Recent Topics

3D Printer: Can a RAMPS 1.4 + Arduino run a RepRap SCARA?

by Bajicoy

Hi, building a RepRap SCARA from scratch, I have the mechanics down but I'm not so sure about electronics before I purchase them. Any help would be appreciated! (Or let me know if this is the wrong group to be asking this, no worries). Listed my anticipated hardware and you can answer any number of my questions, just link the number you're answering down below.

12V30A power supply + RAMPS 1.4 + Arduino Mega 2560 + 4 DRV8825 stepper drivers + ESP 8826 Wifi module, all for $40, if any of you have any alternatives to help me on a budget, feel free to let me know, I just want to be sure I'm not going to burn my house down when I start wiring fans and motors to it.

  1. I want to wire three 12V Fans on this printer, 1 V6 clone for the extruder and two radial cooling fans for the hot end. Diagrams online seem to show the RAMPS only has two 12V slots so I was wondering if I could directly wire the V6 clone fan to the power supply, seen it done on the FolgerTech i3 2020 but stop me if the smaller fans on clones can't handle this, the seller doesn't give a voltage so I am assuming what it is since it's an industry standard.

  2. Also, could I wire both of the radial cooling fans to the D09 slot rather than put one at D09 and the other behind the poly fuses? I just like the idea of controlling both of them from a single output and lets me put the V6 clone behind the poly fuses rather than directly to the power supply.

  3. Would four 2A Nema 17 stepper motors kill the printer? They're beefier than the usual 0.4A motors and I can get these stronger ones cheaper. Picked the DRV8825's specifically to handle current but I don't know how to do the math, 8A for motors + 12A for the heated bed + ??A for the hot end + 3 Fans + Wifi + etc, it makes me worry I should buy the more expensive 0.4A motors and sacrifice the good deal on a stronger printer.

  4. Could I plug a 32 Bit Arduino in as an upgrade later on or should I just get one and ignore the 2560? I don't want to buy something expensive and experimental for a baseline prototype either to burn it out or find out it can't be used. I will certainly look to upgrade the electronics down the road but that probably will be months after the start of the project.

Thank you for answering any of these questions! Feel free to shoot me any questions if I didn't provide enough information.

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Battery Management System ???

by kb3lnn

Hello all, I wanted to know something that was eating at me for some time now, but did not know were to ask. So I though I would try it here.If I were to build two 18650 battery packs using 13s BMS @ 20 Amp.each voltage is 36 VDC. and then I wired them together in parallel, would the then single of the two together result in a 40 Amp. output? And also how would one charge this as one single or as two battery's. Thanks in advance.

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by bboggess

I know this is shameless. But I am in a class and our grade is based on how many likes we get.
Check out my design. If you like it... then like it.


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DCMA Takedown

by gsargent

Just a little heads up that my object I created for the community https://www.thingiverse.com/thing:2220273 just got taken down by a DCMA request from a company called Krazy Kabs. Don't know if they actually own the rights to the Coleco tabletop arcade units from the 80's or if they are just going to steal my design and sell it for themselves. Either way it appears to be gone now. Just wanted to let everyone know.

Happy printing!

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The Filtering questions of MAX9926

by kynix

Good day,everyone~

We are using a IC-- MAX9926 from Maxim Integrated to filter 2 VR signals (from a HONDAS2000 Crank and Cam VR sensors) One being 24 tooth, and one being 3 tooth (per cycle of the Engine). At RPMs below approx 5000-6000 the signal comes through the 9926 fine, and triggers the MCU correctly such that it decodes it fine. At around this RPM we start to get extra/missing teeth on the IRQ lines to the MCU. Note we can 'push through' this noise and get to 9k RPM - just seems to be a 5-6K RPM issue...
MAX9926 Datasheet: http://www.kynix.com/uploadfiles/pdf2286/MAX9926UAEE2fV2b_13987.pdf

Well,We also used a scope to capture the signals at the entrance of the ECU to rule out electrical noise.
The signals are smooth and clear at both idle, AND when hitting the point the ECU loses sync due to the 'phantom' teeth. The scope doesen't show these phantom teeth so I am assuming it is a 9926 issue, or the parts R1, R2, C1, R3, R4, C26. The only difference between perfect idle signal and higher speed 'issue' signal is the frequency of the wave, and its amplitude, as shown in the plots. We have 50v P-P at high speed and around 20v P-P at low speed.

1) Maybe I should and how could I attenuate both signals say by half? (Adding what, where) 2) Should I reduce the value of C1/C26 as they might be acting as a filter?

With regard to (2) if I keep the throttle down and 'push through' the noise the engine will regain sync and run all the way to 9k RPM without issue, so that is also odd!

As a result,
Low speed, IRQs passed via 9926 so perfectly !

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