Yes, THIS. Ballscrews are industrial-grade components and should be the least of your worries. The truth is, you’d probably have to have thousands upon thousands of hours of use before they show even a hint of wear, and only then if you’re doing some very precision work. Contamination is unlikely with reasonable cleaning & care, the seals do a good job of protecting the bearings within the nut. Same for the round rails, they have the least chance of getting contaminated as compared to any other style linear rails.
Thanks for the feedback Bill, Jared, and Jake, very much appreciate your knowledge on the topic! I will stop worrying and just prepare my spot in the garage.
I was already imagining some accordion like cover i could put around the round rails that would expand and contract as the gantry moved to prevent dust and debris from landing on the rail. But that sounds like it might be overkill
Yeah, that doesn’t appear to be an item of concern, really. Nothing wrong with minimizing exposure to dust, but probably not a game-changer.
Here are two pictures a ball nut. They are designed to prevent anything from getting inside the internal part of the nut where the ball bearings are circulating. On both ends of the ball nut you can see a White ring. They are like big thick washers that are threaded to fit the screw. This is a wiper ring and is designed to collect any debris that is on the outside of the screw and push it off. Think of it as a snow plow. The debris will built up on the wiper ring and as it accumulates, it will simply fall off. I’m not sure what the ring is made of but it feels like it delrin or teflon. They fit snug around the screw and do a great job of keeping debris out.
I considered using an accordion style rail cover also, but the mounting of it will be a bit tricky since the machine that uses stall based homing. The spindle gantry has to be able to make contact with the left and front rail ends without obstruction. I’m sure there’s a way around it but from what I’ve been reading if you keep the rails cleaned off every so often the bearing wipers and seals themselves should be sufficient. I still keep coming back to how much better this has to be than rubber belts and v-wheels!
That was my first thought about an accordion-style cover, is the stall homing. That would most certainly be an issue.
I am thinking of cutting some plexi shields to place on the inside of the Y rails. I think that would keep most of the dust off the rails. I don’t think the X rail is much of a worry
So Charley, I haven’t even got mine yet but think I should have some spare parts. What can you tell me that maybe I should get/order for spare parts. Standard size set screws?? Plastic parts? Any ideas?
It looks like 1f just posted replacement ball screws to their site for a decent cost of 62.50. https://www.onefinitycnc.com/product-page/ball-screw-woodworker-version
Didn’t someone make external wipers to install on the 1F to help protect the bearings
Check this, made by @TMToronto
If you have those little threaded standoffs, it shouldn’t interfere with the stall homing…
I do think having something like this would be significantly better.
Does increasing the jerk/accel/velocity to its maximum have an impact on wear of the ballscrew/bearings? I’m weary to increase it, and can deal with excess time if it means less wear.
you did understand that in my previous post above, with the clickable link in the word “precisely”, I led you to the posting where the project of the external wipers is presented, did you?
Anyway, welcome to the forum!
Just in case anyone wants to see how the ball screws actually work. Unlike a lead screw nut (which is subject to wear from friction) the ball screw is like a ball bearing.
My first attempt to protect the ball nuts was indeed a bellows-style setup, but it required me to install standoffs to allow the machine to stall home a couple inches prior to hitting the axis end, this was to leave enough room for the retracted bellows. I assumed most people would not want to lose 4-6" on both X and Y axis… I haven’t abandoned the idea, but I don’t have a better solution that doesn’t reduce travel.
Currently I use curtains and wipers on my machine. The curtains are not the most elegant solution, but really help contain chips and keep the Y axis rails and leadscrews nice and clean.
Defects aside, I think ball nut lifespan will greatly depend on your maintenance routine, materials you work with, lubrication of the machine, humidity levels etc… I have some old DIY machines with cheap ball nuts that are close to 10 years old and still kicking.
Those curtains will be quite effective in containing the mess and minimizing ball screw & rail contamination. I have something similar on my machine. They’re just a couple pieces of scrap vinyl flooring I had. When I get the opportunity, I’m going to replace them with taller pieces to further protect the screws & rails. I can go a couple inches taller with them.
Bill, I seem to recall at least one Pico produced walking beam robot that employed something similar to what you and Tuvix72 are doing here. Though I think they consisted of telescoping sheet metal because flex bellows tended to sag. The end result keep things neat and clean.
Phil, talk about a memory-jog. I recall working on a couple of those when I was at Novi Industries (which was a PICO shop).