Re: Hotbed flatness, voodoo or scientific method? May 07, 2015 12:43PM |
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Re: Hotbed flatness, voodoo or scientific method? May 07, 2015 12:55PM |
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So where would we be if money was no object?
Re: Hotbed flatness, voodoo or scientific method? May 07, 2015 01:05PM |
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Re: Hotbed flatness, voodoo or scientific method? May 07, 2015 01:59PM |
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Re: Hotbed flatness, voodoo or scientific method? May 08, 2015 04:30AM |
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Re: Hotbed flatness, voodoo or scientific method? May 08, 2015 06:25AM |
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Re: Hotbed flatness, voodoo or scientific method? May 09, 2015 10:51PM |
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Re: Hotbed flatness, voodoo or scientific method? May 12, 2015 11:33PM |
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Re: Hotbed flatness, voodoo or scientific method? June 21, 2015 10:38PM |
Registered: 11 years ago Posts: 1,277 |
Where from for that 30 dollars and for those of us without a DP we would need one with holes pre drilled. Funny that this really flat aluminum is not sold for our beds.Quote
the_digital_dentist
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JamesK
That 1/4" plate sounds nice, but it will add a lot of mass to a moving print bed design. The simplicity of the Prusa layout is very appealing, but I keep finding myself drawn to a core-xy layout with the bed motion confined to Z. Maybe next time.
I was wondering about epoxying some pieces of aluminum U channel to the heat bed to increase flatness and rigidity, but I have my doubts about how the combination would cope with thermal expansion/contraction. My current plan is to have the heat bed track side up with a thin aluminum sheet to act as a heat spreader and glass on top as the print surface. I guess with that layout I could tolerate some warp in the heat bed itself as long as the aluminum and glass stayed fairly flat and there was still adequate heat transfer. Maybe I can bond the aluminum to the bed with a thermally conductive glue?
What are you trying to achieve by combining all this stuff? Putting multiple thin layers of different materials together, each with different expansion and warp behaviors over temperature, is a sure fire way to never get the thing flat. An aluminum plate is simple, inexpensive, and works without any screwing around. My 12" x 12.5" x 1/4" plate cost about $30. Are you going to save $5 and 100 gm by using thinner sheet and a piece of glass, and some mystery adhesive?
Re: Hotbed flatness, voodoo or scientific method? June 22, 2015 12:14AM |
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Re: Hotbed flatness, voodoo or scientific method? June 22, 2015 12:54AM |
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Re: Hotbed flatness, voodoo or scientific method? June 22, 2015 07:23AM |
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Re: Hotbed flatness, voodoo or scientific method? June 22, 2015 08:38AM |
Registered: 11 years ago Posts: 5,780 |
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Mic 6 Aluminum
Stability is the defining characteristic of MIC 6® Aluminum. Only MIC 6® is cast to near net thickness with a stress-relieved, granular structure to virtually eliminate distortion from machining and end use temperature fluctuations.
The manufacturing of the MIC 6® is the most advanced process in the cast plate industry. It promotes consistancy between plates and reduces the risk of disrupting material stability by entrapped stress. The optimium in molten metal cleanliness has been achieved by the continuous application of SNIF degassing and impurity removal technology to every MIC 6® plate that is cast.
MIC 6® allows for down-stream processing with precise control of tolerences and dimensionality. MIC 6® is a free cutting aluminum alloy that produces small, uniform chips in a variety of high speed operations.
MIC 6® customers can perform extensive machining routines involving metal removal with minimal risk of distortion, often exceeding the product accuracy requirements of the most demanding uses.
Re: Hotbed flatness, voodoo or scientific method? June 22, 2015 09:15AM |
Registered: 8 years ago Posts: 778 |
Re: Hotbed flatness, voodoo or scientific method? June 22, 2015 09:45AM |
Registered: 11 years ago Posts: 1,277 |
Who is complaining? I never even knew this existed for this cheap. I am glad I found my size that is as exact as to the third place so I do not need to cut it (eliminates a problem). I will just do ground shipping because they are so close to me it is 3 day shipping. Yes, the Prusa i3 rework is a turd as far as design goes but once I can start printing I will fix some of that with those TR8x2 for Z and get on a better Z endstop (I wish I had a repeatable Z endstop but these micro switches are far from repeatable).Quote
the_digital_dentist
Yes, that plate should work.
IRIC, I picked my plate up at the local Speedy Metals two years ago for $30. Yes, unfortunately, prices rise and companies do charge for shipping. I don't understand why you're complaining about the cost of the plate. You just spent extra to get 2nd day air delivery. Someone who does that doesn't seem to actually be too concerned about cost. You don't have to worry, UPS won't be able to bend that 1/4" plate if they try.
Cast tooling plate isn't "tempered" or hardened. Casting is the method by which the plate is manufactured. Here's some verbiage from one manufacturer:
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Mic 6 Aluminum
Stability is the defining characteristic of MIC 6® Aluminum. Only MIC 6® is cast to near net thickness with a stress-relieved, granular structure to virtually eliminate distortion from machining and end use temperature fluctuations.
The manufacturing of the MIC 6® is the most advanced process in the cast plate industry. It promotes consistancy between plates and reduces the risk of disrupting material stability by entrapped stress. The optimium in molten metal cleanliness has been achieved by the continuous application of SNIF degassing and impurity removal technology to every MIC 6® plate that is cast.
MIC 6® allows for down-stream processing with precise control of tolerences and dimensionality. MIC 6® is a free cutting aluminum alloy that produces small, uniform chips in a variety of high speed operations.
MIC 6® customers can perform extensive machining routines involving metal removal with minimal risk of distortion, often exceeding the product accuracy requirements of the most demanding uses.
The stuff about eliminating distortion from end use temperature fluctuations is one of the things that makes this stuff great for 3D printer beds. It's flat, thermally conductive, easily cut/drilled, and maintains its shape with variations in temperature. What more do you need?
Of course, if a 12 x 12 plate won't fit in your printer you either have to find a smaller plate (as you did- that wasn't so hard, was it?) or cut it to fit. You can cut aluminum plate easily with a jigsaw, bandsaw, or a table saw with a carbide blade.
I appreciate that you spent more than $300 on your machine. You bought a bunch of more expensive parts to build an i3 printer than the $300 kits normally come with. Unfortunately, the materials aren't the whole problem- the design is poor and using more expensive materials doesn't fix the design problems. Mild steel, stainless steel, or diamonds doesn't change the fact that threaded rods are bent and have no place in a precision mechanism. 8mm end supported guide rails flex equally whether they are surface hardened or not. Using two motors to drive the Z axis screws means you'll be realigning the X axis frequently.
As my grandmother in Tennessee used to say, "you can't make a silk purse out of a sow's ear".
Re: Hotbed flatness, voodoo or scientific method? June 22, 2015 10:02AM |
Registered: 9 years ago Posts: 1,873 |
Re: Hotbed flatness, voodoo or scientific method? June 22, 2015 10:43AM |
Registered: 11 years ago Posts: 5,780 |
Re: Hotbed flatness, voodoo or scientific method? June 22, 2015 10:43AM |
Registered: 11 years ago Posts: 1,277 |
So, I am asking how much would that plate be for exactly 220mmx220mm @ 6.35mm (1/4") if it is more I will simply get the imperial which is so close to 220mm sq. it really wouldn't matter.Quote
Midwest Steel & Aluminum
We are domestically partnered with Vista Metals out of Fontana CA, our Vista Metals ATP-5™ cast aluminum plate can be produced in custom widths and lengths with a very short lead-time.
Re: Hotbed flatness, voodoo or scientific method? June 22, 2015 10:47AM |
Registered: 11 years ago Posts: 1,277 |
When I used a mechanical switch (exact same one used in endstops) without the paddle for my ABL it was repeatable to exactly two decimal places which is pretty tight but is the optical any tighter?Quote
the_digital_dentist
I was using a microswitch for the Z endstop and it worked fine. I recently switched to an optical endstop to see if it was any better.
If you use a lever on the microswitch I think you'll have problems with precision- the combo of the lever's springiness with the microswitch's internal springs makes for unpredictable switching. If you directly push on the button on the switch it works well enough.
The main difference between an optical and microswitch endstop is that the opto interruptor has no hysteresis. It switches when the beam is blocked/opened. There's no adjusting it until it clicks then backing off the screw "a little" to compensate for the hysteresis. Also, the opto endstop doesn't click when it switches, so you need an LED or other means to monitor the switching. My smoothieboard displays the status of the endstops on the LCD display so that's how I adjusted the opto endstop.
Re: Hotbed flatness, voodoo or scientific method? June 22, 2015 02:05PM |
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Re: Hotbed flatness, voodoo or scientific method? June 22, 2015 03:18PM |
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Re: Hotbed flatness, voodoo or scientific method? June 22, 2015 05:03PM |
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Re: Hotbed flatness, voodoo or scientific method? June 22, 2015 05:18PM |
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Re: Hotbed flatness, voodoo or scientific method? June 22, 2015 06:15PM |
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Re: Hotbed flatness, voodoo or scientific method? June 22, 2015 06:24PM |
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Re: Hotbed flatness, voodoo or scientific method? June 22, 2015 06:27PM |
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Re: Hotbed flatness, voodoo or scientific method? June 22, 2015 07:04PM |
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Re: Hotbed flatness, voodoo or scientific method? June 22, 2015 07:27PM |
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Re: Hotbed flatness, voodoo or scientific method? June 22, 2015 10:16PM |
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Re: Hotbed flatness, voodoo or scientific method? June 22, 2015 10:27PM |
Registered: 11 years ago Posts: 1,277 |
No, it really is pretty easy with how UPS treats their parcels now. Fact is my frame and my frog were both bent by them.Quote
JamesK
Bending a small piece of 1/4" plate is quite difficult. I think you should be ok, even with UPS involved.