Methods for squaring stock?

[sansbury]

I am working on a chess set that is going to require me to make a lot of blocks out of brass and aluminum. Pieces will be made from 1" bar stock, squared up and either 1", 2", or 3" tall depending on the piece. The sizes are all nominal, but I'd like the pieces to match each other by a few thous, or better. Partly for aesthetics, partly as a challenge for me to improve my technique.

For equipment, I have an X2 that has been converted to CNC, and a 7x lathe. My first thought was to take sections of bar 6-7" long and machine them square on the, and then cut smaller chunks off them which only need squaring on the ends. The length limit is so that I can machine the full length in one pass with a fly cutter or shell mill without making any turns near the ends, so I get a consistent finish.

Any tips, techniques, fixturing approaches greatly appreciated. I imagine if I wanted to make more than a couple of these I'd look for a larger mill, at least for preparing the stock on.

[tattoomike68]

Start with square stock.

[Carld]

Sounds like a good plan to me. Tattoomike seems to have the right answer.

[3t-]

sansbury,

Take a look at the videos on this link. Great stuff here. I think it is "Machine Shop #6" that details stock squaring on a mill. If not #6 it is in one of the videos listed.

http://techtv.mit.edu/collections/ehs-videos/videos

I use the process described in "Machine Shop Trade Secrets" by James Harvey, get a copy you won't be disappointed.

[Ken_Shea]

Start with square stock.

While the simplicity of that gave me a chuckle in the real world that often is not possible.

My approach if I wanted them all equal as possible would be to machine each separate side as a lot before machining the next side. Same for the ends after you cut then to length, machine the separate ends as a lot before doing the other end. Also use a positive stop in the vise so each piece has the same starting position.
EDIT:
Once you get one end of each cleaned up you could also stack them vertically in the vice and face off groups of them, but always in lots.

This is a simple but very effective stop similar to what I use only I paid $19 for a pair
http://www.cdcotools.com/index.php
Do a search for Work Stop on their site.

Ken

[Carld]

Ken, the irony of the question is "how to square up stock". Now, if he is a machinist he would know such a simple thing as that. Even with a little imagination he should come up with a way using just a lathe. The problem to me is not many think before asking.

On the other hand I may be a little short with my answer because of the weather we have had.

To be fair, he didn't give any info about what size he is starting with to make it square. If I give him a fish he learns nothing, but if he has to fish he learns.

[Ken_Shea]

No argument there Carl, although, from his question I presumed he was just beginning, and having been in the same boat with many efforts I know that what seems so obvious to the experienced is not to those new at it. When new you want to do everything just perfect and it is a tendency to over think what needs to be done, resulting in even more confusion, with experience, perfect results rarely just happen but good work often does.


Ken

[isaac338]

To be fair, he didn't give any info about what size he is starting with to make it square. If I give him a fish he learns nothing, but if he has to fish he learns.

no no.. it's "give a man a fish, he eats for a day; teach a man to fish, and you give up your monopoly on fisheries"

[Your Old Dog]

...........Pieces will be made from 1" bar stock, squared up and either 1", 2", or 3" tall depending on the piece..........

That's a good stock to use for chess pieces. It allows you to bore out the bottom to 1/2" and press in some rare earth magnets. Sure would create some excitement on the board if you only did a few pieces and started with them on opposite ends of the board

[derekm]

Using sq stock is good because its considerably cheaper. Think about the volume of brass that you are going to make into swarf ...

thats money

because you pay for stock by weight (essentially). Brass maybe cheaper but its still a lot money for a six foot length of 1" bar (which is what will take if you add up 32 pieces av 2" allowing for cutting etc..).

To square it off will waste 36%. (math for max size sq inside a circle)