General 3D Printing Thread


 
I'm running a modified 8" MakerFarm Prusa i3 right now, will hopefully be building a larger printer with a design of my own in the near future.
 
What all mods are you running now Ralph? So far I've changed the head with a e3d hot end, added bed leveling screws and ultem plate. Soon to switch to auto leveling and aluminum bed plate with silicone heater.
 
Well, first I added a base and secured the frame to it to stiffen up the structure a bit, cause I noticed the Z-towers wiggle pretty easily and when they do the print head moves up and down pretty dramatically. (home the head on the bed and then touch one of your z-towers while watching the gap) Next I ditched the wooden bed, mine always wanted to hit the y-idler from the get go, and the wooden bed just flexed too much for my liking. I purchased a raw aluminum plate and made my bed from it, using custom linear bearing mounts I designed and printed, I also added spring loaded build platform leveling. I moved to a Hall sensor Z- endstop because the switch wasn't accurate enough, and it was a PITA to adjust the way it was setup. The hall sensor is awesome, super accurate, and I put the adjuster screw right out front (on the left tower) so it is really easy for me to adjust now. I added a fan (used CPU fan) to blow on the RAMPS board and keep my Pololu drivers cool. I designed my own T shaped Y motor mount to replace the wooden sandwich design cause it flexed WAY too much. I ditched the hospital tubing as the Z motor to rod coupler after they wore out and started to slip. It was a late night emergency situation, I dug up some plastic water tubing (refrigerator water line tube) which fit tight as hell and worked great. I was skeptical about this and was going to design and print some couplers (I printed the nopehead coupler but it didn't fit my motor and rod, and it was too big, it would have hit my smooth rod as it turned), but after using the plastic refrigerator line a while on one side it worked great so I switched over to it on the other z tower as well. So far so good, I've done a lot of printing and my z axis movement is rock solid. I added an articulating arm with a 40mm blower and funnel that can direct air flow directly on the extrusion as it comes out of the J-head, I use this to rapid cool filament when printing bridges so I can bridge longer gaps. The articulating arm design is available on Thingiverse, although I ditched the fan funnel part and designed my own cause my fan couldn't push air through the funnel as designed. I purchased a .35mm J-head to do finer work, at that time I designed and printed a quick release mount for my hotend so I could swap J-heads easily without dismantling the extruder. I also added a molex connector on my hotend(s) so they are quick release. I am using a ceramic heater cartridge on one of the J-heads now instead of the resistor. (six of one, half a dozen of the other here, they both get hot fast and that's all they need to do). Most recently I added a sheet of Ultem as the build surface which is freakin' awesome....

I think that's all the mods for now. I had thought of going for the auto leveling, but when I got to thinking about how it worked I decided to pass on that mod. I just don't like the idea of my Z axis going up and down during the print of a layer, to me that seems to be asking for trouble as the z-axis is the least accurate of all, and the the z threaded rods are the first to wear and get slop so I would prefer not to over use them. I know Bryan has done this mod, I'm pretty sure he was having some issues, getting skips when the hotend would hit high spots on the print as it moved around on some objects with the auto leveling enabled. I like the idea of having the switch there to measure bed height all over to aid you in manually leveling the bed, I don't much care for the idea of printing on an un-leveled bed and having the z-axis move up and down to compensate. Your call on that one though.....
 
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Here's my custom build:

frame: misumi aluminum extrusion and printed parts.
axes: The X and Z axes run on openrail linear rails and the Y axis runs on 2 pieces of 20x80mm v-slot linear rails. I use NEMA 17's for all axes at the moment but am currently in the process of upgrading my y-axis to a NEMA 23. The z-axis uses 8 mm misumi leadscrews.
build plate: The bottom build plate is made from an aluminum sheet that I CNC'd to remove most of the material and reduce it's mass. The top build plate is a solid aluminum sheet with a 12x12" silicone heat pad attached underneath and a sheet of Ultem PEI on top.
electronics: RAMBO run by marlin with auto bed leveling
hotend: e3d

The entire printer is enclosed in a chamber that can be temperature controlled via the PID controller on the right.

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That's an awesome looking machine there Tom! I'm sure you don't need anyone to tell you that you should be proud...
I hope to put together a design of my own in the future and had been leaning toward using linear rails instead of rods like you did... Nice work!
 
Thanks Ralph. I've been very happy with the linear rails. I highly recommend the openbuilds part store for their custom linear rail parts.
 
Thanks for that source Tom, will keep that for the list for when i decide to go bigger. Currently I haven't run into anything that my 8x8 can't print though. I assume that's the same stuff that the Mendel designs use. Not sure of which variant reprap I would go with yet, any suggestions for the larger size print beds?
 
I think that the lulzbot taz series look like well designed larger format printers. They are on v3 now, I believe. You can look up their BOM and make your own rather than pay 2500 ish dollars for a pre built one. The standard design uses round bar for linear motion but I'm almost positive I've seen designs posted on thing inverse that use v-slot linear rails.
 
I am finalizing the XY motion layout on a new corexy implementation this week, moving to the Z-axis this weekend. At this point trying to decide whether to make it a reprap or a 3D printer. Leaning toward cutting as much on my shapeoko as possible and printing only what I have to.

Some references for those who haven't seen a corexy:

http://corexy.com/implementation.html

http://joshuavasquez.com/docs/jVasquez/Projects/coreXY.html

I was going to go with a delta, but I'm not so sure about them. There are so many moving parts to those machines - I just have a tough time believing that they will be reliable in the long-run.

Here's an old pic of my machines. http://i.imgur.com/TsaB0zk.jpg My own take on the Prism Mendel. I've been working on and off on upgrading the larger one to a dual-x setup - the final thing I have to do is get a 6-axis board made. http://i.imgur.com/13ujrWQ.png I could buy a RUMBA or X3 Pro, but where's the fun in that?

On a separate topic...

Tom, Are you going to Robotfest this April in Linthicum? http://www.robotfest.com/ Going to hit that with the family, then Cherry Blossoms after.
 
That Lulzbot Taz v3 looks awesome! Not sure why a RAMBO would be better than a RAMPS for a printer, but I guess they build the board also?

Anyone find a good place to buy a nice assortment of metric socket head screws? I've found this:
http://www.ebay.com/itm/METRIC-STAI...336?pt=LH_DefaultDomain_0&hash=item25817086b8

But it is missing the M5 12mm and 16mm ones, then has many that are too long for printers. Also has a lot of M6 that are not necessary.

I'm tired of not having the right screw for the job on hand and the local HD box stores don't carry a good selection of metric screws.

Hoping someone found a nice selection.

dave
 
It's strange, I've not seen a huge amount about the MM2.0. It's either the users are really happy with it and don't complain/ask questions where I browse, or the adoption rate has been slow.

It looks like a good machine though.
 
Matt, I'm glad you're trying out the corexy. I've been on the fence for the last couple of months on whether to invest my time in it. I figure I might as well since I could probably cnc the whole thing. The only part I don't like is the current design uses round rail and I haven't come up with a good v-slot or open rail design yet.

I wasn't aware of the event in linthicum. Maybe we could meet up.

Dave, amazon has some assorted boxes but nothing great.

JNeil, the biggest advantage of the Rambo board is being able to set driver current in the firmware. So very consistent and easy.

Steve, I've looked at the Mendel max 2 but don't know much about its performance. It looks very solid though.
 
That CoreXY is pretty cool. It took me a second to figure out how the belts moved both axes by connecting them to the same motors. What's the advantages of that over a Cartesian system where the X motor moves with the Z (so weight isn't an issue) and the Y only moves the bed? I guess if you can't move the bed, or the weight of the bed+built item is less than your extruder? I'm guessing this with a bowden style extruder would be wicked fast.

The X3 Pro also has the digital pot but uses removable stepper drivers. The catch is you have to use their drivers because the standard kind don't break out the Vref. I also like that bothe the X3 and RAMBO use regular fuses rather than polyfuses, which start dropping voltage way before their rated cutoff current (e.g. 10A polyfuse passing 12V will drop to 10V at 8A).
 
Bryan Mayland said:
The X3 Pro also has the digital pot but uses removable stepper drivers. The catch is you have to use their drivers because the standard kind don't break out the Vref. I also like that bothe the X3 and RAMBO use regular fuses rather than polyfuses, which start dropping voltage way before their rated cutoff current (e.g. 10A polyfuse passing 12V will drop to 10V at 8A).
Click to expand...

Their 8825 drivers are awesome BTW. I use them along with a RAMPS 1.4 at 24V to push 4 NEMA 23s at 330 oz-in for my CNC.

Steve, it all depends on how big you want to go. Though, I'm not really sure that community support is a big deal anyway unless you are interested in having people design parts for you. Everyone uses pretty similar hotends/motors/electronics/firmware and most problems can be troubleshot by anyone with 3d printing experience. The only thing you miss out on without a large community are upgrades that you can download straight from thingiverse. That being said, if you find some good idea that has been made for another printer you can just tweak it for your own. I find that to be part of the fun.
 
The V3 changed to a 24 volt heated bed. That's really the only difference.

I had been running a 3D Systems SLA 250 for the past 6 years trying to make a business of it. It wasn't working out and I just liked building things. (And could not afford to build things with the SLA. $$$) So, I sold it and bought the Taz. So far I am pretty happy with it although it has had a couple issues that were covered by the warranty. The heated bed failed and a fan bearing in the power supply failed. The round rods on the x really need to be rails. They are a little too flexy for my liking. Oh, and Lulzbot uses IGUS polymer bushings instead of bearing. They seem fine everywhere except the Y bed. I could see the bed twist every time it changed directions. I swapped in some metal bearings and the twist was gone.

I just built an insulated box this past weekend. I have a lot of trouble with abs parts warping enough to peel them off the bed. I will probably put some sort of heater in the box to help reduce the warp.

I have been looking a heaters like this: http://www.omega.com/pptst/SREH.html

Tom, that is a really sweet setup you have there. I love the printer and that it is running on rails. I'll bet the accuracy is way up there. Is that an Auber PID controller? What kind of heater are you running?

Here is a pic of my set up after moving the filament up to the shelf but before the box.

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