Wedge or piston type quick change tool posts?

[jamie76x]

Uncle buck.... Think of it this way.

If the tool holder shift's .005" at the holder, How much did it move at the business end of a 5" boring bar? The correct answer is " Too much."

When the bars shift like that is when you chip the cutter, crack the insert and ruin the cut and or dimension.

When I was 18-22 years old I bought all kinds of low cost tooling. It was not long after that I started replacing it all with better stuff. I look back and think of how much money I wasted having to re-buy things. My new motto is " I am to poor to buy cheap things."
Spend the extra bucks on a wedge tool post.... That way you can never wish you had bought it instead.

 

[george wilson]

The wedge type tool post sucks the tool holder tightly against the tool post. The piston type pushes the tool holder outwards,which is just not as strong a way to hold the tool holder. As several have said,the piston type can allow a little shift in the tool which can be a problem. I only use the wedge type holder.

Parting is NOT such sweet sorrow. Send thee back the piston,get a wedge tomorrow!!

 

[itsme_Bernie]

I have read tons of complaints about the performance of piston type QCTP. Personally, I bought a BXA Phase II piston and I have never had one issue with mine. I have been totally satisfied with the performance and as I said really never have had even one issue. That has been my experience with a piston type QCTP

Buck I had the same experience. I have had piston style posts for years now with no issues at all. I also had a really old Phase II AXA piston style post on my Heavy 10 when I got it 6 months ago which was just fine. I bought some extra holders from CDCO which also worked fine. I only replaced the actual tool post because I came upon a deal I couldn't refuse.

I know it is not ideal, and I am not saying to buy a piston over a wedge, since they are almost the same price imported anyway.

And I'm not saying there are no advantages to having a nice post, but it shouldn't stop someone from getting started. The holders all go back and forth from piston sets to wedge sets, and from the import sets to my DTM Anyway, so now I have lots of holders too. It is definitely worth getting the nice post eventually, which I did.


Bernie

 

[Uncle Buck]

Uncle buck.... Think of it this way.

If the tool holder shift's .005" at the holder, How much did it move at the business end of a 5" boring bar? The correct answer is " Too much."

When the bars shift like that is when you chip the cutter, crack the insert and ruin the cut and or dimension.

When I was 18-22 years old I bought all kinds of low cost tooling. It was not long after that I started replacing it all with better stuff. I look back and think of how much money I wasted having to re-buy things. My new motto is " I am to poor to buy cheap things."
Spend the extra bucks on a wedge tool post.... That way you can never wish you had bought it instead.

The wedge type tool post sucks the tool holder tightly against the tool post. The piston type pushes the tool holder outwards,which is just not as strong a way to hold the tool holder. As several have said,the piston type can allow a little shift in the tool which can be a problem. I only use the wedge type holder.

Parting is NOT such sweet sorrow. Send thee back the piston,get a wedge tomorrow!!

I have not been trying to make a case for piston type QCTP as better than wedge type QCTP. I already know that simply due to the design alone the wedge is widely accepted as superior to the piston. All that said, for me the fact remains that I have not experienced the stated deficiencies with a piston QCTP that I have been using on my lathe. As I said before, it could be because my machine is not subject to the same stresses as explained by others due to the fact that my Atlas is in fact a lighter machine than others and I may not be pushing my machine hard enough for these poor performance issues to reveal themselves. The end result being my piston is serving my needs without problems, but I understood the wedge to be accepted as superior to the piston when I bought the piston.

When I bought my piston there was enough difference in price to warrant my purchasing a piston QCTP simply because the difference was too much for me to go at the time. If there is no difference in cost between the two these days and a guy can afford the wedge then certainly I would encourge purchasing a wedge over a piston QCTP.

Hopefully this clarifies my position better.

 

[epanzella]

I have read tons of complaints about the performance of piston type QCTP. Personally, I bought a BXA Phase II piston and I have never had one issue with mine. I have been totally satisfied with the performance and as I said really never have had even one issue. That has been my experience with a piston type QCTP

I agree 100%. My piston toolpost and two holders came with my Grizzly G4003G. I have since added about 15 holders from CDCO for $10 a pop. I don't get any "jumping around" and once I locktite the threaded adjustment posts the tool height is set & forget. The holder is jammed into a tight fitting dovetail surface that is about almost 2 inches by 1/2 inch on each side. How can that possibly move? I even made a 1.5 inch milling attachment that increases the overhang and that works fine too. To each his own I guess.

 

[cjtoombs]

I have a Phase II BXA wedge type holder and had problems with the CDCO holders working on it. I surface ground about .020 from the face on the dovetail side of the holder and they worked great. The holders were too thick in this area and interfered with the holder. They are meant to index on the sides and bottom of the dovetail, not on the surface that was ground.