Newbie- Couple of simple questions on lead screws

[Huzzah]

Hello, I'm starting to do some research to figure out what I want to buy and had a couple of simple questions. Seems I can find answers to the harder questions but not the easier ones!

I'm assuming it doesn't matter if the threading is right hand or left hand?

How big of difference does finish make to performance, or is it all about rust prevention? Specifically, I'm looking at the cost difference of stainless vs black-oxide vs steel and wondering what the best choice is.

Is Acme threading the same as Hi-Lead? I was looking at Roton and looking at 1/2"-10 lead screws. All multi-start screws are listed as Hi-Lead. The reason I want to know is to determine if I can buy the anti-backlash nuts from dumpstercnc.com which state they are for acme threads.

Thanks,
Steve

[arizonavideo]

"Is Acme threading the same as Hi-Lead? I was looking at Roton and looking at 1/2"-10 lead screws. All multi-start screws are listed as Hi-Lead. The reason I want to know is to determine if I can buy the anti-backlash nuts from dumpstercnc.com which state they are for acme thread"

The Dumpster nuts will fit the Roton 1/2" 2 start 10 TIP screws and the Mc-Master screws but all 4 of my nuts from Dumpster had backlash I had to replace them with the nuts that Roton sells.

The Roton screws work fine and the standard metal is fine.

If you want over 75 IPM you might go with a faster screw and then you will have to get your nuts from Dumpster if you are direct driving your screws with a stepper.

The 1/2" 10 TPI 2 start (5 TPI) is a good starting point for many router tables but if you only plan on wood you might get a faster screw.

[CarveOne]

Originally Posted by Huzzah Hello, I'm starting to do some research to figure out what I want to buy and had a couple of simple questions. Seems I can find answers to the harder questions but not the easier ones! I'm assuming it doesn't matter if the threading is right hand or left hand? How big of difference does finish make to performance, or is it all about rust prevention? Specifically, I'm looking at the cost difference of stainless vs black-oxide vs steel and wondering what the best choice is. Is Acme threading the same as Hi-Lead? I was looking at Roton and looking at 1/2"-10 lead screws. All multi-start screws are listed as Hi-Lead. The reason I want to know is to determine if I can buy the anti-backlash nuts from dumpstercnc.com which state they are for acme threads. Thanks, Steve

Left or right thread should not matter since Mach3 lets you easily reverse the motor rotation. You can also reverse the motor wires on one phase to do the same thing.

Stainless is expensive but has no serious rust issues. Not sure how anodized lead screws will affect delrin lead nuts since I have not used that combination myself.

Two start has a higher lead angle than one start and is why it is called "faster" since it moves twice the distance in one rotation. You will lose a small amount of resolution though. Screws are available in up to 8 starts (individual grooves). 5 and 8 start screws are commonly used on home built CNC machines for woodworking. For accurately machining aluminum the 1 or 2 start ACME screws will give better accuracy at the lower inch per minute speeds that metal machining typically needs. There are lots of trade-offs to consider as you buy or design your machine.

CarveOne

[Huzzah]

Thanks for the replies, very helpful. This is my first go at it and I'm hoping to rout mdf, plastic, and thin aluminum (.050"). It sound like the 1/2" - 10 2 start would be a good compromise of speed vs. accuracy.

I'll do more research on the dumpster nuts before buying, thanks for the warning.