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AlanT

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  1. Hermes seem to take ANYTHING. I bought 2.5Kg of CAUSTIC SODA CRYSTAL. The supplier sealed in a plastic bag and stuck the address label on it, no packaging, no box. It arrived OK, but really it could all have gone anywhere. The crystals are about 2mm across!
  2. I'd get this collected by Parcel-Force. Over 2Kg will be £11 if you have an account. You fill in the item description and can be a bit cryptic. I ship wiper-motors and just put "electric-motor- NO BATTERIES".
  3. AlanT

    More wiper woes

    I should probably stay out of this. But somehow I can't resist. I've now rebuilt getting on for 200 wiper-motors and so I know about wear in them. For every 4 thou of wear in the motor bearings, crank-arm bush, rack teeth and wheelbox gear the sweep angle increases by one degree. The brass bush in the crank-arm and the main bearing for the gear often have 10 thou each. That's five degrees of sweep and about 1in movement at the blade tip. Of course if one blade is worse than the other it must be the rack-teeth and wheelbox not the motor. Good NOS racks are easily available and just push in so this has to be the first thing. I make new brass bushes for the crank-arms and can refit the main Oilite bearing for the big gear. I've got NOS DR3A motors that will get put into TR4A spec. Also a TR6 motor for "research purposes". The TR6, 14W type is really a cost reduced design to replace the DR3A. There was a big saving because of the use of a permanent magnet for the field generation rather than a wound coil. This is a good thing for long-term reliability also. But elsewhere the cost reductions might result in long-term problems. The rack-slide is a plastic insert rather than cast encastre brass. The brush plate is SRBP or Paxolin. The self-park switch is plastic too and not really serviceable. It has a lot of internal parts with not very good registration and retention. You will see brush-plate and park-switches offered on eBay and these are usually far-east repro,
  4. You can probably get a packet from China for 99p.
  5. These cables were traditionally greased not oiled. Any kind of oil/grease getting into a speedo head will mess it up. They work by a spinning magnet dragging an aluminium disk against a light spring. This works because of induced eddy current in the disc. The magnet does not spin very fast and this mechanism does not generate much torque. Just about enough to move a needle.
  6. It's a self-tap with a domed countersink head. About 3/4 in long. Chromed.
  7. I remember who is making wheelboxes in the UK. http://www.lapelec.co.uk/thecompany/ The ebay supplier I mentioned above "lotsofclassicbits" sells LAP product on eBay. You can usually find NOS racks on eBay. You just need to get one long enough. They are easy to shorten as required. There is one for London taxis that will fit. This is on auction at present: https://www.ebay.co.uk/itm/New-Lucas-Wiper-Rack-743251/223535596128?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2 From memory this is the right part-number but just check the length.
  8. https://www.ebay.co.uk/itm/Wiper-Wheel-Box-for-MG-MGA-Triumph-TR3-TR4-TR5-37H6316/222521442203?hash=item33cf4fbf9b:g:seoAAOSwjU9Zz0DS Two things about this listing: 1. this supplier usually has good parts 2. I think these are UK made in the Midlands by a firm that keeps a low profile but makes good stuff, the name escapes me at present.
  9. You may find that 130 tends to make the blades go off-screen. If you try to buy a 120 gear be aware that there are early and late DR2's and the gears do nOT interchange. Also a DR2 runs a bit slower than a DR3A.
  10. Oh I forgot, the grease will most likely have gone hard. And the FAST winding may have failed cotton insulation. And the brushes need to be checked before they cut into the commutator. And lots of these have been overheated at some stage and the armature winding may look black. The good news is that these old motors can always be easily fixed. In the TR6 section I describe recent games with a NEW repro round type wiper motor. This had several original manufacturing defects. Not so easy to fix either.
  11. At the point where the wires come out between the end-cap and the motor body, they often develop a short-circuit. I've seen one where the wires did not pass through the "notch" in the end cap but were trapped in the centre. Anyway this is a weak area and they usually need rewiring at this point. Otherwise the self-parking wire that goes to the cap, gets trapped against the body by the long bolt that holds the end-cap on. Or one of several other places that can easily short out. Anyway this is an unwanted connection to ground somewhere.
  12. In the 60s and 70s a question like this had a meaning. But now its likely that whatever type you chose, they would come from the same factory in China. If not then maybe from India.
  13. This is the inside of the switch from the 14W motor, made in India. I'd expect they are all rather similar. I've removed the top two terminals because are just flat copper sheet that joins the wires coming out of the motor through to the plug on the cable harness. These switches are glued together, so of course I had to break into this one. So what you can see is: 1. the earth terminal on the right, note how it runs right across the top of the switch. 2. two contacts at the bottom, these are the self-parking-switch 3. on the left the plunger that is activated by the cam on the back of the gear wheel Note that when the plunger is OUT, as in the photo, the two self-parker terminals touch. When the plunger is moved up by the cam, the self-park terminals are pushed apart. More exactly the right-hand contact (switch output side) is lifted away from the left-hand contact (12V supply). But something else unexpected happens too. The right-hand contact is lifted so that it touches the earth-terminal. This connects the motor armature to earth and this provides a braking action to bring the motor to rest suddenly. I doubt this is really required, earlier DR3 type motors don't do this. But this does introduce extra complexity and with this comes "points of failure'. You see that on this example, the earth terminal DOES NOT run straight across the switch but "dips down", so that it makes an unwanted contact to the self-parking terminal. This is because it is BENT. The second photo shows this bend was caused by a failed attempt to spot-weld the two parts of the earth-terminal. I tuned-up this terminal with my nippers and all was well. The third photo shows the cam on the back of the gear. In order to change these motors from parking with the rack pushed OUT to rack pulled IN, you prise out the cam and fit it on the other side of the gear. No fine tuning! Just two fixed positions. This motor, bought as being for a TR6, was parking OUT. Unless I am mistaken this would be for a LHD car or maybe just wrong.
  14. There are repro wheel-boxes made in the UK and they are good. But they come in green boxes. To compensate for the poor fit they make the spindle a bit short so that the C-washer is a very tight fit.
  15. A member contacted me via HQ and offered me the new TR6 motor, that he had just bought. The story was that this had run a turn or so, but then blew the fuse and now was short-circuit. He clearly thought this had destroyed itself in a major way. I thought this unlikely, but by then he had bought another. I don't usually rebuild these 14W types because there are lots of cheap new ones about. But I offered to collect this one, on the basis that the forum could learn something from it. It's one of those that come from India in a red box marked Lucas. It didn't actually take much to remedy it and in a little while the forum WILL learn something! But right now I want to get this ready to pass on to somebody that can use it. However the sweep-angle is NOT marked on the gear, like the original ones were. So in order to make sure this is correct for a TR6, I need some help from the forum. I made some pencil marks next to the slider that guides the end of the wire-rack cable. This allowed me to measure the distance traveled by the end of the crank-arm. This is easier than trying to measure the distance of the crank-pin from the axis of the gear. So could an owner with a 14W motor that sweeps properly, tell me how much the end of the wire-rack moves, as the blades move from one extreme to the other. You only have to get this to within a few millimetres or so, so that holding a rule next to it would do. These motors are reasonably good and this one only had a simple manufacturing error. But it amused me to find that the fit of the main-gear into the Oilite bush is pretty loose. Technical term is "rattle-fit". If I dismantled a DR2 made in 1957, that had had a hard working life and the gear was as loose as this, I would extract the Oilite bush and fit a new one!
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