Hans makes a build thread for a Rostock Max V2

[Hans]

I almost would have preferred a no-psu option to be honest, and did put in a message on my order that I kinda didn't want it..... but since it came with the machine, might as well see what I can do with the power supply. Anyway, I cracked it open of course, after cutting all the connectors off the wiring, and it's just a basic power supply really... nothing fancy. I know, I can't expect much from a cheap power supply... but I build medical PCB's all day for a living, so going from IPC class 2 and class 3 to stuff that isn't built to any real standard at all, it's a hard switch for me.

[img]http://www.siegecraft.us/rostock/IMGP4431.JPG[/img]

All the grounds go to a single pad, most of the 12v lines go to rail 1, and 4 wires go to rail 2. So I'll likely be powering the heat bed from rail 1, and everything else off rail 2. But I don't have a datasheet to give me amperage ratings on these rails, so it's a crapshoot. I may just go back and run it all from rail 1 eventually if I have problems.

Given the lumps of solder holding it all together I decided to just remove all the wires and re-install the ones I want.... it's just easier that way. I found little gems like this on the PCB. Looks like they just drilled a few more holes in the pad to add more ground wires. This is also a single sided board, non-plated thru-holes, cheap material for the board, no solder mask. This makes for weak solder joints and compromising them in this manner doesn't help. So if you do this kind of work, be really careful not to lift pads and traces.

[img]http://www.siegecraft.us/rostock/IMGP4437.JPG[/img]

Out came all the 3.3v, 5v, -12v (which had a solder bridge connecting the wire to the 5v pad), and any other wire that won't be used for this build. I also put a layer of fish paper under the PCB in place of the thin clear plastic sheet that was originally there. It already looks a lot cleaner, and I have some other plans for cleaning up all the wiring fiasco when I do my build. I just haven't decided on lacing or sleeving it all.

[img]http://www.siegecraft.us/rostock/IMGP4440.JPG[/img]

Pulling all the excess out gave me a nice big heap of wire to use for other projects too. No real need for the SATA connectors, but I will probably keep the molex's for various things. I go through a lot of red, black and yellow doing my pinball work.

[Eaglezsoar]

Very nice tutorial on the power supply with great pictures.
Thanks for sending this to the forum. A lot of people can learn from this.

[Hans]

Already learning things on this build that I'd do differently should I build another one.
Big change #1 would be to first use some kind of grain sealer on the wood before painting. It's crazy how many coats this stuff is taking to get a good finish. I'd be assembling already if I had sealed it before doing the color. I should have known better, but impatience does get in my way sometimes.

I also completely forgot I wanted to look into a threaded thermistor for the hot end. <Had a bunch of other stuff here, removed it as I kinda stuck my foot in my mouth>
Long story short though is I am going to skip it. Looked into them a bit, and apparently they are all just a bead thermistor that's epoxied into another kind of housing.
So I'm going to search out a good high-temp thermally conductive epoxy instead of the ultra copper RTV. As good as the ultra copper is as a sealant, it also peels easily and I don't want that thermistor dropping out of the hot end.

[Hans]

I forgot to add, Permatex Ultra Copper and I are old friends... I've used many a tube of the stuff. So this step went quite easy for me. It's skinned over nicely, but with this thickness I'd venture at least 24 hours minimum cure time. I won't be powering up for at least a week, so shouldn't be an issue. I used some silly old thing laying around to hold the hot end up, make the picture easier.

[img]http://www.siegecraft.us/rostock/IMGP4443.JPG[/img]

[Tinyhead]

My hot end used to look nice too. After a few print failures with filament melted all over it... it looks like the rest of 'em.

[Hans]

Here's a dumb question about how things are assembled. Is the power supply actually being installed upside down? There's a big hole on the bottom panel of the printer, which would line up perfectly with the 120mm fan on the power supply.... except the fan is on the top and thus not aligned with the hole.

Another random thought as well. I don't see a chassis ground for the Rambo at all, nor a body ground for the stepper motors. I've seen more than one system start displaying flaky performance due to this, and have seen some grumblings in this forum about similar flaky problems with the Rostock at time. If I get any oddball performance that seems to be interference related, this will definitely be part of the attack plan.

[Hans]

I also decided to change the wire I'll be using for the endstops. With all the talk of cross-inductance and noise getting on the lines, I'll be using this stuff instead of doing three separate un-shielded pairs. Will hopefully keep things a lot cleaner, and also the shielding should help prevent jitters.
http://www.siegecraft.us/presta/index.p ... &id_lang=1

Yet more coats of paint.... and more coats of paint.... but finally starting to make some headway and getting usable parts to start assembling.
NOW we're starting to get somewhere!

[img]http://www.siegecraft.us/rostock/IMGP4444.JPG[/img]
[img]http://www.siegecraft.us/rostock/IMGP4445.JPG[/img]

[geneb]

As long as you follow the wiring guide, there won't BE any crosstalk issues with the end stop wires.

g.

[Hans]

Probably not via cross-inductance, no. I just don't trust the grounding situation on the Rambo board as it is, with the previous version having the static failure issues like it did, and stepper motors generate a heap of RF noise. Once I get it up and running I can throw the scope on the power leads and see what kind of noises the machine is subjected to. If I still had my radio gear it would be even easier to spot on a spectrum waterfall. Either way, I've always had the habit of doing chassis grounds whenever possible and it's easy enough to do while while I'm still assembling.

-Hans

[Hans]

Ok, got the junction blocks I was waiting for, was able to finish up the power supply wiring. In hindsight, since I already opened the darned thing up, I should have just put in a single 16 gauge wire instead of bringing out 4 of the 20ga wires and connecting them up. But sometimes you just have to stick with what you have and keep moving, or you'll never get finished.

[img]http://www.siegecraft.us/rostock/IMGP4451.JPG[/img]

Mostly been proceeding as per the instructions otherwise. Stuck with Gene's excellent wiring plan for getting through the towers. Why the change from using the original Rambo kit supplied 26 gauge wires for the hot end thermistor, and swapping to the 18 gauge? These are pretty stiff wires, and serious overkill for the signal on the thermistor. I'm doing things in a pretty widely different sequence though, to get it all run all cleanly the way I want for the wiring. A lot of work to do still. Like that old Guns and Roses album.... The Spaghetti Incident.

[img]http://www.siegecraft.us/rostock/IMGP4453.JPG[/img]
[img]http://www.siegecraft.us/rostock/IMGP4454.JPG[/img]


Lastly, did a couple modifications to my Rambo board. Added a .100 header for the fan connection instead of directly soldering. Also spotted a location for another 6 pin header that can handle my LED outputs. Wouldn't recommend doing this though unless you're good at soldering. Very easy to bridge the backside on this one and short out your output circuits. Will still make things easier for me in the long run.

[img]http://www.siegecraft.us/rostock/IMGP4455.JPG[/img]

[astroboy907]

Hey Hans, how did the installation of dampers go for you?

[Hans]

Hey Hans, how did the installation of dampers go for you?

Seamless... honestly it went so easy I forgot to even mention them here.

[astroboy907]

Hey Hans, how did the installation of dampers go for you?

Seamless... honestly it went so easy I forgot to even mention them here.

Sweet, just wanted to check in. Your build looks really awesome!

[Hans]

Man, I just have the worst luck with my thermistor....

First I tap the hot end for a 3mm standoff, and realize I already JB-welded my thermistor into a 6-32 standoff. Yeah, I need to pay attention better than that.
I Get that resolved, and stupid me busts a lead off the thermistor anyway. I've always hated working with the stupid things. Now I need to wait for new ones to arrive.

Getting so close to being done now too!

-Hans

[Hans]

Mechanically complete, other than cleaning up some wiring. If I hadn't busted that thermistor I'd probably be doing final calibrations and first print already. Have to wait till Tuesday for new ones to arrive, and till Wednesday for the epoxy to set in the fitting.

So time to break out the twine and needle, get lacing.

[Hans]

I was able to get the broken thermistor to work temporarily, there was just a tiny nub of lead protruding from the epoxy and I was able to solder some wire onto it.

Calibrations are all done, bed is heating up for the first test print as I type this. Here goes nothing!

[Hans]

You take your time....

You follow the instructions...

You learn what things mean, and how they work...

And 100 layers in on the first try....

[img]http://siegecraft.us/wp/wp-content/uplo ... 00x241.jpg[/img]

Unfortunately, it popped off the bed on layer 115 of 124. Good enough to use though, until I get some red PLA to make it match the rest of the machine. My own fault really. The ABS smell was annoying me a bit, so I opened up a window (right behind the printer), and turned on the ceiling fan. Whoops!

-Hans

[geneb]

Do NOT print the fan shrouds out of PLA! They'll melt.

g.

[Hans]

All ABS here, meant to say red ABS in my previous post.... but yeah, definitely a great reminder!

Speaking of fan shrouds, I have a pair of them completed and mounted on the head. This is all TiT wiring, meaning "Temporary, in theory". Once I get the final fan shrouds printed, a repaired thermistor, and quick disconnects, I'll be re-wiring from the top plate on down.

[img]http://www.siegecraft.us/rostock/IMGP4465.JPG[/img]

Having some print issues to figure out. This is the filament guide funnel off Repables. The problem here came from from Slic3r, it wants to start adding a lot of infill blobs at certain layers, which shows up as these thick rings in this case. I can't get it to stop trying to do this infill. Trying Cura, but have been struggling to get the basic performance the way I want. It's running before the extruder and bed are up to temp, things like that. I think I finally have it just about dialed in, but keep having to tweak a bit here and there. The biggest problem I'm having right now is that I don't think my bed is level in the center. Having first layer issues where the nozzle is right on the bed in some sections, but air printing in others.

[img]http://www.siegecraft.us/rostock/IMGP4468.JPG[/img]

[Hans]

I'm finding this natural colored ABS is hard as hell to photograph during the day, too much ambient light from all the windows. Short version though is that I've worked through this latest set of issues. Re-did all the endstop calibrations, and z-height zero. This cured my level issue with the prints, and I'm getting a good first layer again now. Slicing the funnel with Cura eliminated the blobby issue from when Slic3r was trying to force the un-necessary infill onto the print. 5mm cube stack came out pretty good, except the very top cube. I thought I had a minimum layer time programmed in, looks like I didn't, and it was heat soaking too much on that tiny top cube from printing too rapidly.

I'm not a fan of how Cura handles bridging though. Just a perimeter and then going straight to the infill, of course it's going to have sag issues.

New thermistors arrived today, haven't ordered connectors yet.... soon.

-Hans

[Eaglezsoar]

All ABS here, meant to say red ABS in my previous post.... but yeah, definitely a great reminder!

Speaking of fan shrouds, I have a pair of them completed and mounted on the head. This is all TiT wiring, meaning "Temporary, in theory". Once I get the final fan shrouds printed, a repaired thermistor, and quick disconnects, I'll be re-wiring from the top plate on down.

[img]http://www.siegecraft.us/rostock/IMGP4465.JPG[/img]

Having some print issues to figure out. This is the filament guide funnel off Repables. The problem here came from from Slic3r, it wants to start adding a lot of infill blobs at certain layers, which shows up as these thick rings in this case. I can't get it to stop trying to do this infill. Trying Cura, but have been struggling to get the basic performance the way I want. It's running before the extruder and bed are up to temp, things like that. I think I finally have it just about dialed in, but keep having to tweak a bit here and there. The biggest problem I'm having right now is that I don't think my bed is level in the center. Having first layer issues where the nozzle is right on the bed in some sections, but air printing in others.

[img]http://www.siegecraft.us/rostock/IMGP4468.JPG[/img]

Hi Hans, just wondering where you got the stl files for the fan shrouds you are using.
I looked on repables.com and did not see them.

[Hans]

PEEK shroud
http://repables.com/r/140/

layer duct
http://repables.com/r/200/

Filament funnel
http://repables.com/r/289/

[Eaglezsoar]

Thank you for those links Hans!

[Hans]

I'm rapidly learning that if I ever have issues with the first layer, and anything at all looks un-even on it, the first thing to do is re-calibrate the end stops. And if I ever touch anything component mounted on the head, to re-calibrate the end stops.

That, and the honeycomb infill pattern in Slic3r vibrates the hell out of the head. If anything shakes loose, and I have to tighten it back down, I have to re-calibrate the end stops.

Would be great to incorporate an auto leveling system into this unit somehow.

-Hans

[Hans]

I need to look into a better way to calibrate temperatures. Dropping my ABS temp to 215 seems to have cured most of my blobbing issues, which seems as a quite low temperature. I think that having the threaded thermistor is skewing my temps, as the threaded fitting moves it a few mm away from the hot end instead of being embedded into it. I might go back to the RTV method of retaining it in the hot end.... or just pick up an E3DV6 when funding allows.

I'm also finding that having the thermistor extended out in the threaded fitting makes fan placement very critical. If a fan blows across the fitting that's holding the thermistor, it really makes temps go wacky. Heater goes full power, but the temp readout drops down to 175 or so, which I suspect is more that the thermistor is cooling than the hot end itself. This fan duct may also be an issue too, as it is directed more at the body of the hot end as opposed to the plastic itself. Will look into some different designs.

-Hans