trying for an elegant and effective quick change tool post

[Lew Hartswick]

Come on Keith and Jack, that is the kind of responses I'd expect on PM site.
Everyone there is a "professional" machinist. Us tinkerers like to play with
the machines. :-) Even build for $50 dollars what could be bought for $5.
:-)
...lew...

[Roundrocktom]

Then again some of us like the challenge.... I'm of the opinion you can not have enough quick change tool holders.

[Shade Tree Welder]

Originally Posted by burdickjp

That's not something I'd expect to read on a forum about fabrication...

It is a point of view thing, hobby work vs. making a living work. I closed my
fab shop in '08; took a few years to enjoy being in the shop as a hobby. You
do things, and think differently when you need to get paid for your time versus
the enjoyment of the time.

Originally Posted by burdickjp

I finished out my initial idea. Things changed: perpendicular and parallel
through screws are now centered and intersect, so you get one or the other,
but not both. This puts the t-slot nut centered between the two rods. The tool
post stud is offset. There's a screw and two thumb nuts to locate the tool
holder vertically. The vertical locating screw is M6. The screws holding the
rods to the tool post are M4. The through screw is M10. It'd be nice to reduce
the tooling requirement to as few tools as possible.

My only suggestion is to move the height adjust to the middle of the block
having it to one side you will risk having a cant on your tool.

[Shade Tree Welder]

Originally Posted by Roundrocktom

...half the fun is making something. I'm in the
shop for pleasure work. ,Not my daily job, but
something I enjoy.

Having been on both sides of that equation, it is
a much bigger difference than you might think.

[LKeithR]

Originally Posted by Lew Hartswick

Come on Keith and Jack, that is the kind of responses I'd expect on PM site. Everyone there is a "professional" machinist. Us tinkerers like to play with the machines. :-) Even build for $50 dollars what could be bought for $5...

Well, I'm no "professional" machinist--it's a supplement to our main business of welding and fabricating--but I'm still working so I have to consider the "value" of every hour I spend in the shop. As I said before, it just doesn't make sense to be "making" tooling I can buy off the shelf, especially when I know I can't make stuff as cost-efficiently as I can buy it. In our case it's really a moot point since I have a Multi-Fix style toolpost (wouldn't have anything else) on my lathe and toolholders would be very difficult to make anyway.

Some day, when I quit "working", I'm sure I'll be more inclined to make some of my own tooling but I'll bet that 45 plus years of "buy rather than build" will be a hard habit to break. In any case, I have no doubt that I'll be able to keep as "busy" as I want to till the day I die...

[platypus20]

Originally Posted by Lew Hartswick

Come on Keith and Jack, that is the kind of responses I'd expect on PM site.
Everyone there is a "professional" machinist. Us tinkerers like to play with
the machines. :-) Even build for $50 dollars what could be bought for $5.
:-)
...lew...

Lew,

I could give you a couple of PM quality responses, but I try not to stoop that low.

As to the building a QCTP, why bother, when you can by new blocks from CDCO for $9-$25/ea, depending on size. I use the wedge type AXA (100 series) QCTP, used on the Phase II (sold through the swapsheet), the Aloris (sold to LW) and now on the Dorian, they all fit and work perfectly, for $9/ea. At times it pays to make tooling, other times it doesn't. I can have more blocks here in about 2-3 days, as many as I want, all the same, they are so cheap, I don't remove the tool, I leave it set up for the next time, just grab another block, load that, then keep that in hot standby.

I've known about 50 people who just HAD to make their own QCTP, all of them saw their folly, eventfully and now use a bought QCTP system.


http://cdcotools.com/


below the 50 or so loaded and ready.

[GWIZ]

If I wanted too get more machine time in, the route I would take is make a tool-post that will accept off the shelf tool holders.

[Roundrocktom]

Oh MY! When I made mine, Aloris was still in the $$$ range per tool holder. $200-$300 type price. Even with five hours into a tool holder, it was cheaper to make than buy.

The knock offs on Enco are in $80 to $120 range. Hmm, but I've gotten faster at making them.

CDCO.... $17! It's been so long I don't remember if I need CA or CXA tooling. Hell, I might splurge and buy more of them as they are made of "high strength steel" and tool blackened. Mine just get a patina of rust over 1045. Edit.... limited C size tooling.

When you can buy a post and set of tools for $100... damn, just buy them and get back to turning metal.

Meanwhile for my CNC Router.... it was much better to build ($5K) than versus a commercial machine ($15K). 4' x 4' bed with 8" Z height. I suck at wood carving, so this is kinda of cool.

[platypus20]

Don't get me wrong, I think what Lew did is exceptional, I couldn't justify the time involved and along with the current pricing, I got too much else to do.

[burdickjp]

Some of the import QCTPs are looking more appealing. Thanks for the links!

So I finally got some dimensions for my cross-slide and immediately trashed my initial design. It just plain would not fit. Here's round 2.

Things changed:
The T-slot is now in the tool post block rather than the holder. Holders are now simpler!
There is now a short (20mm) socket-head cap screw between the tool holder and the T-slot nut. It being shorter will reduce flexing compared to a longer screw.
The tool holder has 8mm thick flanges for securing tools.

Bad things I'm seeing now:
The tool sits quite a bit below the T-slot nut
Vertical travel is very short
Larger tooling will exacerbate the above problems

Changes I'm investigating:
making everything smaller: 8mm rod instead of 10mm. M8 securing screw instead of M10. 10mm T-slot nut instead of 12mm.