Transient DIY

Hi folks,
So after trying it live, I've decided to give it a shot. After searching for the schematic for like 2 oe 3 weeks, I've found this site :
http://www.jhaible.de/transient/jh_tran_gate.html

So you can breadboard it... Great!
But I like pcbs...
So I've decided to design my own.
First try : 2 boards of 160mm x 100mm above one of the other.
And I've finally decided to do it on double sided board (74mm X 204mm - so 4 of those can fit a 300x210 board...)
First try is not really good, even if I'm good at etching single sided boards. I think I've been too fast on this, so I'll have to redo it. The 2 etchings are not really on top of each other, so it's unusable... Do you have any advice on how to do this? I'll be glad to ear...
Anyway, I'll keep you informed about this particular project. I've decided to add Balanced and unbalanced in/outputs, so I can use it live or in the studio.
I won't post etching files here, as this unit is still on production, but shoot me an email if you need it. I'll send it as soon as I'm shure it's working (probably in january 2013) Please, keep this as a educational/hobby project, don't sell it.

I wish there were more transient designer projects or retail units for that matter.  Now I'm summing my drums I really miss it.

Last I read, I thought Igor was working on one? Envy Looper?

First try is not really good, even if I'm good at etching single sided boards. I think I've been too fast on this, so I'll have to redo it. The 2 etchings are not really on top of each other, so it's unusable... Do you have any advice on how to do this? I'll be glad to ear...

Click to expand...

How did you do it on the first place, maybe it's a good technique and just need some more care?

Yes, I think I was too excited about my first double sided board.
Here is what I want to do next time.
1 - print on regular paper the design.
2 - Drill 4 holes (8mm) on the pcb as marks
3 - drill the same 4 holes on the transparent sheet
4 - put 4 resistor legs on those holes
5 - fit the 2 transparent sheet on thos legs
6 - put scotch tape to secure all that
7 - expose this to the uv.

I think my solder side was not secured enough on th first try, and moved when I switched sides. Well, sh#t happens, sometimes...

What would you do?

Well there is a lot of fancy ways for doing this, depends on the amount of double sided home etched board you'd want to do in the future....

One fancy and easier solution would be to have a double side UV box, but you still need to have some flat weight on the board and the Transparent sheet or whatever.
I've seen people DIY'ing air tightening device (don't know how you call it in english) "Machine sous vide" in French, so to take all air out and to have a flat design on both sides.
That's how Big Companys do i believe.

I was going to build a box, using just one side of UV lamps and fit it like a cartridge when need to do double sided, so expose bottom side, than take the UV Cartridge out and fit it to expose Top side, you don't move design like this. Center section beeing the design and sandwiched between two thick glass panels, like 10mm or more for having it as heavy and flat as possible.

The other solution is like you mentionned, having some centering holes or so, but that means having like an aluminium or steel template frame for drilling the holes, two should suffice then guess. Drilling by hand won't make it very centered enough i guess, dunno never tried.....

I don't do that much double sided so i sticked to my easy pizzy "not much headache technique" well at least for me, since i got use to it now, so here it is, never got any faults so far (knock on wood)
This way of doing it has a limitation on size tough, meaning a little less than A4 since we need some room around, you'll see why.

- I print on transparent paper, or blurred type..
- Add two layers of the design for having a deeper black if needed, and drop some dots of crazy glue for keeping both prints in right place.
- Do same thing with the top design.
- Then take both assembly and align them together, and seal the alignment, top and bottom, with drops of crazy glue on one of the sides by drawing a line or whatever.
- Cut the board to the dimension required, but leaving some frame space around the design, i like to have at least 10mm, maybe a little more on one side.
- Fit the board between two design paper. EDIT: TRIM the cutted edges, we don't want bumps or whatever from the cutting process...
- Then do a crazy glue frame around it, on 3 sides of course, a U shape frame, leave one side wit more room to take the design out after all this....
For doing this, i draw a line of crazy glue on one side, and using two hard flat metal sheet,  press both the PCB and the glued line together, to make things fit properly. We don't want to have too much "Wave" shape on edges or so on the design when putting some weight on, if you understand what i mean?
Do this on the 2 other faces, and you'll have yourself a nice trap for the PCB not to move when you turn it upside down.
OF course it will maybe feel a little loose because you take the Photosensitive protection off, but that ok, if you left a little more empty space on on side as mentionned earlier, you then just need to push the design in the trap a little more to keeping it in place.

Seems a long process reading this, but actually when you get your marks it's pretty quick, at least there is less concern about beeing aligned i think, well if your alignment was done on first place.
Try it on a small board or whatever, and see if it works good for you as well.


Hope that helps.


T.

THanks for those advices Zayance, I don't do that much of double sided board, so I will go with your second option. I'll let you know in december, when I'll have time to finish this.

It's a nice project!

Tell me when working and I could give them a shot!

JS

Will do!

HI,Sam,
what works for me :
I cut the boards at the exact final desired size .
on the PCB design software, materialize each corner of the board with a cross.
I print it on a sheet wich will remain larger than the board (actually two sheets for more opacity) and tape the sheets on the glass of my UV box.
this way, I can precisely position the board thanks to the crosses at each corner.
of course, the corner crosses should be drawn on each layer on the software.

Laurent.

So today I tried again, with thiner board (0.8mm).

I print the layers, I cut a U shape (board size) on some paper (not thin, 0.5mm) and put it on the bottom layer, with scotch tape.
The top layer was also taped on the bottom layer.
The second layer is glued on the paper.
this is what I've got at the end :


Turned out pretty well (I would say I still have some error, but I can work with it, the pads are almost perfectly on top of each other, I guess I will be able to say it's good in a few trys)


BTW, I've change a little bit the design, to get a shorter board (194mmX71mm)

Thanks to all for your advices/interrest, I've learned things those past few days, that's why I love this place.

@Laurent : your way seems way easier than mine