College Ivatt 2 tender loco project kit help and advice needed

Discussion in 'Workbenches, including workshop techniques.' started by Fred Astaire, 29 September 2018.

  1. Fred Astaire

    Fred Astaire Member

    After a few years N gauge I wanted to try our clubs O gauge layout. On looking to dip my toes in the water with a starter Loco, I sort of fell in headfirst to the deep end. I was offered a part started ACME kit which of course is the College Kit originally, it dates to 2001 and has the tender 80% built, thats all. The kit is complete with Slaters wheelsets and motor / gearbox.
    Ive now bought the Metalworks rivetter (made my own 0 gauge punch and die for it), and bought a 10 inch mini roller, both tools new unused bought at auction. Ive already made a bending jig / clamplate and have bought books on EtchBrass Loco building.
    Im well used to large scale modelling as I restore Austin Pedal cars, have my own Myford Super 7 and make my own tooling for home pressworks and welding jigs. So whilst i'm sort of capable on engineering and modelmaking this is a new avenue...
    I'm to model it on Ivatt 46521 from Loughboro for which ive taken a compendium of reference photos.

    So background given, i'm starting the Loco chassis, ive bought Slaters sprung hornblocks and now trying to figure out their precise fittment, at the moment i'm planning to use my lathe vertical toolpost and the crosslide to drill a thick steel sheet at axle centres, using the crosslide to index across for the 3 axle centres, make some dowel pins so as to make a setting jig for the chassis sides / connecting rods, (flip it over for the second side).
    Basically i'm wondering if anybody on the forum has built or is building one of these College Kits who might generally steer me in correct chassis build. The instructions leave items somewhat imprecise, next tech point is the cylinders rear left-right 'bulkhead', there is a massive vertical cut-out length in the slots compared to the chassis lugs, if just soldered as per instructions the piston rod CL will never point at the middle driver axle centre. I wondering if i'm better to construct the cylinders on a separate jig as an assembly so as to get the correct inclination angle relative to the footplate.
    Ive searched using google and all I can locate is negative comments toward College Kits
    So............can anybody help point me in the right directions on build?
     
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  2. Peter Cross

    Peter Cross Western Thunderer

    Hi I've built one of these they are not the easiest kit to do. Have you built much in the way of brass kits?
    This is my build here.
    I compensated mine rather than sprung. I don't seem to get along with Slater's sprung hornguides. I would do things slightly differently now, like do full compensation.
     
  3. Fred Astaire

    Fred Astaire Member

    This is my very first starter kit! as a retired experienced engineer its not frightening me, I just need steering in the right directions. I have a mentor in my local club however as hes not built either this kit or and College Kit thats why I'm doing the research before I start. So thank you Peter for your link, ive already viewed on my I phone last night, I now need to view on my laptop at full size. In last nights viewing ive already picked up that your tender is centre sprung where the kit is solid, Ive also been looking at the chassis centre brace beween those heavy cast brass motion side carriers for the slide bars. I'm copying the Loughborough based Ivatt, this centre crossmember is much lower down and smaller in scale, any comments?
    I would still be most pleased to hear of other member who have built this College / ACME Kit with their comments and advice.
    Question for Peter, the kit specifically states NOT to use the Slaters motion journal pins and to use the ones of the kit, may I ask which makers journal pins you used? I'm particularly querying the centre driver which has the eccentric (return) crank to be fitted (and not come loose).
    Should I be posting a blog on this forum? if so then where? or do I add notes on this post?
     

    Attached Files:

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  4. Dikitriki

    Dikitriki Flying Squad

    Welcome to WT!

    This thread is fine where it is.

    I would suggest you post pictures full-size, rather than as thumb nails (button next to the picture) as it makes it easier to follow. They can also be added mid-text if you wish to relate the picture to a specific point.

    You have not chosen an easy kit to commence your 7mm scale journey, but with your skill set, you have a fighting chance. Just bear in mind that this kit is not typical of better current offerings, and if you want help in choosing a second kit - or if you get fed up half way through fighting this one, give the collective a shout.

    Richard
     
  5. Fred Astaire

    Fred Astaire Member

    Thank you Richard, the Ivatt picked me! I was looking for a non runner or a part started 040 or 060 and was about to put a posting on our club noticeboard, before picking up pen and paper a colleague said he had a part started kit from years ago, he was so pleased that it would reappear at our club so it was offered at ‘club colleague’ price. As i was anticipating a loco build and the tender is mostly built then ive actually got a ‘loco build’ , so in at the deep end and reading the book on how to swim! Im normally repairing N gauge locos and have built an N gauge Beyer Garret and finished a W1 so this is big time big scale. Current i’m finishing an Austin J40 so actual Ivatt build start is two weeks away. Thanks again
     
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  6. Threadmark: 7mm Ivatt 2MT Build Started no 1
    Fred Astaire

    Fred Astaire Member

    So i'm on the starting blocks with my first build.
    ive bought a rivetter and rolling jig off ebay Ivat mini roller.JPG rivetter.JPG
    made a bending jigplate ivatt bender.JPG
    made a chassis sidemember jig plate ivatt chassis jig.JPG so I can chop out for slaters hornplates. jig plate was drilled on my Myford to get accurate axle centres using the crosslide for indexing.
    Questions
    1/. my kit and slaters wheelsets are 17 years old, what should I do for crankpins? the instructions from 2001 say dont use Slaters because you cant solder the eccentric, there are lost wax ones in the kit but you have to screw them into the Slaters wheel, I also see Derek Munday heavy duty crank pins mentioned on the net - so what should I do?

    Kind regards
     
    Last edited: 13 October 2018
  7. adrian

    adrian Flying Squad

    If you place the cursor where you want the photo to go - then in the list of attached photos use the "full image" button.
    Screenshot 2018-10-13 at 14.00.58.png
     
  8. Fred Astaire

    Fred Astaire Member

    Thanks Adrian, I think i need to save photos turned 1/4 turn next try at an update, I'll get there eventually.
     
  9. wychcan

    wychcan Member

    I too have built the kit, (not the easiest of kits to put together).
    As for the attachment of the return crank I threaded the slaters wheels with a 10ba tap also the slaters brass bushes and by using 2 bushes face to face you can solder the return crank to the flat part of the outer bush. ( bushes will need some filling back) Also the return crank can be tapped as well.
    Good luck with the build
    Nigel
     
  10. Fred Astaire

    Fred Astaire Member

    Thats excellent news Nigel that Ive found somebody else who has built this kit, thanks for the reply. Ive had a look at Peter Cross's build notes. I would be pleased to hear of how you approached the cylinders build, ive seen Peters approach where he built a separate detachable front chassis but would like to hear of other options if there are any. there is no kit alignment precision for the cylinders, If I followed the assembly soldering process they would be out of position most certainly. I'm well used to making alignment and assembly jigs for my Austin Pedal cars hobby so i'm well up for making any tooling to help me with the Ivatt build. so... advice and recommendations would be welcomed, particularly any other problem areas I an going to reach. Kind regards
     
  11. Fred Astaire

    Fred Astaire Member

    At last a proper start. ive made the precise jig using my Myford crosslide and vertical mill attachment. fitted the chassis sides on dowel pins, marked out and 'first fit' Slaters sprung hornblocks. I', proposing to solder the hornblocks with standard high temp solder so I can leave medium and low temp for next stages of component addition. Chassis jig mod.jpg
    A few questions:-
    1/.Ive now to drill for Slaters Pickups, whilst aware that generally they should go on the axles centre line, any comments on this and should I go for 'at the front' or rear of each wheel? i'm wondering about hiding wiring. (motor position still not decided).
    2/.I'm wondering about how to leave the cylinders removable, do I leave as the pair, (with front chassis), as the separation line or follow the MOK Std 4 style and make left and right single detachable cylinders / slide bars / J bracket?
    Any other construction advice welcome as this is my first O gauge build.
    Kind regards to all
     
  12. adrian

    adrian Flying Squad

    Much to my chagrin I've yet to finish my scratchbuild effort. I started it in finescale and I was unhappy with the proportions and it tipped me into Scale7. One day I'll work up the enthusiasm to rebuild the chassis in Scale7.

    In the meantime my solution for the loco was for the standard chassis behind the cylinders, in front of the cylinders wider dummy frames attached to the footplate/bodywork.

    The cylinders themselves are individual units that bolt onto the main chassis. One little trick that worked extremely well was to make a tiny little dovetail joint at the end of the slidebars to locate in the motion bracket. This makes it easy to separate the slide bars from the motion bracket to get the crosshead out.

    Photo's here hopefully show the arrangement.

    Ivatt slide bars - Cherry Clan
     
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  13. Fred Astaire

    Fred Astaire Member

    Thanks Adrian, have you any photos of either your ivatt 2 or ivatt 4 that show the rear fixings of the J bracket and cylinder? Im thinking of building the cylinders as the pair so i can solder the outer etch wrappers with high temp solder, fit backplates with medium temp solder before cutting the centre sections out to use for the chassis spacers, (as per College design), leaving individual cylinders as per your Ivatt 2
    Comments appreciated.
     
  14. adrian

    adrian Flying Squad

    Hi, it's an Ivatt 2 - or will be if it ever gets finished.

    So it's a little grubby as it's sat on a shelf for a number of years. From the front an illustration of the arrangement of the cylinders and motion bracket. The motion bracket is held in place with a couple of 10BA countersunk screws. You can see I made the cylinders up for the dummy frames and then fitted spacers to get them out to the right width. 6BA studs in the cylinders and bolted to the inner frame.

    Ivatt_2 - 1.jpg

    At the rear of the cylinder it's extended inwards to meet the inner frame.
    Ivatt_2 - 2.jpg

    Ivatt_2 - 3.jpg

    The front dummy frames extend below the footplate

    Ivatt_2 - 4.jpg

    Ivatt_2 - 5.jpg

    Hopefully this shows how it all fits together

    Ivatt_2 - 6.jpg

    Ivatt_2 - 7.jpg

    When I get round to converting to Scale7 I'll take the spacers out from the cylinders and make an inner chassis that stops just short of the dummy frames. The cylinders will bolt to this and the joint will be hidden behind the cylinder.

    Regards

    Adrian
     
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  15. Fred Astaire

    Fred Astaire Member

    Adrian, thanks so much, thats settled that decision, its separate cylinders for my build.
    And...wow, thats some scratchbuild, I trust it will get dusted off and finished soon.
    Kind regards Fred
     
  16. Dan Randall

    Dan Randall Western Thunderer

    I couldn't agree more - it definitely needs liberating from whichever shelf it's been Queen of all this time!


    Regards

    Dan

     
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  17. adrian

    adrian Flying Squad

    I know - I know. It just needs some enthusiasm and some suitable Scale7 drivers. It's just the thought of scrapping the chassis and starting again. I can't remember if I've posted this before but I sorted out the tender so some work has been done.

    ivatt_tender - 1.jpg

    ivatt_tender - 2.jpg

    ivatt_tender - 3.jpg

    ivatt_tender - 4.jpg

    ivatt_tender - 5.jpg
     
  18. Threadmark: 7mm Ivatt 2MT Build Started no 2
    Fred Astaire

    Fred Astaire Member

    I'm progressing with chassis initial build and have it fastened together with rubber bands and on track, Slaters sprung hornblocks successfully fitted on my jig.
    Three questions
    1/. Slaters sprung contacts - the instructions give no hole size, tried ringing them and got a sarcastic man on phone who said 'use a measuring stick' and then stated 1/8 inch which I find is wrong. So, what is the drill size and should they be a clear fit or slight interference?
    2/.I have Slaters wheelsets and the ex College kit - what do I do for the wheel balance weights? there are none on the etch; does anybody make them or is it 'self scratch build' ? if the latter do I use brass or plastic sheet?
    3/. I was hoping to leave the Sprung Hornblocks unobstructed to enable dropping the axleboxes out for initial painting and future maintenance - however Im supposed to solder the dummy underslung axle springs to the chassis sides which prevents an axledrop. any ideas as to how to fix these dummy axlesprings
    Comments appreciated
     
    Last edited: 31 October 2018
  19. Peter Cross

    Peter Cross Western Thunderer

    Hopefully this may help.

    1. I don't know because I either use 4mm ones or backscratchers. I would start smaller and broach out to fit. Drills do not drill the same size holes everytime.

    2. Brass or plastic. The later are easier to make. I don't think you will be able to buy them. My kit had them on the frame etch.

    3. If you want to drop the wheels all the bits underneath need to be made removable including brakes. Springs either fix with screws to games or solder to keeps so they screw on with the keeps. With slaters wheels there is no need to drop, just take the wheels off. This is easier once the cylinders and motion bracket are removable.
     
  20. Fred Astaire

    Fred Astaire Member

    Thanks Peter, ive gone back to the etch photocopies in the instruction, these date to Sept 97 and are without wheelcounterbalance wieghts. Im wondering about turning some brass discs on the lathe to fit ‘only just’ inside the slaters wheels which will then provide one radius ready made, ill have to get the piercing saw out for the inner radius before reaching for the file.
    Rgds F
     
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