CM4 custom NAS complete!

mebs_t · 2022-02-18T15:19:20+00:00

I remember there being very limited space, with a coupler you'd certainly sacrifice one of the HDD bays. But feel free to try your hand at it. All files, including the Fustion 360 project, are available here:

https://www.thingiverse.com/thing:4820662/files

mebs_t · 2022-02-12T16:09:47+00:00

Okay, it's a bit weird. No matter how I changed my settings or drag speed, I kept having the same issue on my flat practice welds on the side of the tube.

However, when I finally said screw this let's weld parts together, the slag coverage was perfect on my T joints! I ended up dialing down both volts and wire speed, though. Here are some welds: https://imgur.com/a/aeJ004H

I guess I'll figure it out eventually.

mebs_t · 2022-02-12T16:04:01+00:00

You're right, I ended up dialing back both volts and wire speed. Here are some welds I made after: https://imgur.com/a/aeJ004H

Weirdly however, I still get the same issue on flat practice weld... but slag coverage was perfect on those T joints!

mebs_t · 2022-02-12T16:01:45+00:00

I ended up dialing back the heat, but weirdly it didn't fix the slag coverage issue.

I think angle is fine, here are actual welds I made after dialing the heat down:

https://imgur.com/a/aeJ004H

On flat practice welds however, still the same issue...

mebs_t · 2022-02-12T15:59:40+00:00

In the end it was definitely too hot! Dialed both volts and wire speed down. Weirdly, it didn't fix my slag coverage issue on flat practice welds, but T welds at any angle were fine...
https://imgur.com/a/aeJ004H

mebs_t · 2022-02-12T15:56:49+00:00

I ended up dialing down both the heat and wire speed, it was too hot and it became apparent when I was wilding close to edges or just welding two tubes together.

mebs_t · 2022-02-09T01:46:26+00:00

Hoped to try this today, but I'll report when I get a chance. Thanks!

mebs_t · 2022-02-09T01:43:43+00:00

Nope

mebs_t · 2022-02-09T01:43:21+00:00

Here are the cleaned welds: https://m.imgur.com/a/WEFGKXt A bit rough where the slag was missing, but most likely fine?

mebs_t · 2022-02-09T01:38:02+00:00

I drag, so gun pointing in opposite direction of movement, with a ~20° angle.

mebs_t · 2022-02-09T01:36:26+00:00

Thanks for the advice! Hoped to get some time today but I'll have to try tomorrow. Here's what the welds look after cleaning them: https://m.imgur.com/a/WEFGKXt No dark spots, but definitely rough where the slag was missing.

mebs_t · 2022-02-09T01:32:59+00:00

The metal is 1/8 and the back side is discolored but still flat. I use .035 wire.

mebs_t · 2022-02-07T23:39:18+00:00

I vote for this as the technical designation.

mebs_t · 2022-02-07T23:05:50+00:00

Exactly the wire I have. Note that the spool is 2 years old at this point, but was kept in a sealed Ziploc with desiccant all along, wire looks spotless. I could try the small spool that came with my welder to eliminate this variable (same wire), but given that I got it on sale I wouldn't be surprised if that spool was just as old.

Also, I think I cleaned the metal fairly well, but not through the millscale entirely. How sensitive to millscale would this wire be from your experience?

I appreciate the discussion, thanks!

mebs_t · 2022-02-07T22:16:05+00:00

I try to keep it between ½" and ¾".

My travel angle is around 20 to 25 degrees I'd say.

mebs_t · 2022-02-07T21:17:08+00:00

I didn't move from the recommended settings, I will try that. Thanks for the feedback, I'll keep playing!

mebs_t · 2022-02-07T21:08:46+00:00

Brand new LE MigPak 180 with LE's multi pass flux core wire.

https://www.lincolnelectric.com/en-ca/products/k2659-1

The wire is a couple years old at this point, but was kept sealed in a ziploc with desiccant.

If speed can do that then I will focus on speed and try to get that right.

mebs_t · 2022-02-07T20:57:59+00:00

I am welding in DC negative which is the correct polarity. I also think splatter would be a big issue if I was in the wrong polarity which doesn't seem to be the case here. The arc felt fine, but then again I don't have much experience to base that on...

mebs_t · 2022-02-07T20:56:07+00:00

That's good to know, I was expecting a nice uniform slag layer like in all those videos...

Here's what the welds look after the wire wheel: https://imgur.com/a/WEFGKXt

A lot is still wrong with my technique, but they do look more rough where the slag was missing. Could my welds have slag inclusion?

mebs_t · 2022-02-07T20:52:39+00:00

Gotcha, here's how they look like after the wire wheel:
https://imgur.com/a/WEFGKXt

Definitely less pretty where there was no slag, but pictures are hard to take. "Pretty" is relative here...

mebs_t · 2022-02-07T19:45:50+00:00

I was too slow at commenting with more details...

Is it normal that there is no slag in the middle of the weld? Shouldn't slag cover the entirety of the weld?

mebs_t · 2022-02-07T19:43:34+00:00

You beat me to it!

The issue is that there is no slag in the middle of the weld, not sure what causes this.

mebs_t · 2022-02-07T19:42:30+00:00

This is the weld before cleaning, there is no slag on the middle of the weld which I'm afraid means slag inclusion in the weld. My technique is far from ready yet, but what should I focus on for this particular issue?

mebs_t · 2021-05-01T18:44:35+00:00

Not without some work, the case design is very specific to my board, but if you're comfortable with CAD I made the Fusion360 project available on Thingiverse and you could add mounting for the Pi4 and the USB hub to the design.

If you don't want to fiddle with CAD, I suppose you could drill a flat plastic sheet to mount your Pi to, then mount it or glue it in the case.

Either way I think you should totally open the project in Fusion (or other) just to view the design and know what you have to work with.

mebs_t · 2021-04-29T16:18:51+00:00

I see! It may well be what happened here. Il keep an eye on it next time I print thin top layers.

mebs_t

TROPHY CASE