Norman Patent Style Qctp

I made a similar set to the Norman patent for my 9" Hercus Lathe. The main difference is that mine doesn't have the flat on one side of the centre post. Quite easy to make, works well. Here are a couple of shots of it holding a tool post grinder.
PA191048a.jpg
PA191047a.jpg
 
the toolpost looks simple enough to make
the toolholders however..

you only need one toolpost and lots of toolholders

i would go for the pistontype
toolholders are very simple to make
and it gives you the opportunity to adapt the tool itself to work without a toolholder
 
The one in the picture posted by prasad looks like it would make a good tool post for a cross slide. So the tool post could be moved to either side of the spindle.
Is this one of the advantages vs a QCTP?

I am thinking of giving the upside down parting a try and noticed I cant easily move my tool post without using the compound dial to move the whole compound slide.
 
I made a QCTP using the Patterson plans, but I didn't put a radius on the holders -- I left 'em rectangular. Steel post and 6061 aluminum tool holders, used on a 7x12 mini lathe. I used my benchtop mill to make the tool holders. They are holding up fine.

The tool holders have a lot of "meat" around the mounting hole, so the hole can only be a few thousandths oversize -- much larger and it's difficult to squeeze it tight around the post. To make it a little easier, I drilled a 1/8" hole on the side opposite the slot, halfway between the edge of the holder and mounting hole. Then I cut another slot down to the 1/8" hole. The radius provides some stress relief -- no sharp corners at the bottom of the slot.
 
I made one of these. https://www.hobby-machinist.com/threads/tool-post-holder.69487/ It works good. Although I cut the slot on a mill/drill you can also cut the slot using a lathe. Chuck up the end mill in the lathe and with the tool holder mounted on the cross slide you move the cross slide to cut the slot. Search online for norman style tool post and you will get a bunch of hits. A fair number of forum members have made these and all seem to be pleased with the result.
 
Here is a design from Mikes Workshop. It features an expanding post, I used this design fro quite a while and it works really well, with a little imagination you could make it indexable.

mikesworkshop.weebly.com

Novel quick change tool post

There has been a number of designs of quick change toolpost (QCTP) that are based on a pillar, securely mounted on the top slide, onto which the tool holder slides and is then clamped to the post by...
mikesworkshop.weebly.com
 
That's the first one I have seen with the "quick change" lever- interesting, and eliminates the need for a separate wrench
However, a round post design might be more practical- the flat prevents you from rotating the unit easily, and the ability to rotate is essential I think
Mark
 
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It looks relatively simple without any traps for the beginner. Also it should work quite well. If you opt for the round post you will have no method of indexing, only presetting for height. However, with the flat on the side of the post it allows a form of indexing, as well as height setting. Good luck.
 
Creating indexing is fairly simple. I did a lot of research on this when I made mine thinking that indexing was some really difficult thing to achieve. What I found was all you have to do is machine indents in the base with a corresponding shape on the end of the height adjustment screw. The screw will sit in the indent. Something like this.

tool post holder round base.jpg
 
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