Hi Kane – here, as they say, is one I made earlier!

Thread the piece of rod to fit the tool post stud and insert a handle with a nice knob. Make up a thick washer to fit between the bottom of the rod and the body of the tool post. Adjust the thickness of this washer by trial and error until the new "nut" is tight when in the position shown. ( Quite a small amount removed will make quite a difference to the position of the handle) The advantage of this method is that it is quick to use and you will never need to search for that spanner amongst the swarf or in your pocket or…..

What's more it is aesthetically pleasing – well I think so anyway!

Regards

Norman

Edited By NJH on 24/03/2013 21:15:15

Kane,

You may also need a spacer/washer to fit down the 'ole in the toolpost to ensure it is a snug fit on the toolpost stud. It may already be so, these generic types do vary.

If you can't get a 7/16" BSF nut without paying a fiver, PM me and I'll send you one.

Phil

John,

That sounds like a description of the standard Myford toolpost clamp, like this

Phil

Robbo.

You are quite correct, but my post actually started with "My S-7" etc.

John

Hi Kane,
If you want to know how much to reduce the thickness of the washer this is how to work it out.
This is for 7/16 BSF thread.
7/16 BSF is 18 TPI 1/18 = 0.0555"
So 1 degree of rotation of the nut is 1/(18 x 360) = 1/6480 = 0.00015432"
So for every degree you want the handle to move clockwise (Direction to tighten) remove 0.00015432" from the thickness of the washer. So if you wanted the handle to move 90 degrees clockwise you would need to make the washer thiner by 0.00015432 x 90 = 0.0138888"
(About 14 thou)
If you want to make a washer from scratch then the thickness needs to be
N x 0.0555" + A x 0.00015432"
N is any integer. A is the number of degrees you want the handle to move ANTICLOCKWISE from its position without any washer.

Les.

Hi Norman,
Like you I would have just have used the trial and error method. My main reason for this post was to get the OP to think about how things work (Threads in this case.) Threre was a comment earlier in this thread that someone had not thought about adding washers which made me think they did not even think about how a thread works. I thought showing the calculation would get them in the frame of mind to think about how things work when trying to solve a problem. I think that thinking this way is needed to work out the best way to do a job using the equipment available. A recent example of someone not thinking how something works was someone I know who had a problem with water leaking from a compression joint. He said he put PTFE tape around the thread. He had not thought that the olive makes the seal and the thread only holds the parts together.

Les.

Hi Kane,
I think I have the same QCTP as you have which I ftted to my Chester DB10G lathe. It looks the same and was sold by Chronos to fit a myford ML7 / S7 lathe. Next time I go down to my shed I will run a file over the bottom of one of the tool holders to see if it is hardened. If it is not you could file it down. If it is hardened you could face it off in you lathe using a carbide tool. Even if you do not have a 4 jaw chuck I think you could mount it using a 3 jaw chuck. Bare in mind that thinning the holder under the tool will weaken it to some extent nullifying your desire to use 3/8" tool bits to gain rigidity over 5/16"
I would have thought an your size of lathe 5/16" tooling would be rigid enough. There is no reason why you should not grind the top of an HSS tool to get the correct centre height. This would occure any way after sharpening the bit a number of times. It would not be a good idea to grind much off the top of a brazed tip carbide tool as it might leave the tip too thin. (You would not normaly take much off the top of a carbide tool when sharpenning.)

Les.

I does seem daft to me to have a handle at all on the fixing nut which just gets in the way. It's not as if you are moving the block every five minutes like you would a 4-way which seems to be where the idea came from.
From the earlier picture of a toolpost the holder locking nut which you do want to use every five minutes has a removable handle and the other doesn't – it's the wrong way round. I suggest you stick with the nut and if you really need to release it that often make a special spanner from a tight fitting socket. that you can leave on.

Bazyle,

Daft is a bit strong. It works for me. I often adjust the position of the tool, its easier than rotating the topslide, which involves loosening 2 sometimes awkward-to-get-to screws. I already have the lever and it has never got in the way. Anyway, the point was that the OP didn't have a nut but had the lever.

Rod