Mandrel making

[jalbert]

After suffering through using aluminum mandrels for years, I am undertaking what will be a horrifically unpleasant task: Retooling all my mandrels in steel. I grabbed some free-machining steel off eBay for the project (12L14) as I've made tool holders from it before and it machined quite well. I remade my main barrel mandrel (foreground) and it works superbly, with no flex and perfect concentricity. Now only about 15 more mandrels to do

 

[Bats]

Before looking at the picture, my first thought (imagining a standard 7mm two-barrel mandrel) was "why does he need to machine that when he could just get some appropriately sized drill rod?"

My second thought was "Mmmmm.... 12L14....". There are just no words for how nicely that stuff turns - especially since my first handful of projects after getting the metal lathe were out of hardware store cold-rolled mystery steel, which had me convinced there was something terribly broken about either the machine or the operator. I've had aluminum that's more difficult to turn than 12L14.

(not that this should be taken as a recommendation to replace aluminum with 12L14 in segmenting projects. that would likely be a Bad Idea™)

 

[jalbert]

Before looking at the picture, my first thought (imagining a standard 7mm two-barrel mandrel) was "why does he need to machine that when he could just get some appropriately sized drill rod?"

I'm not sure I follow. Regardless of the material used, the mandrel has to conform to the inside of the part of the pen that is going to be held on the mandrel, and threaded to accept the pen part, both of which require significant machining.

 

[Bats]

I'm not sure I follow. Regardless of the material used, the mandrel has to conform to the inside of the part of the pen that is going to be held on the mandrel, and threaded to accept the pen part, both of which require significant machining.

This is also called a pen mandrel. Nothing but a glorified bit of drill rod stuck in a morse taper with a nut on the end:

Hence my (brief) confusion.

 

[Aces-High]

I've made mine from brass. Seems to be doing ok so far.

 

[jalbert]

I've made mine from brass. Seems to be doing ok so far.

Brass works fine. Much stiffer than aluminum, however steel is cheaper than brass.

 

[Dalecamino]

Nicely machined John. Did you cut the threads with a die?

 

[jalbert]

Nicely machined John. Did you cut the threads with a die?

No, single point.

 

[Psychmike22]

I've made mine from brass. Seems to be doing ok so far.

Same here.