Question for Iggy

Well, some ideas you just have to go make some chips to learn what you really need to do. Some ideas you need to wrap your mind around for a while and then just go crank it out. Some ideas you need to do the 2nd first and then the 1st 2nd before going back to the 2nd before getting back to the 1st to make a real part. (Clear as mud right?) I'm somewhere in the middle. Fortunately all the other projects and ideas help with the hard won knowledge and experience of the chip making process. There are a number of approaches and cost is a major factor.

For example its pretty hard to beat a preloaded ball screw nut with some spring pressure on it. Ok... so just make it with top quality ball screws right with antibacklash preloaded drive nuts? Not if you have a price target. Top quality ball screws alone without the cost of the rest of the parts of the machine cost as much as some machines. At the opposite end of the spectrum are 60 deg V thread lead screws with simple brass (or bronze for more money) pinch nuts. Cheap, effective, and somewhat accurate ones can be had, but at the cost of long term life and accuracy and uneven wear making it more complicated as your machine ages.

How about using a combination of things for a compromise. Delrin wears very nicely, but it has a load coefficient that will destroy it pretty quickly once you go over it... once. Backlash reduction... elimination... Backlash nuts work, but many machines can apply more force than the springs can take and when pushing hard you can lose your compensation, although repeatability on the same cut will be decent. Beef up the spring? Then you are working your motors harder too. Get bigger motors you say? Then your price goes up.

I said was "playing" with the idea. LOL.

Reply to
Bob La Londe
Loading thread data ...

Quality rolled ballscrews with minimal backlash, and software backlash compensation. Just keep the backlash to compensatable levels, and the drive system up to performing the compensation. Don't forget the pitch error screw mapping as well.

My little X2 mini-mill performs decently with it's stock ACME screws and bronze nuts, driven by 600oz steppers at 30 IPM which is a decent feed rate for a fractional HP spindle with a 2,500 RPM top speed. Even the much crummier Z performs surprisingly well with a stepper driving it's stock "fine feed". Certainly I could improve things, but I had about a week to get the machine running for a project and it's done quite well.

Reply to
Pete C.

It does require compressed air. For what specifically I have not determined yet. There is a filter drier (cheap kind) on the back of the machine. and it specifically lists some air requirements in the manuals. I was thinking it might be for the lubrications system, but it would make sense to be for an air release brake.

I was thinking about all this stuff, but I am still cleaning up the shop right now to make room for it, and to get he trailer inside.

Reply to
Bob La Londe

How many times has this one been posted? I seem to have seen at least a half dozen. Is there some problem with your newsreader, your computer, or your news server?

I'll trim the quoted text (below -- uncommon for my postings to bottom quote, but it fits for this, I think) to only what you posted -- but this should be enough to identify the article in question.

Good luck, D [ ... ]

Reply to
DoN. Nichols

I think it was a problem with aioe and Live. That post showed in the outbox forever, but there was never a was never an error on the send/receive. I don't seem to have that problem with Teranews or Eternal September.

Reply to
Bob La Londe

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.