Etch Press Build

[Wal]

Hi John,

I think the springs are in the wrong place - really you want them to take the weight of the top roller to make it easier to get the plate/blanket sandwich under the roller, then use the screws to apply compression.

Hmm - that's an odd thing to throw in at this stage - it was fairly obvious from my earlier posts that I was going for a 'sprung above' approach. There are a lot of vagaries on putting together one of these presses - so as well as taking advice from good folk such as yourself, I've had to (for better or for worse) go my own way a bit here...

Anyway - allow me to explain my approach... Instead of a collar, I made a couple of threaded flanges and used a thrust bearing in the take up unit (flange stud-locked and captive to the threaded rod) - this means that there is very little friction turning the pressure adjustment knobs to raise or lower the roller, it's literally as easy as turning a tap.



As I understand it, the springs have two purposes:

• sprung under they can aid with lifting the roller
• sprung over or under they apply a bit of pre-load to the roller to stop it flapping about when not under pressure

So, the thrust bearing negates the need for the spring to help lift the roller, but that downwards pre-load is still very useful. If you look at the side-on view of the take-up bearing you'll notice a gap between the threaded rod and where it would normally contact the take-up unit.



This effectively means that the press has a bit of suspension - the roller can still be positioned to kiss the plate or print at lower/softer spring pressure when printing from lino or wood - of course, these gaps can also be shimmed for a hard stop when printing etched plates.

I don't know why you bothered to get it ground

Ah yes, my mistake - a chunk covered in mill-scale that's been sat in the garden for a few years would have done the job! Joking aside - I totally get your point, but for the price there was no harm in at least attempting to get it as parallel as possible, job worth doing and all that...

Regarding blankets, yep - there's a fair amount of gap available - not loads, but should be enough. If I run into any problems I have the option to either a. get myself one of those thin rusty plates you've been advocating , or b. deepen the pockets that hold the springs on the underside of the pressure plates.



This is probably all moot anyway - I'm shite at art...