Building the "Repeat" printer

That is a pretty print.

I agree with you on speed. It obviously matters for Ryan. And I won’t print slower if I can print faster. But my printer is idle most days. Most prints are done overnight, at the latest. So speed isn’t the most important factor for me.

There is at least some value to the idea that a faster printer can print better quality at the same speeds too though. And if you want to go into crazy detailed prints, or print anything very large, the speed can affect even us weekend warriors.

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This is basically what I mean. A bad printer will not make good prints at any speed, but a good one can. A faster one can (usually) do it faster. It’s always a trade-off for getting the print quality that you want.

My previous workhorse printer (Which is still something of a workhorse) is slower, but was built to be as precise as possible, which it is, so long as I don’t go too fast. For mechanical parts, I tend to run it at a speed that gives me visible artefacts, but for “nice” pieces, I run it much slower. Thinner layers, lower speeds. particularly for perimeters, but still, as fast as I can for the desired end result. I don’t think any of us would choose the printer that does the same thing slower.

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Can you tell me more about your Neje laser? I saw you were cutting thick material with it and you mention 80w but I cannot seem to find an 80w. I contacted Neje and they said to go with the NEJE A40640 - but if I understand that is just a 40w.

To be clear, that is 40W input and 15W output, I think. So not comparable to a 40W CO2.

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What length M5 machine screws did you use for this build? The instructions list 30mm long but that seems to long imo.

Nope they are all M5x30

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Should I get locknuts or regular?

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Locknuts.

I have a handful of pictures up in the docs, and have more to add this evening.

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For what it’s worth…

30mm is long enough for everything, but I actually found that there are a few things for which longer screws are a nice to have.

For the bed hold-down screws, those can benefit from being a little longer. My bed plate is 1/4" MDF, and I had to compress the springs a bit more than I like to get it held down. 35-40mm screws might have been nice there, but I’m working with the 30mm screws that I bought. Everything else, it’s fine as long as you get the nuts fully seated into their traps. Nowhere are the 30mm screws excessively long.

Good catch, that was designed for ~1/8" I will make a not on the BOM and instructions.

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And that’s among, what, five or so who have more than 0?

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Seeing as how video hasn’t popped up earlier…

So, I’ve been using the printer hard for a while. Most stuff has been printed at “Git 'er Done” speeds, nearly half again this fast, and one of my Ali Express pulleys is making … interesting sounds here. Also my cheap 5015 fan died the other day, and I just clipped the wire and kept going.

60mm/s perimeters, 80mm/s infill. This speed produces prints with no visible ringing or voids, best cosmetic quality. It’s going to be a stand for the Oculus Quest 2.

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What’s rubbing?

Okay am I going crazy? The holes for the wooden pieces are 3.5mm diameter but the diameter of M5 screw is a bit over 5mm. Am I missing something?

image

EDIT:

I see that some of the holes should be that small because the linear rails call for M3 screws. However the holes where you mount the Stepper Block are too small to allow M5 screws. Should I open these holes up to allow M5? Then I also notice that the mating hole on the Stepper Block itself is too small for an M5 screw so I am not sure how to mount the Stepper Blocks to the wood frame.

One of the toothed idlers on the Y axis is making that noise. It will have to wait until I have the time to take the whole thing apart to replace it.

Also mounted with M3 screws. Done (presumably) so that you only need 1 type of hammer head nut if you’re using 2020 extrusion.

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I see. So any plastic-to-plastic screws are going to be the M5 bolts and lock washers while any other fasteners such as plastic-to-wood are going to be M3. Is that correct?

Pretty much. I suppose that the bed mount screws are an exception, it’s probably easier to think that anything that mounts to the frame or rails is M3.

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Yes and no.

The M5’s are obvious, beyond those if you use extrusions most the mounting is all done with M3 x8 (mounts might use M3x10 not sure) When using wood or plastic I use small wood or plastic screws…or the inserts I found in the other thread.

Make more sense, the machine is m5, steppers m3x10 same with the endstops, the frame, the only variable is different depending on how you build it.

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I know the BOM and instructions are still a work-in-progress. But can anyone tell me how many idlers/toothed idlers/wheels and length of belt is needed? I’m about to order from the V1 shop and I hope to get the quantities right the first time around

Each Z axis requires 1 16T motor pulley and 1 toothed idler. That’s 3 toothed idlers there.

Each corner block at the back needs 2 toothed idlers, so that’s another 4.

Each Y truck needs 1 toothed idler, and 1 smooth idler. That’s 2 more toothed idlers, and 2 smooth ones.

The core uses 6 of the POM wheels.

Belt is a pretty standard calculation for CoreXY. Basically, you need 4X the length of your X axis + 4X the length of your Y axis, plus “a bit” My check before I started threading was that I was able to wrap each of the 2 belt segments around the outside of the printer frame.

So you need 9 toothed idlers (Not in the V1 shop, I think) and 2 smooth ones. You need 5 16T motor pulleys, 6 POM wheels, and enough 10mm belt to wrap around the enclosure twice. You need 5 optical endstops, and 5 stepper motors.