Camlock chucks

[jpigg55]

I have a question about the different type camlocks. I know of the D1-4, D1-5, & D1-6 types, but wasn't sure if any other types and/or styles exist.
I'm also curious of opinions concerning advantages or disadvantages of one over the other. This subject has been broached in various thread posts, but I don't recall or find a dedicated thread.
I found a couple methods on how to lock chucks on threaded spindles to prevent them from un-threading during reverse turning operations or quick braking on lathes that have that feature.
As I'm shopping for a 4-jaw chuck, I'm considering converting to camlock style chucks, but I'm not sure why one may be better than the other when it comes to functionality, price, and availability.

[4GSR]

To use a camlock mounted chuck, your lathe spindle has to be equipped with a camlock flange.  This is a integral piece as part of the spindle when built.  It has been talked about on other forums of people that have made their own conversion to thier threaded spindle nose.  As for one that is commercially sold, I'm not aware of any. 

[RayH]

As usual, I'm not sure exactly what your question is. The linked info explains common Lathe nose types.

Regarding D1-4 vs other D1 sizes, the primary issue is the size (capacity) of the lathe. The different D1 size nose types are incorporated in lathes with spindles of compatible sizes.

I think reading the linked info (and further research of published text) will help focus your search.

I have a D1-4 spindle decent hobbyist (Taiwan) lathe. I think the D1 types are quick and easy enough to change chucks but I'm not in love with the type. Like many things in life, the D1 types are a compromise, IMO. The crux of the issue is that the design is fundamentally OVER CONSTRAINED. It is commonly stated that D1 chuck should be mounted in intimate contact with both the taper and the flange face simultaneously. That common opinion, although ideal, is a practical quagmire. It's not my desire to get into a big discussion of it here. If someone disagrees, so be it. You do you, I'll do me.

I have significant experience with an "American Standard Type L - Long Taper" lathe spindle. I like the type. However, I think the spindle/bearing/support SYSTEM must be designed accordingly and I would not recommend an adaptor be attached to a spindle without a comprehensive engineering analysis (HaHa). The short explanation of my concern is that the length of the Type L system puts the chuck/workpiece/cutting forces further away from the front spindle bearings than other nose types. Compared to other systems, Type L requires a beefier system to handle the higher loads resulting from the greater leverage.

Not knowing what lathe you're starting with (not stated in the OP), I feel like I'm talking to myself.

https://www.tools-n-gizmos.com/specs/Lathe_Spindle_Mount.html#:~:text=Type%20A1%3A%20tapped%20holes%20on,holes%20on%20inner%2Dbolt%20circle.

[RayH]

I have a question about the different type camlocks. I know of the D1-4, D1-5, & D1-6 types, but wasn't sure if any other types and/or styles exist.
I'm also curious of opinions concerning advantages or disadvantages of one over the other. This subject has been broached in various thread posts, but I don't recall or find a dedicated thread.
I found a couple methods on how to lock chucks on threaded spindles to prevent them from un-threading during reverse turning operations or quick braking on lathes that have that feature.
As I'm shopping for a 4-jaw chuck, I'm considering converting to camlock style chucks, but I'm not sure why one may be better than the other when it comes to functionality, price, and availability.

I have just reread the OP and realized why I had trouble understanding the "question".
There was no question. Not one sentence that ended with a question mark.
You wrote "I have a question" but you didn't ask a question.

[ddickey]

D1-3 is the smallest and D-15 the largest.
There is no other style that uses camlocks as far as I know.
There is an A type spindle that shares the same taper and depth as the camlock type.

[jpigg55]

I'm currently shopping for a 4-jaw chuck for the Logan 6560. Easy enough to find as well as a backplate having the 2-1/4"-8 threads.
Here's the rub, I want to modify the backplate to install locking tabs that prevent the chuck from spinning off during reverse operations.
The choices I have, as I see it, is either modify t chuck backplates and install/remove the lock tabs every time I swap chucks or get a camlock backplate that can be threaded to fit the spindle or attach it to a threaded backplate where I can keep the lock tabs on and just swap chucks. Would still have to remove it when using collets, face plate, or dog plate, but you can't have everything.

I found a couple options listed at Lost Creek Machine:
https://lostcreekmachine.com/product/back-plate-6-1-2%e2%80%b3-2-1-4-8-semi-finished/
https://lostcreekmachine.com/product/back-plate-camlock-d1-4-6-1-2-diameter/

[Carpenter84]

Jimmy, I'd really suggest trying the lathe for a while before making any major changes. My 10" lathe has a 1-1/4 - 8 spindle nose. When using that lathe I tend to switch between a 5" three jaw, a 6" four jaw, and a 5" Pratt Bernerd collet chuck. I've turned forward and reverse, threaded right and left (running in reverse), tapped left hand. I have the VFD set for 0.5s brake stop. In 7 years I've never once spun a chuck off.

[jpigg55]

Jimmy, I'd really suggest trying the lathe for a while before making any major changes. My 10" lathe has a 1-1/4 - 8 spindle nose. When using that lathe I tend to switch between a 5" three jaw, a 6" four jaw, and a 5" Pratt Bernerd collet chuck. I've turned forward and reverse, threaded right and left (running in reverse), tapped left hand. I have the VFD set for 0.5s brake stop. In 7 years I've never once spun a chuck off.

I got you beat. The first time I ran my SB9 cutting in reverse I nearly spun the chuck off. It stayed on by half a thread only because I was watching for it and stopped.
As for waiting and learning the machine. Normally, I'd agree, but a couple reasons for buying the bigger lathe were for projects where my South Bend was too small to do.
1. Spindle thru hole too small to pass longer material.
2. Inadequate speed and power to effectively use carbide tooling.

Ir-regardless, I know I'll need a 4-jaw chuck and I'm too impatient to wait until I need it to buy one.

[4GSR]

Jimmy,

What you are going to find out is that those 2-1/4" 8-thread back plates are not going to come off as easily as the ones on your 9" lathe can.  Your over thinking this.  Like Shawn said play with the lathe a bit first and get a feel for it.  I think you will find it's not going to happen as you think it will.

I've cut lots of threads with the spindle reversed on my 9" SBL in years past.  Only recall one time the chuck backed off a thread or two. I caught it in time to tighten the chuck back up.  The reason it backed off is I threw the switch in reverse before the spindle came to a stop.  It does get your attention!

Edit: I had a old 18" lathe one time that the backplate was on the spindle so tight I couldn't get it to budge.  It stayed that way until the day it left the shop to a new home.