Survey, Acme rod .... how long and size?

[johntbyrne]

Short and sweet. As subject says, what size rods are you using with success and how long are they? Particular interest is smaller rod since I've aquired some 1/4" ball nuts.

Thanks
John

[NeoMoses]

On the Z-axis mod that I did on my CNC conversion, I used about 8"-10" of 1/2"-10TPI Acme rod. Hope it helps.

[johntbyrne]

59 views, one response. Does this mean that only 1 in 59 people have actually built a machine?

[Chagrin]

I think some of us might be confused by your association of acme screws with ballnuts.

[johntbyrne]

Ahhh, now maybe my inexperience with this is showing. I do want to know what size acme rod folks have used so I can duplicate this. Nothing better in design than a copy of success.

With respect to the ball nut, what type of threaded rod do they fit if not Acme rod? Sorry if this is dumb question.

Thanks
John

[buscht]

Ball nuts usually fit Ball Screws.
Acme nuts fit Acme threaded rod.
Machine nuts fit all threard machine rod

[johntbyrne]

I guess I knew that if I had taken time to think about it. Still interested in how long and diam of the rod being used in successful machines.

[InventIt]

1/2" 10tpi acme, about 4' Works good.

[yukonho]

I just received my 3/8-12 Acme rod from McMaster Carr. I have not installed it yet. I can tell you it looks very nice and is leagues ahead of threaded rod. I also received some brass threaded nuts for the rod. The precision cut nuts are not available in 3/8-12, I got standard ones, and I will probably end up making my nuts from delrin. Just have to either successfully make a tap from an off cut of rod or cough up 60 bucks for a tap.
Dimentions. My x will be 24" long, Y will be 10" Z 4" I currently use threaded rod 1/4-20 for an 18" span with no whip problems, so I dont expect any whip problems with the Acme over 24".
I ordered some cheap thrust washers and will use them, and I am considering tensioning the rod to prevent any whip. It will be an easy task to do that with the thrust washers.
Hope this helps some,
co

[cnczane]

Same here.
1/2" 10tpi acme x 3' for a 30 x 30 MDF based machine.

I used 10tpi for easy math. Of course 1 Million/in would've been even easier...

[kanankeban]

Originally posted by dnelson Same here. 1/2" 10tpi acme x 3' for a 30 x 30 MDF based machine. I used 10tpi for easy math. Of course 1 Million/in would've been even easier...

What type of fanges do you use for mounting the acme rod, and what type of nuts do you use...to make all the assembly? And what material is best to get, stainless steal?
REgards...
Hector

[Chagrin]

The "oil finish" acme rod is good. I would expect stainless steel to just be more difficult to work with.

Enco or such will sell acme nuts to go with the rod but most people here have created their own from from a hard plastic like Acetal (aka Delrin), Teflon, UHMW, plastic cutting boards, etc for less backlash -- search the forums for examples of such, since there's many different ways of doing this. Tapping the plastic can be done by creating a tap from a short length of the acme rod itself.