Hf qctp

[gweloboy]

Has anyone used the Harbor Freight QCTP?
Will it work on a 9" SB?

Cheers

[gellfex]

I think this unit is small for your lathe. You'd be better off with a Phase II AXA, not that much more $ and much better made and accurate. I had a cheaper grade import before getting the Phase II and the difference was notable.

[Illinoyance]

+1 on Phase II. Get the wedge type.

[ken]

spend the few extra bucks and buy something better then the HF tool post. I bought one once it will work but they are rough Ken

[PStechPaul]

Here is the link to the HF QCTP:

http://www.harborfreight.com/quick-change-tool-post-set-for-mini-lathe-42806.html

It seems to be made for the mini-lathe, which is like a 7x10 or 7x12.

[danlb]

I had one 10 years ago. Tried it on my 7x12. It was "ok", but I did not like it much. I was expecting something like a Phase II. I gave it to my buddy for his 7x10 lathe. I bought a phase II.

Pluses: much better than the 3 tool turret that came with it. The repeatability should be good since the holder is forced into the solid dovetail nearest the spindle, just like an Aloris wedge style.

Minuses: The screw that tightens requires that you keep an allen key handy. I did not feel that I could tighten them constantly. The tool holders are not standard sizes.

It would probably work on a 9 inch swing, but may require a spacer to bring it up to center height.

Dan

[dalee100]

Hi,

Can't speak to the quality of the HF unit, but I made one from scratch for my 8x14 lathe. The design works very well, it's rigid and repeats as good as any wedge post I've used.



Daee

[dbingen]

I have one and I don't like it. It puts the cutting tool to far from the center of the cross slide, causing excess deflection and chatter. I went back to the 4-way, and use shims to adjust tool height.

[Doozer]

I have a (purchased new)
Phase II AXA wedge.
I was pleasantly surprised to see
the working parts were nicely hardened.
You still have to take it all apart,
clean out the grit, and re-grease it.

Dalee, Nice use of a flexure in your design.
I know it is common, but I like to see good
design practice.

The Hardinge HLV toolpost is a great design
and simple to copy. I wonder why more guys
don't make one like it themselves.





-Doozer

[dalee100]

Hi,

Thanks for the compliment. But honestly, the design isn't mine, I just scaled it for my use.

The Hardinge post is interesting. I think I've seen some variations of it floating around the web. It is a pretty simple design when looking at it. But I suspect the devil is in the details to make. To me, (and I could well be wrong - haven't ever used one like this), it seems to need a very close and proper fit on the dovetails. Since it appears to pull the holders straight back into the post. So a sloppy fit might cause a headache. Not to mention that the internals should really be properly hardened to last. That often throws many HSMers off, even if it shouldn't.

Wedge types or even the HF design, can tolerate a pretty fair amount of loose fit in the dovetails and still work well.

I really should put a Hardinge style post on my list to make for fun. I've already made a round style and this dovetail clamp type. (Old toolmakers gotta make tools!!)

Dalee

[Paul Alciatore]

I personally wonder why more people don't use my design. It is as solid as they come, totally repeatable, easy to change holders WITH ONE HAND and no tools, and there are no dovetails or other complicated parts to machine. All the adjustments are easy to make and mostly independent of each other.



This shot shows the parts. Nothing really hard to make.



Oh, it is easily scaled to almost any size, but the original design was for an SB9.

The complete construction article can be found here.

https://groups.yahoo.com/neo/groups/MachiningTips/files/Lathe%20Accessories/

[dalee100]

Hi,

It's a good improvement over the traditional Norman round post. I would bet it's as easy to make as the Norman with nothing more than a lathe and one end mill. I like the simple 90 degree index. I have recomended it on several different boards but don't know if anyone has made it.

Dalee

[sarge41]

I have a (purchased new)
Phase II AXA wedge.
I was pleasantly surprised to see
the working parts were nicely hardened.
You still have to take it all apart,
clean out the grit, and re-grease it.

Dalee, Nice use of a flexure in your design.
I know it is common, but I like to see good
design practice.

The Hardinge HLV toolpost is a great design
and simple to copy. I wonder why more guys
don't make one like it themselves.





-Doozer

Doozer: Because it is basically a piston type which leaves a bit to be desired when compared to the wedge type.

Sarge

[Doozer]

It is not a piston type.
The Hardinge wedges the dovetail.
No internal parts to harden,
just a thru bolt and a triangular T nut.
Could not be any more simple.



Close up of the triangular T nut.
Not at all difficult to make.
I would not even harden it.
Easy mill job.
Tolerances are very forgiving.
A little sloppy, just draw up the
T nut a little more on the lock handle,
which is just a fancy bolt with a lever
and a plastic ball.
And you want heavy duty,
I use 2 studs to hold it to the compound,
which necessitates it being set at 45deg,
but that is no problem. The 2 studs make
a difference in rigidity, especially when
hard turning things like bearing races
and when parting off.
And yes, a Hardinge lathe can hard turn
ball bearing races. Try that with a POS
lathe.
-Doozer

[danlb]

It is not a piston type.
The Hardinge wedges the dovetail.
No internal parts to harden,
-Doozer

The tool post in the picture has a post that pushes the holder out, forcing the dovetail faces to mate, same as the a2z or phaseII piston style.

The wedge type forces the leading edge of the tool post into the holder. Cutting forces push the holder's solid dovetail even harder into the tool post solid dovetail.

Dan