A2Z CNC monster mill X and Y setup ordered with Kerk Screws

[Teyber12]

im going to veer slightly off topic here. for our purposes (benchtop cnc milling machines, not a haas), as long as you have the power to move... is there any disadvantage of running a low TPI screw to increase rapids? backlash is the same for any tpi screw, and the resolution of steppers is way higher then the accuracy of the machines (resolution != accuracy). just curious.

cheers

[GeneK]

Teyber12, I had an e-mail discussion with Tim at A2Z about the 5 tpi vs 20 tpi, he assured me that the 5 tpi uses the higher torque of the lower step rate.
I have found that he was right, before my max traverse was 20 ipm, with the new lead screws I easily get 40 ipm. I had thought that losing the mechanical advantage of the finer pitch would marginalize or even over load the Sherline steppers. But I find the low TPI has improved performance of my mill, and the extra length on the x and y axes is great.

GeneK

Originally Posted by Teyber12 im going to veer slightly off topic here. for our purposes (benchtop cnc milling machines, not a haas), as long as you have the power to move... is there any disadvantage of running a low TPI screw to increase rapids? backlash is the same for any tpi screw, and the resolution of steppers is way higher then the accuracy of the machines (resolution != accuracy). just curious. cheers

[g29cc]

Originally Posted by GeneK g29cc, I had my Y axis break in just the same way. I found the c-shaped adapter plate between the stepper mount and the mill base was tapered by about 17 thousand's from top to bottom. I mounted the adapter on a face plate on my lathe and skimmed the back surface to make them parallel. Before that I think the lead screw was not parallel to the mill base and the closer the saddle got to the stepper the more flex at the point where it broke. At least that's my analysis of what I think happened. GeneK

I'll Check that out today when I get to the shop.

I also wanted to mention that Customer Service with A2Z is good.

This originally was supposed to be an table and base upgrade for my Sherline, but ended up as a complete new mill before I knew it. Now I look at upgrading my Sherline again ( because it needs a base and table ) and I am at the same idea of making another Monster Mill. But I have a new NM145 Novakon coming soon, so maybe I ll just leave the little Sherline alone and let it cut little parts and stuff. Its still good for some basic parts that are super tolerant.

I ll post what I find on the stepper mount plate.

[g29cc]

Well still waiting on the return of my lead screw from A2Z. I am glad I went on my better judgment and bought a new screw. As its been 1 day shy 3 weeks of A2Z having my original broken lead screw with an original quote of 2-3 day turn around on machining ( figure 3 days return shipping so all in all about a week and a half turn around with shipping if everything was a perfect world ). I called today and the screw is supposed to be machined tomorrow and shipping. Maybe Cathleen meant 2-3 weeks on turn around for re-machining the screw.

I am just glad I ordered and bought a new one, or I would be sitting here with customers wondering whats going on. I ll have a spare lead screw I guess, so if another one breaks, I can atleast fix it while without waiting.

[GeneK]

I don't think mine was that long, but I did have to call after about a week. Then it was about two or three days. Just as a thought, if it happens again I plan to simply cut off the rest of the 1/4" part and center drill and tap so I can insert a home made stud to replace it.

GeneK

[g29cc]

I am not sure if I mentioned, but I have mine set to rapid at 160 ipm.

[Randall]

I have upgraded my X Y axis and lead screws and tuned it 120inch per minute rapids just until I reinstall limit switches. I have 200ounce inch steppers times 4 is 800oz inch. I don't understand the worry about loss of tourqe. A2z has great products.
Randall

[Fastest1]

I too have a Monster Mill. I noticed the wobbling of the X stepper mount when rapiding. I knew it was an alignment issue but have ignored it so far. Also I cant stop the Z carriage from moving just a little. I have adjusted the Gibs til the carriage wont move but the movement is still there. I really needed a bigger machine. I have made mine run in the 300ipm range. Here is a video running a 3D printing code as a test.
Stepper Songs running Slic3r GCode - YouTube

[Randall]

What size steppers are you running. That's blazing fast. I have not noticed any movement in X motor mount.
Randall

[Fastest1]

23-205-DS8 (3V 3A) steppers from the Hobby Cnc Pro kit.

Originally Posted by Randall What size steppers are you running. That's blazing fast. I have not noticed any movement in X motor mount. Randall