X-axis

I had looked at a similar design on thingiverse and even bought all the parts to build it. But, I could barely get through a print long enough to even make the parts for that!

I will likely go this route as well, or perhaps even an extension to add smooth rods along the front. But I am really impressed already at how much more stable it is with just the one spring jammed in there (hardware store is closed tonight, so I can't build anything proper until tomorrow.)

It is a thought, and I did try that. But the Z-end stop would not allow the bed to raise high enough when the leveling screws were tightened. So, yeah, the bed is essentially just floating on those leveling screw springs. I had thought that if some of the bed were actually touching the base, it would help to stabilize. But, no... the bed can't reach the extruder (even if I remove the Z-stop screw completely.) In fact, the knob that they added to the Z-Stop screw hits the top of the cutout long before you can ever back it out far enough, even if you could. I ended up removing the knob. When you lower the Z-Stop more (like if you were using a thick glass bed) the knob will obstruct the Z-axis bracket when it tries to go to zero.

Your suspicion would be wrong. I have not only run through that once, but countless times. In fact any time I switch to a new filament, I run it again. It is helpful for accurate layer widths and heights, yes, but that is not the issue here.

I have went through every calibration suggestion (though several seem to have been written for the SD2 and don't work as described on the SD4.) I have calibrated all of my steps/mm, flow rates, feed rates, acceleration, jerk, filament widths, etc....

Just to give you a sense of how frustrating it was. To the point I actually just tried jamming a spring under the bed. If I print something very small, it is nearly perfect and amazing quality. But even something as medium sized as a replacement carriage has been nearly impossible for me to print until I put this spring in place. Finally it printed to completion with no issues after days of trying.

"Perfectly flat" is a bit of a stretch. But, I am planning on that, too. However, if the bed pushes down and rocks, it really doesn't matter if you use glass (except the extra weight may help some.) Also, once I clamped the aluminum bed to some stone in 8 points, it is (nearly) completely flat and even now. It is pretty much the same thing done to straighten out a warped engine block. I have also been using a dial indicator since day one. So, it is not really a flatness issue.

And besides, my Y axis lines are perfect. It is only the X-axis lines that seem to flake out.

Another thought would be that maybe I have the Z-axis too close to the nozzle and it is pushing too hard into the bed. No. I used a thickness gauge under the nozzle instead of paper and have even run several calibration prints to ensure I am getting perfect layer heights and widths which I do, except on the X axis lines. So that's not it.

It is a combination of several things that result in the bed being very unstable. I may just try adding stiffer springs to the leveling screws, but I am leaning toward four points to ensure it is always square. I am even thinking about braces on the bottom of the Z carriage to bring the springs out to the four corners.

There are issues with the belts not aligning correctly, the Y ends bending and twisting, the Y axis bars are not perfectly straight so it "sticks" at certain points in the movement, too much wobble in the Z lead screw, the extruder carriage bounces up and down even at a reasonable speed/acceleration. Screws were loose all over and won't stay tightened. The cable bundle going to the extruder/hotend is too short and catches on the bed preventing it from reaching the front right corner unless you move it over the side of the bed manually. The filament cooling fan smashes into the left front Y axis end screw when it tries to go to that corner (almost busted my fan when it shoved the screw right into the blades!) I had to limit my bed size to 194x194 to prevent it from moving into that corner. The limit switches appear to be cheap switches which bounce a lot (not a huge deal, but it does seem to affect repeatability of movements.)

It is poor overall system design. At least in my unit, but I imagine all the others are the same. But, that's ok. I bought this to learn, and dealing with all these issues is definitely doing that. The solidoodle looked like the best printer for using standard parts to upgrade. And I am a tinkerer, anyway, so I don't mind. Coming from a Cube printer that my work had bought me (I didn't get a choice...) it was an immediate improvement even with all these issues.

Very true and that is another thing to address. I have already picked up linear bearings and flex couplers to upgrade all around. In fact, the objects I have been trying to print have been parts to do the upgrades, but until now I couldn't even get that far.

One of the planned upgrades is to put in a new Z-rod that extends all the way to the top captive in a bushing for stability. My brother works in a machine shop with a CNC thread rolling machine (Tesker). I am an electrical engineer and help them out on the side maintaining their machines and they will be making a custom lead rod and nut for me in return. A goal is to have all the printed parts re-done in aluminum.

I could have paid more and bought a machine with many of these upgrades already in place, but I expected that I would have some issues with those as well (nothing is perfect.) So, I decided on the Solidoodle as a starter since it looked to be the best and most solid sub $1000 printer. Upgrades were already planned before the purchase and lots of research was done. However, I did not expect it to be impossible to print some things right from the get-go even after calibration.

Thanks. Hopefully I will be able to contribute around here as well and detail my upgrades as much as I have read and plan to implement upgrades that others here have developed.

BTW, do you know if the solidoodle 4 has a stepper with integrated threaded rod for the Z-Axis? It appears to be that way but I haven't removed it yet. That means I will need to purchase a replacement stepper in order to do a Z axis upgrade.

Thanks Adrian! Yeah, I noticed that. All sorts of things I have discovered so far that are different than things talked about in here and even different in some cases to what others are showing with their SD4s. Most of the tutorials and Wiki stuff has nothing about the SD4.

There really should be sub-forums for the different models at least. Anyway.. fairly proficient SD4 user here (although new to it), so maybe I will be able to help fill some of the gaps.

My E3D just arrived yesterday, in fact. Waiting on my power supply and SSRs to arrive before I install it. One of the parts I had been trying to print is the MK4 extruder for it. I just ordered one from Filastruder instead. If nothing else, though, this is the one part I would really want to be made in aluminum.

I also ordered a MK2B heated bed that I will be replacing.

Don't quote me on it (yet), but I doubt aluminum parts weigh more than the 100% solid printed plastic parts. If anything, it will likely weigh less. My block of aluminum sitting here approximately the size of the X end carriage weighs about the same (by feel, haven't put them on the scale.) The type of aluminum may make a difference. I am not 100% sure what this block is as it was scrap.

As for the SD4 being the same as the SD3, I am not so sure. Youtube clips I have seen have looked different than mine in a few cases.

Anyway, all important points to consider. As for this particular post, I have went to the hardware store today and picked up 3 5/8x1 1/4 stiffer springs to replace the springs on the leveling screws. I also purchased a couple 3/4" springs and placed them on the right and left center beneath the bed. Very little movement in the bed now and prints are coming out much better now.

An upgrade I had been toying with is to put smooth rods in the front corners and attach the bed to those with a brace. That would help with stability as well, I think. All it takes is a slight wobble and it just stacks up to the point the print is ruined, and sadly it happens when you are pretty far into the print and wasted a ton of filament.

It's less about the strength and more about heat tolerance for me. I eventually plan to build a heated chamber. Not to mention there are several others on this forum having melt-downs of the Y axis stepper bracket. Even if not noticable visually, any warping will cause defects in your print that you are unable to "calibrate out."

My main purpose for a 3D printer is to print precision (at least as precise as can be done with a 3D printer) prototype parts. Not Octopi, vases, and Owls.

But yes, you are right: ABS is light. The real difference is the aluminum is strong enough to cut out a great deal of it to shave the weight off and will still be far stronger than it needs to be for this purpose. And you don't have to worry about layer direction causing cracks.

Another option I had considered would be to cast the parts using a high temp resin. Also within my capabilities, though I think that would be significantly heavier.

Oh! I agree aluminum is nice. I guess I was objecting to "this block of aluminum weighs like a block of ABS" but I don't remember exactly and may have been too nitpicky.

Right now I run a semi-heated build temp and even the 45-55 celsius I get tremendously helps reduce warp.  Eventually I hope to go higher to 55-65, maybe 70, but before then I might replace all my internal plastic parts with printed PC parts as it has a higher transition temp than ABS. Aluminum would be nicer, though.