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David Herbert

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Everything posted by David Herbert

  1. You havn't got the characters that come before the NSN that you gave, have you? They would normaly be on the packaging but often not on the item. They give a guide to application. For example 9ACR is FV430 series vehicles (which I don't think its for - certainly not 432 or 434). I do agree that it's a headrest though. David
  2. Tank tyres are typicaly expected to carry 2.5 tons plus per tyre (5 tons per wheel station) at 50 mph continuously in desert conditions. At slow speeds they are expected to survive gravel and much bigger rocks getting between them and the tracks as the vehicle turns. It is heat build up through speed, and damage that kills solid tyres, not traction and turning forces. As you say there is a limited relationship between the needs of a modern tank and a WW1 truck that weighs 5 tons and does 20mph. David
  3. If you had access to a suitable press the classic way to remove the old rubber is to roll a steel band of say 6mm steel to fit as closely as possible over the steel band of the tyre and press it on in the manner of a pastry cutter. If you only had a smaller press, it would be quite easy to make a curved knife that did about 6" at a time and just work your way round. Incidentaly, polyurethane tyres, although cheaper than real rubber, are actually much better which is why they are used on modern tank wheels which must be about the harshest application possible. Synthetic rubber got a bad reputation in WW2 but things have come a long way since then. David
  4. The repair to the diff cover is great. Confronted with that crappy aluminium it is easy to convince yourself that you have to make a new casting. In this case it would not have been too frightening but you have made the original live again. What exactly was the material you used? Did you just clean the break and pour the repair metal against it or did you need to 'tin' it in some way or use something as flux? Getting the wheels home must feel good, have they got tyres on them or do you still need that mortgage? David
  5. Thats 'the land of the free' for you. I prefer it in the UK. My local town is bigger than 700 people and not only can do without armoured Humvees but also does without a police station and most of the time any police at all! It is not a posh middle class suburb but is actually classed as a deprived area. We occasionaly get 'traveling people' stealing quad bikes and tools from unlocked farm buildings and idiots in town getting drunk and fighting but I think that tying them to a post so people could throw vegatables at them would be a better response than assult rifles. Mods, feel free to remove this if it is not appropriate ! David
  6. Surely this is a replacement for Warrior, which did not replace CVRT because it was too big, too heavy and too expensive. How is this a step forward? David
  7. Isn't the grass big ! David
  8. Isn't the middle can the same dimensions of the standard 1 gallon can that we used to buy oil in from Halfords before oil started to be sold in plastic cans sculpted to a shape intended to make people think that they will be able to fly if they use that brand of oil. If it is I would assume that it was easier for the military to get small portions of oil from commercial suppliers without having to decant it from bigger drums into the type of can that is on the left of the photo. David
  9. First, the octane rating of fuel is the measure of its tendancy to detonate during combustion (knocking or pinking). In addition to raising the octane rating, lead was added as a way of reducing the erosion of valves and seats. Contrary to many peoples belief, high octane fuel is actualy less "explosive" than low octane - that is the point of it. As Clive has shown, the B series engines will happily burn any petrol available these days. In my experience you can run with the ignition significantly advanced compared to the official setting with noticable improvements to drivability and fuel consumption. The issue with a Saracen is that the fuel pump (on the engine) has a long way to pull the fuel from the tank and the resulting level of suction makes the fuel seperate into the actual petrol and flamable gasses that are normaly disolved in it. The gasses get to the fuel pump and just get squashed and un-squashed, so no pumping happens. Result is fuel starvation. The simple solution is an electric pump at the tank wired into the ignition. David
  10. Don't worry about the voices, they are normal with tank owners, or at least so the voices tell me! David
  11. Well done Neil. I admit I was wondering if you would ever get posession of it. At least it fits in the garage to work on it. Good luck, David
  12. As it has a centrifugal clutch the starter is not trying to turn the gearbox unless the clutch has a problem. Are you trying to start with the forward/reverse in neutral ? That is a big no no with almost any vehicle with a crash type F to R change (rather than friction clutches for each direction). You must always start with it in either F or R and then when you need to change direction, stop the vehicle completely, drop the revs to idle and very smartly move the F/R lever across all the way in one move. Anything else produces the grinding noises as you demonstrated and destroys the F/R dog clutches. Sorry to be blunt :-D David
  13. Why on earth was that a better device than a tipper? David
  14. Mark, I was last on Warcop about twenty years ago scavenging tank bits with the full cooperation of the range authorities. At that time there were the remains of M47s, M10s, Churchills and some lighter wheeled armour. Soon after two good, partly stripped Grizzlies and I think two T34s were purchaced (this was before CFE) and put out as hard targets and destroyed. There was then a major tidy up and the majority of the interesting wrecks were cleared away. I certainly never saw any evidence of a M4A2 or M4A3 and I very much doubt if there have ever been M4A3s on British ranges as we virtually did not have them and to my knowledge none have been imported since. I would love to be proved wrong, has anyone got more recent photos ? David
  15. I agree that a plasma cutter is probably the best way of cutting bites out of a piece of angle and lots of other profiling and cutting jobs. The problem is that you do need quite a big compressor as well, probably big enough to run a blast cabinet which would also be very usefull. I think most people can't justify this level of plant but I must admit that a 9" angle grinder with a thin cutting blade would have considerably reduced the chain drilling and the subsequent tidying up. Then again most people have neighbours that don't appreciate the noise of angle grinders. Back to chain drilling then :-(. David
  16. Can anyone explain how it is that crushed glass is regarded as safe when glass is basicaly made of melted down sand ? David
  17. I am very pleased to be wrong about the width and pitch. That makes it much more possible to piggy-back Cletrac tracks off the Halftrack project. Hopefully the Halftrack tracks are made in a segmented mould in which case it should be fairly easy to do a batch of longer ones that are otherwise identical. That can certainly be done with modern mini digger / snowmobile tracks, hence the Weasle tracks that are being made in China now and sold by Joop Staaman. Looking at the photos of the one with joined up Halftrack tracks it looks quite good I think, but I would love to know how he joined them. Actually the lack of bolt on pads should make them last longer as there will be no tipping force on the metal cross bar which would tend to fatigue the cables more. In OZITIM's first photo you can see the two different types of halftrack guide horn: one with a wiggly top edge and one with a straight top which I believe is the latter type. David
  18. Tiffy_massive Your post seems to have shrunk, did you wash it on too hot a setting? David
  19. If the Landrover is a 24V one I would have thought it was a very good idea. A Cent engine can certainly be started from a couple of decent car batteries as long as it does not have any problems, so a running Landrover should do the job very well, particularly if you leave it connected for a few minutes before going for a start. In the electrics section there are a couple of threads where people have been very keen on 'pulse' type electronic chargers. One of the problems with owning any type of classic vehicle, and especially armour, is that the batteries don't get used enough and sulphate up. A conventional charger which is basicaly a transformer can't do anything about this but pulse chargers make great claims of recovering sulphated batteries. As I have too many big batteries to watch them die from lack of use, I recently invested in an Optimate 6 (see Ebay!). This is the price of a decent size battery but it has already recovered two that I thought were dead and can be left trickle charging indefinately. I intend to connect it to every battery that I have for three days at a time in turns to try to keep them healthy, particularly through the winter. Of course it can't help a battery that has been frozen or otherwise damaged but if it can stop the sulphating that is a huge benefit. David
  20. It's for tensioning wire. I think that the triangular bit is what you hold to do the easy part of the pull, then you run the rope round another pulley that is hooked onto a tree or something, back round the pulley on the device and then pull on the end of the rope and you have a three times mechanical advantage. You have enough wire sticking out of the device to the left to fasten it off to something solid, then you can remove the device. David
  21. Surely Cletrac tracks are not only longer but wider too and have bolt on 'pads' and so have totally different cross pieces inside the rubber. Has anyone checked that the guide horns are interchangeable or what the pitch of the cross pieces is (which is the pitch of the sprocket) ? I find it hard to believe that there would be anything in common at all between Cletrac and halftrack track other than the general concept. Sorry to be negative but this all needs checking and decisions making but I agree that the standard Halftrack 'tread pattern' would not look bad on a Cletrac. The width issue is potentially more of a problem because none of these tracks are over-strong and wider tracks have more cables in them which is the main strength. Make them narrower than original and they will be weaker quite apart from looking strange. A different pitch certainly means different tooling altogether. I hope someone comes up with a solution but getting enough Cletrac owners to invest will be the big challenge. Good luck, David
  22. Thanks Peter, I was trying to present myself as a carefull, responsible and caring owner of an historic vehicle and you have just blown my cover! Actually it coped with it very well and cleaning up was easy as the ground is relatively dry so the 434 didn't get caked with runny mud. I was very impressed with how agile it is. I had my neighbour's 18 acre field to play in which had just had the crop taken off but there is a very rough strip with a double row of trees along two edges which is ideal as it is much more fun than just doing ovals in a big empty space. Apart from the bit in the photo it was suprising how little sign there was of where we had been. Also it is now steering much better than when I got it so a very good evening's fun. David
  23. Thanks, Grasshopper, That's probably much the same distance from me that Maidstone is, about 1000 miles round trip! If the new owner sees this, please make contact. Same applies to any other 434 owners, there must be more of you out there. David
  24. Thanks Dougy, Yes I did know about Metroman but he seems not to have been on HMVF since 2011 when he sold his 436. There was no mention of him selling the 434 but the last reference to it was in 2009 at about the time that he got the 436. You are right that it had its radio table in it, there is a photo fairly early in the thread. I suspected that the photo I pinched from you was at Withams - well done for having the foresight to record what at the time you didn't need and then making it available to the rest of us. Thanks David
  25. I have now got my 434 home and have a much better idea of what needs doing. With the help of a number of kind people on the forum I have aquired quite a pleasing pile of the parts that were missing, and I keep getting calls from the guy that I bought it from saying that he has found another bit of it if I want it. As he is not an enthusiast but a purely commercial business I must say that I am very gratefull - most people wouldn't bother. Great bloke! It starts and drives beautifully but has enough issues that I can make my mark usefully and of course it has lost most of its removable bits but the shopping list is getting shorter. The biggest problem I have hit is that in the conversion to Bowman radio system (which I am reversing), the Clansman radio shelf has been removed. Does anyone know of a 434 that still has its Clansman radio shelf in place that I could measure up, or of course a spare shelf would be good too! This shelf is not very similar to a 432 one as it hangs from the roof and only has room for one radio plus the commander's IC box. Dougy put the following photo on the 432 forum but I don't know whose 434 it is. The photo is taken looking down through the commander's hatch and you can see the slew ram of the crane below the radio shelf (with writing on it). I can't believe that there are no Clansman 434s left - please can someone point me towards one. Another 'want' is that some kind person has pinched the engine oil filler cap which is a fairly small brass flip top device with "engine oil" engraved on the top and a female screw thread on the bottom to fit the top of the filler pipe (about 2"). If anyone has one that they could part with it would be a great help. If anyone can help please PM me. Thanks, David
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