How does the side mounted ball screw work? ? I'd be worried about the torque trying to turn the milling head.
The design I like better places the screw on center line and almost touching the existing rack.? The head's weight is basically hung off the stationary screw.? The screw does not turn.? A motor is used to rotate the nut.? I think the overall design is simpler.
People are getting better than .001" with this kind of setup.
Searching around I find a photo of this design here.? It lifts from the center of mass.? Disadvantage is you need a full height ceiling but likely a non-issue for most.
Allthat said.? I have a simple DRO mounted to the z-axis and it is accurate to .001 and reads to .0005 if I use the gib lock if there is any depth movement it does the DRO is not detecting it so I amuse not movement over .0005" ?and this is with a stock mill, I'm not done with the CNC conversion.
On Tue, Jul 25, 2017 at 8:01 AM, WAM
ajawam2@... [7x12minilathe]
<7x12minilathe@...> wrote:
I bagged that whole rack-pinion thing for something a bit more robust:
Actually my wife wanted it changed. She used it when we first got it,
said it sucks, and suggested the stepper I did, or something like this:
I can send the 3D model of that if you'd like...Uses off the shelf gears
from Boston Gear. Uses the same CNC Fusion ball screw.
I've been using the stepper/Arduino thing for years and really like it.
I can get accurate depths that hold.
As to the stock mini mill setup, everyone states you should lock the
gibs, or tighten them up. Also you can check your rack-pinion mesh and
shim the rack to make it a bit more tight.
I didn't like any of those suggestions. A rack-pinion is great for a
drill press; not so much for a mill, at least in my opinion...
//
On 7/25/2017 10:12 AM, 'Johannes' johannes@... [7x12minilathe] wrote:
>
> l.JPG?dl=0
>
>
>
> This is the fine-adjuster to LMS 4700 Mill.
>
> Have somebody made a lock for this?
>
>
>
> My adjuster is moving (turning) when I am milling, and before I am doing
> something stupid, I want an advice from you.
>
>
>
> Best regards
>
> Johannes
>
>
>
>
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