Friday, 26 December 2014

New Year's reading

A very merry Yuletide to all! I hope you are excited about what the new year will bring. For me, if all goes well, it will bring a working printer: at the rate I'm going calibration should start in January and real printing (knock wood) in February -- surely to be rudely interrupted by our upcoming move.

In the meanwhile, since I'll have some downtime away from Internet for several days around New Year's, I'm collecting some educational reading on modelling software - having learned that I can't effectively just try out a few things and then move on to complex tasks with success. So far, I've checked out:

OpenSCAD: OpenSCAD User Manual (printable version)

TinkerCAD: I have an old account but even after password reset I can't log in, and there are no significant manuals outside of it.

FreeCAD: FreeCAD Manual (printable version)

3DTin: Looks somewhat primitive in comparison with the above. Manuals only in video form.

MakerBot Customizer: Sounds interesting, but when I log in I hit a login loop :(

OmNomNom Creator: Only 2D to 3D conversion.

ModelBuilder (Mk2 seems incomplete?): Geometry library. Docs only in raw HTML form, fairly impractical on a ChromeBook.

Google SketchUp - I have tried it and found it initially useful, but prone to difficult gaps.

Sculptris: Possibly too artist-oriented for me, and doesn't have downloadable docs.

Art of Illusion: Aimed at graphics, but supposedly useful for design, too. Has a downloadable manual.

CadQuery: jQuery for CAD programs. Has documentation, but not in a readily downloadable format.

ShapeSmith: In-browser parametric CAD, but no downloadable docs.

Wings3D: Erlang-based subdivision modeler. Interesting concept, no downloadable manual.

123D Design: Commercial, but has a free version (I'd rather not pay until I have an idea what I should pay for). Only video tutorials, though.

...and many more. 3Ders has a long list but with no indication of which ones are the most useful for 3D printing, and includes a lot of graphics-oriented software.'s list is even longer. And even those are not complete. This is a big field.

Tuesday, 16 December 2014

When bad rods happen to good print beds

Print Bed Assembly: The hex pillars I have just have a hole straight through, so I use M3x30 bolts to fasten them. A bit unclear which side of the PCB was up, but an image shows the side with MK2a turned up, I'll trust that.

It was a bit tricky to get the cable in right. Looping the cable loosely through the clamps before putting bed and dibond together would have been easier.

Again using that weird misdimensioned multicolored Conrad ribbon cable instead of polypropylene. I hope it doesn't cause weird electromagnetic effects.

Y Axis Assembly: Twisted green wires are a little short, but the manual says "about 750mm".

My microswitches have a little "blade" above the button. If it turns out to be a problem, I'm still orienting the button as indicated. Slotted screws are stupid. Throw rocks at them.

I don't see a mouse hole in the right stay (except for the one the motor is using). Around the side it is.

Great! The Y motor wires are way too short. Fix later.

Unclear which way the belt should be threaded through the idler. Does it matter? I know not yet.

Attached rods. The carriage does not slide lightly back and forth. If I don't hold against the frame, the entire machine moves along. That cannot be right. I suspect the odd matte rods I got are too rough, maybe. Could also be a side-effect of the holders not being fastened yet, but I would expect the manual to mention that. Also, the right-hand bearing was to be loose until now, but fastening it while on here is difficult.

Check out in this video how the frame moves along:

Additionally, the Y motor wires come out the top, where they would be better off coming out the side. I guess I misunderstood "downwards", but now at least I have an excuse to take off the motor and extend the wires.

I notice the right-hand rod holders were missing screws. Added, but since those rods were also of the bad kind, I didn't move further on that.

One of the first things to print would be more cable ties. I like a well-organized cable setup, and the printed parts only come with the bare minimum.

Current state of the machine (which should get a name soon):

With that, since I won't have time to do more work the rest of the year, I will just wish you a Merry Christmas (or whichever) and a Gutes Rutsch.

Sunday, 14 December 2014

Splicing and assembling X & Z axes, and some printbed work

X Motor Assembly: With the M3x45 screws acquired from Schrauben Preisinger, I can now properly fasten the remaining part of the motor holder. Required 4 nuts to span the gap. Due to the hole in the motor being just between a nut trap and a too smal for a nut, I added a washer, but it also kept skittering around the edge, leading the screw to go slanted and push against the holder instead of going nicely in. On my second attempt, keeping it more straight, a crack appeared in the screw holder. Removing the washer made it work, but now there's a big gap around the nuts - one actually dug up into the holder - so that already-cracked piece is now going to get unexpected stress. This piece is now first on my list for replacement once I can print. I can probably offload it a bit by putting some open washers in after the fact.

Fastening the microswitch was a bit tricky - No2 screws are unknown here, so I got slightly bigger ones. Also, Schrauben Preisinger seems to have a predeliction for slotted screws rather than Phillips or hex, which makes it fiddlier. Would be nice to have a slotted bit that fit over the outside of the screw, so it couldn't slide.

Splicing together the wires, I re-learned how to do a good inline splice thanks to this Instructable.

Y Motor Assembly: Since this will be under tension, I re-fastened all board connections with M4x20 screws, adding extra washers to compensate for the extra length. This ain't going nowhere now!

Z Motor Assemblies: Took some of the extra wire from the extruder motor (it has meters and meters!) and extended the left-side wiring across to the right-hand side where the electronics is. Much faster to splice now that I know what I'm doing. Also, putting on the heatshrink before stripping insulation is a lot easier. I'm still not sure which cable ties go where. I'm leaving them loose for now so I can swap them when I can see it.

Extruder Motor Assembly: Finally got the remaining screws. All fastened and good to go.

Z Axis Assembly: Added microswitch and threaded it. Almost stripped the Z markers on the home-cut end of the threaded rod. Somewhat confusing instructions on the couplings, but then my shaft has no flat. Everything of this now mounted and tightened.

Y Carriage Assembly: Got the last two LM10UUs in. Slightly funny that the bearing holders have slots instead of nut traps, maybe that's just an older version. Using M3x20 in general since my M3x16s are slotted. Doesn't look like it'll affect anything.

Print Bed Assembly: Stripped and soldered on the 26-way flat cable. Stripping worked incredibly well with this little snipper - notice the flat piece of metal along one edge.

This one is a Knipex 78 71 125. I may need to get one of my own.

The 2x12 twisted-together pieces need to join with the 32/0.2 red/black wires. I don't even know that designation. It's 0.2mm copper (sensibly) overall diameter 2.5mm. I guess the 32 is strands. Need 635/620 mm of these. I guess another trip to Conrad is in order. My time here tonight is up, anyway.

Saturday, 6 December 2014

I should have gone to Schrauben Preisinger at once

Having purchased many more pieces, some serious putting-together can now be done.

The extruder is essentially the Wade's I already have, phew, but with an attachment I left at home thinking it would be part of the Wade's. I also forgot the rods at home. Also need the M3x20mm hex columns that Toom didn't have.

X Idler Assembly is done, no problem.

Y Idler Assembly is done, though I had to get some M5 washers that weren't bent - I'd taken some from the old machine, but they had been under enough stress to bend, and that made them too thick. Also, tricky to get this in.

X Carriage Assembly is done. It was a little unclear how the belt was supposed to go, and I still don't get the tensioning part.

Ah, bother. The Extruder Motor Assembly requires M3x45, which are not available in Toom nor Bauhaus, nor are any lying around here randomly. I'll use the M3x40 for now with some warning tape. I should go to Schrauben Preisinger, also for the No2x13mm. I should actually have done that at once, just brought the list and said "find me these screws, please". And they'd do it for me.

Also need to get some heatshrink.

Tuesday, 2 December 2014

Sourcing things

Between Balzer yesterday, Conrad today, and various online places, I have almost all things sourced:

From Conrad:

THS15 Alu clad 10R
THS15 Alu clad 4R7



Belt T5 6mmx680mm
Belt T5 6mmx905mm

4x624 bearings

From balzer:

Fan 60mmx15mm (I did not have one at home of appropriate size)
15 way D IDC socket
Microswitches (wrong kind)

From nophead:

PCB bed 214x214mm (with thermistor)
Glass sheet 214x202x2mm

1 Dibond sheet 216x216x3mm

From Toom:

Smooth rod 10x290mm
2 brass nuts M8
2 smooth rods 10x336mm
2 threaded rod 8x296mm

M3 star washers
M3x16mm bolts
From ebay:

Remaining to be acquired:

Polypropylene strip 501 x 25 x 0.5mm and 410 x 18 x 0.5mm
Polypropylene strip 278x33x0.5mm
1 micro SD card (no, I don't have any randomly lying around!)
MicroSD to USB adapter

2 smooth rods 10mmx403mm (Toom)
Smooth rod 10x432mm (Toom)
4 hex male/female pillar M3x20mm (Toom)

I'm unclear on what role the polypropylene strips really play. I think I'll just take a reasonably strong piece of something, maybe the flat colored cable that wasn't quite the right width.

The MicroSD adapter that goes on the Melzi is a bit tricky to find for all the regular adapters.

The microswitches would appear to be roughly this kind, which I can just go get in Conrad.

Monday, 1 December 2014

A few more bits acquired

I went to Balzer Elektronic to get some pieces. Only got the 15-way IDC, a fan, and some microswitches.

The microswitches are the wrong size.

Fastened the fan in the fan holder, no problem.

The IDC is correct, but the ribbon cable I have is a very colorful one that apparently is just meant to be a supply of single cables. It is just a little bit off the size of a regular ribbon cable. Good thing I noticed before I squeezed the IDC.

Also, I found my Melzi.