7mm Scale Gladiator J6 - with working inside motion

Discussion in 'Loco Builds' started by Rob Pulham, Feb 19, 2018.

  1. Rob Pulham

    Rob Pulham Staff Member Moderator Feature Contributor

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  2. Toto

    Toto Staff Member Founder Administrator

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    Not your average kit Rob. They look really finely produced parts.
     
  3. Rob Pulham

    Rob Pulham Staff Member Moderator Feature Contributor

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    Laurie's site is a proper rabbit hole. you can lose hours gazing at castings. Not to mention empty your wallet on buying them....
     
  4. jakesdad13

    jakesdad13 Staff Member Moderator

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  5. paul_l

    paul_l Staff Member Administrator

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    What a difference rebuilding the springs made, the original castings were ok - I've bought worse, but that made a massive change.
    As for the motion gear, I've got the popcorn in, and I'm sitting comfortably - don't tell Toto or I'll get another job.

    Paul
     
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  6. Rob Pulham

    Rob Pulham Staff Member Moderator Feature Contributor

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    Thanks Paul,

    As you say there was nothing wrong with the original castings (I find Ragstone castings to be excellent) but they were wrong for this loco and Andy Beaton/Laurie Griffin didn't appear to have anything that was the right shape. After seeing what I have done with them David Hill (Gladiator) is going to talk to Andy Beaton about getting a master made to replicate what I have done as a white metal casting.
     
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  7. jakesdad13

    jakesdad13 Staff Member Moderator

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    Hope you get a copyright fee Rob ;);)

    Cheer's, Pete.
     
  8. Rob Pulham

    Rob Pulham Staff Member Moderator Feature Contributor

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    I had originally planned to go to Kettering show this weekend with a stop over on Friday night. Taking the decision not to go has given me an extra couple of days of thinking/modelling time in which to really get my head into the inside motion.

    A friend with a profile cutter had offered to cut out a motion plate for the J6 for (he has also supplied lots of information and answered my 'newby' questions regarding inside motion for which I am eternally grateful). While studying the GA drawing to work out which bit was which on Wednesday evening I had the thought of importing it into Inkscape (the drawing package that I use to draw for the silhouette), rescaling it to 7mm scale and then highlighting the components that make up the motion so that I could see what they are.

    [​IMG]

    You can see the difference in the layout of the motion compared with the Midland variation in which the motion set from Laurie Griffin is based - below is a snip from the LG instructions.


    LG Motion snip.jpg
    While I was doing my stuff in Inkscape Chris suggested using my silhouette to create a template for the motion plate to test whether it would fit between the frames etc. I thought that a great idea and within a very short space of time I had drawn up and cut this

    [​IMG]

    I used that to transfer the measurements onto a spare frame spacer and drilled/cut filed it out. Due to using it as a template to scribe around, some of the measurements were fractionally over size, while the internal ones were slightly undersized. I kept filing until the slide bars fit and I got this. - I added the framing top and bottom afterwards.

    [​IMG]

    Looking at a couple of fellow modellers motion plates I realise that I will have to file some relief in the tops and bottom of the slide bar seats in a similar manner to the centre opening where the eccentric rods will pass through to allow for the up/down movement of the piston rods.

    This is it in the frames - held by a blob of Blue tack

    [​IMG]
     
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  9. Rob Pulham

    Rob Pulham Staff Member Moderator Feature Contributor

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    Alongside creation of the motion plate, I had to prepare the slide bars and make the cross heads fit.

    Once I had them running nice and smooth and having test fitted them in the motion plate, I detailed them with the very prominent oil pots on the tops. Made from spare etch and nickel rod

    I am not sure why but these proved and absolute pain to take photos of...

    [​IMG]

    [​IMG]
     
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  10. paul_l

    paul_l Staff Member Administrator

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    WOW - this thread is raising the bar high enough for me to easily walk under it :avatar:

    However it is giving me thoughts for putting the outside cylinders on Nellie.

    Paul
     
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  11. Rob Pulham

    Rob Pulham Staff Member Moderator Feature Contributor

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    Hi Paul,

    You can get slide bars and cross heads from Laurie and Premier Components do various lengths of coupling/connecting rods.
     
  12. York Paul

    York Paul Full Member

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    Brilliant write up and pictures there Rob... its a masterclass lesson as well as a hugely interesting read.
     
  13. Rob Pulham

    Rob Pulham Staff Member Moderator Feature Contributor

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    Steady progress is being made on the motion, last night I managed to get the slidebars attached to the motion plate.

    It was interesting trying to hold it square in both planes while applying solder.:headbanger::hammer:

    [​IMG]

    [​IMG]
     
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  14. paul_l

    paul_l Staff Member Administrator

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    Now there's a euphemism and a half :avatar:, glad you weren't at the keyboard at the time, Toto might have had to get the electronic tippex out.

    I can understand why people tend not to model inside valve gear, but I suppose it'll be one of those projects to add to the bucket list.

    Think I need a bigger bucket.

    Paul
     
  15. York Paul

    York Paul Full Member

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    Rob just going back to the hornblock fitting onto the chassis for a moment, do you think the springing action over three axles on 7mm kits could bring up potential issues if fitted to locos with outside motion? I'm thinking of my Standard 4... I've just read through the ABC Gears Locomotive Compensation pdf written by Brian Clapperton which doesn't rate hornblock fitting too highly on the grounds of wear, spring setting and potential sideways fore and aft motion of wheels leading to shorting out electrically. Then I'm reading projects by top league modellers like Jazz and PEN and yourself who I'm sure wouldn't build prestige locos with hornblock springing if this was any real issue, so I'm confused and a directive /opinion would be most appreciated please before (or even if) I mark out centres for cutting on the frames. Thanks for any help in the mean time.:thumbup: cheers Paul
     
    Last edited: Mar 14, 2018
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  16. Rob Pulham

    Rob Pulham Staff Member Moderator Feature Contributor

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    Hi Paul,

    I think that virtually every builder you talk to may have a different opinion on Hornblocks or more specifically the way that Hornblocks are used.

    By that I mean sprung, compensation beams or continuous springy beams. This will be my first foray into using springs although in the first instance I will only be using them on the tender (I am only using the tender for pickups). The reason that I have added Hornguides/blocks to the loco is primarily so that tit's possible to remove the inside valve gear in case it needs attention.

    I have built a couple of locos with compensation beams which were very much designed into the chassis and there really wasn't much option to build it any other way (GP Model J63 and the 06/8F currently under construction both of which were designed by Dave Sharp of MOK).

    I have also built some with just the centre driver sprung with piano wire which rides on the top hat bearing in an elongated hole in the frames - see my J79 thread.

    I have also compensated a couple of 4 wheeled locos in variation of Jim McGewon's recommended rocking front axle. These I did using ball races on both axles but again the front axle holes in the frames were elongated allowing up/down movement and then I slipped a length of K&S tube over the part of the ball races which protrude between the frames (they were top hat style from here) they are very effective and both locos (Connoiseur 'Nellie' and LNER Y6 tram engine) run very well on DCC.

    Your query has prompted me to have a look at the kit's in my stash and quite a few of them are designed for hornblocks and come with them included in the kit (Finney V2/A4 and Duchess, Snowhill Models WD, Gladiator G5) and then there are some that have optional either half etches or tagged centres which would allow the easy use of hornblocks but they are not included and then there are those where if you wish to use them you will have to mark out and cut the frames.

    Of the latter which surprises me a little is the Gladiator B1 in which the etchs look to be very precise and high quality but yet it has no built in provision for the use of hornblocks.

    Sorry about the war and peace answer but it's a broad subject and one which some modellers can be quite passionate about depending on what their preferred method is. At some point I will try CSB to see if it makes life any easier or not.

    Lastly and in answer to your direct question, I am using them because a lot of modellers who I greatly respect for their abilities and the quality of the models they turn out, use them. And I feel that they must think it worth the time and effort so it should be of benefit to the models that I produce.
     
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  17. York Paul

    York Paul Full Member

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    Hi Rob,

    Thank you for your extremely informative and comprehensive reply, you have helped me see clarity and I now know my decision. The Standard 4 has option to use a compensation beam which is included and this pivots on a 2.4mm drilled hole between the middle and rear axles with axleway holes elongated, the front axle is rigid and the motor gear arrangement sits on the rear axle in the beam. I got confused with the David Andrews Duchess which is to be reissued later this year, in that thread on RMWeb the builder uses hornblocks which for me I now understand places things into a different league. I am going with the kits compensation beam option as originally designed by Jim Harris and feel tempted to elongate the frame axle holes by 0.5mm in the vertical upper and lower planes, this will give me a 4 point suspension system with good stability and place the centre of gravity nearer the middle driving wheels. I figure if this loco runs where track alignment heights are anything beyond 1mm then it will be the condition of the railroad which is at fault and not instability of the engine, also this option allows me to add weight for increased traction. Anyway thank you again Rob... I have learned a lot this evening from your advice and apologies for hijacking your build thread.
    York Paul
     
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  18. Rob Pulham

    Rob Pulham Staff Member Moderator Feature Contributor

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    Not a problem Paul,

    I have to be honest and say that my locos with compensation (both beams and rocking axles) run superb and I have thought about adding compensation beams to the J6 tender. I may still do that now I have to make a new tender.
     
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  19. York Paul

    York Paul Full Member

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    That sounds good enough for me Rob,:thumbs: I look forward to reading about the tender build too.
    Paul.
     
  20. Rob Pulham

    Rob Pulham Staff Member Moderator Feature Contributor

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    Recently I seem to have been spending far too much time browsing and not enough time modelling but I have made some positive progress which I can share.

    I have fitted the motionplate with some angle brackets to allow it to be screwed to the frames.

    [​IMG]

    Not the best photo in the world but hopefully it's good enough.

    Then last night saw the horn guides installed using my Hobby Holidays jig. I also made use of the Use of the springs allowed me to position the horn guides much better without them moving.


    [​IMG]

    [​IMG]

    Because I am using Finney LNER horn guides I now need to file out the bits that protrude into the holes in the frames etc. marked in red on the photo so that's this evening main task.

    Edited to change "motions" to "motion", a bit of a Freudian slip I wonder....
     
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