Proxxon GE70 and GE20 engraving units

Discussion in 'Workbenches, including workshop techniques.' started by Chris Veitch, 3 February 2019.

  1. Chris Veitch

    Chris Veitch Active Member

    I'd dearly like a pantograph mill but I suspect most of them would cause serious structural problems to the floor joists in an upstairs bedroom (i.e. where my workshop is located), as well as a divorce. So, having only a need to cut out fairly tiny stuff anyway, I picked up on a few references to Proxxon engraving devices which seem to be capable of the same sort of task - I'm pretty sure I've even seen a recent magazine article or forum post on precisely that use, but obviously I've forgotten where it is now. I don't have a Proxxon MF70 mill but I'm seriously considering one, and the fact that there's an Axminster shop just a few miles away just makes it more tempting...

    So I had a look at the engraving devices and it appears that there's a GE70 for the mill and a GE20 for their hand drill range. The issue is that (typically) the GE70 now appears to be out of production. There's an article on WT referring one buying one but nothing further about its use. So the inevitable questions are:
    • Is the GE20 man enough for actually cutting rather than engraving? I'm thinking of 5-10thou brass or NS for wagon strapping and the like in 4mm scale.
    • The parts of the two devices seem to be relatively similar - does it look as though it's possible to convert a GE20 into a GE70?
    • I've seen a review that says that the GE70 has so much play in it as to be effectively useless - does anyone have experience of this, and is this a clue as to why it was withdrawn?
    • If (as I suspect) it's a non-starter, are there similar but more accurate products of around the same size available?
    Thanks in advance,

    Chris
     
  2. simond

    simond Western Thunderer

    Chris

    I believe Giles Favell has the smaller unit and is happy with it. I recall a post on RMWeb, in my Loco Loco thread, I think. If I can find it, I’ll link it here.

    Found at least part of it
    Another Beyer Garratt 0-4-4-0


    Best
    Simon
     
  3. Arty

    Arty Western Thunderer

    I had a GE20 for a short period of time, it can be used for cutting but requires the correct tip for cutting - not supplied by Proxxon, there is a video on YouTube by a chap who has used one for cutting, but even for thin material, seems to require multiple passes.
    So it will engrave, on suitable hard engraving brass, but I wasn’t impressed so I sold mine.
     
  4. Giles

    Giles Western Thunderer

    I do indeed have the GE20, and within its limitations I find it excellent and extremely accurate.
    First, being a small machine, it will only handle fairly small pieces of work (as the arms need to articulate all round) So a large, long 7mm loco frame is out, but a tank loco frame would be doable. 4mm no problem...
    Secondly, yes, you do need appropriate cutters and the smaller they are, the more you will break! I get on best with about 1.6mm dia, although I have successfully cut with 0.8mm (at some penalty of a learning curve). I use D bits bought from China.

    The accuracy is only going to be as good as the spindle (drill) for which I use the mains powered Proxxon, which I found so good I bought a second for general use, and the accuracy of the templates, which I laser cut for convenience, But useing this method, I have been able to produce valve gear (4mm equivalent -7mm narrow gauge) rods, chassis etc. from Nickel Silver (I used 28 thou for the frames.) That took two passes.

    I would use either nickel silver or a hard brass, avoiding soft brasses.

    You do need to make stylus of the appropriate diameter, as the one it is built with is pointy, and you need a parallel one!

     
    Arty and BrushType4 like this.
  5. Chris Veitch

    Chris Veitch Active Member

    Many thanks for that Giles - it certainly looks tinkering with.

    Regards,

    Chris