TheBackShed.com

Forum Index : Microcontroller and PC projects : Air Quality Sensors and Systems for MM?

Page 4 of 4

Author

Message

Volhout
Guru

Joined: 05/03/2018
Location: Netherlands
Posts: 3510

Posted: 11:57am 02 Apr 2020

Copy link to clipboard

Print this post

Quote

I never really like strip board, only used it for basic stuff. I preferred paperboard with the land around each hole or eurocard style ones laid out for ICs. Then backwire from a net list.

These days, I don't do either (for single sided stuff), I etch a single PCB. Circuit ends up in Eagle anyway, lay-up a board - which I find quite therapeutic. Then save out the track, pads & vias image of the board as a PNG, covert to SVG with Inkscape and cut it onto a bit of black-painted board and etch. The export, convert, cut, etch takes less than an hour and I have a guaranteed working hookup - barring mistakes. I did two yesterday alone. I lay the board up as two-sided, avoiding the top as much as possible and then use that to top-links where I get stuck. Can't do really fine stuff though as my laser etcher is a only cheapie, but it can just about do down to tracks of 32 thou. Prefer 50 thou as a standard which give a very robust board.

Just Curious...
Can you clarify a bit more. I tried black pray-painting (thin layer) copper, and burning it away with a 2.5 watt laser (Eleksmaker 3A), but was not succesfull.
- isolation between copper parts was so narrow, I had a lot of shorts. Especially where the laser started (seemed almost as if it did not completely finalize, skipped a segment).
- due to the narrow isolation, and lack of solder resist, soldering caused additional shorts.
- maybe som eplay in the system, but pads did not seem round, but shaped like an egg.

Have you mastered these things, how did you solve them?

Regards,

Volhout
Edited 2020-04-02 21:57 by Volhout

PicomiteVGA PETSCII ROBOTS

CaptainBoing

Guru

Joined: 07/09/2016
Location: United Kingdom
Posts: 1985

Posted: 06:16pm 02 Apr 2020

Copy link to clipboard

Print this post

Hey Volhout.

Exactly my setup. I'll put together a vid for you if you would like that. I'll go out and do a board from start to finish and chuck it on youtube if that helps.

The pads do vary as there is evidently some registration error (not returning precisely) -
check out the top two pads in the first pic and I do occasionally get some shorts on my boards - post-production includes me "toning out" the tracks and clearing any shorts with a sharp scriber. The etched lines are very thin but I give new boards an all over coat of liquid flux which means that even with my ham-fisted soldering where I bridge a land to the "flood" it tends to clear nicely when I lift the iron away. That said; I do always check and solder with a tiny bit to avoid it as much as possible.

I think you are right about play in the belts and I have a couple of modifications to my laser to provide better alignment of the belts. It was a cow to get the right trade-off between tightness and reluctance for the carriages to move. Perseverance one night after lots of googling (which turned out not to be related to my problem) and about 2 hours later I had a decent setup.

My Eleksmaker does have the x coordinates reversed for some reason, but as it does the auto-flip of a PCB foil for me, serendipitously, I have little driver to investigate as it would only introduce another step in my process. Have to remember that when i use the laser for other things (which is rare).

Here's some boards and close-ups of boards I made yesterday. Photographing bright shiny copper makes the image look crappy but it is clean and bright in reality

Ready for drilling

straight out of the ferric and paint cleaned

do get some variation in trace width but I can live with it for one-offs

the magnified pix make the etches look jaggy, dunno why - they are much cleaner in real life.

h
Edited 2020-04-03 04:30 by CaptainBoing

Volhout
Guru

Joined: 05/03/2018
Location: Netherlands
Posts: 3510

Posted: 10:39am 03 Apr 2020

Copy link to clipboard

Print this post

Hi CaptainBoing,

This is roughly what I see also. As you say, spend some time in tuning the play out of the system...
For the reverse X axis: you can simply swap 2 wires on one of the X axis motor coils to solve that.

How do you get from PNG/SVG to GRBL ? Any tool you use, or do you scan the SVG with the Eleksmaker tool, and adjust X and Y dimensions.

Anyway, idea's enough to pick this up again. The Eleksmaker has been in storage for 1 year, only used for engraving once in a while.

Volhout

--Sorry for hijacking the thread
Edited 2020-04-03 20:40 by Volhout

PicomiteVGA PETSCII ROBOTS

CaptainBoing

Guru

Joined: 07/09/2016
Location: United Kingdom
Posts: 1985

Posted: 05:19pm 03 Apr 2020

Copy link to clipboard

Print this post

Hi volhout.

Rather than clutter this thread more, I posted a new thread here:
https://www.thebackshed.com/forum/ViewTopic.php?PID=144938#144938

hope this helps. Post any questions in that new thread

enjoy

zeitfest
Guru

Joined: 31/07/2019
Location: Australia
Posts: 377

Posted: 01:45am 07 Apr 2020

Copy link to clipboard

Print this post

The new Altronics catalog lists an air dust/smoke sensor, Sharp GP2Y1014AU . Looks like a led instead of a laser so might have longer operating span (?)
Edited 2020-04-07 11:46 by zeitfest

Phil23
Guru

Joined: 27/03/2016
Location: Australia
Posts: 1664

Posted: 01:55am 08 Apr 2020

Copy link to clipboard

Print this post

zeitfest said The new Altronics catalog lists an air dust/smoke sensor, Sharp GP2Y1014AU

Haven't seen the Catalog yet & can't find it online.

Core Electronics list it @ $22.36 and have a datasheet, but it doesn't say a real lot.

I has a table that indicates an analog output of about 0.9 to 3.4V for "Dust Densities" from 0 to 3.6mg/m�.

No mention at all of particle size.

The Sensirion I mentioned above covers 4 ranges, and the March 2020 datasheet state the lifetime as >10 years 24/7.
(Thought I read 7 or 8 before).

$84.00 delivered from RS.

zeitfest
Guru

Joined: 31/07/2019
Location: Australia
Posts: 377

Posted: 09:06am 08 Apr 2020

Copy link to clipboard

Print this post

The Sensirion looks a more (ed) in-depth unit for sure.

Here is the download Altronics catalog link (2 or 3 meg) for a browse �

Edited 2020-04-08 19:09 by zeitfest

Phil23
Guru

Joined: 27/03/2016
Location: Australia
Posts: 1664

Posted: 02:12am 09 Apr 2020

Copy link to clipboard

Print this post

Still can't seem to find it in the Catalog above.

I did spot it in JayCar's latest Cattle Dog though.
Page 105.

zeitfest
Guru

Joined: 31/07/2019
Location: Australia
Posts: 377

Posted: 05:59am 09 Apr 2020

Copy link to clipboard

Print this post

Ersh...my bad...yes I meant the Jaycar... �

�

ed- new Jaycar cat here
Edited 2020-04-10 06:59 by zeitfest

Andrew_G
Guru

Joined: 18/10/2016
Location: Australia
Posts: 840

Posted: 01:38am 04 Jun 2023

Copy link to clipboard

Print this post

G'day all,

Any updates to the above discussion?

Sorry to resurrect an old thread but it makes sense to me.
We are six months away from moving into our new home. A heavily insulated, airtight European design called "Passivhaus".
Jackie and I both have health issues that mean we need to have a low-VOC and dust-free environment (we will have all sorts of expensive gear built in to help achieve this).

I want to get my VOC and particulate sensors working again so I am just checking if Shedders have any better sensors and systems than those discussed above.
I also want to add UV sensor(s) too.

Cheers,

Andrew

(I stopped updating my above system because it proved that we had a dust and mould issue, confirmed by professional tests, which lead us to demolish and build anew)

Page 4 of 4

Print this page

To reply to this topic, you need to log in.