Mike Trice's 4mm Workbench

Discussion in 'Workbenches, including workshop techniques.' started by Mike Trice, 1 March 2020.

  1. Mike Trice

    Mike Trice Western Thunderer

    We were due to go away for a week tomorrow but the holiday has been cancelled due to Coronavirus precautions in Madeira.

    What this does mean is I have been able to order some brass sections from Eileen's in order to scratchbuild the angle trussing. Build progress will continue ASAP.
  2. Mike Trice

    Mike Trice Western Thunderer

    While waiting for the brass sections to arrive I thought it would make sense to progress the 3D Prints I would need so after some 3D modelling and firing up the Photon I managed (at third attempt) to produce a later battery box:
    At the same time I also did some vacuum reservoirs:
    With the machine on good form I also printed the bucket seats from an earlier 3D model:
    I now have lurking in the back of my mind whether to do the angled cross piece as a 3D molding or whether to try it in brass which would give additional strength to the brass trussing. Prototype looks like this (taken of a catering vehicle hence location of vac reservoir):
    JimG, jonte, AJC and 5 others like this.
  3. Mike Trice

    Mike Trice Western Thunderer

    Brass has arrived. Brilliant service from Eileen's.

    Trouble is I really should cut the grass first!
  4. Mike Trice

    Mike Trice Western Thunderer

    Well, the grass is still waitingto be cut. There is always tomorrow.

    First off I produced a drawing to work from. LNER angle trussing is 3.5" x 3.5" and brass angle typically comes in 1 x 1mm (top) or 1.5 x 1.5mm (bottom) sizes. 1mm is quite close but does still look skinny against the real thing. 1.5mm is overscale but considerably stronger and can be thinned down if desired:

    Before any attempt at soldering I decided I needed some form of crude jig to help the angles and hold everything correctly. Various pieces of mount board and extra prints of the drawing were cut and glued to form a holding system. Pieces of the 1.5mm angle were used as spacers so that the "slots" were the correct width to hold the angle in place: IMG_1944.JPG

    This one looks odd as some of the paper template has peeled off: IMG_1946.JPG

    A length of 1.5mm angle is partially cut through with a piercing saw, bent, and inserted in the jig. Lengths of 1.5mm are trimmed to length and one end rebated to form the uprights. Both parts are tinned: IMG_1948.JPG

    After soldering and initial cleanup: IMG_1949.JPG

    For the crosspieces I really needed a jig so used the same technique to make one. Brass angle was partially cut through, filed for the internal angles, bent and slotted into the jig. Due to the way I went about this there were small gaps at the joint that I decided to fill for strength as below. In hindsight I could have assembled the crosspieces by mitering short lengths of angle together but thought that too fiddly: IMG_1953.JPG

    On removal from the jig and cleanup it does not look too bad: IMG_1957.JPG

    The other side less so but I doubt it will be seen when in place: IMG_1960.JPG

    So one set down, one more set to make. Phew!
    JimG, Jason L, iak63 and 5 others like this.
  5. Mike Trice

    Mike Trice Western Thunderer

    Before going any further I made up a paper template using Inkscape to show the locations of the various items in the floorpan:

    With the second trussing formed in the jig, the first could be located in the floorpan and held upright against an offcut of 2*1" timber whilst the end was tacked behind the solebar:

    Repeat for the other end then tack the two truss posts and repeat for the other side: IMG_1965.JPG

    The straight cross pieces were cut from 1.5mm angle and sweated in place. I found that the Templer's Soldering Flux that I use would hold the cross piece and let me turn the underframe right side up and allow a fine tipped iron access: IMG_1967.JPG

    Both cross pieces in place: IMG_1968.JPG

    Unfortunately the angled cross piece I made earlier is too wide caused partially by me using wider brass angle for the rest of the trussing: IMG_1971.JPG
    Len Cattley, JimG, Scale7JB and 6 others like this.
  6. Mike Trice

    Mike Trice Western Thunderer

    Before rushing in to start bending brass I produced a simple template to check dimensions against the underframe:

    Two new angled cross members have been made after making a second jig: IMG_1975.JPG

    I am now scratching my head as to how to fit them!
    Len Cattley, JimG, Scale7JB and 8 others like this.
  7. Mike Trice

    Mike Trice Western Thunderer

    Having scratched my head, this is what I came up with. I removed the straight cross pieces from the underframe then cut a slot in my soldering block, wedged the flange of the straight cross piece into it then carefully soldered one of the new angled cross pieces to it using a suitable spacer:
    Worried that they might come unsoldered when fixing them in place to the trussing I wrapped some wire inners around the joints. I would have used something that would not solder like some anodised jewellery wire but did not have any to hand and could not see the point of making a special journey out for some:
    I just about managed to hold the pieces in place without burning myself with the iron. I also managed to not solder the wire wrappers:
    Using oversize brass for the trussing does mean that some things no longer fit, so I am going to have to shorten them and reprint:
    Have not worked out exactly how I am going to be able to slot them in place!
  8. Dave Holt

    Dave Holt Western Thunderer

    Couldn't you just file the flange of the angle, so the boxes just slide in?
  9. Mike Trice

    Mike Trice Western Thunderer

    I did consider this, but it is just as easy to scale and reprint. In order to get them in I think I am going to have to reduce the height. At present they mount directly to the floor, but if I reduce their height they can then be slid into place and glued with a plasticard spacer. That's the theory.

    Currently contemplating a 3D printed vac cylinder and v hangers which could be printed at the same time. I already have the dynamo and bogies.
  10. Mike Trice

    Mike Trice Western Thunderer

    A quick experiment with the current battery box print suggests that if I cut them in half and do a little filing they can be fitted withthe joint hardly visible:
  11. Mike Trice

    Mike Trice Western Thunderer

    The revised battery boxes have been printed and tested:
  12. Mike Trice

    Mike Trice Western Thunderer

    To have a break from the underframe thought I would do more work on the roof.

    First job was to establish the centre line using a paper template:

    Torpedo vent positions were marked and hand drilled to pop mark them. Not obvious from this photo is the coach bodie is resting on a piece of 2*1" timber to take any strain off of the sides: IMG_1994.JPG

    The torpedo vent holes were opened up 1.5mm ready to receive my 3D printed vents from Shapeways. As an aside this is how I keep my small drills. I bought a load of these little containers from ebay a while ago and this way keep all my drills of a specific size in one place: IMG_1997.JPG

    The next problem was the rainstrips and just as important where they are located. My vision at this point was to scribe the roof and glue 0.3mm wire into the grooves. Prototype drawings only give vertical distances for the rainstrip locations so I had to do some complicated calculations to come up with a flattened version. Eventually produced a template in Inkscape. Here it is under test: IMG_1999.JPG

    In order to be able to scribe the roof and minimise the risk of slipping I really wanted a "shell" that I could fix to the roof and scribe along. Some 20thou styrene was clamped between two spare roofs and bunged in the oven: IMG_2001.JPG

    My previous template was then glue stick'd to the moulding and trimmed to the correct profile: IMG_2003.JPG

    The resulting template was then stuck to the actual roof with double sided tape: IMG_2005.JPG

    After careful scribing the template was eased off. Not certain what I am going to use to stick the brass wire into the grooves, probably cyano. IMG_2009.JPG
  13. Mike Trice

    Mike Trice Western Thunderer

    Lengths of 0.31mm brass wire to represent the door cornice plates were cut to reflect the prototype length of 2'10" and fixed in place with cyano:

    Filler is applied over the joint and allowed to dry: IMG_2015.JPG

    They can then be filed down. Bit more to do on this one. I really should have used styrene, oh well: IMG_2018.JPG

    Cyano applied along first groove and 0.31mm wire rolled into place and trimmed to length: IMG_2019.JPG

    Then the second one. Will let this go off more before cleaning up: IMG_2021.JPG
  14. Mike Trice

    Mike Trice Western Thunderer

    I really did not feel in the mood to do anything yesterday partly because the next job is one I hate. End pipes.

    The water filler pipes were fashioned out of 0.5mm brass wire. It took several attmpts to get them so I was satisfied:
    Some 0.45mm brass wire was softed and flattened in a pair of pliers. A bend is formed and the piece snipped off:
    The "staple" is held against a spare piece of 0.5mm wire:

    A pair of flat nose pliers were used to close up the "staple" around the wire:

    Some time later with a few breathers in between:
    Holes marked on end of coach and 0.88mm holes drilled to accept the mounting brackets. The brackets were threaded onto the filler pipe and coaxed into the holes aacompanied by a lot of cursing and swearing. When everything was in place tiny drops of superglue were applied with an offcut of wire to fix the brackets in the holes and the pipes to the brackets.
    Still more to do but they will have to wait until I am in the mood again.
  15. Mike Trice

    Mike Trice Western Thunderer

    Outer pipes fitted, likewise those at the other end. Boy is that primer finish rough!
    Holes filled with Deluxe Plastic Putty and given a final blast of primer:

    Turning back to the underframe there are some rivets which are not in the correct position shown marked in permanent marker:

    These were filed off with an appropriate Riffler:

    I thought it would be difficult making good but they worked out fine:
    One reason for removing them is I decided to add missing rivets elsewhere on the underframe using Archer's Rivet Transfers so it would not be an issue repositioning the incorrect ones using the same method.
    Rob Pulham, P A D and jonte like this.
  16. Mike Trice

    Mike Trice Western Thunderer

    I have got to the stage where I am not very happy with the way the Gresley end and its piping have come out. With the pipework being metal I used Halford's Etch Primer which does not appear anywhere near as fine as Humbrol Primer. I must admit it did occur to me belatedly, that I could probably produce a special end moulding with all the pipework and fittings in situ (and much neater). Also being moulded they would not need the etch primer. So basically I am considering reducing it back to its main components, dunking in IPA to strip the paint (assuming it will touch the etch primer) and rebuilding it. Better than it was! The underframe can stay as it is.

    So before taking this drastic action I will try the revised ends and see how they look.
    Rob Pulham and GrahameH like this.
  17. Mike Trice

    Mike Trice Western Thunderer

    Assuming these print ok tomorrow I think it should be a great improvement. Much neater:
    open end.jpg
    Rob Pulham and Mick Bennett like this.
  18. Mike Trice

    Mike Trice Western Thunderer

    Decision time:
  19. Heather Kay

    Heather Kay Western Thunderer

    No question from me. They look fabulous.
    Jason L likes this.
  20. Mike Trice

    Mike Trice Western Thunderer

    Glad you agree. Body now in bath of IPA.