Quick to load and set lathe spindle back stop

[thehomeengineer]

Hi All
Easy to use lathe spindle backstop.
Hi All
This is a back stop I made for my Colchester Student 1800 lathe. The stop is machined with a piece of square stock clamped it one end with a counter sunk screw and a through thread at the other end. (like a key in a key way slot) The main body is then turned to the correct dimension to give a slide fit into the lathes head stock spindle. The square stock has the same outer diameter profile. A suitable sized hole is drilled and reamed for the stop bar (in my case 12mm) A hole is also drilled and tapped the opposite side to the square stock for a brass slug and a grub screw to clamp the stop bar at the desired position (the brass slug stops the grub screw from chewing up the stop bar so it is easy to slide in the main body. To operate the main body is slid into the spindle and the tapped hole in the opposite end to the counter sunk screw is tightened which forces the now turned square stock to raise and clamp the main body within the spindle. The stop bar can then be set using the clamping stop bar grub screw. The two thick washers are clamped using the same brass and grub screw method and are there to stop the bar from whipping at high speeds.



Fitted and locked in lathe spindle

Photo showing stop bar lock screw opposite square clamp


Thank you for viewing.
Hope this all makes sense if not please ask questions
The Home Engineer

[DIYer]

Thanks thehomeengineer! We've added your Adjustable Lathe Spindle Backstop to our Lathe Accessories category,
as well as to your builder page: thehomeengineer's Homemade Tools. Your receipt:

Adjustable Lathe Spindle Backstop by thehomeengineer

tags: spindle, adjustable, stop

[Toolmaker51]

Hi All
Easy to use lathe spindle backstop. The Home Engineer

This pic sold me. Other expanding barrels have the wedge fully inside the spindle actuated by a horizontal cap screw; too close to spin a hex key, generally just plain clumsy. Internal wedge also dictates a lot of non-productive work to machine an inclined member and its seat pocket, within the circular body. Again, clumsy with a capital PITA. Another lazy feature is those dependent on all-thread for stop bar adjustment.
There are self-declared toolmakers who truly are unimaginative, lack initiative & creativity, not to mention a decent grasp of mechanical properties.

Yours sir thehomeengineer, cures dilemma for one at work. I'll readily admit, images of all the crappy stops I've seen hampered my vision to get outside that box.
I'll be creating one using your principle come Monday morning. Before, on work machines or my own lathe, I've been pleased with one of two size tailpipe expanders, just had to make a long enough socket extension to operate it. But neither will fit machine at current employer....Thankfully few multiple parts [so far] hadn't tee'd me off too much.
They still think I'm civilized!

edit. Occurs to me; adding a light coil spring for part ejection is beneficial. I'm visualizing different versions now.

[thehomeengineer]

Thank you for the kind words

[Paul Jones]

The Home Engineer,

I agree with Toolmaker51 regarding your design for locking the spindle back stop into the lathe spindle bore. It is a good design.

You also gave me an idea of re-using my lathe rear spider to hold a spindle back stop rod and add a couple of thick washers to prevent whipping around in the spindle bore. Setting this up using the lathe rear spider would be slower but it might work okay before building a back stop based on your design and could reuse the central rod and washers.

Rgards,

Paul

[thehomeengineer]

Looking forward to seeing your design. I must make a rear spider one day but will wait and see what you come up with first.
Many thanks
The Home Engineeer