Charts say KDK tool post is too large for lathe? KDK 100 / 150 / 200

Hi all,

Can you teach me what I must be missing.

I have a Cadillac 1428 (14x28) that I am restoring and I have been grabbing any and all KDK stuff that last few years when the price was right. That's maybe half of it in the photos.

According to the charts:

0 series: 8-12" swing lathe, 3/8" max tool bit
100 series: 12-16" swing lathe, 1/2" max tool bit
150 series: 15-18" swing lathe, 5/8" max tool bit
200 Series: 18-24 Swing Lathe

But if I set the 200 Series tool post on my lathe the tooling can be below center line. And I can still use 100 /150 tooling on that post (or use smaller posts that I have).

So, what am I missing? Why is this stated not to be used on a lathe this size?

The 200 Series sure opens up a lot of options as I often find industrial sized tooling for cheap.

Thanks, Dave (sorry, IDK why the pictures are sideways)

''So, what am I missing? Why is this stated not to be used on a lathe this size? ''

IMO - those charts are a general guide, don't worry about it, more consider yourself lucky the larger post fits your machine.

If it's legal, works for you and feels good - do it

Thank you, Sir. That is reassuring!

When i was searching for a tool post for my ancient Stark #4 i found the really important measurement is the distance between the top surface of the slide and the center of the spindle. I'm quessing that specing in tool post sizes by swing is for buyers of modern lathes.

Beefier is better with a toolpost, up to a point .

I can’t see the angles in the picture too well on my phone, but your pic shows a large post with a large holder and a big tool... all sticking out 4-6” out over the compound and even the saddle. Cutting forces are best transferred straight down to the saddle ways(closer to the center of the cross slide is ideal)not trying to tip the saddle off the ways on the tailstock side.

Edit- many/most modern lathes have short stubby saddle way wings? on the headstock side because the ways don’t extend past the headstock gear gear box like many older designs and modern high end stuff.

Sent from my iPhone using Tapatalk Pro

MrStretch said:

When i was searching for a tool post for my ancient Stark #4 i found the really important measurement is the distance between the top surface of the slide and the center of the spindle. I'm quessing that specing in tool post sizes by swing is for buyers of modern lathes.

Click to expand...

If you want to run a KDK use the biggest one that will fit on the lathe. With the dovetail being narrower than an Aloris and most of the tool holders being longer than an Aloris the thing is a flexy flyer, much less useful than an Aloris as well with a dovetail only on the front and none on the side. I use an Aloris and a KDk every day so I do know what I am talking about.

ripperj said:

Beefier is better with a toolpost, up to a point .

I can’t see the angles in the picture too well on my phone, but your pic shows a large post with a large holder and a big tool... all sticking out 4-6” out over the compound and even the saddle. Cutting forces are best transferred straight down to the saddle ways(closer to the center of the cross slide is ideal)not trying to tip the saddle off the ways on the tailstock side.

Edit- many/most modern lathes have short stubby saddle way wings? on the headstock side because the ways don’t extend past the headstock gear gear box like many older designs and modern high end stuff.

Sent from my iPhone using Tapatalk Pro

Click to expand...

Ahhh.. I see/realize the leverage you speak of. This big holder would only be ideal when used somewhat perpendicular to the saddle (to sit on the saddle) and with a shorter tool. Makes sense. Thank you!

moonlight machine said:

If you want to run a KDK use the biggest one that will fit on the lathe. With the dovetail being narrower than an Aloris and most of the tool holders being longer than an Aloris the thing is a flexy flyer, much less useful than an Aloris as well with a dovetail only on the front and none on the side. I use an Aloris and a KDk every day so I do know what I am talking about.

Click to expand...

Agreed. When I started buying the KDK stuff, I was real wet behind the ears...I still am, just less. lol. Thanks!

Mohawk Dave said:

Agreed. When I started buying the KDK stuff, I was real wet behind the ears...I still am, just less. lol. Thanks!

Click to expand...

Moonlight called it. And then there is Multifix.

Even so, those of us dry back of the ears three-quattahs of a century ago still enjoy the odd SE grin... with a McCrosky or similarly stout 4-Way mounted directly to the topslide of the cross..

..and the "compound" flimsiness clear OFF the lathe, outright...safely stored ...until needed to do a short, steep taper or such.

Learnt on BIG lathes, heavy work. But it "scales well" to even GREATER advantage to flakey-shakey noodle-beds, too.

See "Gibralter" TP for Myford, Boxford featherweights.

Other options abound:

Alternative to a QCTP? | Model Engineer

Happiness in life?

Older whisky, younger women, faster horses, more money......and greater stiffness in machine tools... so yah don't HAVE to "swing YOUR d**k"....