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Author Topic: Final Build  (Read 21527 times)

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Offline BarryB

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Re: Final Build
« Reply #20 on: November 23, 2009, 09:08:49 PM »
More picts.  I didn't get as much done as I wanted to today.  Working with the Z axis was a biotch.  Still though, after doing this much I had to see it move, even though, really only the x mechanics were hooked up.  It moved like a champ though, awesome!





Barry
Re: Final Build
« Reply #21 on: November 23, 2009, 09:19:15 PM »
I want a copy of your plans!  This thing will be great for 5 or 6 axis!  Great work there Barry!!!!!  8)  I'll bet 80/20 loves you!!

Offline BarryB

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Re: Final Build
« Reply #22 on: November 23, 2009, 09:28:33 PM »
I'm not opposed to making my plans available.  I designed this to be 6 axis, and that's what my wiring diagram would be in the plans.  Do you think people would pay a fee for the plans?  I did spend a crazy amount of time modeling everything.

Heh, 80/20 loves me spending my money;)  I'd love to be in the 'made with 80/20' catalog though.  I'm not sure how you get in that though.

Barry

Offline Sam

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Re: Final Build
« Reply #23 on: November 24, 2009, 02:18:23 PM »
Great looking machine Barry. I like it. I do have a question for you, though.

Put an indicator at the bottom of the Z axis, so as to read the distance between the axis and the table.
Push the top of the Z axis.
Pull at the bottom of the Z axis.
How much did it flex?
Keep in mind you will have the section with the trucks added on, along with the spindle, and any other mounts. All adding more weight to the equation.

I too, have a gantry made with 80/20. The rails are mounted the same as yours-directly to the 80/20. The posts, however are made from steel. The length of the gantry is roughly the same. I think yours is a 2 or 3 inches taller than mine. I am less than pleased with my gantry. Actually, it is one of the "live and learn" lessons on my build. I found that the rigidity of the 80/20 is comparable to a wet noodle. Well, o.k. maybe not that bad literally, but in terms where you need a halfway decent finish on a part, it's a pretty fair comparison. I find that the Z-axis bounces around so much (because of the flex in the X-axis) that I have to make more finishing passes than I should have to, and the speed at which I make the finishing passes is far slower (to minimize the bounce) than what it should be. This in turn can create other problems, especially if you need the speed, to get a proper cutter finish.  Cuts in the X directions are fairly good, but when you exert any force or motion in Y or Z directions, the demon shows its teeth. 3D paths and\or many short changes in movement are an absolutely horrid affair. That sums up 90% of the machining I do, coincidentally.
In my case, you don't even need an indicator to see the flex, and my Z axis has only 6 or so inches of travel. I'm in no way trying to shoot your design or build down. I like it, and hope that you can throw it off the top of a building, run over it with a tank and explode some C-4 on it, and it never skip a beat and run like a champ. I'm simply stating a concern where a potential flaw is present, and thereby saving you allot of grief at a later stage. It would be much easier and convenient to fix it now rather than later, (if your has the same problem as mine) as you are somewhat still in the design and build phase.
I see that you have dual ball-screws for the Y movement. I had a short ball-screw on mine for testing purposes. I didn't have 2 long ball-screws, so I decided to drive mine with 2 belts. Big mistake, wish I would have bit the bullet and purchased 2 ball-screws like yours.
« Last Edit: November 24, 2009, 08:36:15 PM by Sam »
"CONFIDENCE: it's the feeling you experience before you fully understand the situation."

Offline BarryB

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Re: Final Build
« Reply #24 on: November 24, 2009, 09:51:35 PM »
Thanks for the concerns Sam, I'll keep that in mind if I do a mill 2.0.  The design phase has been over for a while.  This is now assembly.  Here's the progress for today.  The Z-axis is now done, and I've hooked up the B/C drive as well.  The spindle looks rather lonely by itself on the table now, but I didn't have time to connect it.  I'll do that in the morning.  The Z axis is still really stiff, but we shall see if it's still that stiff once the weight of the spindle is on it.



Barry

Offline BarryB

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Re: Final Build
« Reply #25 on: November 26, 2009, 06:58:32 PM »
Hey folks, I'm trying to finish the build over break, but the family is so needy;)

Here's the machine with the spindle on it, and also limit switches and plus/minus x, y and z.

For some reason Mach3 is crashing right now when I tell the spindle to turn on.  It didn't used to do that, that's damn annoying.  Anybody run into that oddness before?



Barry
Re: Final Build
« Reply #26 on: November 26, 2009, 07:06:02 PM »
Looks great there Barry.  Maybe your problem is that now that you have something really hooked up it needs to be switched in the config file.  Someone else will chime in that would know more about this than I. 

Offline BarryB

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Re: Final Build
« Reply #27 on: November 26, 2009, 07:17:42 PM »
thanks, it's been a struggle getting all this together.  I did put one part in wrong (didn't follow my own design) and that caused havoc.  I had to take a bunch apart and put back together.

Yeah, if anybody has experienced the spindle crashing, I'd like to know.

Barry
Re: Final Build
« Reply #28 on: November 26, 2009, 11:20:36 PM »
Maybe you have 2 axis assigned to the same setting?

Offline Tweakie.CNC

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Re: Final Build
« Reply #29 on: November 27, 2009, 06:46:15 AM »
Hi Barry,

Please don’t take this the wrong way – I am not trying to be critical or clever but…

Looking at your last photo I notice that there is a large unsupported distance between the position where the tip of your cutter will be and the first trucks on your Z slide.
It would involve a bit of a design change but if you reverse the positions of the slides and trucks (fit the slides to the moving part and the trucks to the fixed part) it will offer a reduction in this distance and possibly a considerable reduction in the resonance of this axis.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.