# Chuck backstop



## Bogstandard (Aug 23, 2007)

How many times have you had to make a few turned parts that all had to be the same length, what a pain just nibble a bit off, remeasure, touch on, nibble a bit more.
There is a lot easier way and it is called a chuck backstop.
What it is is a fitting that goes up the 'spout' of your lathe and puts a fixed stop where you can push the job against and turn out as many parts as you need, all the same length (or within a couple of thou).
Here is mine, all it is is a morse taper mandrel to match the taper in your lathe. You can buy these with a blank end for a few pounds (or bucks), or if you are really stuck for cash and have an old morse taper shank drill that fits your lathe, you will find that the shank is soft enough to turn. You have to make the 'nose' so all your chucks can be fitted without it fouling the back of the chuck.
All you do is mount the taper into your lathe and drill say a 3/8" hole in the centre of it, make it about 1.5" deep. Put a grub screw in the side to hold the different length of spigots you can make.
The spigots can be made of almost anything, and are made to fit the different chucks lengths and diameters of job you will be doing.







This is a picture of it fitted up the spout of my lathe. Make sure your lathe taper fitting is clean on the inside before fitting. To turn a new spigot, just mount it into the taper and turn to whatever length and size required. You could if you wanted to, fit a spigot out with a thread in the end so you can just use a bit of threaded rod to give you in and out adjustment. I use the threaded rod method on the collet chuck backstops.
The way I use this is to only just tighten the grub screw against the spigot, then with the chuck mounted I can just tap the spigot back with a hammer and punch to get whatever holding depth I require for the parts to be made.






Here is what it looks like with a chuck fitted.
The way I do it is turn all the parts to within a safe one hit cut, say 10 thou away from size (if you have a saddle stop this is not necessary).
Then just put the first part in the chuck with the saddle locked and using the compound turn to the length required, don't touch your setting from now on, just put a new piece in the chuck and push back to the stop and face it off, do this with as many components that you need.






To get it out just tap it with a bit of bar from the other end of the lathe spindle hole.

John


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## lugnut (Aug 23, 2007)

That's great John, I just wish you would have shown me this a couple days ago before I made the pistons for my elbow engine :shock:
Thanks 
Mel


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## Bogstandard (Aug 23, 2007)

Hi Mel,
The pistons for your elbow engines can be made almost any length because you have to trim them down to correct size before the engine will run.

John


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## lugnut (Aug 23, 2007)

John thats what I'm doing this morning in between other chores the wife has laid out.  I was surprised just how much too long they was.  I will be making chuck backstop, it's on my to-do-list.
Mel


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