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21st century lathe setup question

View attachment 1037258 View attachment 1037259 The first photo shows one side of the shoulder and the second the opposite side.


I have a new 21st century neck turning Lathe that I am setting up.

My cut on the shoulder is uneven. Could somepne tell me how to correct this.

Also the instructions don't discuss the cutting tool assembly alignment screw. Is it just snug?


I need you to send this back to us so we can see what is happening. send it back just the way it is ."make no adjustments don't tighten anything send it back the way it is." I need to see for myself what is going on. After seeing the tool ill update this thread with results. Please send three cases that are prepped and ready to turn and on case that you already turned; Thank you
 
Just after I posted I see John sent me an e-mailed.

I will send it back for you to check. Thanks
 
A couple more personal observations on turning brass with the 21C lathe: (I have two 21C lathes, one set up for 6mm and one for 6.5mm)

The necks on my Lapua brass are often tilted slightly - both new and fired. When I load the brass onto the turning mandrel and lock the rim down with collet, if the rim end of the case wobbles off center slightly while advancing onto the mandrel, this means that neck cannot be concentric with the main case. Cases that exibit this behavior, most certainly have tilted necks and will not have perfectly conical shoulder profiles either. These cases also often have loaded bullet runout in excess of .003” even though the neck wall thickness is perfectly consistent. A case with a true and concentric neck will run on the lathe straight and true - clearly with no runout or wobble at the rim. You will see this, if you pay attention while turning.

The 30 degree cutter John provides is just that. A sharp angle from 0 to 30 degrees. Unfortunately, brass is not made this way even after firing in a good chamber. There is nearly always a radius that transitions from the neck to the shoulder. Using a sharp cutter in this radius, at the junction, will remove material from the radius and potentially make the material thickness there very thin, and nearly impossible to measure or identify. I actually had some 6.5x47 cases seperate in the junction - where the neck was no longer attached to the case - during firing - due to turning into the shoulder.

Great tools and have turned 1000s of necks with them.

My 2 cents
 
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Will be interesting to see what the guys at 21st Century come up with. I see a lot of turned neck photos with this same sort of variance in the shoulder cut.
 
One thing is for sure. I am new to neck turning. And getting an education, as usual on the forum.
 
One thing is for sure. I am new to neck turning. And getting an education, as usual on the forum.

Linko, are you reversing the drill on the way off the neck? It’s supposed to be run cutting in both directions.. may explain the coarseness of the cut.
 
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Linko, are you reversing the drill on the way off the neck? It’s supposed to be run cutting in both directions.. may explain the coarseness of the cut.

No I am not reversing the drill. I did not see the directions indicate reversing the drill when backing off the case. I will try that once the unit comes back ( I fired it off to 21st on Thursday)

Learning as I go....
 
Umm..do not reverse the brass rotation to the cutter. The Brass should rotate clockwise (looking at the rim end) to the cutter both going in and out off the mandrel. I do not stop my drill at all while turning until I am ready to change to a different case.

See video:


SG
 
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Umm..do not reverse the brass rotation to the cutter. The Brass should rotate clockwise (looking at the rim end) to the cutter both going in and out off the mandel. I do not stop my drill at all while turning until I am ready to change to a different case.

See video:


SG

This is how I have been running. slow clockwise in and out
 
No I am not reversing the drill. I did not see the directions indicate reversing the drill when backing off the case. I will try that once the unit comes back ( I fired it off to 21st on Thursday)

Learning as I go....

Lol, no don’t reverse it. Just asking if you did...
 
SOLUTION.. I loosened the bolt that fastens the neck turning tool to the L-bracket on the lathe.
I also added a little die wax on the washers, The rubber washers were squeezed so that it wouldn't
let the neck turning tool FLOAT......the two cases I turned had less than .0001 difference in neck wall thickness finish was good. Thanks John
 
SOLUTION.. I loosened the bolt that fastens the neck turning tool to the L-bracket on the lathe.
I also added a little die wax on the washers, The rubber washers were squeezed so that it wouldn't
let the neck turning tool FLOAT......the two cases I turned had less than .0001 difference in neck wall thickness finish was good. Thanks John

Thanks for checking it John.

The walking of the cutter on the neck is a concentric cut now, or is that not expected?
 
Does anyone have a recommended drill or driver that runs at 300rpm and is small for this lathe operation?
 
Does anyone have a recommended drill or driver that runs at 300rpm and is small for this lathe operation?

I got this 12v Ridgid for mine. I was using my much larger 18v Bosch and this one is much lighter and smaller. $79 at Home Depot. Don't see the low speed listed. Max is 1500 in the high speed mode. Seems to work great for this application. Has lifetime warranty even on the batteries. Also works great to power my Giraud trimmer.

https://www.homedepot.com/p/12-Volt...PIPHorizontal1_rr-_-205914071-_-205754094-_-N

 
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SOLUTION.. I loosened the bolt that fastens the neck turning tool to the L-bracket on the lathe.
I also added a little die wax on the washers, The rubber washers were squeezed so that it wouldn't
let the neck turning tool FLOAT......the two cases I turned had less than .0001 difference in neck wall thickness finish was good. Thanks John
This is Customer service as it should be.
 

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