Re: [atlas_craftsman] Re: piston type / wedge type ?
- Steve Forslind wrote:
>Sheeeesh! Sheldon is bigger; Sheldon is heavier, Sheldon is tougher,I read how to do this in the book "machine tool reconditioning" by Edward
>Sheldon is is better.... I feel so inferior... ;->
>--- In email@example.com, Jon Elson <elson@p...> wrote:
>>I have a 15" Sheldon lathe, now, and I do think the greater
>>gripping power of the wedge design could make a difference on this
>>machine, as it is capable of MUCH heavier cutting, and is vastly more
>>rigid that the Atlas. (The tailstock on the Sheldon weighs as much
>as the ENTIRE 12" Atlas machine!)
>You're right, Jon; I think I'll do the dovetails myself.
F. Connelly. This is the thing he is selling for $92.50 I think in the
Home Shop Machinist. A bit high, but a really good book with an amazing
amount of neat tricks to make tough stuff easy.
- Jon Elson wrote:
> mark67chevelle509 wrote:All the advice I got was that a wedge was superior just as Jon mentioned
>>When describing quick change tool posts, what exactly is the
>>difference between piston and wedge ?
> Both have dovetails. The piston type has a plunger that forces the
> holder out from the dovetail, causing the tapered sides of the
> dovetail to grip against the post.
> The wedge has a tapered gib that actually PULLS the holder tighter
> in against the post, as well as exerting a lot of outward force against
> the tapered sides of the holder. There's no question it holds the tool
> holder more securely.
> I used a piston-type post with my 12" Atlas, and I think it was plenty
> secure. I have a 15" Sheldon lathe, now, and I do think the greater
> gripping power of the wedge design could make a difference on this
> machine, as it is capable of MUCH heavier cutting, and is vastly more
> rigid that the Atlas. (The tailstock on the Sheldon weighs as much as the
> ENTIRE 12" Atlas machine!)
but a piston would be fine on a machine the size of the Atlas.
The piston models tend to be much less expensive. I was going to go
wedge (because it was "better") until Enco lowered the price on their
Phase II AXA-sized piston post to $89.95 for the post and a complete set
of folders (www.use-enco.com part #505-2253). I couldn't justify twice
the price for a wedge (almost twice the price).
At that price point there is really *no* reason to stick with a lantern
style post and I haven't regretted it for a moment.
You need to do a little grinding on the T-slot nut but it's not a big
deal (it's really more of a "plate" and it's sized to fit a pretty good
range of applications).
You'll end up with something that is strong, repeatable, holds well, and
makes your life a whole *lot* easier!
Chris Herzog Software Technologies Group, Inc.
(708) 547-0110 x225 FAX (708) 547-0783
- In a message dated 4/2/2004 11:51:19 AM Central Standard Time, zog@...
> At that price point there is really *no* reason to stick with a lanternagreed ...but dont dispose of the lantern post ...it is still valuable for
> style post and I haven't regretted it for a moment.
certain reaches /jam up situations .........find many uses yet ....also learn
how to grind a chipbreaker so there is back & side rake on hi speed bits
......the Q.C. precludes the built in back rake of the lantern toolpost holder .....&
finessing to a tight tolerance/finish goes easier w/ HS..........also
cheaper!.......these machines were not designed for high speed /high pressure
carbide tooling .......u will have more residual spring left making finish cuts a
pain w/ carbide....read that as .005 under , or putting on .010 & getting less
, then adding more & getting the total after springing out , causing
undersize parts .......
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