Issues holding T-type parting tool in AXA parting tool holder

9t8z28

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I am having issues keeping my .065" HSS parting blade held in my Knock-off Aloris AXA parting tool holder. When I tighten it down it wants to rotate leaving a gap on the top. It also rotates horizontally. I can fix the horizontal movement by moving the tool post but the tilt I cannot. I have thicker Somma T-type Parting blades and I dont have either of these issues with them. I have machined a horizontal groove the length of the holder so that the T-section of the blade can lay flat against the tool holder but it still kicks out on me. Any suggestions? Maybe machine a taper or angle on the wedge so that it pulls the parting blade in and down as I torque it down?

Here are 3 pics of the parting blade in the holder

IMG_1867.JPG

IMG_1868.JPG

IMG_1869.JPG
 
One way to deal with that is to shim the bottom of the blade outwards. If you measure the blade thickness, you can determine how much
shim is required. I use a feeler gauge of the correct thickness.
 
That's a nicer blade than the chinese were planning on you using.
Need to machine a groove in the top of the channel so that style of blade will stand up straight when tightened down.
It's been years but I had to do that to mine also.
 
One way to deal with that is to shim the bottom of the blade outwards. If you measure the blade thickness, you can determine how much
shim is required. I use a feeler gauge of the correct thickness.
I already milled a slot on the tool holder to except the T so the shims will not fix the problem . This modification now matches the true Aloris.
 
That's a nicer blade than the chinese were planning on you using.
Need to machine a groove in the top of the channel so that style of blade will stand up straight when tightened down.
It's been years but I had to do that to mine also.
As I stated in my first post I have already done this modification
 
Odd behavior, especially since you ground clearance for the top of the blade. However, take a look here:

Screen Shot 02-26-18 at 08.40 PM.PNG

There is a radius in the bottom clearance slot and that might be canting the blade; possibly clean that up? The top of the blade in this shot looks asymmetrical - is that a real thing or is this just an artifact? Shouldn't have anything to do with alignment, though.

The only other thing I can think of is that the clamping dog that bears down on the blade is angled somehow. Maybe you can take a clean up cut where it contacts the blade and that might help.
 
Have a closer look at how the toolholder is machined. You didn't mention what brand of holder you have, but some of the Chinese stuff
is pretty rough. Look for parallel or perpendicular surfaces, surface finish and whether the clamping nut is machined and moves properly.
What you may be up against is a poorly machined tool.
 
Do you have clearance on both sides? You could mill a groove or shim it if necessary, but unless the sides are rubbing I don't know that it actually matters.

The parting blades without the t-top have a wedge cross-section, and I've found that those work fine despite not being shimmed.

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Do you have clearance on both sides? You could mill a groove or shim it if necessary, but unless the sides are rubbing I don't know that it actually matters.

The parting blades without the t-top have a wedge cross-section, and I've found that those work fine despite not being shimmed.

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As stated again, I already milled a slot. Shimming will not help. Clearance on both sides while making a cut? No its crooked. Being tilted forces the bottom to rub and that bends the blade making a convex or concave cut
 
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Do you have clearance on both sides? You could mill a groove or shim it if necessary, but unless the sides are rubbing I don't know that it actually matters.

The parting blades without the t-top have a wedge cross-section, and I've found that those work fine despite not being shimmed.

Have a closer look at how the toolholder is machined. You didn't mention what brand of holder you have, but some of the Chinese stuff
is pretty rough. Look for parallel or perpendicular surfaces, surface finish and whether the clamping nut is machined and moves properly.
What you may be up against is a poorly machined tool.
All surfaces are square and parellel to each other and a good finish. The front side is a little rough but it doesnt make contact with any of the blade or wedge. Its an Aloris style from Little Machine Shop which are typically pretty good quality. I think the issue may lie in the wedge but I was hopping someone else had the same issue. As I torque it down I cannot see the wedge twisting but I guess I could check it with a DTI to see what its doing. I know I am not overtorquing it since I have had it get pushed back a few times from not being tight enough. The entire tool holder has been heat treated and is pretty tough material. I had a rough time machining the groove on the mill but its got clearance now
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