The LNER Encyclopedia

John,

You mentioned the Micromark etching kit. Yes, a bit pricey for me at the moment - esp. with budget and time constraints. Looking at it, I may already have a lot of the parts in an unused PCB etching kit that I have. Other supplies can be easily bought for a few dollars a piece. Which leaves the laminator, which must take up the bulk of the price? Is it a normal laminator? I don't know if there are different kinds, but I could perhaps beg or borrow one

I can see why you need a laminator: You need a backing for the brass. The PCB kit didn't need one because the board was the backing to the copper.


Richard

Well, I haven't actually used the MicroMark kit!

You are going to use the same basic technique as for PCB making. Probably even use Ferric Chloride to etch. I design some parts for other products which rely either on etched parts or on some chemical milling for specific jobs. The shop that does them for me also does some simple PCB work. They use DuPont Riston resists and I understand that much of the simple brass etching they do for me is using the standard EtchMaster (I think it is called) resist. They use a large heated drum laminator, but I suspect the MicroMark one is not too different to a good office type laminator.

There is a specific resist for chemical milling which has a very high resolution, but I understand it is somewhat more difficult to work with responding best to a specific wavelength light source. The standard PCB type resist is pretty forgiving as to what light source you use and carefully handled it has more than adequate resolution.

We are now using 0.1 or 0.12mm brass for a number of small robot parts and about 0.25 and 0.35mm for some milled compnents. Nickel silver and stainless steel also etch very well.

Sadly I have no space for anything other than the most limited workshop here so I am restricted to having any of this work done outside.

John