Simpson,

Can't see how the aluminum parts are heavier than cast iron Are they that much bigger in size (almost 3 times) or what?

I will be building an entire new machine frame also from aluminum and making a complete new head from aluminum.

Got to find a new name for your machine... you can't call it X2 any more I guess

Daniel

I watched your video of the grinding on the leadscrew. Impressive adaptation as always. Is there any reason why you grind rather than turn? Is the screw hardened so much regular cutters dont work well? Also I see you using rotary tables and indexers, do you control the table with a distance on the DROS referring to inches traveled or degrees? Seems like inches traveled would be different depending on how far away from the center of the rotary table as the work is spinning. Does any of that make sense?

Good questions. The shaft is very hard. In general: you can turn hardened shafts with ceramic or boron or diamond, but it takes an extremely rigid and powerful machine and the tools are very expensive. In the case of a leadscrew, you are facing an interrupted cut as well so to have success, you would probably need one of the reinforced versions of the inserts  . . now you are talking 30 times the cost of carbide. 

I'm not using a rotary table. I had a big one many years ago and recently I bought a small 6 inch rotary table  (PhaseII brand, pretty nice actually). But I only used it once before I sold it after converting to CNC.

I have only turned small 3/4" and down alum and steel parts, so for turning, the 4th axis is always running flat out at approx. 1,200 to 1,400 RPM. Other than that I use it for indexing and position it via azimuth (degrees). I have not messed with trying to set a surface speed via Mach using the part diameter. 

Simpson,

Can't see how the aluminum parts are heavier than cast iron Are they that much bigger in size (almost 3 times) or what?

Yes, bigger. Bigger and also thicker walls. The table for example is much bigger. Aluminum is light, but not THAT light. You would not want to carry a 1" x 6" x 48" piece of it very far. The X2 is very light, very thin wall castings. There really isn't a lot of material there.  I'm old enough to remember when cast iron was dirt cheap and aluminum was stupid expensive . . . and the very idea of an aluminum soft drink can was pretty outrageous . . . . . well, obviously . . . . things have changed.  In designing with aluminum, it is cheaper to go heavy with a less expensive alloy than to get the same strength from smaller parts made from the more expensive high strength alloys. If you are designing aircraft parts, weight and strength are primary, so you usually stick to the 7000 series, but for a machine tool, you have room for 'fat' parts and the weight is an advantage, so it plays well. I am making the head heavier intentionally to absorb as much vibration as possible on the tool side of the slide bearings. That mass has to be moved around by motors and leadscrews, so you can't just go crazy with it. I'll be putting cooling fins on the spindle for sustained high RPM running.

Quote from: simpson36 on November 10, 2009, 04:33:52 PM

I will be building an entire new machine frame also from aluminum and making a complete new head from aluminum.

Got to find a new name for your machine... you can't call it X2 any more I guess

Daniel

Suggestions?

Well, with all those modifications it can't be an X series any more... should move on to Z1 ("Y1" doesn't sound well)

Daniel

Well, with all those modifications it can't be an X series any more... should move on to Z1 ("Y1" doesn't sound well)

Daniel

When I was a teenager, someone remarked that my car could be very easily fixed up nice. All I needed to do was jack up the gas cap, roll a new car underneath and then let the gas cap down. 

If I use only the spindle from an X2 . . . . would that be considered 'contamination' of the 'Z1'?

You got to leave something from the X2, otherwise we won't believe you it was an X2

Daniel

:DYou got to leave something from the X2, otherwise we won't believe you it was an X2
Daniel

I found a heat treating place about a hundred miles away here in Texas, so I *might* be making my own spindles after all. We shall see

Here is the latest video showing the final iteration of the PCB routing and drilling operations. http://www.youtube.com/watch?v=r9Zf_5yHB1I

Based on some feedback I got, I kicked up the feedrate and am using my mister to provide a constant air stream. I'll mount a vacuum nozzle on the fixture, but not make a new video just for that, so this will be it until I finish or make significant progress on the new frame including the all new Z axis.

After much whining on my part, I have convinced CNCdrives to provide these little circuits free to US customers of their drives until the function is built into the drives (planned for future version apparently) I even offered to make the parts (just for fun really, cause I think it's very cool that I can actually make an electronic anything that actually works . .LOL!!) Well, they said OK, but it would need a cap across the power pins and also a top quality IC socket. The one I used initially was apparently an embarrassingly cheapo version that they object to. So I made the changes and the part will be available to anyone who wants it . . free to US buyers of any CNCdrive Whale or Dugong servo drive.

I would assume that heat treating is the easiest step in making a spindle. If you can handle the machining involved, then why not.

What PCB are you talking about and who is CNCdrives and what's their story?

Daniel

I would assume that heat treating is the easiest step in making a spindle.
What PCB are you talking about and who is CNCdrives and what's their story?

Heat treating is easy enough if you know what your doing AND have the equipment. I sold the whole shop many years ago and the furnace went with.

Here on the Mach forum a search should turn up a thread where I did a review of several available servo drives. In that review I refer to a weakness in the error line of the DNCdrive products which prevented them from driving my optoisolated BOB reliably. I am not an electronics guy, but I came up with a sort of Rube Goldberg contraption that did fix the problem. CNCdrives showed me the better way to do it and provided the information I needed to design the physical PCB that would not only boost the error signal for an optoisolated BOB, but would also drive a remote LED indicator light that I insisted on having. Credit goes to them for the circuit, I just made the physical parts . . . which was actually big fun for me.

The circuit was born of those necessities, but it has many applicatons since it can take in a pretty wide vaiety of voltages and signal strengths and convert them all to a clean 5V signal, as well as split out a second identical clean 5V to power a remote LED from the same input.  For example I had a lot od problems with false e-stops from the limit switches. One solution is to run the switches at 12V, but you then must convert that back to 5V for the BOB or you burn things up, so this little board is a perfect solution to that.

My BOB is a CNC4PC brand and has lots of LEDs on it. I love that whole concept of montoring what's going on, and in it's present iteration, Mach is pretty vaugue as to why it e-stopped and an indicator is not much good under the counter in a closed steel box. This little cicuit board can tap into literally any signal in your boix and drive a remote LED. I think it is a very important solution. 

Ah.... Lucky CNCdrive to have customers like you

Routing PCBs on the mill is fun indeed. Did it once and really enjoyed the process.

Daniel