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Improving pickups

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  • Improving pickups

    I have almost every 73 released so far but I have an issue with running. After speaking to other modellers at shows it seems there is an issue with the pickups, how do I rectify this ?

  • #2
    What issue with pick-ups ? Do you mean they are bent, so don't collect. Or possibly the vertical movement of the bogies is having an adverse effect etc, etc ?

    The Duke 71000


    • #3
      Hi Duke. It’s the movement of the bogies, and for such a lovely loco it’s most annoying when it’s continuously stalls.


      • #4
        The probable cure for Class 73 intermittant running...

        Okay you are in luck.... Photos also included....

        I thought this a good opportunity to take my own Dapol class 73 to pieces, and find out what is inside. My loco has only done about 15 minutes of running and has spent most of its time in its box, as my layout is not complete yet. So I didn't expect to find any problems ! However there ARE issues with the pick up system and further problems became apparant whilst solving the problem pick-up situation. It would appear there are also major issues with Dapols assembly methods !!!

        The instruction sheet as with many modern models is at best not very helpful. On this model an exploded diagram of the whole loco is firstly too small, and there is no reference as to the order of assembly. So just ascertaining whether the bogies can be dissasembled without having to dismantle the whole loco first is not made clear. Thankfully having had decades of experience with many of the Worlds model manufactures British, European and Japanese, helped !

        So the conclusion is that the bogies CAN be partially dismantled in situ so as to get at the bogie pick-up system. This however is not simple, and is made far worse, at least on my model, by numerous detail parts simply falling off when touched. Examination of these detail parts, revealed that the glue used to hold the detail parts on, is in all cases insufficient in quantity to do the job. What glue there was appeared not to have adhered to the plastic, as it came off like flaking paint. Worse still a major plastic part between the bogies glued to the metal chassis block, fell off to reveal that the two lugs designed to locate it in slots in the chassis appear to have been CUT OFF, prior to assembly, and plastic cement used to try and hold it in place !!!!!

        Click image for larger version  Name:	P1017169.JPG Views:	1 Size:	322.9 KB ID:	7389
        Above: Step 1 remove the bodyshell simply to prevent it getting damaged. The FOUR retaining screws are located one behind each buffer. Note the wiring inside the roof on my loco was flopping about, so I used a little masking tape just to keep them in place.

        As the model is therefore very fragile I decided it best to remove the bodyshell before attempting to open up the bogie. This is done by removing four Philips crosshead screws located one behind each buffer.

        Step two is to ascertain how the onepiece bogie frame and central baseplate is held in place. Four clips are used. Two large clips one each end of the central section containing the gears and axles, and two smaller clips one each side of the centre of the bogie.

        Click image for larger version  Name:	P1017170.JPG Views:	2 Size:	303.0 KB ID:	7391
        Above: The bogie frames can be removed without dismantling the whole loco. This shows my loco after removal of one bogie frame, and one of the axles. The odd White plastic bits, are 4mm thick strips of plasticard, to reduce the irritating excessive vertical play in the bogies. Which unless cured can increase the risk of accessory parts getting knocked off the bogies, a problem that had me crawling around on the floor for 30 minutes looking for the missing bits....

        The only way to remove the bogie frame is to begin by releasing one of the end clips. The one at the coupling end of the bogie being the safest one to unclip first. As the inner end clip is very close to the tiny wires going to the pick ups inside the bogie, and trying to undo this one first will most likely catch and break the tiny wires. It is therefore best to also remove any coupling from the NEM pocket first.

        Click image for larger version  Name:	P1017172.JPG Views:	1 Size:	252.7 KB ID:	7387
        Above: A side view of the chassis with the bogie frame and one axle removed. This reveals that the somewhat excessive amount of grease inside the bogies, is sufficient to stop the other axle falling out !

        You will need a small flathead screwdriver. This has to be inserted inbetween the chassis floor and the bogie and into the slot at the coupling end of the bogie to release it. This is not easy as it is hard to see exactly where the slot is. However it helps to tip the coupling end of the bogie away from the chassis, to get the screwdriver in. Once this end is unclipped, you then need to carefully release the smaller clips either side of the centre of the bogie. These smaller clips are more fragile and if you try and lever them outwards too much they are likely to beak off. So just insert the flathead screwdriver very carefully and each should release. Now ensure the loco is upside down on a flat surface before carefully lifting the bogie frame off the last clip carefully so as NOT to allow all the little gears and bits inside to drop out !!!

        Click image for larger version  Name:	P1017176.JPG Views:	1 Size:	305.7 KB ID:	7390
        Above: The removed bogie frame. Examine this picture carefully. You will see that I have indicated by the RED arrows marked on the paper beneath. The position of the end and side clips. Ascertain carefully that you understand exactly where each clip is, before you try inserting a small flathead screwdriver into any of the slots. See MY instructions for more important details.

        You will now see the two pick up strips running the length of the bogie. These pick-up strips disappear under the axle of each wheelset. The wheels are actually fitted to a three piece axle where the centre plastic cog also acts as the insulator. The outer metal axle sections are made in two diameters, where the thicker inner end is designed to locate inside the plastic bogie centre. Over the metal axle section are sleeved brass bearings. These have a groove in them to locate them on the edge of the plastic central gear box. The thick section of the brass bearing also provides the area for the pick-ups to rub against. I therfore lifted out carefully the two axles to examine the method of actual pick-up contact.

        There appeared to be a mix of grease and oil over everything. Grease or oil is fine on the gears and drive cogs but I feel not necessary on the pick-up ends or on the outside of the brass bearings where the pick-ups must contact, as this may impede electrical contact. I therefore cleaned both the pick-up ends and the outside of the brass bearings.

        Click image for larger version  Name:	P1017177.JPG Views:	1 Size:	241.4 KB ID:	7388
        Above: The removed bogie frame, one wheelset and the coupling (my preferred type being Kadee). Note the complexity of design of the wheelset which appears to be made of seven seperate pieces. (Two wheels; three piece axles and two sleeved brass rings). The pick-ups should run in the groove provided in the two brass rings, The centre of the axle being a plastic part for insulation which also includies the drive cog.

        The pick-up strips appeared to be randomly bent, a clear sign that one or more may be bent down too far and not contact with the outside of the brass bearing where it is supposed too. I therefore bent all mine upwards carefully so all four ends were in line with the centre of the axles. When the axles and their brass bearings are carefully re-installed, so that the groove in each bearing locates on the gearbox wall in the slot for the axle. The brass bearing will push the pick-up downwards making hopefully a good reliable contact point.

        The bogie frame can then be carefully re-fitted by locating it firstly over the inner end clip of the central gearbox, and gently pressing it back into place over the side clips and finally the coupling end clip. Ensure that the small side clips actually click back into place !

        This should ensure the loco now runs as you would expect. However I am not particularly impressed with the way the pick-up strips are held to the inside of the gearbox wall (between the axles) by three small lugs. There is enough slop in this design to allow and encourage the pick-up strips to bend upwards in their centres (when viewing the upturned loco), so that they loose contact with the brass bearings. Possibly the reason I found three of mine (despite lack of use) where definately not contacting properly......

        One of things I have learnt down the years, with exhibiting large exhibition layouts, is that you cannot remember all the minor problems afflicting your locomotive fleet. Particularly if you have around 130 odd locos as I do, with my layout "Basingstoke 1958-67". Therefore I keep "Record cards" (on my PC), of each loco. On these "cards" I record everything even wheel cleaning. Such records can quickly reveal if something is amiss with a particular model. More frequent wheel cleaning of a particular loco, can for example, indicate problems with pick-ups not working properly, or wheel treads getting worn so that the brass or copper base metal starts showing through ! Such problems when revealed, usually result in that model either being part exchanged for a new one, or kept for spares......

        The Duke 71000
        Attached Files
        Last edited by The Duke 71000; 13 June 2018, 01:53. Reason: Edited, to add detail problems encountered during loco re-assembly....