Meatball / McMeat Layouts with on-board switches

[Skruffyhound]

Good work!
I'm also tight for time, finishing builds already started will take the next couple of weeks, but the layout looks good, if I manage to get a big enough piece of board I'll try to build it within the next month. Thanks for making the effort.

[chicago_mike]

Man I wish I had more time. I was going to try to get this in a smaller enclosure as well as a ground plane. The work you guys are doing is really really good.

[ringworm]

The pcb  I posted should refresh soon through photobucket. A small fix to correct the 3 pole pins on the switches.
I've got the jack socket and switch wiring mapped as per the original. someone will need to take a look as there are a couple of points I'm not sure about. I'll post it when I get a tidy drawing done.
In another Meatball thread here someone has said that the mcmeat switch wiring for 'Range' is wrong but as far as I can tell from the gutshots and the position of that switch's 'orienting pin' the mcmeat schematic is fine. Not sure what to make of that 

[Strategy]

I hope to etch this in the coming weeks and give it a test here!
- Strategy

[ringworm]

Here's what Ive figured out for the wiring for the switch and jacks. Anyone see if there are any faults?

[chicago_mike]

Quick Question...


At 3...025 dpi or whatever, its super small in photoshop. Its like 1" b 2 ".  Whats the correct board size?

[ringworm]

You're right, photobucket or the forum must resize images to view.
Board should be 181.51mm x 92.96mm @ 300.025 dpi but i'll email you the file.

[chicago_mike]

michael_stram@hotmail.com   ty

I can print this out on transparency and do an etch next week. Im doing UV light method and it wors as long as you have good coverage.

reminds me to check my etches..3 RC boosters and 2 Neutrons.

[ringworm]

Looking forward to hearing how it goes, I'm not gonna get a chance to have a go at this until February.

[bigandtall]

Also looking forward to seeing how this one goes. Looks much easier than the McMeat.

[chicago_mike]

Well I printed out the transfer. Did 2 as I have a box of OHT sheets.

Im telling you guys now, if you still do the photo glossy paper method..stop it now! Do the UV method. 

I use 3 GE Blacklight bulbs (party type) THe ones you get at menards the twisty looking suckers. 4 or 5 bucks a pop. You can do this in your bed room. PLace the sheet over a positive sensitized board and place a clean plexiglass sheet over that. with weight to keep anything from moving. You can use desktop tube style blacklights as well. just make sure you get good even coverage and its pretty well lit.

run the bulbs for like 8 to 10 minutes, maybe even less..depending on board size. The Meatball fullsize I would to maybe 8 to 10. have the bulbs around 3 to 4" above the transfer.

To remove the resist, You CAN make a mixture of caustic soda, but its a temperamental mix, I use the GC mixture. Infact my sensitized boards are GC as well. 9 to 1 mixture...and then ferric chloride or sodium persulphate.

And the fact that I can reuse the overhead sheet as many times as I want, Its pretty easy to do runs of certain boards if need be.

[ringworm]

I've just been pm'd by jota.ventura with a fix for the layout and pcb. There was a missing jumper that was connected to the trace that runs from pin 11 of the TL074 right beside R1. It should be easily remedied if you've already printed a board with some careful drilling and soldering, it's a jumper that needs to connect that trace to ground (i had the empty ground pad on the board but hadn't connected it to anything). I've updated the pcb and the layout (it doesn't affect wiring) so refresh your browser when you go to page 4 of this thread and you should see the fixes.
Sorry again for those that have printed a board.

[ringworm]

go to page 4 of this thread and you should see the fixes.

Edit to say "page 3". Fixed files are up now.

[ChanchoPancho]

Hi everyone, I was looking for the PCB of this effect with pots and switches included and finally found this post. Congrats for all the great work. Now there are a couple of things i'd like to say that I think will help some of you. Before I etched the board i found that the size of the circles in which components are soldered are too small, so I took rigworm's layout and redraw it. I've included the last correction, the jumper form pin 11 of tl074 to ground. Here it is:


Now there are three things to correct in the image of rigworm's reply #59 i circled them in red:

First, the jumper marked as E$29 has to be raplaced by R16, 1k5. Then there's the other thing: the R of the LED1 (on/off led) is marked as R16. It has to be corrected I suggest R22, 2k2.
Finally the numeration of R14 & R15 are inverted. According to Joep's McMeat's layout R15 is the one that goes to ground and R14 to 9v.

I have not finished the board so when I do, I'll comment more.

One comment about the layout I posted: The size is not ready to print. It has to re-scale to 157%. FYI: I do it inserting the image in word and re-scaling there.

Hope this helps you.

[ringworm]

You're right, many thanks for that. I'll amend the layout and update it.
Let me know if anything else shows up.

[ChanchoPancho]

One more thing: there's a short between lugs 1 & 3 of the decay pot. You need to eliminate the conection between the two pads below (R16 & jumper E$24).

[ringworm]

The decay pot connects through lug 1 to  R8 and then to the attack pot. Lug 3 goes to the pedal 1 socket, they're not connected to R16 or the E$24 jumper so I can't see how it is shorted. The intens and colour pots are connected through lugs 1 and 3 but that is as per the schematic and from the traces on the original pcb as far as I can tell. Which two pads are you referring to?

[ChanchoPancho]

Sorry, the decay pot is ok, my mistake. The pot shorted is the colour. I uploaded your layout pointing out the loop. The blue line shows where to cut.

[Skruffyhound]

Good to see you hammering out the details. Thanks for all the hard work. I've got parts on order. Looking forward to building this.

[chicago_mike]

Wheres the best place to get the plastic rotaries. My local shop doesnt carry enough variety to do a true meatball.