That's a big bed. Just make sure you find a headbed that works on 110v.

 

Are you talking about the 3d electronics ?? If so I am very familiar. You also can look at my design called the BAFP 3d printer. It not quite as big as you need but the design ideas might save you some time. You might also be able to get 1 heated bed that size.

Thanks Steven

 

The Rumba board may have enough drivers for your extruders, etc. Trigger the heat beds with a couple relays and separate power supplies. Run the 4 z steppers using separate driver boards, like a CNC mill. 4 Nema17's can run on one supply and pull the direction and pulse signals from the Z axis Ramps chip socket.

We have a huge assortment of very, very smart builders here that I learn a new trick from every time I check in. I'll be watching as much for their responses as seeing your build come to life. It should be impressive.

 

FWiW, I think I'd increase the build plate to at least 1/4" (0.250"), or even 3/8" (0.375") would be better. A 42x47" plate is going to have a tendency to bow a lot unless you put a lot of support under it or have it much thicker than you'd like.

 

I have a Rumba card on my big printer and we are also using it for the new one I am building. I like how big the printer is going to be. I am just concerned that you are using a moving build plate vs a stationary one. That is going to be a huge amount of weight to move up and down.

Thanks Steven

 

Hey Steven, I just received my first Rumba, Are there any oddities with the firmware? I really like the appearance of the board.

 

There is only one weird thing that can possibly happen. Sometimes there has been an incompatibility between the rumba drivers and the USB drivers on specific computers. I have seen this happen twice where you cant load the drivers on a computer. But most computers work fine. After that, just load the current Marlin release and make your changes to the configuration file. Also always power down / up the rumba board before you load firmware changes.

 

So why not move your print head up and down. A lot less weight / motors / drivers and thibgs to go wrong

 

I have seen them but rumba board is a great value. They all work basically the same anyway

 

Hey, any updates on this ?? I want to see this one finished !! Its going to be big

 

That thing is gigantic...

 

That is so solid looking, I bet you could hold up a car! If you had a GOOD tig welder around who could tig those corners together it might be stronger, but other than that, I couldn't guess what else you could do to improve them. Great Job!

 

Any new progress ??

 

Indeed, it may sound counter intuitive at first, but lowering the bed one layer at a time seems to be a better solution than having the extruder flying around.
Imagine you have to print a large section (worst case scenario). The bed won't move down until the first layer is completed, which may take a while, depending on the complexity. If the x and y axis are part of the machine frame, they will be inherently stiffer.
On the other hand, keeping the bed fixed and having the extruder move around on its own mobile sub-frame, might invite trouble.
One gives up the natural stiffness, provided best by the very machine frame, and I believe the gain in speed would not be very significant.
My first approach was fixed bed and mobile x and y axis, until I realized that when a 2lbs. extruder such as mine, when moving along the axis at high speed, will create quite a push onto the rails and the screws due to inertial forces.
Resting the x and y axis on the frame and having the bed move down one layer at a time seems to be the best approach, especially for large printers.

 

Greg, I am using a smoothieboard for my printer.
The printer has four nema23 for the bed lead screws, two nema23 for the y axis, two nema17 for the x axis and two nema11 for the dual extruder.
If you can wait a bit, the new smoothieboard 2.0 is in the works, check with arthur wolfe for more info.

 

Hi Greg,

Yes, the smoothie handles everything with no problem whatsoever. In order to give you the right picture, please be advised I am using external stepper drivers, rated at 5 amps, whereas the nemas 23 are rated at 4.5 amps. The four z axis stepper drivers are linked in parallel, as are the two nemas 23 for the parallel y axis, and the two nemas 17 for the x axis. As far as setup is concerned, all I had to do was the proper wiring (parallel, as mentioned) of the stepper drivers, bypass the onboard drivers (which, at 2 amps are too weak to handle a nema 23) then plug in the end stops, smoothie, the works, and it worked at first crank. If you follow the proper procedures, it will work. The reasons I chose the smoothie are its arm32 processor, several times faster than arduino's cpu. Configuring it is really simple, and the onboard firmware is updatable like a computer. Please find attached pdf, showing the axis and steppers layout, very similar to yours, and a picture showing the parallel connections of the stepper drivers, to help you visualize my above explanation. One more thing: I am not an electronics expert myself, but my associate has a PhD and a lot of experience in this field, and he warmly recommended the smoothie over arduino or rambo, due to its setup simplicity and ease of use.

 

Val, Greg, You seem to have good knowledge of the smoothieboard setup so I'mhoping you might be able to make a suggestion ( I'm not trying to hijack the thread) My son and I have built the physical parts of our printer, and are trying to install the smoothie board. We are stuck at the wiring layout where they suggest directly running pos+ power to each of the mosfets. They also show that a diode needs to be the pos+ line (to left part of the image near the 12-24v inputs) . In all my reading I have found no real indication of the proper type or size for the diode they suggest be placed inline, at the VBB (a notation about the fan section shows 2 small 1a ones to install behind fan mosfets, but that is all). Is something like a # 1N2128A .. 50v 60A Power silicone rectifier diode the right kind? do I need to worry about any voltage drop? Thanks,

 

looks very nice !!!

 

hi alar,

you give me too much credit with regards to the smoothieboard.
as i was saying in my previous post, i have a lot of help with the electronics from my associate. i regret i cannot help you myself with the technical question you posted, but please be advised i connected my smoothie to a windows 8 samsung tablet via usb port, thus solving the power supplying issue to the board itself. while this may not be a permanent solution if one wants to run the printer independently via sd card, it does help greatly in the incipient phase of fine tuning and adjusting the machine, where one needs access to configuration parameters, manual control, etc, via a computer interface, not to mention it is the quickest shortcut for an electronics ignoramus like me.
however, since your question should be answered, may i suggest you contact arthur wolf, the inventor of smoothieboard?
his email is [email protected], and, obviously, he is the most knowledgeable person in the world to help you, he IS smoothieboard, and a very nice guy who always helps the users of his products.

 

Thanks for the info Val. Yesterday I had actually posted the question to Arthur because his name showed up a lot on the smoothieboard forum, I didn't know he was the creator. I haven't heard back yet but I figure he's at CES so it may be a few more days till I get his answer. We are using the sub to program and 5v. The diodes were