Stream of I3V 12" Build Consciousness

[lakester]

I took delivery of my 12" I3V kit yesterday.

Ordinarily, I would share an obsessively detailed log of my experiences with something new.

But not this time...

Instead this will be more of a stream of consciousness record of whatever comes to mind during the assembly, tuning, and usage of the printer.

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A little background: I didn't really think too much about getting a 3D printer up until maybe 1.5 months ago. I had told myself that I wasn't going to make the purchase until I really had some other reasons than to just build one. In some sense, it had to earn its keep.

So..., I started a list of items that I wanted/needed that a 3D printer was uniquely suited to provide with the proviso that no printer would be bought until I had at least 10 items on the list.

Heh..., I was a little surprised as to how quickly that list grew. Some items were minor, but nice-to-have, but others were really compelling and aligned well with my other interests, chief among those is pottery..., which seems strangely appropriate.

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So, list in hand, it was time to pick a printer. I'll skip all the details, but I will say that PrintRBot was in the lead for a long time. I liked the mechanical aesthetic of Brook's machines, and was hoping to get a Metal Plus. Unfortunately, I had too many nagging doubts about "issues" with the Plus, and was sorta indirectly steered in the direction of a reprap style kit by comments from someone on the PrintRBot forum.

As I looked into the reprap/open source/kit options, it really became apparent that quite possibly a functionally and practically better choice could be had outside the store-bought options. True, "better" is judged from my specific interests and needs, but there ya are.

Ultimately, my search took me to Makerfarm. What finally sold me was:

• Utility of the finished product.
• Adaptability.
• Support of the reprap community, and this forum in particular.
• Success of others with assembly/tuning.
• Colin. I swear, I don't know how he does the support thing, but he does, and its incredible.

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Some early decisions:

Controller Board: Initially I was gonna go with the RAMPS, but decided on the RUMBA since it seems to position things better when/if comes the time to contemplate a conversion to 24V.

12V vs 24V: I was tempted to build the machine as a 24V system from the start, mainly owing to concerns about heating the 12" bed. Based on comments from Colin, I decided to stick w/ 12V for now and save 24V for another day.

Vinyl Tubing vs Metal Flex Couplers on Z: Decided to stick with the tubing until I've gotten some experience with the machine, on the off chance that the tubing will act as a clutch in the event of an, er, unplanned Z excursion. I would almost be tempted to sacrifice accuracy/reliability early on by lubing the tubing to make sure it slips in the event of "badness". Later, I'd switch to the metal couplings.

Power Supply: I'm a little ashamed that I've decided to go with the cheap option, but mostly for reasons unrelated to "cheap". I got one of the $23 specials off of Amazon..., hopefully it will work out, at least long enough to get things working. What really drove the decision was entirely unrelated to the printer. I needed some obscure spark plugs that no one was stocking..., but they were available as "add-on" items on Amazon. I had kept forgetting about them on earlier orders, and so I figured I'd roll the dice with the cheap power supply, and AT LEAST get the darn spark plugs.

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For now..., that is all!

[lakester]

What have we here?

20150423_171239-blurred.jpg

[beerdart]

Congrats on your new baby..

[lakester]

I've used my trusty dial mic for a number of years.

Clearly..., this will not do.

A. It's not metric..., the 3d printing world is.
B. Everyone else has a digital, metric mic, and I'm feeling very self-conscious about that.

This will be fixed soon.

[jasay]

Hey, I like dial calipers. Decent dual measurement dial calipers cost more than dual measurement digital ones though. And being able to zero the caliper at arbitrary positions lends itself to some neat measurement tricks. Looking forward to seeing your build.

Edit: Oh wait, you said mics. Would be nice to have to filament measurements. Sorry went off to lala land for a bit.

[lakester]

So far so good.

The pile of unassembled pieces is starting to shrink in relation to the other pile that looks like it's trying to be something.

The build is happening when and where I can grab the time. My old workshop is starting to become usable again, but I'm actually building this thing in 3 separate parts of the house while things settle down.

One quasi-tip:

• When tightening the delron/bearing assemblies, I'd suggest focusing on tightening the nut, and NOT the bolt. I found that this permitted the tightest overall fitting without binding. (It's a standard mechanical assy practice anywayz). So far, all the delron wheels have gone together very nicely with this method, but...

A couple of quasi-gripes:

• The (4) M124 idler bearings, seem to be a problem, or at least this application of them. I think the source of the problem is that the tolerances between the full length threaded M5 bolts and the washers is too loose, possibly permitting the washers to slip off center and interfere with something. Not sure really..., I just know that I haven't really successfully tightened the idler assys without binding the M124 bearings. May look for other M5 bolts that are only partially threaded...
• The M3 nuts that ship with the kit are 25% poo poo. The M3 bolts seem fine, but the nuts, not so much. Honestly, the 25% was earlier in the day..., later in the afternoon it seemed like every other nut that came out of the bag was bogus. My trusty magnifying app has revealed a lot of bum threads.

Apart from the above, I'm applying a MinWax stain/seal, 1 coat, incrementally as I proceed with each assembly. So far, no issues with interference related to the finish, it's almost dimensionally invisible. The only component I won't be finishing is the Y-bed. Just thought I'd leave well enough alone wrt chances for warping, it's kinda unseen anyway, and the fact that I didn't feel like trying to make the stiffeners epoxy joints look nice when stained.

Oh yeah..., as for the glue I'm using for the stiffeners(aka stabilizers), it's epoxy.

Maaaaybe will have a large part of the mechanical assembly done by the end of the weekend.

That is all.

[ex-egll]

+1 on the lousy M3 nuts. I wrote to Colin about this, and evidently there was a bad batch came through the system. Supplier informed!

[Hankus]

Binding of the Delrin wheels reminded me, that in my 10" kit the wheels washers and bearings came preassembled but I found the washers were too thin to allow any tightening without binding of the wheels. The seperate 5mm washers that came in the kit were about .2mm thicker, so I ended up swapping all the washers to make things work. When I talked to Colin about the problem with the washers it was like he didn't understand, and said I was tightening too much. If the bolt and nut can still spin with the fingers in the wood frame I wasn't tightening enough in my book.

[lakester]

Thx Hankus...

Yah..., the binding I first experienced was with the idlers..., but after I wrote my earlier post, the last two delrin wheels to go on my y-bed also had binding issues. It was as you say..., you couldn't tighten them AT ALL to keep the assembly from rattling around w/o creating at least some binding.

I held off trying to dis-assemble the delrin wheels..., so I take it the bearings can be removed w/o damaging the wheels?

Binding of the Delrin wheels reminded me, that in my 10" kit the wheels washers and bearings came preassembled but I found the washers were too thin to allow any tightening without binding of the wheels. The seperate 5mm washers that came in the kit were about .2mm thicker, so I ended up swapping all the washers to make things work. When I talked to Colin about the problem with the washers it was like he didn't understand, and said I was tightening too much. If the bolt and nut can still spin with the fingers in the wood frame I wasn't tightening enough in my book.

[Draled]

I didn't have issues with them binding, but yes, the bearings can be removed.