PM1340 Solid Tool Post for Dorian BXA QC

[9t8z28]

I can either use class 40 cast iron or 01 tool steel. What do you recommend ? My block will be very similar in size, height and width to yours.

 

[davidpbest]

A
Did you have any purpose behind tapering the block the way you did or It was just for cosmetics ?

Thank you
Brandon

Thanks. I angled the solid tool block to encourage chips to fall away and not collect on various ledges. I can't really speak to your question regarding cast iron or tool steel. I used steel because it was more easily obtainable and less expensive than cast iron (at least from the suppliers I use), and because I try to avoid machining cast iron when I have that option.

 

[Buffalo20]

Interesting project, the workmanship is excellent, you had me right up until, the alignment blocks. I'm constantly angling and pivoting the QCTP, to me the blocks, would be a limiting PITA.

 

[ddickey]

The solid tool post even without the alignment block and the dowel pins will still increase rigidity.
If I will just be turning or using my knurler I'll put my dowel pins in. If not they come out.

 

[davidpbest]

Interesting project, the workmanship is excellent, you had me right up until, the alignment blocks. I'm constantly angling and pivoting the QCTP, to me the blocks, would be a limiting PITA.

To each his/her own I guess. Like Robin Renzetti, who initially posted on YouTube about this, my tool inventory on QC tool holders has grown extensive enough that I no longer have to rotate the tool post for the types of things I do.

I also like being able to program the DRO with my tool library, and just call up the tool number of the just-mounted tool and know that it's cutting position relative to the CL of the spindle is already calibrated in the DRO.

But I completely understand the sentiment and need for a rotating tool post if the selection of tools is limited or you need more flexibility. It's hard to know how much rigidity would be sacrificed without the anti-rotation stops since I never tested it in that manner. In an ideal world, I suppose this could be a rotating sold mount with some kind of plunger-indexed stop system operable from above to secure the tool post from rotating - at least in a few positions, one of which is indexed to 90-degrees off spindle CL axis for parting operations (which is one of the main motivations for me tackling this project in the first place).

 

[Buffalo20]

David,

I wasn't trying to belittle your project in any way, maybe I'm lucky, but I've never has the QCTP twist, no matter what I've done, including breaking the head off a boring bar. I broke the brass shear pin in the drive, but the QCTP never flinched. Obviously, I'm still learning, by watching and listening to other people practices and opinions, to me, is like going to school.

I have about 75 blocks load with tools, but no DRO as of yet.

To me, the block, you made, to replace the compound is excellent, that alone should increase rigidity greatly. What do you think. the block weights??

 

[davidpbest]

To me, the block, you made, to replace the compound is excellent, that alone should increase rigidity greatly. What do you think. the block weights??

Thanks Jack. The solid tool mounting block, without the Dorian QCTP attached to it weighs 15 pounds, give or take a few ounces. I've had the QCTP twist off axis on the compound many times using a scissors-type knurling tool with 12 TPI pitch straight cut (not diamond) carbide knurling wheels when machining 316 stainless steel. Example - 1.25" diameter, couldn't get the knurl buried deep enough to get a clean point between teeth no matter how honked down the tool post was:

With the solid mount I no longer have that problem and can really bury the knurling teeth in stainless. The extra rigidity has really helped parting-off ops too - especially in stainless. But I have yet to break a boring bar - that does not sound like fun. Maybe I should push it harder?

 

[Contract_Pilot]

Thanks Just What I was looking for.

 

[ddickey]

Any opinion on relieving the bottom portion of the solid post around the compound/cross slide interface? The total circular section where the bolts go to hold onto the compound.
Another thing I just realized is my center section to reference my compound is not in the middle of the cross slide but offset ~ .040"

 

[Rooster]

Greetings David, that is some beautiful work you have done.