Thursday, June 11, 2015

Time to Buy A CNC Mill?

One of the 3D printed parts I used to make parts for the Vixen VHAL tripods failed catastrophically.
It took several months, but the right solution is not ABS but aluminum.  I have requested quotes from several CNC vendors, but in the meantime, I find myself wondering if I just need to buy a CNC mill.  Ghost Gunner makes one primarily intended for machining AR-15 lowers from aluminum, but they are currently out of stock.  I have an STL file for the part.

If I could get my cranky old vertical mill to work reliably, this is what I really need to make.

UPDATE: I bought this Sherline mill used, and the miles show.  There are a lot of clever aspects to the Sherline products, but how the handwheels attach to the lead screws isn't one of them.  They used a 10-32 setsccrew through the handwheel on to the end of the leadscrew, and only friction, and after a while, hope, holds them there.  This one keeps working loose.  It feels like the threads in the wheel are wrong, and tightening it down doesn't work.  Until I got to cutting the notch above, it was going very well.  I have been working on this all afternoon.  (I was inspired to simplify the design diuring Bible study this morning.)  This is the most productive burst of energy I have had in weeks!

UPDATE 2: With some assistance from my son, I got the vertical mill on end in the drill press, and retapped the end of the lead screw 6-32  (not 10-32), and now the bolt that connects the lead screw and handwheel coupler seems pretty secure.  If it works loose again, I'll LocTite in.

UPDATE 3: Let me retract that criticism of the Sherline product.  What I am fighting with is the A2Z monster mill upgrade of the Sherline.mill.  The end of the Sherline lead screw is a solid piece of steel, not a composite like the A2Z replacement.  Since I am about to buy the Sherline CNC upgrade, I will be converting it back to a standard Sherline 5000 mill.


Sebastian said...

Taig mills are relatively inexpensive.

See here

jon spencer said...

Grizzly has a few that are relatively inexpensive.
And the owner is a shooting sports backer, big time.