Fast Change Rocker Tool Post Holders for the Lathe QCTP

[jjr2001]

I may make or buy a QCTP for my Sherline in the future but for now I had this idea to use the rocker type tool post on the lathe.
The rocker tool post as implemented on the Sherline will allow easy change out without changing any tool bit height settings.
The rocker can be made with two rockers on one tool holder which improves speed even more. Anyhow that is how I see it so I thought it was worth a try.

Rockers were made on the CNC machine and trimmed by hand with a file.
The main blocks were profiled with the radius for the rocker on the CNC machine.
The holes were drilled on the CNC machine. Center hole was only spotted on the CNC and
then finished on the drill press. This required a .200" hole thru the part to the bottom.
Then the bottom was re-drilled .325" diameter to clear the shaft of the Sherline extended T-nut.
This re-drill stopped .300" from the top of the tool holder.
The holes for the clamping screws were tapped on the bench.
I bought 6 extended T-nuts from Sherline to save a bit of time. Only $3.00 each so my total investment in my QCTP is $18.00.
Should work fine, I made 3 single tool and 3 double tool holders for a total of 9 tool bits.

The black one is the one supplied by Sherline.

Cheers, JR

[rossbotics]

Very nice, those should work just fine

[hemmjo]

Those are pretty. I really do like that idea of the individual "Tool Blocks", each with it's own tool all set up and ready to go. You really got me thinking....

I have been toying with the idea of getting a QCTP for my 11" Logan lathe. But cannot justify that cost. It is not much different sliding a "Tool Block" in and out of the slot on the compound rest than it would be on and off a QCTP. I could just make blocks similar to yours that fit my compound. I do not have a CNC to make those curved slots, but I not a fan of rocker type height adjustment anyway. Rocking the tool changes the cutting angles ground on the tool. I long ago replaced the rocker type adjustment on my lantern type tool post with a flat plate. Shims (hacksaw blades with the teeth removed, etc) are used to adjust tool height. The tool slots would just be straight, with tool height set on each block with shims.

Thanks for the idea!!

John

[jjr2001]

Thanks guys, I also considered the straight slot with shims but went with the rocker type for ease of adjustment. Straight slot tool posts are easier to make without a CNC. The mini lathe is supplied with a 4 tool holder with straight slots. If you make a bunch of short tool bits you can have 4 tool bits at the ready with that design.

Cheers, JR

[Toolmaker51]

As a suggestion to those without CNC. Rockers and Posts could be produced via rotary table quite easily.
I start with a bar of flat stock [for either part] and fixture the table to radius one at a time, then 'part off' on a bandsaw. That sacrifices a minimal amount to chips.

Mechanically, I'd tend to cut rockers with a slightly larger [.003-.006] radius than tool post to broaden the contact points. Ro-tab or CNC, cut and finish mating faces with same direction.
It also seems logical to use dissimilar materials to avoid galling, if they aren't to be heat-treated.

It strikes me, more practical than seen earlier. Quick Change usually denotes repeatable tool positioning...but unless production is involved that's not a particular advantage.
jjr2001's Quick Change Posts add the modular advantage, a bit more rigidity, flexible setup, and less overhang than any QCTP I can recall. All those are positive features.
I rate better usability for these over import copies of the Aloris without hesitation. Work lathe has a set of those, and don't impress me at all.

[jjr2001]

Thanks for the tips TM51. I may make more rockers using brass. Meanwhile I will use a small amount of anti-seize on the bottom of the rockers.

Cheers, JR

[thehomeengineer]

Nice work again. I remember using a similar type of design on a Myford lathe but the tool had the saddle part machined into the base of the tool and this sat on a mating part for setting the centre height. Not as good as your tool post holders as each time the tool needed changing all settings were lost. I have never seen these tools again, had a quick look on the web but could not find anything like them.

[jjr2001]

Thanks homeengineer, back in the day when I was in High School my dad (tool and die maker) brought home a 9" South Bend and gave me a few tips on how to use it and not kill myself! I made my favorite stuff back then with it. (Cannons) That lathe had a nice rocker (lantern) type tool post. Worked fine but you always needed to reset the tool height for every tool change.
I like the rocker but wanted to make it "Quick". Maybe I should call this one the QCRP or Quick Change Rocker Post!

Cheers, JR

[thehomeengineer]

Thanks homeengineer, back in the day when I was in High School my dad (tool and die maker) brought home a 9" South Bend and gave me a few tips on how to use it and not kill myself! I made my favorite stuff back then with it. (Cannons) That lathe had a nice rocker (lantern) type tool post. Worked fine but you always needed to reset the tool height for every tool change.
I like the rocker but wanted to make it "Quick". Maybe I should call this one the QCRP or Quick Change Rocker Post!

Cheers, JR

I like it! if I was musical (which unfortunately I don’t have any talent in this field) and I was starting up a band I would now call it “Quick change Rocker Post” sounds really cool
The Home Engineer

[olderdan]

The more I think about it (this takes longer than it used to) the more I like your rocker tool posts, It occurs that you could also use them with a small L shaped location plate fixed in your second T slot to give a repeat location function.