[jjh122]

Sparky, That sounds like it's exactly what I'm looking for... Can you post a pic?
John

[Sparky_NY]

Sparky, That sounds like it's exactly what I'm looking for... Can you post a pic?
John

I sent you a private message

[Sparky_NY]

Found that older thread here discussing a Z drive. The one post has a link to some excellent pictures of a homebrew Z drive.

http://www.cnczone.com/forums/showthread.php?t=33456

[M96Jay]

Elrod Z axis patent

[rolfinator2002]

Bump.
Anyone have any drawings or plans that they can share of a z axis housing design?
I like the Elrod type design and don't really wan to reinvent the wheel.
Max

[79TigerPilot]

I am planning on driving the knee on my J head step pulley BP. I mounted a timing pulley on the existing Z acme lead screw just below the bearing. I had to remove an inch or so of the lead screw threads to provide some space for the pulley to mount. I then cut a window in the right side of the knee casting between the ribs to route the timing belt to a 2800 in-oz stepper that will be mounted via a bracket on the outside of the casting. My pulley ratio is 3:1 and I am planning on a couple of air cylinders to take up some of the knee weight. This was as large of pulley I could fit and still get the timing belt through the window without cutting through casting ribs or using idler rollers. I recorded all the weights of the pieces when I put the mill back together to make it easier to size the assist cylinders.

Just got the mill back running last week after cleaning and painting and still need to build the Z stepper mounting bracket before I can test the Z drive system.

Pictures of the mounted pulley can be seen about half way down the album: http://picasaweb.google.com/cschaffter/CNCMillProject#

Craig

[Derek_J]

I converted my own series 1 manual machine recently, all 3 axis (4 actually, did the rotary table too). I made all my own brackets etc. and used nema 34 steppers. The X and Y are super simple, just a flat 1/2" aluminum plate with some slotted bolt holes for the motor and table attachments. I used 2:1 timing belt drive. I made the timing pulleys on the 4th axis.

For the Z I used a pretty simple aluminum bracket assembly. The main plate mounts up against the factory bosses at each end of the downfeed adjustment screw. Those flat bosses are the first surface machined on the head and used as a reference by the factory as the quill bore and other features are machined so they are a proper locating surface for a Z drive. I drilled/tapped those flats for the 2 mounting bolts that mounts the entire Z assembly. The ballscew is vertical with a standard ball bearing on the top and a thrust bearing on the bottom. The ballnut mounts to a steel "arm" that is drilled through and attaches to the quill using the 3/8-24 existing hole in the quill that mounts the round depth stop ring. The quill drive "arm" has a radius cut at the quill attachment end that matches the quill radius.

On my first try, I used the round hole in the stock quill depth stop ring to drive the quill. Bad idea, the dowel pin flexed and gave lots of backlash. The arm with radius matching the quill solved all the problems.

Oh yea, I used a 425oz Nema23 stepper for the quill because I had it onhand. It drives the ballscrew with a 3:1 ratio timing belt drive. I have the quill set a 80 IPM and honestly do no know how much faster it will go because 80 is plenty fast for me right now.

My whole cnc conversion cost $1500 or less and that is including $700 for a Rockford ballscrew kit for the table. I am flat out amazed how much they get in the market for motor mounting brackets and such considering how simple they are.

COUOL


Could you please send me some pictures of this? I would love to do the same on my mill.

[Kevin Taylor]

Find a Boss 3 Mill and poach the head

[mongoose]

Find a Boss 3 Mill and poach the head

i second that !

here are a couple i have for current / future retrofits

boss cnc head

hiedenhain conversion

centroid conversion ( i think this is the elrod kit )

they pop up on ebay occasionally and i try and scoop them up..

also had another off a prototrak that was similar to the elrod...

good stuff !

[mongoose]

and the boss head most likely will have the erickson 30 taper or quik 200 spindle for quick change tooling