Tom Mallard's Workbench

Discussion in 'Workbenches, including workshop techniques.' started by Tom Mallard, 27 December 2013.

  1. Tom Mallard

    Tom Mallard Western Thunderer

    Moving on from introducing myself on the new members page, I have come to Area 51 to start things off. Should I ever be asked to go Great Western again, then I'll take the trouble to post there.

    The first item here is 4mm scale and an ex-LNER B2. I'll record progress as I go and post it here.
    Other 4mm scale projects planned for inclusion for the coming year (at least) ought to be an ex-LNER K3 and LNER O1, LSWR D15 and maybe something else if things go well. If any of my clients read this, I hope they're reassured by this public statement!

    Looking ahead some distance, future plans include scratch built projects in 7mm scale or even 1/32. These require interested and genuine patrons or clients to commit for some time before hand. Compared to the 4mm scale work I have concentrated on I hope to make a further step forward in detail commensurate with the change in scale, with as many parts machined or turned as possible. To maintain a grain of cost effectiveness, they will be built in 3's as a minimum, unless someone is happy to take on a unique bespoke project.

    Best regards

    Tom Mallard
     
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  2. Tom Mallard

    Tom Mallard Western Thunderer

    The first images of the ex-LNER B2 build on this thread - one having previously appeared on my New Members thread.

    The model is probably going to be about 50% scratchbuilding, with the modified ex-P1 tender mostly to my own design of etches with as many castings and detail components as possible gleaned from the Dave Bradwell or Martin Finney Group Standard 4200 gallon tender kit. I chose Dave Bradwell's axlebox and hanger castings as they are excellent. The chassis for the loco will be mostly from the Dave Bradwell B1, modified to tie in where the prototype requires it (such as replacement frames), but the key bodywork parts will again have to be from specially commissioned etches by myself with the rest of the sheet metal cut and built up by hand.

    Having a thread here ought to give me an incentive to write a little on how things go with it.

    Best regards

    Tom Mallard
     

    Attached Files:

  3. 7mmMick

    7mmMick Western Thunderer

    Hi Tom,

    Apologies for missing you in the Welcome thread, I haven't been looking on WT as much as I would like in recent months but hopefully next year that will change. The B2 tender looks fantastic and I look forward to the K3 and O1 builds as these prototypes are on the horizon for me at some point. Looking forward to your next postings,

    ATB Mick :thumbs:
     
  4. Tom Mallard

    Tom Mallard Western Thunderer

    After the usual slow start on frame erecting, I've finally got the hornblocks and axleboxes in, with the rods there too, to jig everything up. The limited amount of progress for the time taken is all due to the effort in trying to make sure the foundations are up to scratch.

    The Dave Bradwell B1 chassis kit uses an innovative fold up sub frame to build the chassis around, but much of the rear portion was cut away so it wouldn't impinge on the B17 frames with all their lightening holes that the B2's kept. The frames for the B2 were also etched by Dave for my client, so there was some useful location aids using some existing holes on the fold up sub frame to pin through them.

    The Exactoscale hornguides are a bit on the vague side and needed a lot of re-working to better fit the supplied axleboxes. Is still make each one a bit tight to start with so I know that when I work them in (using Brasso) they should be a pretty good sliding fit and not a rattling fit. They were positioned on the horseshoe shaped backing plate using a slot machined into Tufnol to set the front to back displacement in the frames.

    The rod parts were carefully drilled in sets so as to improve the likelihood of the hole centres matching up on each side. Unfortunately there seemed to be a small mismatch on the register between the front and back phototools leaving things fractionally skewed, but I spotted this early and I was thankful that the rods came out OK. The rods pivot prototypically but are designed with a lap joint so I added a little overlay at the back to give a proper knuckle joint. It may be totally unnecessary, but from my perspective it made putting the rods together a bit simpler.

    I have included a picture of the rebuilt gearbox for reference. This is the recently released 4mm scale Slaters item and as supplied is really very nice indeed. I needed to reconfigure it significantly so I thought I'd show what was inside... The bottom pair of plates are the supplied CNC machined sides and are quite impressive. Slaters tell me that they manufacture the entire thing in-house.

    Onto the wheelsets next, amongst other amusing things...

    Best regards

    Tom
     

    Attached Files:

  5. Tom Mallard

    Tom Mallard Western Thunderer

    The latest developments on the B2 build are the review and application of a few details for the chassis.

    As supplied, the B1 chassis details for the spring hangers do not match those of the B2's Gresley type. Development of a retro-fit etched set of cosmetic hangers was undertaken, and a new keeper plate with the springs themselves on. The concept reproduces those features included in the Bradwell kit, but makes provision for a few upgrades to the spring wire adjustment screw centres by moving them and their opposite tail supports inboard a little to give an overall active length of 20mm or so. I've also relocated the driven axle to the middle set to get the greatest possible amount of extra weight where it is most needed and kept the motor directed towards the front of the engine (there's never a shortage of weight over the front of a 4-6-0).

    Another set of parts I've had to add are for the brake pull rods and cross-beams, which are totally different to those on the B1.

    The ash pan is intended to slot in after the motor and gearbox are in position, and provision is left for lead weight. The gearbox is stabilised using a tower attached to a plate which should screw down on top of the ash pan assembly. Well that is the plan according to the drawing work and beard stroking (thinking) I've done to make sure things fit...

    Not really picture worthy yet though.

    Tom
     
  6. Tom Mallard

    Tom Mallard Western Thunderer

    Does designing a model on my computer count as modelling here? So no physical model, just a virtual one until the metal comes back from the etchers...

    From the work carried out on the B2 drawing up a retro-fit set of parts for the chassis, I have also been very busy researching, drawing and laying out parts for a Gresley K3. Unsurprisingly, it turned out to be no easier than the artwork developed for the Gresley O2 (as seen in MRJ 223 and 228), but at least I could be more certain of which approach to take in designing it.

    I have chosen not to etch every part - what is the point of etching something as straightforward as a boiler barrel - but still have drawn maybe 90 - 95% of the model.

    Tom
     

    Attached Files:

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  7. dibateg

    dibateg Western Thunderer

    Interesting stuff Tom, yes I think it does count - there is no decent K3 in 7mm scale. I did battle with the Proscale 4mm years ago, that was an assisted scratch build, as was the 7mm Anchorage one - which interestingly bore no relationship to the 4mm version.

    I have a theory about K3s in that the sweep in the running plate under the cab starts differently between the early and late versions. I could be wrong and that could come from staring at too many K3 pictures when I was doing my 7mm build, I'm probably on my own on that one.

    Where did you source the drawings from out of interest?

    Best Regards

    Tony
     
  8. Hester

    Hester Banned


    Hello Tom, very impressive stuff here.:thumbs:

    Tony, do you think if enough of us ganged up on Tom, he would make his etches available as 7mm(without castings, boiler etc) ?:D

    Hester
    P.S. If I remember rightly, there are a few on the OPC lists at the NRM, and yes you might be right about that curve.
     
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  9. Tom Mallard

    Tom Mallard Western Thunderer

    Well, Tony, the drawings came from the NRM and are taken from their OPC microfiche list and I obtained numerous GA and pipe and rod drawings to get a feel for things. The client supplied a few of his own, too. I expect that for the North British ones you could make enquiries at the Mitchell Library in Glasgow.

    Unfortunately the quality of the reproductions from the microfisches is poor, but I couldn't find any others at the time. It also turned out that because the class as a whole is very large, the design went through various revisions over time mainly regarding GNR cab or composite loading gauge NER pattern cab, the choice of brake, reversing gear, valve travel and left or right hand drive: - these are detailed in the RCTS book. I settled on an Armstrong Whitworth 1934 built version which will come with a welded Group Standard tender. Getting a useful photo of one in period and from a suitable shed also made selection a bit awkward but I think we're there now.

    Best regards

    Tom
     
  10. 7mmMick

    7mmMick Western Thunderer

    Fantastic work Tom, I have little understanding of CAD but the drawings there look extremely impressive.

    My battle is yet to begin as you know Tony, my Anchorage kit sits in the draw for a suitable time when I can really get stuck into it.

    Tom,

    Out of interest has producing a set of 7mm etches of either your O2 or K3 ever appealed ? I understand and I speak as a complete novice with regards CAD, that it's not a straight forward job to upscale? A 7mm O2, fantastic :thumbs: :))

    ATB Mick
     
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  11. Hester

    Hester Banned

    Yes Tom, there are serious gaps in the 7mm market and these etches could even just be sold as a scratchbuilders aids as apposed to you producing a new kit for market. Mick has already expressed to me about Arthur Kimber and his 4mm NER kits being upgraded to 7mm to no avail.
    On the kit theme, the best kits I`ve ever assembled are those by MOK. The little slot and tab design that you twist to make an initial hold before soldering is a very clever simple stroke of genius. Would there be a copyright issue there ?
    If I had the CAD ability myself or someone to design the etchings for me, :thumbs: I would happily go down the kit marketing route, being in business myself. I know the risks involved but I also the market gaps and would take a punt.

    Keep up the good work.

    Hester
     
  12. Tom Mallard

    Tom Mallard Western Thunderer

    Thanks for the comment Mick.

    I have never tried producing any of my etches in anything other then 4mm scale as that is the scale they have been designed for, and this takes into account things such as hornblocks, motor and gearbox arrangement, frame spacing, suspension systems and screw sizes. The task of scaling anything within CAD is incredibly simple and is a matter of a few key strokes and clicks of the mouse. However, I know from friends of mine who produce locomotive kits that it is not quite so straightforward as scaling the artwork accordingly and the etch factors applicable to thicker material might not scale very well. It would be a different matter making them smaller and onto thinner material as the effect of etch factors will become less and less critical.

    I don't sell seperate etches as a rule since I cannot be responsible for the outcome or providing 'the missing bits' - the etches are a means to an end just as the pattern making is. So the answer is 'not really'!

    A 7mm scale O2 would indeed be lovely. People have asked before...

    All the best

    Tom
     
  13. Steph Dale

    Steph Dale Western Thunderer

    Hester,
    Nope, it's a pretty standard DFM/A (Design for Manufacture/Assembly) approach, it's just that Dave Sharp is the first to bring it to market in UK model railway kits. I've got European kits in HO which assemble in the same means. I also use a similar idea for my gearboxes.


    There are people on this forum who can help with any of that! There are probably enough of us on this site who develop our own artwork to help you develop your CAD skills, or even draft things up for you... :thumbs:

    Steph
     
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  14. Tom Mallard

    Tom Mallard Western Thunderer

    Thanks Hester.

    Please see my detailed response to Mick's enquiry.

    I like the look of the MOK kits and Dave's take on design is refreshingly innovative. I don't know about copyright or intellectual property but it is a nice detail - anyway who first came up with slots and tabs?

    I agree that there are large gaps in the 7mm and 4mm markets for Gresley prototypes. Having made a few now, I propose that it is because they are very difficult to make as models! The other reason is that kit designers are commonly quite fickle about their choices and the smaller companies will choose things they personally quite like.

    Best regards

    Tom
     
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  15. Hester

    Hester Banned


    Thank you Steph,
    Scale 7 and kit manufacturing all in one day ! oh Mr Darcy, one must take refuge from too much inclination. Swoon :confused:
     
  16. 7mmMick

    7mmMick Western Thunderer

    Hi Tom,

    Thanks for replying and what you say is really what others have said in the past as much as the scaling can be done quickly but everything that goes with it is much more diffcult and not straight forward. I do agree though that a 7mm O2 would be lovely and if it turned out half as good as your 4mm one that would be great:thumbs:. I particularly enjoyed your recent article, especially the part on casting.

    Thinking along the K3 lines, as you've probably guessed I'm hoping to bash about a K3 kit this year and need to get to the NRM myself to have a look at drawings ( luckily the place is only twenty minutes away for me ). At the minute I'm stuck on the crank axle as I will build mine with the centre connecting rod/congugated valve gear working. I was lucky enough to get some pictures underneath the V2 ( not the best as the kids were running around screaming etc ) and wondered if this arrangement is similar to the K3?

    Copy of 2011_0414NRM140420110025.JPG Copy of 2011_0414NRM140420110027.JPG Copy of 2011_0414NRM140420110035.JPG

    I have sourced the Valve castings from Laurie Griffin, just the crank webs and middle conecting rod, slide bar etc to sort. I wish I had got some better photos :headbang:

    ATB Mick
     
  17. Hester

    Hester Banned



    Tell me what views you need and I`ll see what the Library has to offer. Can`t promise owt!

    Hester
     
  18. Tom Mallard

    Tom Mallard Western Thunderer

    Hi Mick,

    I hope you have a chance to look at more than just the GA's. As you're probably aware, the NRM has a super list of the Doncaster and Darlington drawings which they can retrieve for you to view in their special humidity/temperature controlled glass boxes. I wish they'd just give me the keys to the archive so I can save them the bother!

    The arrangement isn't likely to be identical but it should certainly give an understanding of the way Doncaster did things. I think a number of the small details will certainly be similar, particularly as many of the K3's were built at the same time as the V2's. Very well done on including the inside workings - it'll be interesting to see how you get on with it. 4mm scale functionality and keeping an eye on haulage capabilities precludes me from including it on this one.

    I think Hobbyhorse may have some castings of interest to you from the Reynalds range?

    Best regards

    Tom
     
  19. 7mmMick

    7mmMick Western Thunderer

    Thanks Tom, I hope that's the case, that way I can refer to the V2 for some details difficult to find from drawings. I will also have a good look at Hobbyhorse. I've been a few times to the search engine, me and my mate usually make a day of it. A few hours in there looking over and photographing drawings then a wander round the NRM. Followed by a pint and pie and chips in the Maltings :thumbs: I love thumbing over the old drawings, it's amazing to look through works drawings that fitters of the past have thumbed over and used for reference, looking forward to the next trip. I have a long list for next time, K3, A7 and probably J71. Only problem is I think you're now limited to how many you're allowed to view, spoil sports !!

    ATB Mick
     
  20. Tom Mallard

    Tom Mallard Western Thunderer

    Work seemed to be like treading water whilst a set of etches described earlier on the thread very slowly failed to materialise. Choose your etcher carefully! Hopefully plan B will come up with the goods so that things can be resolved and I can get the B2 chassis completed and the K3 underway.

    Talking of the K3, I've got the tender underway on this. The tender has to match the approach taken on the engine, and also take onto account the cosmetic requirements for the Armstrong Whitworth builds which had flush sided welded tanks on their 4200 gallon group standard tenders. The frames appeared to still be riveted and the valences were omitted. I had both the Dave Bradwell and Martin Finney kits in hand so as the client prefers sprung models, I am using the Bradwell chassis with replacement nickel silver frames so I can use my preferred 8 thou nickel silver steps. The new sides for the tank were cut from 8 thou nickel silver with the beading added from half round wire filed up from 0.45mm material. A lot of effort went into blending these with the existing Finney tank components so that the whole came out at the correct overall dimensions.

    So, the tricky work on the K3 tender is done and the B2 has reached a chassis impasse but has it's motion, cylinders, bogie and wheel sets done plus a cab, boiler and smokebox.

    Pictures to follow!

    Tom
     
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