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Has anyone here set up a CNC fourth axis with a strong (rigid) tailstock? That is to say a tailstock that rotates and uses a chuck like the headstock. I'm thinking about doing this. I understand the alignment must be perfect. Any posts on the subject? I did a few searches and found nothing. Has anyone done this either DIY or with commercially bought parts?
Here's an example of one available commercially.
Strong Tailstocks | Strong Rotary Table Tailstocks
Any luck with this. I'd like to do the same.
I see I made the first post a while ago...when I was in the design stages of this build. I've been working on building the machine and am contemplating doing a build log for the remaining work. Right now I'm tapping holes for my rails. I'm looking at being ready for paint and completing the 4th axis this summer.Quote:
Originally Posted by sil9mm
To answer your question, as far as the 4th axis of my build is concerned, it will be the last thing I make. I have procured an alpha wittenstein torque plus planetary gear with less than 1 arcminute of backlash and a gear ratio of 38:1. It's very nice, weighs about 90 lbs. I think it will be an excellent 4th axis platform and I will be making a mount for it and an adapter plate for mounting a chuck. I will be implementing a two chuck system, the exact details of what I use for the 2nd chuck are TBD. I'd love to see your progress if you try something similar.
If you can find a small old used lathe and re-purpose it that might be a cheap alternative. Swapping to a stepper or servo motor setup would be fairly simple.
What's the point of doing this, exactly? Most 4th axis setups use a chuck at one end, and a live center (or dead one) in the tailstock. That way, the workpiece won't be torn apart if the speed on both ends isn't perfectly synchronized. Having to run another driver and motor to power another chuck on the opposite end of your workpiece sounds like a big waste of money and effort to me - but maybe I'm missing something?
Yes. I'm planning to incorporate a lathe bed and lathe parts. For the headstock, the planetary gear is where it's at, not only for the gear ratio, but also for the lack of backlash.Quote:
Originally Posted by coherent
Yes, you're missing something. Only one end is driven. The second is free spinning even though there is a chuck attached to it. The point is that I don't want to have to worry about drilling a perfectly centered hole to insert a live center every time I change the work piece. Just take the old work piece out, and put a new one in. Is there an easier way to accomplish this? Am I missing something?Quote:
Originally Posted by awerby
I built a small 5th axis of measured dimension 24"Lx6"W. It is mainly of aluminum material construction. With harmonic drives on both axis. Before the build, I had the thought of using twice drives on trunion axis as what you plan. Because of the budget and the complexity, the final outcome is a single drive on this axis. What I thought was that the material on turnion bed is aluminum and also relatively long, so it had the chance of twisting. The problem of complexity is that the synchronization of the two drive is quite difficult. They must be mechanical linked together. I have a purchased gantry High Z-S400 router milling machine, I had a diy mechanical link to the two drives. This is a most safe way! I use it mainly for aluminum machining.
But, depending on the rigidity of the 4th/5th axis construction and on the cutting if is heavy. Then, it may or may not be a necessity....
That sounds interesting. I'd love to see a picture of what you did.Quote:
Originally Posted by raychar1234