This seems kind of important. LOL 
I’m certainly no engineer. I think the one (rail) is guidance/bearing surface, while the other (threaded rod/lead screw) is propulsion. In this regard, for the Repeat V4, I think the analogy is rail for guidance/bearing surface, with belt for propulsion. ??
It may not be a correct term but we always call a “drop” material left over. So a welding shop gets a full sheet of steel aluminum whatever for a project. Cuts what they need off of it. Im sure charges the customer for the full sheet. Then sells the “drop” at a reduced price. The welding shop near me cut the price of that aluminum just about in half of what it would have been from the new supplier where i would have had to get a full 4x8 sheet at $800+
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quarter inch hdpe won’t be rigid enough for a box by itself.
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Work in progress…
Fastener BOM break down:
Related
-
Dan reco fasteners
- 4 M2.5 x 12mm Bolts
- 4 = 2 x 2 Endstops
- 40 ??? M3 x 8mm Bolts (8mm for extrusion, maybe 10mm for wood/plastic panels with inserts)
- 6 = 6 x 1 per Z Belt Holder
- 20 = 5 x 4 per Y and Z Linear Rails (~100mm spacing)
- 4 = 2 x 2 per Tension Block
- 10 = 5 x 2 per Motor Block
- 44 M5 x 10mm Bolts
- 12 = 6 x 2 per Right Angle Corners (Z Mid extrusion)
- 32 = 4 x 4 corner brackets x 2 nuts per Z Corner extrusion
- ??? M5 x 30mm Bolts Pan Head (reco Philips)
- v3 required 29
- ??? M5 x Nylock Nuts
- v3 required 29
- 30 M3 Sliding T Nuts amzn
- 6 = 6 x 1 per Z Belt Holder
- 20 = 5 x 4 per Y and Z Linear Rails (~100mm spacing)
- ?? = X Linear Rails?
- 4 = 2 x 2 per Tension Block
- 44 M5 Slide in Nuts amzn
- 12 = 3 x 2 corner brackets x 2 nuts per Z Mid extrusion
- 32 = 4 x 4 corner brackets x 2 nuts per Z Corner extrusion
- 20 ??? Corner Bracket Right Angle
- 6 = 3 x 2 per Z Mid extrusion
14 = 7 x 2 per Z Corner extrusion
- 6 = 3 x 2 per Z Mid extrusion
- 4 M2.5 x 12mm Bolts
Panels are extra…
| QTY | Description | Comment | Link |
|---|---|---|---|
| ~113 | M3 or M5 Button head by 8+ mm | - 4 x 25 Side/Back/Bottom Panels - 13 Front lower Panel - (M5’s will have less wiggle room) - 8mm for 1/8" panels, 10mm for 5.5mm+ (e.g. 1/4") - Measure/check length needed for panel thickness |
Panel bolts |
| ~113 | M3 or M5 Slide in Nuts | - Use slide-in nuts, rotating T-Nuts are horrible | amzn |
- TODO:
- Stepper?
- Board Mount?
- Fans?
- Hot end?
- Cable mounts/brackets?
- PSU?
- Panels / doors?
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While looking at enclosure ideas, noticed Rat Rig mount Alu plates directly to the Z Posts. Could help reduce weight/material/time to make a bed support plate? No idea if this is a good/bad thing? Would have to make a custom Alu bed though. Current MP3DP design allows pretty much any existing bed to be mounted to the bed support.
Rat Rig BOM BOM - Rat Rig - V-Core
Rat Rig Alu plates are 5mm-6mm thick. Seems like many MP3DP builders already buy ~1/4" thick Alu.
What is that ball though? The bed needs to be able to tilt at least a little.
Similar idea, I just saved a lot of space adding teh stepper to the Rail, that has the stepper under the rail, so the mp3dp is shorter by a stepper height, and coupler. They have the ball there to really allow for crazy bed tilt, I believe it is actually stuck to a magnet but the ball rides on two small rails each. I love that and I am sure it is super precise but if I need more tilt I just make the bubble on my Z holder steeper (and the slot longer in the plate). I am sure the two small rails are inline as the slots are in mine to the centroid.
Developing a printer is super fun, just a whole slew of choices to make.
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I mentioned eddy currents in the other thread. Maybe it was just good timing but I saw this video yesterday:
I have no idea how hard it would be. But imagine if one of the idlers had a copper disk and there were magnets attached to the frame. Then when the bed moved at reasonable speeds, nothing would happen. But if it fell, the eddy currents would slow it way down…
This kind of thing is super fun to design. But the juice isn’t always worth the squeeze.
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Personally, I think most people are hard wired to not appreciate asymmetry, my self included.
Anyone already thought about, or gone ahead even, with creating a symmetrical build plate support, knowning full well that the right side is unreachable because of how Hemera/BIQU H2 has Nozzle to one side?
Some notching will be required to clear the belt/pulleys/rollers, but for the love of symmetry, am tempted to try this out…
I have a Biqu H2 sitting here…I bet that could be symmetrical. That thing is Tiny!
Mine is much closer to symmetrical with the H2 Revo.
Yeah, but when the extruder is right there in your face, that is the asymmetry that I see…
So something’s gotta give. I kind of want to tey to find a way to rotate the extruder theough 90°. Still not symmetrical, but enough that the rest could almost be, but that pretty much has to waste space vertically.
I could place the print bed in the center on mine because I have enough extra X space, but that’s still wasted space, and I might actually want the 235mm print bed later.
If you mount the electronics inside the box on the larger side, I think it balances out and gives the asymmetry a double purpose. Then it is wonderful.
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Thoughts on electronics box underneath? Less vibrations, and easier to repurpose/service? For 250x250 usable am noticing lots of space (260mm wide x 340mm deep x 80mm high) between the Z steppers.
That cavernous void is before adding feet, or, the excessive 100mm stilts I added.
Leaning towards separate box, WAGO’d to barely work for now, but upgrade with some screw/spring terminal plugs for quick connect. Not aviation connectors, since that requires soldering and am trying to keep this approachable. Still stealing ideas from Voron for component layout.
Display(s) and controls attached to front of electronics box, pitched 45 degrees.
Even at the minimum height, there is tons of room down there. You can fit your electronics and a spare spool.
If you are putting the electronics down there, are you going to put your spool inside on the left? Maybe on a door that opens in that panel?
I haven’t thought about putting a spool inside the printer. I need to go look at this again.
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That is an interesting idea! With adding outside panels I have been looking at ways to rout the CAN Bus wires and the reverse bowden. Doesnt seem like enough room to route behind the back belts Is there room in fron of them to be able to make a bracket?