Discussion in 'Off-Topic' started by Robin Mitchell, Sep 11, 2015.
If anyone was interested in seeing a photo of my latest creation...
That's a giant leap on PCB making. Congratulations.
When will double-sided PCB be available?
Double sided is already available with through hole conduction! Its funny to think that the first PCBs I made using the toner transfer method back in 2010 would lead to this. I no longer use toner transfer because of production reasons (+50 boards), it becomes too silly and the yield is terrible. With my new process I can turn out up to 8 A4 sized PCBs/ day single sided or double sided. (That depends on the number of panelised boards because I need to let the CNC cool down between jobs as the motors get hot).
If I could give anyone advice on CNC machines (mainly the cheap Chinese ones like the CNC3020), it would be to never let it do more than one hours of work at a time. I have read so many posts online about these machines breaking after 10 hour jobs and I just say to myself "its because you are overworking it". I figured that if I limit the machine time, keep the motors cool, clean all the dust up and just take care of the machine then it will do fine. So far so good! My machine cost £450 and already has paid itself off. Only this morning I made 42 transistor flasher PCBs and it only took 1 hour to mill/drill. Best part is that I dont even supervise the machine so thats one hour for me to do other things!
But my PCB process is beyond hobby now. So far I can do:
Through hole conduct (thin plate, electroplated)
Silk layers (in funky purple)
Currently I am working on a program to automatically panelise gerbers for me, I am too tight to spend £500 on some software to do it for me. Plus, people submit inches instead of mm (arrrggh), so I need to convert the files too.
All the best,
I was more interested in how you do it...
Stick your mind to it for 5 years plus lots of money, time and effort
So this is an advertisement of your services? Should probably ask the mods to relocate from here to Marketplace sub-forum.
Not an advertisement just though people would like to see some pictures of something I made. That's why its in off-topic
We have a CNC machine (Made in China) to do PCB but only in single sided. At the moment it can only accept PDF files.
We do it one PCB at one time even though it is able to take A4 sized PCB. The problem is it is very hard to lay the PCB totally flat so that the router wouldn't break the drill bit when drilling holes. The tracks are also drilled using another type of drill bits.
We also have a laser CNC but this one is mainly for cutting plastic 0.1" think and also make signs/words for front panels. To make PCB, I have to spray the PCB with paint from a can and dry it under the sun. Then laser the negative of the PCB image so that the tracks are protected. It was later etched the same way like a regular PCB using toner transfer except there is no danger of spoiling the tracks when removing the toner paper.
Those are some beautiful boards. Nice work!
Getting the PCBs flat can be done by heating them up (hot to the touch), and putting bricks ontop of them, alot of bricks. Also make sure the surface is flat and when the boards cool down they "should" be flat. Personally I just bend them to shape and measure against a reference surface. Takes about 10 seconds to do (just need practice). But realise that when the material is warm it is VERY easy to bend.
Thanks a lot ! I work REALLY hard in my workshop (trying to work for myself while working no less than 12 hours a day). Im hoping that in the future I can consider masking my own kits so they are more beginner friendly. So far though its looking good! Im not exaggerating when I say it has taken 5 years of continuous production to get to this level. You will find my PCB pictures date back to 2011 (with other files on my computer dating back to 2010). That was when my dad first let me use ferric chloride (I wanted it so much I made a presentation on the safety aspects of it).
Are you saying these boards are milled?
@MITCH electronics how much would you ask for a 10cm x 5cm board? Or 10?
@Brownout They are edge milled (to get the right dimension), and CNC drilled. The PCBs are etched for the copper layers
@DerStrom8 I will PM you (dont want to make this a market place).
Thanks for the tips. We'll try that on our next batch of PCB making. What we did recently was to put lots of double-sided sticky tape on the under-side of the PCB to make sure that it was totally flat. My method may be different from yours as my whole board is milled and not using any photographic UV exposure method.
I did try to make SMD PCB with using the laser CNC. Just 4 and 16 pin chips like 555 and 4017. But the result was very poor. And without solder mask, the soldering is tough and looks messy and I have to be very careful not to bridge the adjacent pins.
Completely forgot to mention. The secondary method (I use both), is to standardize ALL of your A4 PCBs so that they have a drill hole (3mm), in diameter in each corner. On your bed you add a thick piece of wood with bolts going through so that the tip of the bolt is a cm above the bed. Then you can bolt down the PCB which gives you no movement of the work-piece and keeps it flat. It also helps with origins too.
So just to reiterate: Piece of wood ontop of your CNC bed. Drill holes in the wood so that the bolt head is touching the CNC bed with the ends poking through. Then using nuts, bolt down the A4 PCB material which has 4 drill holes aligned with the bolt.