Trade SDMP/Finney7 - Driving a Geep?

Discussion in 'Resources' started by Steph Dale, 24 February 2013.

  1. mickoo

    mickoo Western Thunderer


    Kewl, prototypical as well, is that a belt drive between the motor and lower output shafts? This format would only be prototypical for D6300 and Hymek classes, the Warships and Westerns with twin engines had two torque converters, one on each bogie so no drive shafts between the fuel tanks to the bogie ends.

    Having said that, I'd prefer this arrangement for Diesel Electric locos as opposed to great big can motors sticking up into the body as it allows you to 'daylight' the space between bogie and underframe, the drive shaft being less of a visual eye sore than the motor sticking up.
  2. Ressaldar

    Ressaldar Western Thunderer

    Hi Steph,

    it seems that I may well have a spare MSC set-up for sale as I will certainly be going for your solution - please let me know when you expect to have all the bits together in one package for sale. Mine will be 6326.


  3. Steph Dale

    Steph Dale Western Thunderer

    It's actually Delrin chain; with the shafts at the correct pitch (i.e. not set by some arbitrary scale distance) and on ball races (as the manufacturer's specifications, in fact) it can be very efficient and quiet too. The form of drive shown here would work with the Warships too, but you'd drop it down within the bogie wheelbase...
    Practically any motor could be used although I suspect ball-raced coreless motors are the way to go if you need very high power. I'm certainly content that a Canon 1833 would work well with the Class 22 drive shown above.
  4. Steph Dale

    Steph Dale Western Thunderer

  5. oldravendale

    oldravendale Western Thunderer

    Did we finish the gear boxes/motors/transmissions for the LMS Twins, Steph.:)

    It's been a while in gestation and I've forgotten! I know I have the replacement inside frames here, purchased a while ago.

  6. Steph Dale

    Steph Dale Western Thunderer

    I thought you were still 'packed up' but everything is available when you want it.
    I do still have a set of instructions to write, but it's not far off now, I have done a test build and have the photos ready...
  7. oldravendale

    oldravendale Western Thunderer

    Thanks Steph. That's good news.

    You're correct - 'er indoors won't like more stuff before we move (well, not on top of two "Terriers", but we can discuss that later). We'll talk some more when the move is done.

    To all those not of the Dale clan this is a badly hidden way of advising that drive units are now available for the LMS Twins and the plethora of other diesel types! Please forgive. :D There will be no more similar coded messages.

    Heather Kay and Purple-haze like this.
  8. Heather Kay

    Heather Kay Western Thunderer

    Hmm. I think I may have to investigate this further. I'm building one of the twins, and its sibling has since appeared for a remotoring.
  9. Steph Dale

    Steph Dale Western Thunderer

    Happy to help :)
    Last edited: 14 September 2015
  10. Steph Dale

    Steph Dale Western Thunderer

    Back again!

    This has been progressing in the background for a little while - a small window has recently opened up in the Finney7 re-introduction schedule, so here we are. I've long wanted to do this; those who know me well will recognise me saying on many occasions that I see the original 'Blines Remote' gearboxes as being the logical way to drive locos like Class 22s, Hymeks and (for those with a German interest), V90s, V160s, etc. Anyway, here goes:

    Class22 drive layout 7-1.jpg

    So the item of interest here will be known as 'Hydro'. This is the central part of the illustration above and I suspect will be provided complete with the motor (Canon 1833), sprockets, bearings, etc. The fitting is simple, a 32mm/1.25" hole through the middle of the chassis; the unit can be assembled and tested out of the chassis and fits on three screws. One trick is that it allows a variety of ratios to be bought into play, from 13-39:1. So yes, it's an interesting basis for a tender drive too. The pink lines are the critical dimensions of a JLTRT Class 22 frame...

    Here's the whole system, with all elevations, again on the JLTRT frame:
    Class22 drive layout 7-2.jpg

    Of course, you don't have to drive all four axles. For those who want an easy life and drive on only two axles, the outer gearboxes need not be purchased and the system will fit the JLTRT kit with minimum modification. The four-axle version requires a modification to the bogie fixings, to allow the propeller shaft to cross underneath the bogie pivot. The modification is known, straightforward and I'm happy to describe to any one who's interested.

    I'll leave it there for the moment, there is something else on the way which is under the working title of 'Elevator' - it's a combined axle drive and transfer gearbox which is a near-drop-in to the JLTRT and other bogie kits. More on that soon...

    Oh yes, and there's some Class 22 sprung bogies on the way too, but a little behind Hydro and Elevator.

    Last edited: 29 January 2017
  11. Steph Dale

    Steph Dale Western Thunderer

    And here, for the sake of developing a couple of elevations is Elevator - shown here on a class 20.

    Elevator planning 02.jpg

    This is a variable height drive - the input shafts for the top and bottom positions are placed over the bonnet doors and the sill. Of course, you'd only need one, the position can be chosen by the builder during assembly; there are several to choose from between the two extremes shown here. The idea behind this one is to support those who want an easy life (higher positions) and those, like me, who may wish to hide the drive completely in the chassis (lower positions). It's worth noting that although this uses acetal 'Delrin' chain drive, the pitch of the shafts is optimised for efficiency, rather than the semi-arbitrary axle spacing of a bogie. The bearings are mounted using a carrier and tabs at all the various spacings available.

    Oh, and both this and Hydro will use the best spec ball races I can get hold of...

    Last edited: 29 January 2017
    auld_boot and Steve Cook like this.
  12. Yorkshire Dave

    Yorkshire Dave Western Thunderer

    Water powered lifts - nothing new.

    And any four axle diesel or electric loco for that matter.

    I presume the Hydro is a bicycle chain drive between the motor shaft gear and propshaft gear. And is there scope for making the distance between these adjustable to allow the lower gear to be completely hidden within a fuel tank and therefore making entire propshaft assembly level?

    Will the Hydro also be offered as a complete package i.e. including the 'remotes' and all parts to assemble a 4 axle drive as shown (Hydro 4?) or a 2 axle drive as you alluded to (Hydro 2?) with or without motor?

    For me this eliminates the 'two or one high current motor and large decoder' syndrome. One low current motor and HO decoder from now on in....
  13. Steph Dale

    Steph Dale Western Thunderer


    The Hydro is mounted on etched washers so you can adjust the height in the chassis, but the spacing between the two shafts is not hugely adjustable.

    The question of the angled input shafts is interesting. First off it's worth noting that the prototype has angled shafts. Secondly, putting the shafts out of line reduces any tendency for the body to tip over on it's bogies - useful for overall efficiency and especially if you've got sprung secondary suspension (between bogies and frame).

    How the components are packaged up is still a little open to debate, but we'll be able to provide drive on 2 or more axles without any issues; as you know the axle-hung gearboxes are already available.

  14. Overseer

    Overseer Western Thunderer


    Has the delrin chain been tested for durability and noise in this application? We know it works well between axles at relatively low speed but the motor speed is significantly faster and the chain is probably subject to higher loads in this use. Protocraft use a miniature toothed belt in this situation, but also use gear head motors with around 1:19 reduction and 1:1 on the axle gearboxes so the belt is not operating as fast as the chain would be in your proposed set up. Toothed belts seem to be readily available and might be a better long term solution than the chain.
  15. SimonT

    SimonT Western Thunderer

    Peter Kirmond rebuilt the Bog Boys on Laramie to get rid of the Stone Age motors. A Maxon motor is connected to the drive shafte by toothed belts. Work a treat. I would give you a link to the company who supplied us but that went when Windows 10 exploded; I will have to try to find it again.
  16. Big Train James

    Big Train James Western Thunderer

  17. SimonT

    SimonT Western Thunderer

    unfortunately no as they were this side of the pond!
  18. Steph Dale

    Steph Dale Western Thunderer

    Fraser, Simon, Jim,
    Good question. I shall stick with yes; I've tested it and am content. It's running well within manufacturer's specifications and although first sight might indicate a high load, it's not the load that's the limiting factor in this case - that seems to be the case with axle drive where the speed is slower and the torque higher. I'm also bound to note that Weaver locos used a similar drive approach to this and they seem to work well, and very well once the chain is replaced with a good quality alternative (i.e. like the version I'm using here).

    Belt drive has an appeal, but I've hit a couple of stumbling blocks. It's difficult to find suitable miniature 2mm-bore pulleys; the radial loads are high, even under static conditions due to belt tension, and; I'd have to design and pack different versions for each belt length. None of the problems are insurmountable, but would represent a bit of a challenge. One I'd be happy to have a go at if I felt I needed to.

    Speaking of Weaver and being aware they're no longer in business, I wondered whether these drives might work for the P&D Geep bogies now that the drives might start getting trickier to get hold of. At least you could stick the motor in the sill or the drive through the cab base. As before, the vertical arrow overlaid on the tower shows the upper and lower positions for the input shaft, so this is somewhere close to the middle. Yes, the drawing has been scaled to 1:48. I could fancy a GP20...

    GP20 drive.JPG

  19. Big Train James

    Big Train James Western Thunderer

    I'm not sure the drive parts are any more difficult to get hold now than before Weaver folded. I believe P&D offers replacement parts for the Weaver drives. The original Weaver chain sprockets are known to fail due to hoop stress and improperly aged plastic. P&D has offered a more robust alternative for a while now. Also, Finescale360 offers a replacement frame and gear towers for the gp9's as well.

    That being said, I believe the Weaver towers do preclude proper detailing of the cab. Something akin to your proposal above would be much more suitable for the cab, and have the added benefit of opening the volume of the long hood for dcc or speaker installations.
  20. Steph Dale

    Steph Dale Western Thunderer

    That's very good news. Certainly the last time I checked there were concerns that with Weaver's demise the parts might become a problem to get hold of. I'm genuinely cheered by your posting. :thumbs: