Proper way to use lantern tool post

[benmychree]

I have been looking for a complete and decent lantern tool post at a great price to fit my 13x40 for years. Still haven't found the right one for the right price. They are definitely better for getting into tight areas than most other tool holding systems. I know there are plenty of them hiding deep in drawers in shops everywhere.

You have a lathe and mill, Bob; make one! I never had one for my 19" Regal, several months ago, I got the bug and made one, only took me about 35 years to get around to it!

 

[dan97526]

Thanks. So does the tool holder go in the lantern with or without the wedge?

 

[RJSakowski]

One advantage of the lantern mount is that you don't have to grind top rake into the HHS tool bits. The rake can be obtained using the existing surface of the bit. This is convenient when regrinding as you don't have to start a completely fresh cut. You can adjust the top rake by adjusting the lantern. OTOH, with the QCTP holders, the bit is presented horizontally so grinding rake in is required.

As previously stated, the lantern tool holders can get into some places that simply aren't possible with a QCTP system. I don't have one for my G0602 but I still have my set for the Atlas/Craftsman 6x18. It doesn't get used often but when I need it, I've got it.

 

[RJSakowski]

Thanks. So does the tool holder go in the lantern with or without the wedge?

If by wedge you mean the half moon piece, you would always use it.

 

[ThinWoodsman]

There was a great article in a 2016 issue of Machinist's workshop called "Getting the most out of your Lantern Toolpost". In it, the author shows how to make repeatable, tool-specific bases for the lantern. Quite impressive, though I am not going to go to that sort of effort when I have a BXA.

Anyways, the way mine works is the wedge more or less sits on the T-bolt for mounting to the compound. The wedge is actually a semi-circle, with the round side down. The tool rests on top (the flat side). The bolt through the top tightens down to clamp the tool to the wedge to the T-bolt. You loosen things up, put the tool in, adjust wedge so the tool is on-center as determined by your preferred method, and tighten things up. You can angle the lantern and leave the compound at 90 degrees, or anchor the lantern at 90 degrees and angle the compound; doesn't matter.

My lathe came with a few pieces of large tooling that just don't fit into QCTP holders, BXA or CA. They work great in the lantern.

 

[benmychree]

For some tools that one may use in a lathe with such a toolpost, such as openside holders intended for use with threading tools, carbide brazed on, radius and form tools, and other special tools a solid ring substituted for the radiused ring and "wedge" work well when the thickness is sized to bring a certain size tool on center, making a more rigid setup. Also helpful is the ring with a flat radius milled into it, that the wedge fits closely in for radius and width, rather than the point bearing of the usual ring and wedge. I saw this type in a school shop on a Pratt & Whitney toolroom lathe, and I made the toolpost for my 19" Regal in that style, using a stagger tooth milling cutter to cut the radius in the ring; the radiused slot is just slightly wider than the rocker wedge.

 

[pontiac428]

I'm curious to hear how those of you using or retaining lantern holders would compare them to an equivalent QCTP and holder system in regards to stiffness and finish quality. Is it a step forward?

 

[Shootymacshootface]

I recently removed my 4 way tool holder to do some internal boring and threading with my lantern tool holder.
True story!!!

 

[Shootymacshootface]

Also, that wedge is called a rocker and it always goes under the tool round side down. It's used to adjust the tool hight.

 

[benmychree]

As regards stiffness, I think there is little difference, in regards to convenience and productivity, the QCTP is the winner, hands down, One thing that I note with my A size QCTP on my 9" lathe, is that, especially with parting off, the tool overhangs the cross slide, tending to tip over and bind up unless shifted all the way to the right of the compound, which is not so convenient for the other tool holders used. The cross slide gibs are tight and the slide is not worn, it still tends to tip and bind.