One thing I have been putting off for a while now is I need to make a couple of basic PCB to be able to put some kits i made into a box.
as such I have the design (i think) and a cheep kit for developing and etching PCB’s, I made ages ago a UV exposure box out of an old scanner ( pictures below).
The one thing I do not have though is a bench press for my Dremel, I guess my question is this, to drill the holes in the PCB is a vertical press needed? I guess it will make it much easier work over just using mark one eyeball…
Also the UV box, is just mainly sitting in my garage since I made it. If anyone wants to use / try it out i am more then happy to donate / leave it for others to use.
Yes you need a press the drill bits are too small and thin to hand drill easily.
They break too quickly as you cant hold them steady enough.
I use a pillar drill. Full size sitting on the bench.
As we have one in the makerspace theres no reason not to use it.
You do need a pin vice for the smaller drill bits but they are very cheap on ebay.
These then clamp into the drill chuck.
So youve effectively got a small chuck in the full size chuck.
Buy a few drill bits as they can break easily and pcb material blunts them quickly.
Difficult to resharpen 0.8mm drill bits. You need a range from around 0.6mm and up.
Youl need to make a small jig to butt the pcb against and slide it along for rows of pins to keep them lined up. As not only can they look messy but also its easy to have them just enough out of line that a row of pins wont fit. The tolerences are very close.
If you want i can bring the bits down on Thursday. you can try them out and see what you need.
Remind me during the day on thursday and ill bring them along. Just bring a board along to try drilling.
When I was making my own PCBs as a DT teacher I used a CAD program to draw the masks and made sure the pads had a little circle in the middle which acted like a centre-punched hole. That seems to locate the drill quite accurately.
When i toner transfer mine I leave a centre hole in the copper as well and its enough to centre the drill press runout and keep it accurate. But without a jig to slide it along its difficult to line up.
Just a more accurate drill press would help.
The lower end drill presses have a lot of runout. The bearings are just not accurate enough to eliminate it.
Maybe a small pcb cnc rig would be better.
But so far theres not been that much interest in the membership to make there own pcb’s.
When i last did a demo we didnt get much interest.
No is the simple answer, we’ve already overspent on the electronics budget with a more basic set, however there is an article about what was proposed somewhere on discourse with the budget spreadsheet… Nothing’s been bought thus far.
That would be good to see it did get a set of carbide bits for this purpose I did not think of using the full size pillar drill with a chuck in the chuck for a smaller diameter bits.
If you are going to be around on Thursday then I may see if I can get the PCB made up this week and bring it with me to try out if that is still okay?
I have meetings in Harrow till around 5:00 but could get the train straight to the space after.
Ive just ordered from Oshpark, from Tom’s recomendation, to get my first ever comercially made pcb. Yesterday.
Havnt needed to till now as ive usually done my own.
But the footprint for the Esp8266-12 Im using was a bit too close on tolerences.
and at $13 dollars for 3 boards its not expensive.
They quoted up to 22 days.
I got an email this morning to say my order had been upgraded as they had space to fill on there fast service. Thats 5 working days plus the postage time. No extra cost.
I designed the board in the free version of eagle and uploaded the .brd file.
They process it to make each of the boards layers and show them on screen before you pay.
Dont forget to dowload there DRC rules file before routing the traces.
Have a look at Tom’s shields used on doorbot.
He had the pcb’s made by Oshpark.
Thats why i got the recomendation for OshPark from Tom.
Its come down in price a lot over the years.
Pity theres not a similar priced service in the UK.
If youve got a lot of vias and small fine footprint parts its well worth the wait.
Its the vias that make home made boards hard work as theres no home brew method to add through hole plating to link the 2 sides of the board. So you can end up with a lot of extra vias with wire soldered on each side. Obviously not a problem with single sided boards.
The website looks shonky, but what you get a personal relationship with someone who ensures everything goes through China to spec. Very cheap yet sanity checked by a human who cares.
