UK Vintage Radio Repair and Restoration Discussion Forum

UK Vintage Radio Repair and Restoration Discussion Forum (https://www.vintage-radio.net/forum/index.php)
-   Cabinet and Chassis Restoration and Refinishing (https://www.vintage-radio.net/forum/forumdisplay.php?f=21)
-   -   Which Dremel tool..? (https://www.vintage-radio.net/forum/showthread.php?t=163133)

Al (astral highway) 20th Jan 2020 6:28 pm

Which Dremel tool..?
 
Iíve just bought a Dremel portable. It comes with limited instructions and assumes some previous knowledge.

Much is of course pretty intuitive (cutting etc) but Iím posting for specific advice - what sort of attachment : tool am I looking for to tidily remove a narrow path of copper from some copper-clad glass fibre board ?

Itís goong to be quite a series of long strips and aesthetics / neatness are important (as in a nice tidy edge).

If you can post a pic of the relevant bit that youíd use, much appreciated . Also , in the absence of a dedicated workshop or router attachment , how to get my straight line and keep it . Thank you

Bazz4CQJ 20th Jan 2020 8:00 pm

Re: Which Dremel tool..?
 
While I've been a big fan of mini-drills for a long time, I don't recall ever doing anything like you propose. How wide are the lines where the copper is removed? How deeply can you go below the copper?

Just intuitively, I think this sounds more like a job do be done by etching?

B

cheerfulcharlie 20th Jan 2020 8:54 pm

Re: Which Dremel tool..?
 
1 Attachment(s)
This is the Dremel with its basic router attachment, the Dremel drill bit kit range
here is 0.8 mm to 3.2mm

If the material is softish ie pc boards then you can set the router for a cut,skim or traditional drill though but you still need a steady hand.

Al (astral highway) 20th Jan 2020 9:30 pm

Re: Which Dremel tool..?
 
Bazz: thank you , but I bought the tool specifically to do this so I’m determined to find a way

CheerfullCharlie : that’s a helpful visual . I’ll see if that router comes with the kit I bought , thank you

G0HZU_JMR 20th Jan 2020 10:54 pm

Re: Which Dremel tool..?
 
From what I've read online I think some of the Dremel branded accessories like the router stand and the drill stand are not very solid in terms of build quality. So I'd expect the setup to be a bit wobbly and imprecise in operation.

The classic way to neatly cut strips out of PCB material is to use a steel ruler and a sharp scalpel. Then peel up a corner and heat and peel the (unwanted) strip areas with a soldering iron and some fine pliers or tweezers. It's possible to cut fairly accurate microstrip traces on a PCB like this and I'd be amazed if anyone could beat this with a Dremel and a cheapo plastic support tool.

The other issue with using the Dremel on fibreglass is that it will generate quite a bit of fine dust if you end up drilling lots of lines in the PCB material.

Here at home I have a dedicated PCB milling machine to do stuff like this and it uses a dust extraction system that sucks away the dust and vents it outside. Without the extraction system it gets quite dusty even on a small job. The copper layer on a typical PCB might only be about 0.0014" thick so any excess cutting depth beyond this just adds to more fibreglass dust. My guess is that you will have to set the depth fairly deep if you want it to cut reliably and cleanly on a single pass. So be prepared for lots of dust...

I have a new Dremel here somewhere with all the accessories plus the engraver but I've never used it. It was part of a long service gift at work. The whole setup feels clumsy and I think it will take a lot of skill and a steady hand to do any accurate cutting with this crude and heavy tool. Mine has been in the box for 5 years and never been used because I've always found a better alternative for any given task.

Al (astral highway) 22nd Jan 2020 12:11 pm

Re: Which Dremel tool..?
 
Hi Jeremy ,

Thanks for your detailed post. I will try the traditional method you mention, only may need to remove up to 2 mm wide at once ... is that still a ‘microstrip’?

kalee20 22nd Jan 2020 12:37 pm

Re: Which Dremel tool..?
 
Agree Jeremy's advice - and I've removed 5mm wide strips, no problem.

After cutting with a scalpel or Stanley knife, I get the soldering iron, start tinning the bit I want to lift, and start peeling. When at solder-melting temperatures, the copper peels much more easily as epoxy loses strength. You have to do it hot, as the strength returns on cooling.

G0HZU_JMR 22nd Jan 2020 9:33 pm

Re: Which Dremel tool..?
 
One thing to watch out for is that I usually overdo it with the soldering iron when trying to heat up the first part of the strip. I'm always that bit too impatient when trying to lift the first corner... This always leaves a discoloured area where the soldering iron causes heat damage to the fibreglass. So patience is required here if you want it to look nice. The same applies to the scalpel work. Always use a fresh scalpel and don't press too hard or the scalpel tip will fracture slightly.

It will take some practice to score the lines such that they remain straight and it might be difficult to get two parallel cuts to look straight if they are only 2mm apart. I can see why you considered using the Dremel for this but you would need to have some sort of vacuum extractor with the Dremel otherwise the dust would hide where you were trying to cut. The dust can be nasty stuff as well and I definitely wouldn't recommend using the household vacuum cleaner to scoop up this dust as it will remain circulating in the dustbag every time the cleaner is used around the house. The vacuum extractor I use has a special HEPA filter to prevent the fine particles of fibreglass from escaping out of the dustbag back into the room. However, I vent the vacuum to the outside of the house even with the HEPA filter inline.


All times are GMT. The time now is 5:23 am.

Powered by vBulletin®
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
Copyright ©2002 - 2021, Paul Stenning.