of them would be tapped for a grubscrew. That is how it works on the ones I have inherited and made anyway.

John

Hi yes the cutter is clamped by a grub screw in the other hole which overlaps the cutter hole. You can set the cutter diameter by using a dial test indicator datum set on the boring bar and winding out the difference to set the bore diameter.

David

The 2 holes should just intersect each other .

One of those pieces of tool steel should then have a flat on the side.

This is used to act as a wedge against the cutting tool in the adjacent hole !

I have one the same and don't really like it as i find it difficult to adjust finely, its much easier to adjust and clamp with a couple of screws

TB is right. I have one of these and one hole holds the cutter while the other has piece that is flatted on one side in a slight taper. The cutter is wedged in place quite firmly but adjustment is tricky.

One of the ME books describes a gadget with a micrometer screw and presumably some sort of vee block that bears against the bar, so the screw can adjust the cutter by small amounts. Obviously applied between cuts. Can't remember where I saw it, Quorn book maybe?

Hello Mark,

It looks as if your boring bar is faulty, as others have said, do talk to Myford.

I don't like that type of boring bar, as I find it terribly difficult to adjust the tool accurately. I much prefer the type with a micrometer adjustment to set the tool protrusion. GHT gives a good design in his Workshop Manual. Another type is marketed by Hemingway Kits and doesn't take long to construct. In fact the kit makes up three boring bars of different diameters. If memory serves me correctly, the kit for three bars is about 50% more than the single bar from Myford.

I made up the Hemingway kit and was given a GHT boring bar as well! They are a joy to use, much easier than the Myford offering. Having said that, I am sure someone has found an easy way of adjusting tool protrusion on a simple between centres boring bar. It is just that I have not worked out how to do it!

Andrew.

If they do not possess a milling machine, perhaps to bore holes?

Seems a reasonable reason to me!

Ah, don't worry, that's two of us misunderstood!

Is the wedge in fact a taper pin and does it project from the bar? If so, this seems another disadvantage to this design as it will constrain the projection of the cutter – the bit that matters!

Hello Chris, thanks for pointing out that the bar is not faulty. I didn't realise that the cutter was secured by a wedge. That makes it even more difficult to adjust, unless you know of a good way. I would not give such a boring bar house room. The micrometer type is much, much better.

As an aside, I have a mill as well as a lathe. When boring cylinders. I much prefer to use the lathe and a between centres boring bar, providing that you can fit the cylinder on the cross slide. If the cylinder is too big to fit, I then use the mill as second best.

Andrew.

I can't remember if it's Sparey or Mason but the practice employed for setting the Myford Boring bar is to use a micrometer set to measure half the required bore and half the boring bar shaft diameter. I've found it is possible to gently tap the wedge piece to let go of the cutter slightly, then tap the cutter to the right position before re-wedging it tightly. The measurement is taken from the cutting tip of the cutter to opposite side of the bar. Not the most convenient set up but inexpensive.

Hi Guys,

This is a drawing of mine ! I made it to specifically adjust the cutter. The nice thing is that once used its easy to set the cutter to increase the depth accurately.

It was designed for a upto 20 mm diameter boring bar. It works quite well on a smaller diameter bar as well. Otherwise just adjust dimensions to suit your bar.